console.log("Script execution started.");
// --- Global Variables ---
let generatedCode = [];
let currentCleanedCode = [];

let evolutionTimeline = [];
let activeTimelineIndex = -1;
let selectedVariationGridIndex = -1;
let currentFullscreenHistoryIndex = -1;

let originalUserPromptForCurrentGeneration = '';
let lastPreviewUpdateTime = [];
let previewUpdateInterval = 500;
let numVariationsToGenerate = 4;
let activeApiControllers = [];

let lastGenerationConfig = {
    prompt: '',
    isRefinement: false,
    numVariations: 4,
    refinedTimelineIndex: -1
};


// --- DOM Element References ---
let apiKeyEl, codeOutputEl, errorMessageEl;
let modelSelEl;
let selectButtons = [];
let fullscreenButtons = [];
let previewItems = [];

let refinementLoadingIndicator;
let mainContentEl, configButtonEl;
let intervalSliderEl, intervalValueDisplayEl;

let fullscreenOverlayEl, fullscreenIframeEl, exitFullscreenBtnEl;
let perspectiveViewportEl, previewGridWrapperEl;

let historyPanelEl, historyPanelPlaceholderEl;
let selectedCodeTitleH3El;
let mainContentTitleH1El, mainContentSubtitleH2El;
let fullscreenHistoryNavEl, historyNavPrevBtnEl, historyNavNextBtnEl;
let promptModalOverlayEl, promptModalContentEl, modalUserPromptEl, modalGenerateBtnEl, modalCancelBtnEl, modalLoadingIndicatorEl;
let modalRefinementCheckboxEl, numVariationsSliderEl, numVariationsValueDisplayEl;
let configModalOverlayEl, configModalContentEl, configModalCloseBtnEl, copyCodeButtonEl;
let historyToggleButtonEl, historyArrowDownEl, historyArrowUpEl;
let exportCodeButtonEl;
let newButtonEl;
let confirmModalOverlayEl, confirmModalMessageEl, confirmModalConfirmBtnEl, confirmModalCancelBtnEl;
let currentConfirmCallback = null;
let historyNavLeftBtnEl, historyNavRightBtnEl;
let promptDisplayModalOverlayEl, promptDisplayModalContentEl, fullPromptTextEl, promptDisplayModalCloseBtnEl;
let showPromptModalButtonEl; // Added for the new button
let modalContextSizeValueEl, modalMaxTokensValueEl, modalMaxTokensSliderEl; // Added for new modal elements


// --- Constants ---
const API_BASE_URL = 'https://api.novita.ai/v3/openai'; // New Novita API

const MODEL_DETAILS = {
    "deepseek/deepseek-v3-turbo": { context: 64000, maxOutput: 16000, defaultOutput: 8192 },
    "deepseek/deepseek-r1-turbo": { context: 64000, maxOutput: 16000, defaultOutput: 8192 },
    "qwen/qwen3-235b-a22b-fp8": { context: 128000, maxOutput: 128000, defaultOutput: 16384 },
    "qwen/qwen3-30b-a3b-fp8": { context: 128000, maxOutput: 128000, defaultOutput: 16384 },
    "qwen/qwen3-32b-fp8": { context: 128000, maxOutput: 128000, defaultOutput: 16384 },
    "google/gemma-3-27b-it": { context: 32000, maxOutput: 32000, defaultOutput: 8192 },
    "mistralai/mistral-nemo": { context: 131072, maxOutput: 131072, defaultOutput: 16384 },
    "meta-llama/llama-4-scout-17b-16e-instruct": { context: 131072, maxOutput: 131072, defaultOutput: 16384 },
    "meta-llama/llama-4-maverick-17b-128e-instruct-fp8": { context: 1048576, maxOutput: 1048576, defaultOutput: 16384 }
};


// --- Helper Function to Process Stream for One Variation ---
async function processStreamForVariation(apiKey, userPrompt, variationIndex, modelName, signal) {
    console.log(`[Variation ${variationIndex + 1}] Starting generation with model ${modelName}...`);
    const previewFrame = document.getElementById(`preview-frame-${variationIndex + 1}`);
    const loader = document.getElementById(`preview-loader-${variationIndex + 1}`);
    const selectBtn = selectButtons[variationIndex];
    const fullscreenBtn = fullscreenButtons[variationIndex];

    if (!previewFrame) { console.error(`[Variation ${variationIndex + 1}] Preview frame missing.`); return false; }
    if (!loader) { console.warn(`[Variation ${variationIndex + 1}] Loader missing.`); }


    if (loader) loader.classList.remove('hidden');
    if (selectBtn) selectBtn.disabled = true;
    if (fullscreenBtn) fullscreenBtn.disabled = true;

    if (previewFrame) updateLivePreviewInGrid(variationIndex, '<div class="flex items-center justify-center h-full"><p class="text-slate-500">Generating...</p></div>', false);
    if(lastPreviewUpdateTime[variationIndex] !== undefined) lastPreviewUpdateTime[variationIndex] = 0;


    const API_ENDPOINT = `${API_BASE_URL}/chat/completions`; // New Novita API endpoint
    let rawGeneratedCode = '';
    let htmlBlockStarted = false;
    let success = false;
    let isInsideThinkBlock = false; // Flag to track if we are inside a <think> block

    // Construct conversation history for Novita API
    // The prompt passed to this function (userPrompt) is already formatted with instructions and user request.
    const conversationHistory = [
        { role: "user", content: userPrompt }
    ];

    try {
        console.log(`[Variation ${variationIndex + 1}] Novita API call with model: ${modelName}`);
        const response = await fetch(API_ENDPOINT, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${apiKey}` // Novita uses Bearer token
            },
            body: JSON.stringify({
                model: modelName, // Model name for Novita
                messages: conversationHistory,
                stream: true,
                reasoning: { exclude: true }, // Added reasoning parameter
                max_tokens: parseInt(modalMaxTokensSliderEl.value, 10) // Send max_tokens
            }),
            signal: signal
        });

        if (!response.ok) {
            let errorDetails = `API Error: ${response.status} ${response.statusText}`;
            try { 
                const errorDataText = await response.text(); // Try to get text first for more detailed errors
                console.error(`[Variation ${variationIndex + 1}] Novita API Error Response Text:`, errorDataText);
                const errorData = JSON.parse(errorDataText); // Then try to parse as JSON
                errorDetails += ` - ${errorData?.error?.message || errorData?.detail || errorDataText || 'No specific message.'}`;
            } catch (e) { 
                errorDetails += ` - Could not parse error response.`;
            }
            throw new Error(errorDetails);
        }

        const reader = response.body.getReader();
        const decoder = new TextDecoder();
        let sseBuffer = ""; // Buffer for incomplete SSE messages
        let streamEnded = false;

        while (!streamEnded) {
            const { done, value } = await reader.read();
            if (done) {
                streamEnded = true;
                break;
            }

            sseBuffer += decoder.decode(value, { stream: true });
            let eolIndex;
            while ((eolIndex = sseBuffer.indexOf('\n')) >= 0) {
                const line = sseBuffer.substring(0, eolIndex).trim();
                sseBuffer = sseBuffer.substring(eolIndex + 1);

                if (line.startsWith('data: ')) {
                    const data = line.substring(6).trim();
                    if (data === '[DONE]') {
                        streamEnded = true;
                        break;
                    }
                    try {
                        const json = JSON.parse(data);
                        const deltaContent = json.choices?.[0]?.delta?.content;
                        
                        if (deltaContent) {
                            let currentChunk = deltaContent;
                            let processedChunkForThisDelta = '';

                            while (currentChunk.length > 0) {
                                if (isInsideThinkBlock) {
                                    const endThinkTagIndex = currentChunk.indexOf('</think>');
                                    if (endThinkTagIndex !== -1) {
                                        // Found the end tag. Content after it is actual.
                                        processedChunkForThisDelta += currentChunk.substring(endThinkTagIndex + '</think>'.length);
                                        isInsideThinkBlock = false;
                                        currentChunk = ''; // Current delta's relevant part processed
                                    } else {
                                        // Still inside think block, discard this part of the chunk
                                        currentChunk = ''; // Discard and move to next delta if any
                                    }
                                } else {
                                    const startThinkTagIndex = currentChunk.indexOf('<think>');
                                    if (startThinkTagIndex !== -1) {
                                        // Found a start tag. Content before it is actual.
                                        processedChunkForThisDelta += currentChunk.substring(0, startThinkTagIndex);
                                        isInsideThinkBlock = true;
                                        // The rest of currentChunk starts after <think>
                                        currentChunk = currentChunk.substring(startThinkTagIndex + '<think>'.length);
                                        // This remaining part of currentChunk will be re-evaluated in the next iteration
                                        // of this inner while loop, now with isInsideThinkBlock = true.
                                    } else {
                                        // No think tags, entire chunk is actual content
                                        processedChunkForThisDelta += currentChunk;
                                        currentChunk = '';
                                    }
                                }
                            }

                            if (processedChunkForThisDelta.length > 0) {
                                rawGeneratedCode += processedChunkForThisDelta;
                                // The htmlBlockStarted logic might need re-evaluation.
                                // For now, assume content is part of the HTML stream.
                                if (!htmlBlockStarted) {
                                    // Try to detect '```html' or start accumulating if it appears
                                    const marker = "```html";
                                    let tempAccumulated = rawGeneratedCode; // Use the cleaned rawGeneratedCode
                                    const markerIndex = tempAccumulated.indexOf(marker);
                                    if (markerIndex !== -1) {
                                        htmlBlockStarted = true;
                                        let codeStartIndex = markerIndex + marker.length;
                                        if (tempAccumulated[codeStartIndex] === '\n') {
                                            codeStartIndex++;
                                        }
                                        rawGeneratedCode = tempAccumulated.substring(codeStartIndex);
                                    } else if (tempAccumulated.trim().startsWith("<!DOCTYPE html") || tempAccumulated.trim().startsWith("<html")) {
                                        // If it looks like HTML already, assume block started
                                        htmlBlockStarted = true;
                                    }
                                } 
                                // If htmlBlockStarted is true, or we assume it's direct HTML content
                                if (htmlBlockStarted || !(rawGeneratedCode.includes("```html"))) { 
                                    const now = Date.now();
                                    if (lastPreviewUpdateTime[variationIndex] !== undefined && (now - lastPreviewUpdateTime[variationIndex] >= previewUpdateInterval)) {
                                        // Strip markdown for preview if still present at this stage
                                        let previewCode = rawGeneratedCode; // Use the cleaned rawGeneratedCode
                                        if (previewCode.includes("```html")) {
                                             previewCode = previewCode.substring(previewCode.indexOf("```html") + 7).trimStart();
                                        }
                                        if (previewCode.endsWith("```")) {
                                            previewCode = previewCode.substring(0, previewCode.length - 3).trimEnd();
                                        }
                                        updateLivePreviewInGrid(variationIndex, previewCode, true);
                                        lastPreviewUpdateTime[variationIndex] = now;
                                    }
                                }
                            }
                        }
                    } catch (e) { 
                        console.warn(`[Var ${variationIndex + 1}] JSON parse error in stream:`, e, "Problematic Line:", line, "Data:", data);
                    }
                }
            }
            if (streamEnded) break; // Exit outer loop if [DONE] was processed
        }

        console.log(`[Variation ${variationIndex + 1}] Streaming finished. Raw content length: ${rawGeneratedCode.length}`);
        let finalExtractedHtml = null; 
        let processingErrorMessage = null; 

        // Process the rawGeneratedCode after stream ends
        // This needs to handle potential markdown ```html ... ``` blocks
        let tempHtml = rawGeneratedCode.trim();
        const htmlMarker = "```html";
        const markerIndex = tempHtml.indexOf(htmlMarker);

        if (markerIndex !== -1) {
            htmlBlockStarted = true; // Confirm block started if marker found
            tempHtml = tempHtml.substring(markerIndex + htmlMarker.length).trimStart();
        }
        // Remove trailing ``` if present
        if (tempHtml.endsWith("```")) {
            tempHtml = tempHtml.substring(0, tempHtml.length - 3).trimEnd();
        }

        // If no ```html was found, but it looks like html, use it directly
        if (!htmlBlockStarted && (tempHtml.startsWith("<!DOCTYPE") || tempHtml.startsWith("<html"))) {
            htmlBlockStarted = true; // Assume it's HTML
        }

        if (htmlBlockStarted && tempHtml.length > 0) {
            finalExtractedHtml = tempHtml;
            const minLength = 20;
            const hasStructuralTag = /<!DOCTYPE html|<html[^>]*>|<head[^>]*>|<body[^>]*>/i.test(finalExtractedHtml);
            const hasAnyTag = /<[a-zA-Z][^>]*>/.test(finalExtractedHtml);

            if (finalExtractedHtml.length >= minLength && (hasStructuralTag || hasAnyTag)) {
                success = true;
                console.log(`[Variation ${variationIndex + 1}] HTML validation SUCCEEDED.`);
            } else {
                success = false; 
                console.warn("[Variation " + (variationIndex + 1) + "] HTML validation FAILED (length: " + finalExtractedHtml.length + ", structural: " + hasStructuralTag + ", anyTag: " + hasAnyTag + "). Review content manually.");
                processingErrorMessage = "// Warning: Generated content did not pass basic HTML validation.";
                if (!finalExtractedHtml) finalExtractedHtml = processingErrorMessage; // Ensure some content for display
            }
        } else if (tempHtml.length > 0 && !htmlBlockStarted) { // Content received but not identified as HTML block
             processingErrorMessage = `// Warning: Content received, but 'Written by Novita AI' or similar marker not found, or content doesn't look like HTML. Length: ${tempHtml.length}`;
             console.warn(`[Variation ${variationIndex + 1}] ${processingErrorMessage}`);
             finalExtractedHtml = tempHtml; // Display what was received
             success = false; // Treat as not fully successful if not identified as clean HTML
        } else {
            processingErrorMessage = `// Error: No meaningful content generated or 'Written by Novita AI' marker not found.`;
            console.warn(`[Variation ${variationIndex + 1}] ${processingErrorMessage}`);
            finalExtractedHtml = processingErrorMessage; // Show error message
            success = false;
        }

        if (success && finalExtractedHtml) {
            let processedHtml = finalExtractedHtml;
            const requiredHeadContent = `
                        <meta charset="UTF-8">
                        <meta name="viewport" content="width=device-width, initial-scale=1.0">
                        <script src="https://cdn.tailwindcss.com"><\\/script>
                        <link rel="preconnect" href="https://rsms.me/">
                        <link rel="stylesheet" href="https://rsms.me/inter/inter.css">
                        <style>
                        html { font-family: 'Inter', sans-serif; }
                        @supports (font-variation-settings: normal) {
                            html { font-family: 'Inter var', sans-serif; }
                        }
                        body {
                            background-color: #f8fafc; /* slate-50 */
                            color: #0f172a; /* slate-900 */
                            padding: 1rem;
                        }
                        </style>`; 

            if (!processedHtml.includes('<head>')) {
                processedHtml = `<head>${requiredHeadContent}</head><body>${processedHtml}</body>`;
            } else { 
                let tempRequired = "";
                if (!processedHtml.includes('cdn.tailwindcss.com')) tempRequired += `    <script src="https://cdn.tailwindcss.com"><\\/script>\\n`;
                if (!processedHtml.includes('inter.css')) tempRequired += `    <link rel="preconnect" href="https://rsms.me/">\\n    <link rel="stylesheet" href="https://rsms.me/inter/inter.css">\\n`;
                if (!processedHtml.includes("html { font-family: 'Inter', sans-serif; }")) { 
                    tempRequired += `    <style>\\n      html { font-family: 'Inter', sans-serif; }\\n      @supports (font-variation-settings: normal) { html { font-family: 'Inter var', sans-serif; } }\\n      body { background-color: #f8fafc; color: #0f172a; padding: 1rem; }\\n    </style>\\n`;
                }
                if (tempRequired) { 
                    processedHtml = processedHtml.replace(/<\/head>/i, `${tempRequired}</head>`);
                }
            }
            if(currentCleanedCode[variationIndex] !== undefined) currentCleanedCode[variationIndex] = processedHtml;

            const interactionScript = `<script>(function() { const VARIATION_INDEX = ${variationIndex}; })(); <\\/script>`;
            const bodyEndIndex = processedHtml.lastIndexOf('</body>');
            if(generatedCode[variationIndex] !== undefined) {
                generatedCode[variationIndex] = (bodyEndIndex !== -1)
                    ? processedHtml.slice(0, bodyEndIndex) + interactionScript + processedHtml.slice(bodyEndIndex)
                    : processedHtml + interactionScript;
            }
            updateLivePreviewInGrid(variationIndex, null, true);
        } else {
            generatedCode[variationIndex] = ''; 
            if (finalExtractedHtml) { 
                if(currentCleanedCode[variationIndex] !== undefined) currentCleanedCode[variationIndex] = finalExtractedHtml; // Store the potentially partial/error code
                updateLivePreviewInGrid(variationIndex, finalExtractedHtml, false); 
            } else { 
                const displayError = processingErrorMessage || "// Unknown error during generation.";
                if(currentCleanedCode[variationIndex] !== undefined) currentCleanedCode[variationIndex] = displayError; 
                updateLivePreviewInGrid(variationIndex, `<div class="p-4 text-red-400 font-medium">${displayError.replace(/\\n/g, '<br>')}</div>`, false); 
            }
        }

    } catch (error) {
        if (error.name === 'AbortError') {
            console.log(`[Variation ${variationIndex + 1}] Fetch aborted.`);
            updateLivePreviewInGrid(variationIndex, `<div class="p-4 text-yellow-400 font-medium">Generation Cancelled.</div>`, false);
        } else {
            console.error(`[Variation ${variationIndex + 1}] Generation error:`, error);
            updateLivePreviewInGrid(variationIndex, `<div class="p-4 text-red-400 font-medium">Error: ${error.message}</div>`, false);
        }
        if(currentCleanedCode[variationIndex] !== undefined) currentCleanedCode[variationIndex] = `// Error: ${error.message}`;
        if(generatedCode[variationIndex] !== undefined) generatedCode[variationIndex] = '';
        success = false; // Explicitly set success to false on error
    } finally {
        const finalLoader = document.getElementById(`preview-loader-${variationIndex + 1}`);
        if (finalLoader) finalLoader.classList.add('hidden');
        if (selectBtn) selectBtn.disabled = !success; 
        if (fullscreenBtn) fullscreenBtn.disabled = !success; 
    }
    return success;
}

// --- Main Function to Generate Variations ---
async function generateVariations() {
    console.log("generateVariations called.");
    const userPromptText = modalUserPromptEl.value.trim(); // Renamed from userPrompt to avoid conflict

    if (!apiKeyEl || !modalUserPromptEl || !modelSelEl || !previewGridWrapperEl || !modalGenerateBtnEl || !modalLoadingIndicatorEl || !errorMessageEl || !codeOutputEl) {
        console.error("Cannot generate variations: One or more critical elements are missing.");
        if (errorMessageEl) errorMessageEl.textContent = "Initialization error. Cannot generate.";
        return;
    }

    const apiKey = apiKeyEl.value.trim();
    const selectedModel = modelSelEl.value;
    const currentIsRefinementMode = modalRefinementCheckboxEl.checked;
    const currentNumVariations = parseInt(numVariationsSliderEl.value, 10);

    if (!apiKey || !userPromptText) {
        errorMessageEl.textContent = 'Error: API Key and Prompt (via Alt+P) are required.';
        if (!userPromptText && !promptModalOverlayEl.classList.contains('visible')) showPromptModal();
        return;
    }
     if (!selectedModel) {
         errorMessageEl.textContent = 'Error: Please select a model.';
         return;
     }

    lastGenerationConfig = {
        prompt: userPromptText,
        isRefinement: currentIsRefinementMode,
        numVariations: currentNumVariations,
        refinedTimelineIndex: currentIsRefinementMode ? activeTimelineIndex : -1
    };


    errorMessageEl.textContent = '';
    console.log(`Mode: ${currentIsRefinementMode ? 'Refinement' : 'Initial'}, Model: ${selectedModel}, Variations: ${currentNumVariations}`);

    let baseCodeForRefinement = null;
    let contextPromptForRefinement = '';
    originalUserPromptForCurrentGeneration = userPromptText; // Use the new variable name

    if (currentIsRefinementMode && activeTimelineIndex !== -1 && evolutionTimeline[activeTimelineIndex]) {
        baseCodeForRefinement = evolutionTimeline[activeTimelineIndex].code;
        contextPromptForRefinement = evolutionTimeline[activeTimelineIndex].originalUserPrompt;
        console.log(`Refining Evolution ${activeTimelineIndex + 1}. Original context: "${contextPromptForRefinement}"`);
    } else if (currentIsRefinementMode) {
         errorMessageEl.textContent = 'Error: No active evolution selected to refine. Uncheck "refine" or select an evolution from history.';
         return;
    }

    modalGenerateBtnEl.disabled = true;
    modalLoadingIndicatorEl.classList.remove('hidden');
    if (codeOutputEl && selectedCodeTitleH3El) {
        codeOutputEl.innerHTML = '<code class="language-html">// Select a variation to view its code.</code>';
        selectedCodeTitleH3El.textContent = "Selected Code:";
    }
    selectedVariationGridIndex = -1;

    numVariationsToGenerate = currentNumVariations;
    generatedCode = Array(numVariationsToGenerate).fill('');
    currentCleanedCode = Array(numVariationsToGenerate).fill('');
    lastPreviewUpdateTime = Array(numVariationsToGenerate).fill(0);
    selectButtons = Array(numVariationsToGenerate).fill(null);
    fullscreenButtons = Array(numVariationsToGenerate).fill(null);
    previewItems = Array(numVariationsToGenerate).fill(null);


    showFourGridPreviewUI();

    activeApiControllers = Array(numVariationsToGenerate).fill(null).map(() => new AbortController());

    // Construct the prompts for Novita - they will be passed as the 'user' message content
    const promptsForNovita = Array(numVariationsToGenerate).fill(null).map((_, i) => {
        if (currentIsRefinementMode && baseCodeForRefinement) {
            // For Novita, the prompt should be structured clearly for the model to understand the task.
            // The API call itself will use a messages array. This is the content for the 'user' role.
            return `
CONTEXT: You are an expert web developer specializing in HTML, Tailwind CSS, and JavaScript.
Original User Request (for context of the base code): "${contextPromptForRefinement}"
Base HTML Code to Refine:
\`\`\`html
${baseCodeForRefinement}
\`\`\`
Your Task: Implement the following refinement instructions for Variation ${i + 1} of ${numVariationsToGenerate}.
User's Refinement Instructions: "${userPromptText}"

Instructions for your output:
1. Analyze the Base Code and the User's Refinement Instructions.
2. Modify ONLY the necessary parts of the Base Code to implement the refinement.
3. Try a slightly different approach if possible, as this is one of several variations.
4. Ensure the refined code remains a single, complete, runnable HTML document.
5. ALWAYS include Tailwind CSS CDN (<script src="https://cdn.tailwindcss.com"><\\/script>) and Inter font (<link rel="stylesheet" href="https://rsms.me/inter/inter.css">) in the <head>.
6. Add basic body styling for readability: <style>html { font-family: 'Inter', sans-serif; } body { background-color: #f8fafc; color: #0f172a; padding: 1rem; }</style>
7. Output ONLY the raw, complete, refined HTML code. Start your response with \`\`\`html and end with \`\`\`
Refined Code:`;
        } else {
            return `
CONTEXT: You are an expert web developer specializing in clean, modern HTML, CSS (using Tailwind CSS classes), and JavaScript.
Your Task: Generate the complete, runnable HTML code for Variation ${i + 1} of ${numVariationsToGenerate} based on the User Request below.

Instructions for your output:
1. Ensure the code is self-contained.
2. ALWAYS include Tailwind CSS CDN (<script src="https://cdn.tailwindcss.com"><\\/script>) in the <head>.
3. ALWAYS include Inter font (<link rel="stylesheet" href="https://rsms.me/inter/inter.css">) and set html { font-family: 'Inter', sans-serif; } in a <style> tag in the <head>.
4. Add basic body styling for readability: body { background-color: #f8fafc; color: #0f172a; padding: 1rem; } in the same <style> tag.
5. Add HTML comments to explain the code if helpful.
6. Try to make this variation distinct.
7. Output ONLY the raw HTML code. Start your response with \`\`\`html and end with \`\`\`

User Request:
"${originalUserPromptForCurrentGeneration}"
Code:`;
        }
    });

    const generationPromises = promptsForNovita.map((promptContent, index) =>
        processStreamForVariation(apiKey, promptContent, index, selectedModel, activeApiControllers[index].signal)
    );

    try {
        const results = await Promise.allSettled(generationPromises);
        console.log("Generation promises settled:", results);
        const successfulGenerations = results.filter(r => r.status === 'fulfilled' && r.value === true).length;
        if (successfulGenerations === 0 && !results.some(r => r.status === 'rejected' && r.reason.name === 'AbortError')) {
            errorMessageElement.textContent = 'Error: All variations failed.';
        }
        else if (successfulGenerations < numVariationsToGenerate && !results.every(r => r.status === 'rejected' && r.reason.name === 'AbortError')) {
            errorMessageElement.textContent = `Warning: ${numVariationsToGenerate - successfulGenerations} var(s) failed or were cancelled.`;
        }

        updateMainContentTitles("Select a Variation", "Click 'Select' on a preview below.");

    } catch (error) {
        console.error("Parallel generation error:", error);
        errorMessageElement.textContent = `Unexpected Error: ${error.message}`;
        showInitialPreviewStateUI();
    } finally {
        modalGenerateBtnEl.disabled = false;
        modalLoadingIndicatorEl.classList.add('hidden');
        console.log("Generation process finished.");
    }
}

// --- UI Update Functions ---
function createPreviewItemDOM(index, isGridItem = true) {
    const item = document.createElement('div');
    item.id = `preview-item-${index + 1}`;
    item.className = isGridItem ? 'preview-item-perspective' : 'single-preview-item';
    if (isGridItem) item.dataset.variationGridIndex = index;

    const header = document.createElement('div'); header.className = 'preview-header';
    const title = document.createElement('span'); title.className = 'preview-header-title';
    title.textContent = isGridItem ? `Variation ${index + 1}` : (evolutionTimeline[activeTimelineIndex]?.prompt.substring(0,30) + '...' || `Evolution ${activeTimelineIndex + 1}`);
    header.appendChild(title);

    const btns = document.createElement('div'); btns.className = 'preview-header-buttons';

    const fsBtn = document.createElement('button');
    fsBtn.className = 'fullscreen-btn p-1 focus:outline-none focus:ring-1 focus:ring-cyan-500 rounded disabled:opacity-50';
    fsBtn.dataset.idx = index;
    fsBtn.title = 'Full Screen'; fsBtn.disabled = true;
    fsBtn.innerHTML = `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M8 3H5a2 2 0 0 0-2 2v3m18 0V5a2 2 0 0 0-2-2h-3m0 18h3a2 2 0 0 0 2-2v-3M3 16v3a2 2 0 0 0 2 2h3"/></svg>`;
    fsBtn.addEventListener('click', (e) => {
        const idxToFullscreen = isGridItem ? parseInt(e.currentTarget.dataset.idx) : activeTimelineIndex;
        const fromHistory = !isGridItem;
        if (!isNaN(idxToFullscreen) && (isGridItem ? generatedCode[idxToFullscreen] : evolutionTimeline[idxToFullscreen]?.code)) {
            enterFullscreen(idxToFullscreen, fromHistory);
        }
    });

    btns.appendChild(fsBtn);

    if (isGridItem) {
        const selBtn = document.createElement('button');
        selBtn.className = 'select-variation-btn futuristic-button px-3 py-1 text-xs';
        selBtn.dataset.variationGridIndex = index; selBtn.disabled = true; selBtn.textContent = 'Select';
        selBtn.addEventListener('click', handleSelectVariationFromGrid);
        selectButtons[index] = selBtn;
        btns.appendChild(selBtn);
    }

    header.appendChild(btns);
    item.appendChild(header);

    const bodyEl = document.createElement('div'); bodyEl.className = 'preview-body';
    const loaderDiv = document.createElement('div'); loaderDiv.id = `preview-loader-${index + 1}`;
    loaderDiv.className = 'preview-loader ' + (isGridItem ? 'hidden' : '');
    loaderDiv.innerHTML = '<div class="spinner"></div>';
    bodyEl.appendChild(loaderDiv);

    const iframeEl = document.createElement('iframe');
    iframeEl.id = isGridItem ? `preview-frame-${index + 1}` : 'single-large-preview-frame';
    iframeEl.title = `Preview ${index + 1}`; iframeEl.className = 'preview-frame';
    iframeEl.srcdoc = '<div class="flex items-center justify-center h-full"><p class="text-slate-400">Preparing...</p></div>';
    bodyEl.appendChild(iframeEl);
    item.appendChild(bodyEl);

    if (isGridItem) {
        previewItems[index] = item;
        fullscreenButtons[index] = fsBtn;
    }
    return item;
}


function showFourGridPreviewUI() {
    previewGridWrapperEl.innerHTML = '';
    if (numVariationsToGenerate === 1) {
        previewGridWrapperEl.className = 'single-mode';
        if(perspectiveViewportEl) perspectiveViewportEl.style.perspective = 'none';
         const item = createPreviewItemDOM(0, true);
         previewGridWrapperEl.appendChild(item);

    } else if (numVariationsToGenerate === 2) {
        previewGridWrapperEl.className = 'grid grid-cols-2 grid-rows-1 gap-6';
        if(perspectiveViewportEl) perspectiveViewportEl.style.perspective = '1500px';
         for (let i = 0; i < numVariationsToGenerate; i++) {
            const item = createPreviewItemDOM(i, true);
            previewGridWrapperEl.appendChild(item);
        }
    } else {
         previewGridWrapperEl.className = 'grid-mode';
         if(perspectiveViewportEl) perspectiveViewportEl.style.perspective = '1500px';
         for (let i = 0; i < numVariationsToGenerate; i++) {
            const item = createPreviewItemDOM(i, true);
            previewGridWrapperEl.appendChild(item);
        }
    }
    updateSelectedGridItemUI();
}

function showSingleLargePreviewUI(htmlContent, titleText, fullPromptText) {
    previewGridWrapperEl.innerHTML = '';
    previewGridWrapperEl.className = 'single-mode';
     if(perspectiveViewportEl) perspectiveViewportEl.style.perspective = 'none';

    const item = document.createElement('div');
    item.className = 'single-preview-item';

    const bodyEl = document.createElement('div');
    bodyEl.className = 'preview-body';

    const iframeEl = document.createElement('iframe');
    iframeEl.id = `single-large-preview-frame`;
    iframeEl.title = titleText;
    iframeEl.className = 'preview-frame';
    iframeEl.srcdoc = htmlContent;

    bodyEl.appendChild(iframeEl);
    item.appendChild(bodyEl);
    previewGridWrapperEl.appendChild(item);

    // Handle subtitle truncation and clickability
    const maxPromptLength = 50;
    let displaySubtitle = fullPromptText;
    mainContentSubtitleH2El.classList.remove('prompt-truncated');
    delete mainContentSubtitleH2El.dataset.fullPrompt;

    if (fullPromptText && fullPromptText.length > maxPromptLength) {
        displaySubtitle = fullPromptText.substring(0, maxPromptLength) + "... (click to view full)";
        mainContentSubtitleH2El.classList.add('prompt-truncated');
        mainContentSubtitleH2El.dataset.fullPrompt = fullPromptText; // Store full prompt
    }

    updateMainContentTitles(titleText, displaySubtitle); // Use potentially truncated text
}

function showInitialPreviewStateUI() {
    previewGridWrapperEl.innerHTML = ''; // Clear existing content

    const initialViewContainer = document.createElement('div');
    initialViewContainer.id = 'initial-view-content';
    initialViewContainer.className = 'flex flex-col items-center justify-center text-slate-300 text-lg p-8 space-y-4 h-full initial-view-animate'; 

    // Novita.AI Logo Container
    const logoContainer = document.createElement('div');
    logoContainer.className = 'w-40 mb-2 novita-logo-container'; // Added class for potential specific styling
    initialViewContainer.appendChild(logoContainer);

    fetch('https://novita.ai/logo/logo.svg')
        .then(response => {
            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }
            return response.text();
        })
        .then(svgText => {
            logoContainer.innerHTML = svgText;
            const svgElement = logoContainer.querySelector('svg');
            if (svgElement) {
                svgElement.classList.add('novita-logo-svg-themed');
                // Optionally set width/height directly if not handled by viewBox and container class
                svgElement.setAttribute('width', '100%');
                svgElement.setAttribute('height', '100%');
            } else {
                console.warn('SVG element not found after fetching Novita logo.');
                 // Fallback to img if SVG injection fails to find svg tag
                logoContainer.innerHTML = '<img src="https://novita.ai/logo/logo.svg" alt="Novita.AI Logo" class="w-full h-full" />';
            }
        })
        .catch(error => {
            console.error('Error fetching Novita.AI logo:', error);
            // Fallback: display the logo as a regular image if fetch fails (e.g., CORS issue)
            logoContainer.innerHTML = '<img src="https://novita.ai/logo/logo.svg" alt="Novita.AI Logo" class="w-full h-full" />';
        });

    // API Key Input Section
    const apiKeySection = document.createElement('div');
    apiKeySection.className = 'w-full max-w-md text-center'; // Centered text for this section

    const apiKeyInput = document.createElement('input');
    apiKeyInput.type = 'password';
    apiKeyInput.id = 'initial-api-key-input';
    apiKeyInput.className = 'futuristic-input w-full text-center'; // Added text-center
    apiKeyInput.placeholder = 'Paste Novita.AI API Key here'; // Changed placeholder
    if (apiKeyEl && apiKeyEl.value) {
        apiKeyInput.value = apiKeyEl.value;
    }
    apiKeyInput.addEventListener('input', (e) => {
        if (apiKeyEl) {
            apiKeyEl.value = e.target.value;
        }
    });
    apiKeySection.appendChild(apiKeyInput);

    const apiKeyLink = document.createElement('p');
    apiKeyLink.className = 'text-xs text-slate-400 mt-2'; // Adjusted margin
    apiKeyLink.innerHTML = 'Get your API Key from <a href="https://novita.ai/" target="_blank" class="text-cyan-400 hover:text-cyan-300 underline">Novita.AI</a>.';
    apiKeySection.appendChild(apiKeyLink);
    initialViewContainer.appendChild(apiKeySection);

    // Example Prompts Section
    const examplePromptsSection = document.createElement('div');
    examplePromptsSection.className = 'w-full max-w-lg text-center pt-4'; // Centered text for this section, added padding top

    const examplePromptsContainer = document.createElement('div');
    examplePromptsContainer.id = 'example-prompts-container';
    examplePromptsContainer.className = 'flex flex-wrap justify-center gap-3';

    const examplePrompts = [
        "A modern landing page for a new meditation app",
        "A portfolio website for a photographer",
        "A simple to-do list application",
        "An e-commerce product card for a smartwatch"
    ];

    examplePrompts.forEach(promptText => {
        const button = document.createElement('button');
        button.className = 'example-prompt-button';
        button.textContent = promptText;
        button.addEventListener('click', () => {
            if (modalUserPromptEl) {
                modalUserPromptEl.value = promptText;
            }
            // Ensure API key from initial input is also considered if config one is empty
            if (apiKeyEl && !apiKeyEl.value && apiKeyInput.value) {
                apiKeyEl.value = apiKeyInput.value;
            }
            showPromptModal();
        });
        examplePromptsContainer.appendChild(button);
    });
    examplePromptsSection.appendChild(examplePromptsContainer);
    initialViewContainer.appendChild(examplePromptsSection);

    // Final instruction
    const instructionText = document.createElement('p');
    instructionText.className = 'text-sm text-slate-400 mt-6'; // Adjusted margin
    instructionText.innerHTML = 'Once you have an API key and a prompt (either typed or from an example),<br>click the <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-pencil inline-block align-middle -mt-1"><path d="M17 3a2.85 2.83 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5Z"/><path d="m15 5 4 4"/></svg> icon or press Alt+P to open the prompt window and generate.';
    initialViewContainer.appendChild(instructionText);
    
    previewGridWrapperEl.appendChild(initialViewContainer);

    previewGridWrapperEl.className = 'grid-mode initial-view-active'; // Keep grid-mode, add a new class for styling
    if(perspectiveViewportEl) perspectiveViewportEl.style.perspective = 'none'; // No perspective for initial flat view

    updateMainContentTitles("Welcome!", "Setup your API Key and enter a prompt to begin.");
    if (codeOutputEl) codeOutputEl.innerHTML = '<code class="language-html">// Code for the selected evolution will appear here.</code>';
    if (selectedCodeTitleH3El) selectedCodeTitleH3El.textContent = "Selected Code:";
    selectedVariationGridIndex = -1;
    if (mainContentSubtitleH2El) {
        mainContentSubtitleH2El.classList.remove('prompt-truncated');
        delete mainContentSubtitleH2El.dataset.fullPrompt;
    }
}

function updateMainContentTitles(title, subtitle) {
    if (mainContentTitleH1El) mainContentTitleH1El.textContent = title;
    if (mainContentSubtitleH2El) mainContentSubtitleH2El.textContent = subtitle;
}

function updateSelectedGridItemUI() {
    previewItems.forEach((item, index) => {
        if (!item) return;
        item.classList.toggle('selected', index === selectedVariationGridIndex);
    });
    selectButtons.forEach((button, index) => {
        if (!button) return;
        // Button enabled/disabled state is handled by procStream's success.
        // const hasCode = currentCleanedCode[index]?.length > 0 && !currentCleanedCode[index].startsWith("// Error");
        // button.disabled = !hasCode;
        // if (fullscreenButtons[index]) { fullscreenButtons[index].disabled = !hasCode; }

        button.classList.remove('selected-state');
        if (index === selectedVariationGridIndex) {
            button.textContent = 'Selected';
            button.classList.add('selected-state');
        } else {
            button.textContent = 'Select';
        }
    });
}

function updateLivePreviewInGrid(index, codeToRender = null, applyZoom = false) {
    let baseHtml = codeToRender !== null ? codeToRender : generatedCode[index];
    const frame = document.getElementById(`preview-frame-${index + 1}`);
    if (!frame) { console.warn(`[updateLivePreviewInGrid][Var ${index + 1}] Frame not found.`); return; }

    if (typeof baseHtml !== 'string') {
        baseHtml = '<div class="p-4 text-orange-500">Invalid content received</div>';
        applyZoom = false;
    }
    let finalHtml = baseHtml;
    try {
        if (applyZoom && numVariationsToGenerate > 1) {
            const scaleStyle = `<style>html { transform: scale(0.5); transform-origin: 0 0; width: 200%; height: 200%; overflow: auto !important; } body { overflow: visible !important; min-height: 100% !important; height: auto !important; width: auto !important; }</style>`;
            const headEndIndex = finalHtml.toLowerCase().lastIndexOf('</head>');
            if (headEndIndex !== -1) {
                finalHtml = finalHtml.slice(0, headEndIndex) + scaleStyle + finalHtml.slice(headEndIndex);
            } else {
                finalHtml = scaleStyle + finalHtml;
            }
        }
        frame.srcdoc = finalHtml;
    } catch (e) {
        console.error(`[Var ${index + 1}] Error setting srcdoc for grid:`, e);
        try {
            frame.srcdoc = `<div class="p-4 text-red-500 font-semibold">Preview Render Error</div>`;
        } catch (finalError) { console.error("Failed to display error in grid iframe:", finalError); }
    }
}

// --- Event Handlers ---
function handleSelectVariationFromGrid(event) {
    const idx = parseInt(event.target.dataset.variationGridIndex, 10);
     // Check if code for this variation is valid (not an error message)
    if (isNaN(idx) || !currentCleanedCode[idx] || currentCleanedCode[idx].startsWith("// Error")) {
        console.warn(`Cannot select variation ${idx + 1}, code is invalid or generation failed.`);
        return;
    }

    activeApiControllers.forEach((controller, controllerIndex) => {
        if (controllerIndex !== idx && controller) {
            console.log(`Aborting request for variation ${controllerIndex + 1}`);
            controller.abort();
        }
    });
    activeApiControllers = [];


    selectedVariationGridIndex = idx;
    const displayCode = generatedCode[idx];
    const storeCode = currentCleanedCode[idx];

    let originalPromptForThisEvolution;
    let parentTimelineIdx = null;

    const wasThisGenerationARefinement = lastGenerationConfig.isRefinement;
    const refinedIndexForThisGen = lastGenerationConfig.refinedTimelineIndex;

    if (wasThisGenerationARefinement && refinedIndexForThisGen !== -1 && evolutionTimeline[refinedIndexForThisGen]) {
        originalPromptForThisEvolution = evolutionTimeline[refinedIndexForThisGen].originalUserPrompt;
        parentTimelineIdx = refinedIndexForThisGen;
    } else {
        originalPromptForThisEvolution = originalUserPromptForCurrentGeneration;
    }

    const newHistoryEntry = {
        id: 'evo-' + Date.now() + '-' + Math.random().toString(36).substr(2, 5),
        prompt: originalUserPromptForCurrentGeneration,
        originalUserPrompt: originalPromptForThisEvolution,
        code: storeCode,
        timestamp: new Date().toLocaleTimeString([], { hour: '2-digit', minute: '2-digit', second: '2-digit'}),
        parentIndex: parentTimelineIdx
    };
    evolutionTimeline.push(newHistoryEntry);
    activeTimelineIndex = evolutionTimeline.length - 1;

    console.log(`Variation ${idx + 1} selected from grid. Added to timeline as Evolution ${activeTimelineIndex + 1}.`);

    renderHistoryPanel();
    showSingleLargePreviewUI(displayCode, `Evolution ${activeTimelineIndex + 1}: Active`, `Prompt: "${newHistoryEntry.prompt}"`);

    if (codeOutputEl) {
        codeOutputEl.textContent = storeCode;
        if (selectedCodeTitleH3El) selectedCodeTitleH3El.textContent = `Code (Evolution ${activeTimelineIndex + 1}):`;
        codeOutputEl.classList.remove('text-slate-200');
        codeOutputEl.classList.add('text-slate-400');
        if (codeOutputEl?.parentElement) { codeOutputEl.parentElement.scrollTop = 0; }
    }


    updateSelectedGridItemUI();
    updateHistoryNavigationButtons(); // Update nav buttons

    if(modalUserPromptEl) modalUserPromptEl.value = '';
    if(modalUserPromptEl) modalUserPromptEl.placeholder = `Refine Evolution ${activeTimelineIndex + 1}...`;
    if(modalRefinementCheckboxEl) modalRefinementCheckboxEl.checked = true;
}

function handleHistoryItemClick(timelineIdxToView) {
    if (timelineIdxToView < 0 || timelineIdxToView >= evolutionTimeline.length) {
        console.warn("Invalid history index clicked:", timelineIdxToView);
        return;
    }
    activeTimelineIndex = timelineIdxToView;
    const historyEntry = evolutionTimeline[activeTimelineIndex];

    console.log(`History item ${activeTimelineIndex + 1} selected.`);

    const displayCodeForHistory = historyEntry.code;

    showSingleLargePreviewUI(displayCodeForHistory, `Evolution ${activeTimelineIndex + 1}: Active (Historical)`, `Prompt: "${historyEntry.prompt}"`);

    if (codeOutputEl) {
        codeOutputEl.textContent = historyEntry.code;
        if (selectedCodeTitleH3El) selectedCodeTitleH3El.textContent = `Code (Evolution ${activeTimelineIndex + 1} - Historical):`;
        codeOutputEl.classList.remove('text-slate-200');
        codeOutputEl.classList.add('text-slate-400');
        if (codeOutputEl?.parentElement) { codeOutputEl.parentElement.scrollTop = 0; }
    }

    renderHistoryPanel();
    updateHistoryNavigationButtons(); // Update nav buttons

    if(modalUserPromptEl) modalUserPromptEl.value = '';
    if(modalUserPromptEl) modalUserPromptEl.placeholder = `Refine Evolution ${activeTimelineIndex + 1}...`;
    if(modalRefinementCheckboxEl) modalRefinementCheckboxEl.checked = true;
    selectedVariationGridIndex = -1;
    updateSelectedGridItemUI();
}


// --- Render History Panel ---
function createHistoryThumbnailDOM(entry, index) {
    const thumbItem = document.createElement('div');
    thumbItem.className = 'history-thumbnail-item group';
    thumbItem.dataset.timelineIndex = index;
    thumbItem.setAttribute('aria-label', `Evolution Step ${index + 1}: ${entry.prompt.substring(0, 30)}...`);

    // Note: Active class and dynamic transforms/z-index are applied in renderHistoryPanel

    const previewContainer = document.createElement('div');
    previewContainer.className = 'history-thumbnail-preview-container';
    previewContainer.title = `Click to view Evolution ${index + 1}`;
    previewContainer.addEventListener('click', () => handleHistoryItemClick(index));

    const iframe = document.createElement('iframe');
    iframe.className = 'history-thumbnail-preview';
    iframe.title = `Preview of Evolution ${index + 1}`;
    const scaledContent = `
                <style>
                    html { transform: scale(0.25); transform-origin: 0 0; width: 400%; height: 400%; overflow: hidden !important; background-color: #fff; }
                    body { width: 100%; height: 100%; overflow: hidden !important; padding: 0 !important; margin: 0 !important; }
                </style>
                ${entry.code}
            `;
    iframe.srcdoc = scaledContent;
    previewContainer.appendChild(iframe);

    const titleEl = document.createElement('div');
    titleEl.className = 'history-thumbnail-title';
    titleEl.textContent = `Evo ${index + 1}: ${entry.prompt.substring(0, 20)}${entry.prompt.length > 20 ? '...' : ''}`;
    titleEl.title = `Prompt: ${entry.prompt}\\nClick to view Evolution ${index + 1}`;
    titleEl.addEventListener('click', () => handleHistoryItemClick(index));

    const fsBtn = document.createElement('button');
    fsBtn.className = 'history-thumbnail-fullscreen-btn';
    fsBtn.title = 'View Fullscreen';
    fsBtn.innerHTML = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><path d="M8 3H5a2 2 0 0 0-2 2v3m18 0V5a2 2 0 0 0-2-2h-3m0 18h3a2 2 0 0 0 2-2v-3M3 16v3a2 2 0 0 0 2 2h3"/></svg>`;
    fsBtn.addEventListener('click', (e) => {
        e.stopPropagation();
        enterFullscreen(index, true);
    });

    thumbItem.appendChild(previewContainer);
    thumbItem.appendChild(titleEl);
    thumbItem.appendChild(fsBtn);
    return thumbItem;
}

function renderHistoryPanel() {
    if (!historyPanelEl || !historyPanelPlaceholderEl) return;
    historyPanelEl.innerHTML = ''; // Clear previous items

    if (evolutionTimeline.length === 0) {
        historyPanelEl.appendChild(historyPanelPlaceholderEl);
        historyPanelPlaceholderEl.classList.remove('hidden');
        return;
    }

    historyPanelPlaceholderEl.classList.add('hidden');

    const totalItems = evolutionTimeline.length;
    const middleIndex = Math.floor(totalItems / 2);
    // const maxRotation = 15; // Max rotation in degrees for edge items (rotation is now 0)
    const yOffsetFactor = 4; // How much non-active items lift towards the edges
    const zOffsetFactor = -15; // How much non-active items move back towards the edges
    const baseZIndex = 10; // Base z-index for non-active items

    // Define specific offsets for the active item to make it stand out
    const activeYOffset = -15; // Moves active item further up
    const activeZOffset = 25;  // Moves active item further forward

    evolutionTimeline.forEach((entry, index) => {
        const thumbItem = createHistoryThumbnailDOM(entry, index);
        let finalTransform;
        let finalZIndex;

        if (index === activeTimelineIndex) {
            thumbItem.classList.add('active-history-item');
            // Transform for the active item: more prominent
            finalTransform = `translateY(${activeYOffset}px) translateZ(${activeZOffset}px) rotate(0deg)`;
            // The .active-history-item class in CSS sets z-index: 50.
            // We can set it here too for consistency or rely on CSS.
            finalZIndex = 50; 
        } else {
            // Calculate transformations relative to the middle for non-active items
            const deltaFromMiddle = index - middleIndex;
            const rotation = 0; // Rotation is kept at 0
            const translateY = Math.abs(deltaFromMiddle) * yOffsetFactor;
            const translateZ = Math.abs(deltaFromMiddle) * zOffsetFactor;

            finalTransform = `translateY(${translateY}px) translateZ(${translateZ}px) rotate(${rotation}deg)`;
            finalZIndex = baseZIndex - Math.abs(deltaFromMiddle);
        }

        thumbItem.style.zIndex = `${finalZIndex}`;
        thumbItem.style.transform = finalTransform;

        historyPanelEl.appendChild(thumbItem);
    });
    const activeThumb = historyPanelEl.querySelector('.active-history-item');
    if (activeThumb) {
        // Keep scrollIntoView, maybe adjust behavior if needed
        activeThumb.scrollIntoView({ behavior: 'smooth', block: 'nearest', inline: 'center' });
    }
}

// --- Full Screen Logic ---
function enterFullscreen(index, isFromHistory = false) {
    if (!fullscreenIframeEl || !fullscreenOverlayEl || !document.body || !fullscreenHistoryNavEl || !historyNavPrevBtnEl || !historyNavNextBtnEl) {
        console.error("Cannot enter fullscreen: Overlay or nav elements missing.");
        return;
    }

    let codeToDisplay;
    currentFullscreenHistoryIndex = -1;
    fullscreenHistoryNavEl.classList.remove('visible');

    if (isFromHistory) {
        if (index < 0 || index >= evolutionTimeline.length || !evolutionTimeline[index]) {
             console.warn("Cannot enter fullscreen for history item", index); return;
        }
        codeToDisplay = evolutionTimeline[index].code;
        currentFullscreenHistoryIndex = index;

        fullscreenHistoryNavEl.classList.add('visible');
        historyNavPrevBtnEl.disabled = (currentFullscreenHistoryIndex <= 0);
        historyNavNextBtnEl.disabled = (currentFullscreenHistoryIndex >= evolutionTimeline.length - 1);

    } else {
         if (index < 0 || index >= numVariationsToGenerate || !generatedCode[index]) {
            console.warn("Cannot enter fullscreen for variation grid item", index); return;
         }
         codeToDisplay = generatedCode[index];
    }

    fullscreenIframeEl.srcdoc = codeToDisplay;
    fullscreenOverlayEl.classList.add('visible');
    document.body.classList.add('fullscreen-active');
    document.documentElement.style.overflow = 'hidden';
}
function exitFullscreen() {
    if (!fullscreenOverlayEl || !document.body || !fullscreenIframeEl || !fullscreenHistoryNavEl) {
        console.error("Cannot exit fullscreen: Overlay or nav elements missing.");
        return;
    }
    fullscreenOverlayEl.classList.remove('visible');
    document.body.classList.remove('fullscreen-active');
    document.documentElement.style.overflow = '';
    currentFullscreenHistoryIndex = -1;
    fullscreenHistoryNavEl.classList.remove('visible');
    setTimeout(() => { if (fullscreenIframeEl) fullscreenIframeEl.srcdoc = 'about:blank'; }, 300);
}

function showPreviousHistoryInFullscreen() {
    if (currentFullscreenHistoryIndex > 0) {
        currentFullscreenHistoryIndex--;
        activeTimelineIndex = currentFullscreenHistoryIndex;
        enterFullscreen(activeTimelineIndex, true);
        renderHistoryPanel();
        const historyEntry = evolutionTimeline[activeTimelineIndex];
        if (historyEntry && codeOutputEl) {
            codeOutputEl.textContent = historyEntry.code;
            if(selectedCodeTitleH3El) selectedCodeTitleH3El.textContent = `Code (Evolution ${activeTimelineIndex + 1} - Historical):`;
        }
    }
}

function showNextHistoryInFullscreen() {
    if (currentFullscreenHistoryIndex < evolutionTimeline.length - 1) {
        currentFullscreenHistoryIndex++;
        activeTimelineIndex = currentFullscreenHistoryIndex;
        enterFullscreen(activeTimelineIndex, true);
        renderHistoryPanel();
        const historyEntry = evolutionTimeline[activeTimelineIndex];
         if (historyEntry && codeOutputEl) {
            codeOutputEl.textContent = historyEntry.code;
            if(selectedCodeTitleH3El) selectedCodeTitleH3El.textContent = `Code (Evolution ${activeTimelineIndex + 1} - Historical):`;
        }
    }
}

// --- Prompt Modal Logic ---
function showPromptModal() {
    if (!promptModalOverlayEl || !modalUserPromptEl || !modalRefinementCheckboxEl || !numVariationsSliderEl || !modelSelEl || !modalContextSizeValueEl || !modalMaxTokensValueEl || !modalMaxTokensSliderEl) return;

    updateModelSpecificUI(modelSelEl.value); // Update UI based on current model when modal opens

    modalRefinementCheckboxEl.checked = (activeTimelineIndex !== -1);
    numVariationsSliderEl.value = lastGenerationConfig.numVariations;
    if(numVariationsValueDisplayEl) numVariationsValueDisplayEl.textContent = numVariationsSliderEl.value;
    
    // modalThinkingBudgetSliderEl.value = lastGenerationConfig.thinkingBudget; // Removed
    // if(modalThinkingBudgetValueDisplayEl) modalThinkingBudgetValueDisplayEl.textContent = lastGenerationConfig.thinkingBudget; // Removed

    // Animation handling
    promptModalOverlayEl.classList.remove('modal-anim-fade-out');
    promptModalOverlayEl.style.display = 'flex'; // Or 'block' if that was its original display type
    promptModalOverlayEl.classList.add('modal-anim-fade-in');
    // promptModalOverlayEl.classList.add('visible'); // Keep this if it controls other things besides opacity/visibility

    modalUserPromptEl.focus();
}

function hidePromptModal() {
    if (!promptModalOverlayEl) return;

    promptModalOverlayEl.classList.remove('modal-anim-fade-in');
    promptModalOverlayEl.classList.add('modal-anim-fade-out');

    // Wait for animation to finish before hiding
    const handleAnimationEnd = () => {
        promptModalOverlayEl.style.display = 'none';
        // promptModalOverlayEl.classList.remove('visible'); // Keep this if it controls other things
        promptModalOverlayEl.removeEventListener('animationend', handleAnimationEnd);
    };
    promptModalOverlayEl.addEventListener('animationend', handleAnimationEnd);
}

function handleModalGenerate() {
    if (!modalUserPromptEl || !modalGenerateBtnEl) return;
    const modalPrompt = modalUserPromptEl.value.trim();
    if (modalPrompt) {
        hidePromptModal();
        if (!modalGenerateBtnEl.disabled) {
            generateVariations();
        }
    } else {
        console.warn("Modal prompt is empty. Not generating.");
    }
}

// --- Config Modal Logic ---
function showConfigModal() {
    if (!configModalOverlayEl) return;

    // Animation handling
    configModalOverlayEl.classList.remove('modal-anim-fade-out');
    configModalOverlayEl.style.display = 'flex'; // Or 'block'
    configModalOverlayEl.classList.add('modal-anim-fade-in');
    // configModalOverlayEl.classList.add('visible');
}
function hideConfigModal() {
    if (!configModalOverlayEl) return;

    configModalOverlayEl.classList.remove('modal-anim-fade-in');
    configModalOverlayEl.classList.add('modal-anim-fade-out');

    const handleAnimationEnd = () => {
        configModalOverlayEl.style.display = 'none';
        // configModalOverlayEl.classList.remove('visible');
        configModalOverlayEl.removeEventListener('animationend', handleAnimationEnd);
    };
    configModalOverlayEl.addEventListener('animationend', handleAnimationEnd);
}

// --- Confirmation Modal Logic ---
function showConfirmModal(message, onConfirmCallback) {
    if (!confirmModalOverlayEl || !confirmModalMessageEl || !confirmModalConfirmBtnEl || !confirmModalCancelBtnEl) {
        console.error("Confirmation modal elements not found!");
        // Fallback to default confirm if modal elements are missing
        if (confirm(message)) { 
            onConfirmCallback(); 
        }
        return;
    }

    confirmModalMessageEl.textContent = message;
    currentConfirmCallback = onConfirmCallback; // Store the callback

    // Clear previous listeners (important!)
    confirmModalConfirmBtnEl.replaceWith(confirmModalConfirmBtnEl.cloneNode(true));
    confirmModalCancelBtnEl.replaceWith(confirmModalCancelBtnEl.cloneNode(true));
    // Re-find buttons after cloning
    confirmModalConfirmBtnEl = document.getElementById('confirm-modal-confirm-button');
    confirmModalCancelBtnEl = document.getElementById('confirm-modal-cancel-button');

    // Add new listeners
    confirmModalConfirmBtnEl.addEventListener('click', handleConfirm); 
    confirmModalCancelBtnEl.addEventListener('click', hideConfirmModal);

    // Show modal with animation
    confirmModalOverlayEl.classList.remove('modal-anim-fade-out');
    confirmModalOverlayEl.style.display = 'flex'; 
    confirmModalOverlayEl.classList.add('modal-anim-fade-in');
}

function hideConfirmModal() {
    if (!confirmModalOverlayEl) return;

    confirmModalOverlayEl.classList.remove('modal-anim-fade-in');
    confirmModalOverlayEl.classList.add('modal-anim-fade-out');

    const handleAnimationEnd = () => {
        confirmModalOverlayEl.style.display = 'none';
        currentConfirmCallback = null; // Clear callback when hidden
        confirmModalOverlayEl.removeEventListener('animationend', handleAnimationEnd);
    };
    confirmModalOverlayEl.addEventListener('animationend', handleAnimationEnd);
}

function handleConfirm() {
    hideConfirmModal();
    if (typeof currentConfirmCallback === 'function') {
        currentConfirmCallback(); // Execute the stored callback
    }
    currentConfirmCallback = null; // Clear callback after execution
}

// --- History Navigation Logic ---
function navigateToPreviousHistory() {
    if (activeTimelineIndex > 0) {
        handleHistoryItemClick(activeTimelineIndex - 1);
    }
}

function navigateToNextHistory() {
    if (activeTimelineIndex < evolutionTimeline.length - 1) {
        handleHistoryItemClick(activeTimelineIndex + 1);
    }
}

function updateHistoryNavigationButtons() {
    if (!historyNavLeftBtnEl || !historyNavRightBtnEl) return;
    historyNavLeftBtnEl.disabled = activeTimelineIndex <= 0;
    historyNavRightBtnEl.disabled = activeTimelineIndex >= evolutionTimeline.length - 1;
}

// --- Helper function to call Gemini for code splitting ---
async function fetchCodeSplitFromGemini(apiKey, fullHtmlContent) {
    const exportModelName = "gemini-2.5-flash-preview-04-17"; // Hardcoded model for export
    const API_ENDPOINT = `${API_BASE_URL}${exportModelName}:generateContent?key=${apiKey}`;
    const prompt = `
You are an expert web developer. You are given a single HTML document that might contain inline CSS within <style> tags and inline JavaScript within <script> tags. Your task is to separate this document into three distinct components: HTML structure, CSS styles, and JavaScript code.

Follow these instructions carefully:
1.  **HTML Output**: This should be the main HTML structure. 
    *   If there were inline <style> tags, remove them. Add a <link rel="stylesheet" href="style.css"> in the <head> instead.
    *   If there were inline <script> tags (especially those not setting up initial variables or configurations that need to be in the head), try to move their content to what will become an external script.js file. Add <script src="script.js" defer><\\/script> before the closing </body> tag. For simple, short scripts that are clearly for page setup and are in the head, they can sometimes remain, but prefer externalizing functional code.
    *   Ensure the HTML output is clean and well-formed.
2.  **CSS Output**: This should contain ALL CSS rules extracted from any <style>...</style> blocks in the original HTML. If no <style> blocks were present, this should be an empty string or a comment indicating no CSS.
3.  **JavaScript Output**: This should contain ALL JavaScript code extracted from any <script>...</script> blocks (that are not JSON-LD or other non-executable script types). If no functional <script> blocks were present, this should be an empty string or a comment indicating no JavaScript.

Provide the output STRICTLY as a JSON object with the following keys: "html_code", "css_code", "js_code".

Example of desired JSON output format:
{
  "html_code": "<!DOCTYPE html>...<link rel=\\\"stylesheet\\\" href=\\\"style.css\\\"><script src=\\\"script.js\\\" defer><\\/script></body></html>",
  "css_code": "body { font-family: sans-serif; } ...",
  "js_code": "console.log(\\\'Hello World!\\\'); ...\"
}

Original HTML content:
\`\`\`html
${fullHtmlContent}\n\`\`\`

Return ONLY the JSON object. Do not include any other explanatory text or markdown formatting outside the JSON structure itself.
`;

    try {
        const response = await fetch(API_ENDPOINT, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ contents: [{ parts: [{ text: prompt }] }] })
        });

        if (!response.ok) {
            const errorData = await response.json().catch(() => null);
            const errorMsg = errorData?.error?.message || `HTTP Error: ${response.status}`;
            console.error('Gemini API Error:', errorMsg);
            throw new Error(`API Error: ${errorMsg}`);
        }

        const responseData = await response.json();
        const candidate = responseData.candidates?.[0];
        if (candidate?.content?.parts?.[0]?.text) {
            let rawText = candidate.content.parts[0].text;
            console.log("Raw response from Gemini for splitting:", rawText); // Log the raw response

            let jsonString = null;

            // Attempt 1: Look for JSON within markdown code blocks
            const markdownJsonMatch = rawText.match(/```json\n(\{[\s\S]*\})\n```/s) || rawText.match(/```\n(\{[\s\S]*\})\n```/s);
            if (markdownJsonMatch && markdownJsonMatch[1]) {
                jsonString = markdownJsonMatch[1];
            } else {
                // Attempt 2: Fallback to existing regex if no markdown block found or it's malformed
                const directJsonMatch = rawText.match(/\{.*\}/s);
                if (directJsonMatch) {
                    jsonString = directJsonMatch[0];
                }
            }

            if (jsonString) {
                try {
                    return JSON.parse(jsonString);
                } catch (parseError) {
                    console.error("Failed to parse JSON string from model:", jsonString, parseError);
                    throw new Error("JSON parsing failed after attempting to clean model response."); // Simplified error
                }
            }
            throw new Error("Clean JSON object not found in model's response after attempting to extract.");
        }
        throw new Error("No valid content found in model's response.");

    } catch (error) {
        console.error('Error fetching or parsing split code:', error);
        throw error; // Re-throw to be caught by caller
    }
}

// --- Full Prompt Display Modal Logic ---
function showFullPromptModal(fullPrompt) {
    if (!promptDisplayModalOverlayEl || !fullPromptTextEl) return;

    fullPromptTextEl.textContent = fullPrompt;

    // Animation handling
    promptDisplayModalOverlayEl.classList.remove('modal-anim-fade-out');
    promptDisplayModalOverlayEl.style.display = 'flex';
    promptDisplayModalOverlayEl.classList.add('modal-anim-fade-in');
}

function hideFullPromptModal() {
    if (!promptDisplayModalOverlayEl) return;

    promptDisplayModalOverlayEl.classList.remove('modal-anim-fade-in');
    promptDisplayModalOverlayEl.classList.add('modal-anim-fade-out');

    const handleAnimationEnd = () => {
        promptDisplayModalOverlayEl.style.display = 'none';
        promptDisplayModalOverlayEl.removeEventListener('animationend', handleAnimationEnd);
    };
    promptDisplayModalOverlayEl.addEventListener('animationend', handleAnimationEnd);
}

// --- Initialization ---
document.addEventListener('DOMContentLoaded', () => {
    console.log("DOMContentLoaded event fired.");

    apiKeyEl = document.getElementById('api-key');
    modelSelEl = document.getElementById('model-select');
    const codeOutputPre = document.getElementById('code-output');
    if (codeOutputPre) { codeOutputEl = codeOutputPre.querySelector('code'); } else { console.error("Code output <pre> not found");}
    errorMessageEl = document.getElementById('error-message');
    refinementLoadingIndicator = document.getElementById('refinement-loading-indicator');
    mainContentEl = document.getElementById('main-content');
    configButtonEl = document.getElementById('config-button');
    intervalSliderEl = document.getElementById('preview-interval-slider');
    intervalValueDisplayEl = document.getElementById('interval-value');
    fullscreenOverlayEl = document.getElementById('fullscreen-overlay');
    fullscreenIframeEl = document.getElementById('fullscreen-iframe');
    exitFullscreenBtnEl = document.getElementById('exit-fullscreen-btn');
    perspectiveViewportEl = document.getElementById('perspective-viewport');
    previewGridWrapperEl = document.getElementById('preview-grid-wrapper');
    historyPanelEl = document.getElementById('history-panel');
    historyPanelPlaceholderEl = document.getElementById('history-panel-placeholder');
    selectedCodeTitleH3El = document.getElementById('selected-code-title');
    mainContentTitleH1El = document.getElementById('main-content-title');
    mainContentSubtitleH2El = document.getElementById('main-content-subtitle');
    fullscreenHistoryNavEl = document.getElementById('fullscreen-history-nav');
    historyNavPrevBtnEl = document.getElementById('history-nav-prev');
    historyNavNextBtnEl = document.getElementById('history-nav-next');
    promptModalOverlayEl = document.getElementById('prompt-modal-overlay');
    promptModalContentEl = document.getElementById('prompt-modal-content');
    modalUserPromptEl = document.getElementById('modal-user-prompt');
    modalGenerateBtnEl = document.getElementById('modal-generate-button');
    modalCancelBtnEl = document.getElementById('modal-cancel-button');
    modalLoadingIndicatorEl = document.getElementById('modal-loading-indicator');
    modalRefinementCheckboxEl = document.getElementById('modal-refinement-checkbox');
    numVariationsSliderEl = document.getElementById('num-variations-slider');
    numVariationsValueDisplayEl = document.getElementById('num-variations-value');
    configModalOverlayEl = document.getElementById('config-modal-overlay');
    configModalContentEl = document.getElementById('config-modal-content');
    configModalCloseBtnEl = document.getElementById('config-modal-close-button');
    copyCodeButtonEl = document.getElementById('copy-code-button');
    exportCodeButtonEl = document.getElementById('export-code-button');
    historyToggleButtonEl = document.getElementById('history-toggle-button');
    historyArrowDownEl = document.getElementById('history-arrow-down');
    historyArrowUpEl = document.getElementById('history-arrow-up');
    newButtonEl = document.getElementById('new-button');
    confirmModalOverlayEl = document.getElementById('confirm-modal-overlay');
    confirmModalMessageEl = document.getElementById('confirm-modal-message');
    confirmModalConfirmBtnEl = document.getElementById('confirm-modal-confirm-button');
    confirmModalCancelBtnEl = document.getElementById('confirm-modal-cancel-button');
    historyNavLeftBtnEl = document.getElementById('history-nav-left-button');
    historyNavRightBtnEl = document.getElementById('history-nav-right-button');
    promptDisplayModalOverlayEl = document.getElementById('prompt-display-modal-overlay');
    promptDisplayModalContentEl = document.getElementById('prompt-display-modal-content');
    fullPromptTextEl = document.getElementById('full-prompt-text');
    promptDisplayModalCloseBtnEl = document.getElementById('prompt-display-modal-close-button');
    showPromptModalButtonEl = document.getElementById('show-prompt-modal-button'); // Added
    modalContextSizeValueEl = document.getElementById('modal-context-size-value'); // Added
    modalMaxTokensValueEl = document.getElementById('modal-max-tokens-value'); // Added
    modalMaxTokensSliderEl = document.getElementById('modal-max-tokens-slider'); // Added

    console.log("Checking history toggle elements:");
    console.log("historyToggleButtonEl:", historyToggleButtonEl);
    console.log("historyPanelEl:", historyPanelEl);
    console.log("historyArrowDownEl:", historyArrowDownEl);
    console.log("historyArrowUpEl:", historyArrowUpEl);

    // --- Check if all required elements exist ---
    let missingElements = [];
    const requiredElements = { apiKeyEl, modelSelEl, codeOutputEl, errorMessageEl, refinementLoadingIndicator, mainContentEl, configButtonEl, intervalSliderEl, intervalValueDisplayEl, fullscreenOverlayEl, fullscreenIframeEl, exitFullscreenBtnEl, perspectiveViewportEl, previewGridWrapperEl, historyPanelEl, historyPanelPlaceholderEl, selectedCodeTitleH3El, mainContentTitleH1El, mainContentSubtitleH2El, fullscreenHistoryNavEl, historyNavPrevBtnEl, historyNavNextBtnEl, promptModalOverlayEl, promptModalContentEl, modalUserPromptEl, modalGenerateBtnEl, modalCancelBtnEl, modalLoadingIndicatorEl, modalRefinementCheckboxEl, numVariationsSliderEl, numVariationsValueDisplayEl, configModalOverlayEl, configModalContentEl, configModalCloseBtnEl, copyCodeButtonEl, exportCodeButtonEl, historyToggleButtonEl, historyArrowDownEl, historyArrowUpEl, newButtonEl, confirmModalOverlayEl, confirmModalMessageEl, confirmModalConfirmBtnEl, confirmModalCancelBtnEl, historyNavLeftBtnEl, historyNavRightBtnEl, promptDisplayModalOverlayEl, promptDisplayModalContentEl, fullPromptTextEl, promptDisplayModalCloseBtnEl, showPromptModalButtonEl, modalContextSizeValueEl, modalMaxTokensValueEl, modalMaxTokensSliderEl }; // Added new modal elements
    for (const key in requiredElements) { if (!requiredElements[key]) { missingElements.push(key); } }

    if (missingElements.length > 0) {
        console.error("Initialization Error: Critical elements missing!", missingElements);
        if (document.body) { document.body.innerHTML = `<div class="fixed inset-0 bg-red-900 text-red-200 p-8 flex flex-col items-center justify-center text-center"><h2 class="text-2xl font-bold mb-4">Application Initialization Error</h2><p class="mb-2">Could not find element(s): ${missingElements.join(', ')}.</p><p>Please ensure the HTML structure is correct.</p></div>`; }
        else { alert(`Initialization Error: Critical elements missing: ${missingElements.join(', ')}.`); }
        return;
    }

    // --- Initial UI Setup ---
    showInitialPreviewStateUI();
    renderHistoryPanel();
    updateHistoryNavigationButtons(); // Initial button state

    // --- Event Listeners ---
    if (newButtonEl) {
        newButtonEl.addEventListener('click', () => {
            showConfirmModal(
                'Start a new session? This will clear the current state.', 
                () => { location.reload(); } // Pass the reload logic as the callback
            );
        });
    }

    if (configButtonEl) configButtonEl.addEventListener('click', showConfigModal);
    if (showPromptModalButtonEl) showPromptModalButtonEl.addEventListener('click', showPromptModal); // Added listener for new button
    if (configModalCloseBtnEl) configModalCloseBtnEl.addEventListener('click', hideConfigModal);
    if (configModalOverlayEl) configModalOverlayEl.addEventListener('click', (e) => {
        if (e.target === configModalOverlayEl) { hideConfigModal(); }
    });

    if (exitFullscreenBtnEl) exitFullscreenBtnEl.addEventListener('click', exitFullscreen);
    if (historyNavPrevBtnEl) historyNavPrevBtnEl.addEventListener('click', showPreviousHistoryInFullscreen);
    if (historyNavNextBtnEl) historyNavNextBtnEl.addEventListener('click', showNextHistoryInFullscreen);

    if (modalGenerateBtnEl) modalGenerateBtnEl.addEventListener('click', handleModalGenerate);
    if (modalCancelBtnEl) modalCancelBtnEl.addEventListener('click', hidePromptModal);
    if (promptModalOverlayEl) promptModalOverlayEl.addEventListener('click', (e) => {
        if (e.target === promptModalOverlayEl) { hidePromptModal(); }
    });
    if (confirmModalOverlayEl) { // Add overlay click listener for confirm modal
        confirmModalOverlayEl.addEventListener('click', (e) => {
            if (e.target === confirmModalOverlayEl) { hideConfirmModal(); }
        });
    }
    if (promptDisplayModalOverlayEl) { // Listener for full prompt display modal overlay click
        promptDisplayModalOverlayEl.addEventListener('click', (e) => {
            if (e.target === promptDisplayModalOverlayEl) { hideFullPromptModal(); }
        });
    }
    if (promptDisplayModalCloseBtnEl) { // Listener for full prompt display modal close button
        promptDisplayModalCloseBtnEl.addEventListener('click', hideFullPromptModal);
    }
    if (mainContentSubtitleH2El) { // Listener for clicking the subtitle
        mainContentSubtitleH2El.addEventListener('click', (e) => {
            const fullPrompt = e.target.dataset.fullPrompt;
            if (fullPrompt) { // Check if the data attribute exists (meaning it was truncated)
                showFullPromptModal(fullPrompt);
            }
        });
    }
     if (modalUserPromptEl) modalUserPromptEl.addEventListener('keydown', (event) => {
         if (event.key === 'Enter' && (event.ctrlKey || event.metaKey)) {
             event.preventDefault(); handleModalGenerate();
         }
     });
    if (numVariationsSliderEl) {
        numVariationsSliderEl.addEventListener('input', (event) => {
            if(numVariationsValueDisplayEl) numVariationsValueDisplayEl.textContent = event.target.value;
        });
        if(numVariationsValueDisplayEl) numVariationsValueDisplayEl.textContent = numVariationsSliderEl.value;
    }

    if (intervalSliderEl) {
        intervalSliderEl.addEventListener('input', (event) => {
            previewUpdateInterval = parseInt(event.target.value, 10);
            if(intervalValueDisplayEl) intervalValueDisplayEl.textContent = previewUpdateInterval;
        });
        previewUpdateInterval = parseInt(intervalSliderEl.value, 10);
        if(intervalValueDisplayEl) intervalValueDisplayEl.textContent = previewUpdateInterval;
    }

    if (copyCodeButtonEl) {
        copyCodeButtonEl.addEventListener('click', () => {
            if (codeOutputEl && codeOutputEl.textContent && codeOutputEl.textContent !== '// Select a variation or history item to view its code.') {
                const textToCopy = codeOutputEl.textContent;
                const textArea = document.createElement("textarea");
                textArea.value = textToCopy;
                textArea.style.position = "fixed"; // Prevent scrolling to bottom
                document.body.appendChild(textArea);
                textArea.focus();
                textArea.select();
                try {
                    const successful = document.execCommand('copy');
                    if (successful) {
                        const originalText = copyCodeButtonEl.innerHTML;
                        copyCodeButtonEl.innerHTML = `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-check inline-block mr-1"><polyline points="20 6 9 17 4 12"></polyline></svg> Copied!`;
                        copyCodeButtonEl.classList.add('copied');
                        setTimeout(() => {
                            copyCodeButtonEl.innerHTML = originalText;
                            copyCodeButtonEl.classList.remove('copied');
                        }, 2000);
                    } else {
                        console.error('Fallback: Failed to copy code using execCommand.');
                    }
                } catch (err) {
                    console.error('Fallback: Error copying code using execCommand: ', err);
                }
                document.body.removeChild(textArea);
            }
        });
    }

    if (exportCodeButtonEl) {
        exportCodeButtonEl.addEventListener('click', async () => {
            const currentCode = codeOutputEl?.textContent;
            const apiKey = apiKeyEl?.value;

            if (!currentCode || currentCode.startsWith('//') || currentCode.trim() === '') {
                alert('No code selected or available to export.');
                return;
            }
            if (!apiKey) {
                alert('API Key is missing. Please configure it in settings.');
                showConfigModal(); // Show config modal if API key is missing
                return;
            }

            const originalButtonContent = exportCodeButtonEl.innerHTML;
            exportCodeButtonEl.disabled = true;
            exportCodeButtonEl.innerHTML = `<svg class="animate-spin h-4 w-4 inline-block mr-1" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
            </svg> Exporting...`;

            try {
                const response = await fetch(`${API_BASE_URL}/chat/completions`, {
                    method: 'POST',
                    headers: {
                        'Content-Type': 'application/json',
                        'Authorization': `Bearer ${apiKey}`
                    },
                    body: JSON.stringify({
                        model: 'qwen/qwen3-235b-a22b-fp8',
                        messages: [{
                            role: "user",
                            content: `Please analyze and optimize the following HTML code for export. Ensure it follows best practices and is production-ready:

\`\`\`html
${currentCode}
\`\`\`

Please provide the optimized code with any necessary improvements for production use.`
                        }],
                        stream: false,
                        max_tokens: MODEL_DETAILS['qwen/qwen3-235b-a22b-fp8'].defaultOutput
                    })
                });

                if (!response.ok) {
                    throw new Error(`API Error: ${response.status} ${response.statusText}`);
                }

                const data = await response.json();
                const optimizedCode = data.choices[0].message.content;

                // Create a blob with the optimized code
                const blob = new Blob([optimizedCode], { type: 'text/html' });
                const url = window.URL.createObjectURL(blob);
                const a = document.createElement('a');
                a.href = url;
                a.download = 'optimized-code.html';
                document.body.appendChild(a);
                a.click();
                window.URL.revokeObjectURL(url);
                document.body.removeChild(a);

                exportCodeButtonEl.innerHTML = `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-check inline-block mr-1"><polyline points="20 6 9 17 4 12"></polyline></svg> Exported!`;
                setTimeout(() => {
                    exportCodeButtonEl.innerHTML = originalButtonContent;
                }, 2000);
            } catch (error) {
                console.error('Export error:', error);
                alert(`Export failed: ${error.message}`);
                exportCodeButtonEl.innerHTML = originalButtonContent;
            } finally {
                exportCodeButtonEl.disabled = false;
            }
        });
    }

    if (historyToggleButtonEl && historyPanelEl && historyArrowDownEl && historyArrowUpEl) {
        historyToggleButtonEl.addEventListener('click', () => {
            const isCollapsed = historyPanelEl.classList.toggle('history-collapsed');
            const rootStyles = getComputedStyle(document.documentElement);
            const expandedHeight = rootStyles.getPropertyValue('--history-panel-expanded-height').trim();
            const collapsedHeight = rootStyles.getPropertyValue('--history-panel-collapsed-height').trim();

            if (isCollapsed) {
                document.documentElement.style.setProperty('--history-panel-current-height', collapsedHeight);
                historyArrowDownEl.classList.add('hidden');
                historyArrowUpEl.classList.remove('hidden');
            } else {
                document.documentElement.style.setProperty('--history-panel-current-height', expandedHeight);
                historyArrowDownEl.classList.remove('hidden');
                historyArrowUpEl.classList.add('hidden');
                // Ensure content is visible if re-expanding and it was set to display:none directly
                // This is now handled by the .history-collapsed CSS rule for children.
                 renderHistoryPanel(); // Re-render to ensure items are correctly displayed if they were hidden
            }
        });
    }

    if (historyNavLeftBtnEl) {
        historyNavLeftBtnEl.addEventListener('click', navigateToPreviousHistory);
    }
    if (historyNavRightBtnEl) {
        historyNavRightBtnEl.addEventListener('click', navigateToNextHistory);
    }

    // Keyboard Shortcuts Listener
    document.addEventListener('keydown', (event) => {
        if (event.key === 'Escape') {
            // Check style.display instead of .visible class for animated modals
            if (configModalOverlayEl.style.display !== 'none' && !configModalOverlayEl.classList.contains('modal-anim-fade-out')) {
                hideConfigModal();
            } else if (promptModalOverlayEl.style.display !== 'none' && !promptModalOverlayEl.classList.contains('modal-anim-fade-out')) {
                 hidePromptModal();
            } else if (confirmModalOverlayEl.style.display !== 'none' && !confirmModalOverlayEl.classList.contains('modal-anim-fade-out')) { // Add Escape handler for confirm modal
                 hideConfirmModal();
            } else if (promptDisplayModalOverlayEl.style.display !== 'none' && !promptDisplayModalOverlayEl.classList.contains('modal-anim-fade-out')) { // Add Escape handler for prompt display modal
                 hideFullPromptModal();
            } else if (document.body.classList.contains('fullscreen-active')) {
                exitFullscreen();
            }
        }
        const targetTagName = event.target ? event.target.tagName.toLowerCase() : null;
        const isTypingInInputOrTextarea = targetTagName === 'input' || targetTagName === 'textarea';

        if (document.body.classList.contains('fullscreen-active') && currentFullscreenHistoryIndex !== -1 && !isTypingInInputOrTextarea) {
            if (event.key.toLowerCase() === 'w') {
                event.preventDefault();
                showPreviousHistoryInFullscreen();
            } else if (event.key.toLowerCase() === 'd') {
                event.preventDefault();
                showNextHistoryInFullscreen();
            }
        }
        if (event.altKey && !isTypingInInputOrTextarea) {
            if (event.key.toLowerCase() === 'p' || event.code === 'KeyP') {
                event.preventDefault();
                if (!promptModalOverlayEl.classList.contains('visible') && !configModalOverlayEl.classList.contains('visible')) {
                     showPromptModal();
                }
            }
            else if (event.key.toLowerCase() === 'j' || event.code === 'KeyJ') {
                event.preventDefault();
                if (lastGenerationConfig.prompt) {
                    console.log("Alt+J: Regenerating with last settings:", lastGenerationConfig);
                    modalUserPromptEl.value = lastGenerationConfig.prompt;
                    modalRefinementCheckboxEl.checked = lastGenerationConfig.isRefinement;
                    numVariationsSliderEl.value = lastGenerationConfig.numVariations;
                    if(numVariationsValueDisplayEl) numVariationsValueDisplayEl.textContent = numVariationsSliderEl.value;
                    // Lines below referencing removed elements must be commented out:
                    // modalThinkingBudgetSliderEl.value = lastGenerationConfig.thinkingBudget; 
                    // if(modalThinkingBudgetValueDisplayEl) modalThinkingBudgetValueDisplayEl.textContent = lastGenerationConfig.thinkingBudget;

                    if (lastGenerationConfig.isRefinement) {
                        activeTimelineIndex = lastGenerationConfig.refinedTimelineIndex;
                    }
                    handleModalGenerate();
                } else {
                    console.log("Alt+J: No last generation settings found. Opening prompt modal.");
                    showPromptModal();
                }
            }
            else if (event.key.toLowerCase() === 'o' || event.code === 'KeyO') {
                event.preventDefault();
                 if (!configModalOverlayEl.classList.contains('visible') && !promptModalOverlayEl.classList.contains('visible')) {
                    showConfigModal();
                }
            }
            // History navigation shortcuts (non-fullscreen)
            if (event.key === 'PageUp') {
                event.preventDefault();
                navigateToPreviousHistory();
            } else if (event.key === 'PageDown') {
                event.preventDefault();
                navigateToNextHistory();
            }
        }
    });
    console.log("Initialization setup complete.");

    if (modelSelEl) { // Add event listener for model selection change
        modelSelEl.addEventListener('change', (event) => {
            updateModelSpecificUI(event.target.value);
        });
    }

    if (modalMaxTokensSliderEl) { // Add event listener for max tokens slider
        modalMaxTokensSliderEl.addEventListener('input', (event) => {
            if (modalMaxTokensValueEl) {
                // Convert the slider value to a number and then to a locale string
                const numericValue = parseInt(event.target.value, 10);
                modalMaxTokensValueEl.textContent = numericValue.toLocaleString();
            }
        });
    }
}); 

// --- Function to Update Model-Specific UI Elements ---
function updateModelSpecificUI(selectedModelName) {
    if (!modalContextSizeValueEl || !modalMaxTokensValueEl || !modalMaxTokensSliderEl) return;

    const details = MODEL_DETAILS[selectedModelName];
    if (details) {
        modalContextSizeValueEl.textContent = details.context.toLocaleString();
        
        modalMaxTokensSliderEl.min = 256; // A sensible minimum
        modalMaxTokensSliderEl.max = details.maxOutput;
        
        // Set the slider to the model's maximum output tokens by default
        let defaultValue = details.maxOutput; 
        // Ensure it's not less than the slider's defined minimum (though maxOutput should always be higher)
        defaultValue = Math.max(parseInt(modalMaxTokensSliderEl.min, 10), defaultValue); 
        modalMaxTokensSliderEl.value = defaultValue; 
        modalMaxTokensValueEl.textContent = defaultValue.toLocaleString();

        // Adjust step for very large ranges if necessary, or keep it fixed.
        // For simplicity, keeping step fixed for now as defined in HTML or can be dynamic.
        // Example: if maxOutput is very large, step might be larger.
        if (details.maxOutput > 32000) {
            modalMaxTokensSliderEl.step = 512;
        } else if (details.maxOutput > 8000) {
            modalMaxTokensSliderEl.step = 256;
        } else {
            modalMaxTokensSliderEl.step = 128;
        }

    } else {
        modalContextSizeValueEl.textContent = "N/A";
        modalMaxTokensValueEl.textContent = "N/A";
        modalMaxTokensSliderEl.min = 256;
        modalMaxTokensSliderEl.max = 4096; // Default if model not found
        modalMaxTokensSliderEl.value = 1024;
        modalMaxTokensSliderEl.step = 128;
    }
}