/* --- Color Palette (CSS Variables) --- */
/* Palette 2: Warm & Encouraging (Mint Green) */
:root {
    --bg-primary: #fdfdfa;
    --bg-secondary: #ffffff;
    --text-primary: #4a4a4a;
    --text-secondary: #7a7a7a;
    --accent-primary: #00897B;
    --accent-hover: #00695C;
    --accent-text: #ffffff;
    --code-bg: #2d2d2d;
    --code-text: #f8f8f2;
    --explanation-bg: #f0f9f8;
    --explanation-border: #00897B;
    --button-disabled-bg: #c0c0c0;
    --shadow-color: rgba(0,0,0,0.1);
}

/* Basic CSS Reset */
body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, figcaption, blockquote, dl, dd {
    margin: 0;
    padding: 0;
}

*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    /* Respect device safe area insets (iPhone notch / rounded corners) */
    padding: 20px;
    padding-top: calc(20px + env(safe-area-inset-top));
    padding-right: calc(20px + env(safe-area-inset-right));
    padding-bottom: calc(20px + env(safe-area-inset-bottom));
    padding-left: calc(20px + env(safe-area-inset-left));
    transition: background-color 0.3s, color 0.3s;
}

header {
    background-color: var(--accent-primary);
    color: var(--accent-text);
    padding: 15px 20px;
    padding-top: calc(15px + env(safe-area-inset-top)); /* push header content below notch */
    text-align: center;
    margin-bottom: 20px;
    border-radius: 8px;
    display: flex;
    flex-direction: column; /* Keep this to stack header-top and stats-bar */
    gap: 15px;
}

/* Make header a positioned container so absolutely positioned menus are positioned relative to it */
header { position: relative; }

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-buttons {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* Header button individual styling to support icon + text layout */
.hdr-btn { display: inline-flex; align-items: center; gap: 8px; padding: 8px 10px; border: 1px solid var(--accent-text); background: transparent; color: var(--accent-text); border-radius: 5px; cursor: pointer; font-size: 0.95rem; }

.hdr-btn .icon { font-size: 1.1rem; line-height: 1; }
.hdr-btn .text { display: inline-block; }

#header-menu-btn { display: none; }

header h1 {
    font-size: 1.5rem;
}

#theme-toggle-button {
    background-color: transparent;
    border: none;
    cursor: pointer;
    font-size: 1.5rem; /* Size of the emoji */
    padding: 5px;
    line-height: 1;
    transition: transform 0.2s;
}

#theme-toggle-button:hover { transform: scale(1.1); background-color: transparent; /* Remove hover bg if set elsewhere */ }

main {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow-color);
    transition: background-color 0.3s;
}

footer {
    text-align: center;
    margin-top: 30px;
    color: var(--text-secondary);
    font-size: 0.9em;
}

/* --- Progress Bar --- */
#progress-container {
    width: 100%;
    background-color: var(--explanation-bg);
    border-radius: 10px;
    margin-bottom: 1.5rem;
    overflow: hidden; /* Keeps the inner bar's corners rounded */
}

#progress-bar {
    width: 0%; /* Starts at 0, will be updated by JS */
    height: 20px;
    background-color: var(--accent-primary);
    border-radius: 10px;
    transition: width 0.4s ease-in-out;
}


/* --- Dynamic Content Styles --- */

#app-container {
    min-height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.slide h2 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.slide p {
    margin-bottom: 1rem;
}

/* Syntax Slide Styles */
.slide-syntax pre {
    background-color: var(--code-bg);
    color: var(--code-text);
    padding: 1rem;
    border-radius: 6px;
    overflow-x: auto;
    margin-bottom: 1rem;
}

.slide-syntax .explanation {
    font-style: italic;
    color: var(--text-secondary);
    background-color: var(--explanation-bg);
    padding: 0.75rem;
    border-left: 4px solid var(--explanation-border);
    border-radius: 0 4px 4px 0;
}

/* Quiz Slide Styles */
.slide-quiz .question {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}
.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.quiz-option {
    width: 100%;
    padding: 1rem;
    text-align: left;
    background-color: var(--bg-primary);
    border: 1px solid var(--text-secondary);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}
.quiz-option:hover:not(:disabled) {
    background-color: var(--accent-primary);
    color: var(--accent-text);
    border-color: var(--accent-primary);
}
.quiz-option.correct {
    background-color: #28a745;
    color: white;
    border-color: #28a745;
}
.quiz-option.incorrect {
    background-color: #dc3545;
    color: white;
    border-color: #dc3545;
}
.quiz-option:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

/* Fill-in-the-blank Styles */
.slide-fill-in-the-blank .question {
    margin-bottom: 1rem;
}
.fill-in-the-blank-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--code-bg);
    padding: 1rem;
    border-radius: 6px;
    font-family: 'Courier New', Courier, monospace;
    color: var(--code-text);
}
.fill-in-the-blank-container input {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--text-secondary);
    border-radius: 4px;
    padding: 0.5rem;
    font-size: 1rem;
    text-align: center;
    width: 150px;
}
.fill-in-the-blank-container input.correct {
    border: 2px solid #28a745;
}
.fill-in-the-blank-container input.incorrect {
    border: 2px solid #dc3545;
}

/* Build-a-function Styles */
.slide-build-a-function .prompt {
    margin-bottom: 1rem;
}
.answer-blocks, .source-blocks {
    min-height: 50px;
    padding: 0.5rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
}
.answer-blocks {
    background-color: var(--explanation-bg);
    border: 1px dashed var(--text-secondary);
}
.source-blocks {
    background-color: var(--bg-primary);
}
.code-block {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    border: 1px solid var(--text-secondary);
    font-family: 'Courier New', Courier, monospace;
    white-space: pre;
}

/* General UI Elements */
.check-answer-btn {
    margin-top: 1rem;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    background-color: var(--accent-primary);
    color: var(--accent-text);
    font-size: 1rem;
    cursor: pointer;
}
.check-answer-btn:hover {
    background-color: var(--accent-hover);
}
.feedback {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 6px;
    font-weight: bold;
}
.feedback.correct {
    background-color: rgba(40, 167, 69, 0.2);
    color: #155724;
}
.feedback.incorrect {
    background-color: rgba(220, 53, 69, 0.2);
    color: #721c24;
}
body.dark-mode .feedback.correct {
    color: #c3e6cb;
}
body.dark-mode .feedback.incorrect {
    color: #f5c6cb;
}

/* --- Hint Feature Styles --- */
.hint-container {
    margin-top: 1.5rem;
    text-align: center;
}

.show-hint-btn {
    background-color: transparent;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
    padding: 5px 15px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.show-hint-btn:hover {
    background-color: var(--explanation-bg);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.hint-text {
    margin-top: 1rem;
    font-style: italic;
    color: var(--text-secondary);
}

/* Navigation Styles */
.navigation-controls {
    margin-top: 2rem;
    border-top: 1px solid #eee;
    padding-top: 1rem;
    display: flex;
    justify-content: space-between;
}

.navigation-controls button {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    background-color: var(--accent-primary);
    color: var(--accent-text);
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s;
}

.navigation-controls button:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.navigation-controls button:disabled {
    background-color: var(--button-disabled-bg);
    cursor: not-allowed;
}

/* --- Dark Mode Palette --- */
body.dark-mode {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent-primary: #378dfc; /* A slightly brighter blue for dark backgrounds */
    --accent-hover: #5a9eee;
    --accent-text: #ffffff;
    --code-bg: #2d2d2d; /* This was already dark, looks good */
    --code-text: #f8f8f2;
    --explanation-bg: #2a2a2a;
    --explanation-border: #378dfc;
    --button-disabled-bg: #4f4f4f;
    --shadow-color: rgba(0,0,0,0.4);
}

/* --- Stats Bar --- */
.stats-bar {
    display: flex;
    justify-content: space-around;
    background-color: var(--bg-primary);
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
    /* We add this to the dark mode transition */
    transition: background-color 0.3s, color 0.3s;
}

.stat {
    text-align: center;
}

.stat span {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.stat span:last-child {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-primary);
    white-space: nowrap; /* Prevents heart from wrapping */
}

/* Make stats bar background darker in dark mode */
body.dark-mode .stats-bar {
    background-color: #121212; /* Match the dark primary bg */
}

/* --- Build-a-function Correction --- */
.code-block.correct {
    background-color: #28a745 !important;
    color: white !important;
    border-color: #28a745 !important;
    cursor: default;
}

/* --- Lesson Complete Screen --- */
.lesson-complete-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 300px; /* Same min-height as app-container */
    animation: fadeIn 0.5s ease-in-out;
}

.lesson-complete-screen h2 {
    font-size: 2.5rem;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

.lesson-complete-screen .xp-reward {
    font-size: 1.5rem;
    font-weight: bold;
    color: #28a745; /* Green for reward */
    margin-bottom: 1.5rem;
}

.lesson-complete-screen .continue-btn {
    padding: 12px 25px;
    border: none;
    border-radius: 5px;
    background-color: var(--accent-primary);
    color: var(--accent-text);
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
}

.lesson-complete-screen .continue-btn:hover {
    background-color: var(--accent-hover);
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

/* --- Dashboard View --- */
#dashboard-view {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow-color);
}
.unit-container { margin-bottom: 2.5rem; }

.unit-container h3 { font-size: 1.8rem; color: var(--accent-primary); border-bottom: 2px solid var(--explanation-bg); padding-bottom: 0.5rem; margin-bottom: 0.5rem; }

.unit-container p { font-style: italic; color: var(--text-secondary); margin-bottom: 1.5rem; }

.lessons-container { display: flex; flex-wrap: wrap; gap: 20px; }

.lesson-node { background-color: var(--bg-primary); border: 2px solid var(--button-disabled-bg); color: var(--text-secondary); border-radius: 50%; /* Makes it a circle */ width: 120px; height: 120px; display: flex; align-items: center; justify-content: center; text-align: center; padding: 10px; font-size: 0.9rem; font-weight: bold; cursor: pointer; transition: all 0.2s ease-in-out; }

.lesson-node span { display: block; line-height: 1.3; }

.lesson-node.locked { cursor: not-allowed; }

.lesson-node.current { border-color: var(--accent-primary); color: var(--accent-primary); background-color: var(--bg-secondary); }

.lesson-node.current:hover { transform: scale(1.05); background-color: var(--accent-primary); color: var(--accent-text); }

.lesson-node.completed { border-color: #28a745; background-color: #28a745; color: white; }

.lesson-node.completed:hover { transform: scale(1.05); background-color: #218838; border-color: #218838; }

/* --- Close Lesson Button --- */
.header-close-btn {
    display: none; /* Hidden by default */
    background: transparent;
    border: none;
    color: var(--accent-text);
    font-size: 2.5rem; /* Makes a nice 'X' */
    font-weight: 300;
    cursor: pointer;
    line-height: 1; /* Aligns the 'X' vertically */
    padding: 0;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.header-close-btn:hover { opacity: 1; }

/* --- Mobile Responsive Styles --- */
@media (max-width: 700px) {

/* Make main layout use full width */
body {
    padding: 0;
}

/* Make overlays / modals full-screen on small screens for better mobile UX */
@media (max-width: 700px) {
    #profile-overlay, #auth-overlay, #leaderboard-overlay {
        align-items: flex-start;
        padding-top: env(safe-area-inset-top);
    }

    #profile-modal, #auth-modal, #leaderboard-modal {
        width: 100%;
        max-width: 100%;
        height: calc(100vh - env(safe-area-inset-top));
        max-height: none;
        border-radius: 0;
        padding: 18px;
        box-sizing: border-box;
        overflow-y: auto;
    }

    /* Larger close buttons for easier tapping */
    #close-profile-btn, #close-leaderboard-btn {
        font-size: 2rem;
        padding: 8px;
    }

    /* Make leaderboard rows more touch-friendly */
    .leaderboard-row {
        padding: 16px;
        font-size: 1.05rem;
    }
}

main {
    padding: 10px;
    border-radius: 0;
}

/* --- Header --- */
header {
    border-radius: 0;
    padding: 10px;
    padding-top: calc(10px + env(safe-area-inset-top));
}

.header-top h1 {
    font-size: 1.2rem;
}

/* Make header buttons larger and easier to tap on mobile */
.header-top {
    /* Stack the title and controls vertically: title first, controls second */
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.header-top h1, #header-title {
    order: 0;
    width: 100%;
    text-align: center;
}

.header-buttons-wrapper {
    order: 1;
    width: 100%;
    display: flex;
    justify-content: center;
}

.header-buttons {
    /* ensure the inline icons stay together on the second line */
    flex-wrap: nowrap;
    align-items: center;
}

.header-buttons .hdr-btn { min-width: 44px; }

.header-buttons button {
    min-width: 48px;
    min-height: 44px;
    padding: 8px 10px;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Compact header behavior: keep icons visible and hide text labels on small screens (no hamburger menu) */
@media (max-width:700px) {
    .header-buttons .text { display: none; }
    .header-buttons { gap: 8px; }
}

/* Make stats bar wrap instead of shrink */
.stats-bar {
    flex-wrap: wrap;
    gap: 15px;
}

.stat {
    /* Allow 2 stats per line */
    flex-basis: calc(50% - 10px);
}

/* --- Dashboard --- */
.lessons-container {
    /* Center the lesson circles */
    justify-content: center; 
    gap: 15px;
}

.lesson-node {
    /* Make nodes slightly smaller */
    width: 92px;
    height: 92px;
    font-size: 0.88rem;
    min-width: 72px;
    min-height: 72px;
    padding: 5px; /* Reduce padding on mobile to prevent text overflow */
}

/* --- Lesson View --- */
.slide-quiz .question,
.slide-fill-in-the-blank .question,
.slide-build-a-function .prompt {
    font-size: 1.1rem; /* Make text a bit bigger for mobile */
}

/* Make fill-in-the-blank stack vertically */
.fill-in-the-blank-container {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
}

.fill-in-the-blank-container input {
    width: 100%;
}

/* Make navigation buttons bigger */
.navigation-controls button {
    padding: 12px 15px;
    font-size: 1.1rem;
}

}

/* --- Footer & Reset Button --- */
footer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}
#reset-progress-btn { background-color: transparent; border: 1px solid var(--text-secondary); color: var(--text-secondary); padding: 8px 15px; border-radius: 20px; cursor: pointer; font-size: 0.9rem; transition: all 0.2s; }

#reset-progress-btn:hover { background-color: #dc3545; /* Red on hover */ border-color: #dc3545; color: white; }

/* --- Header Auth Buttons --- */
#login-btn, #logout-btn, #profile-btn, #leaderboard-btn {
    padding: 8px 12px;
    border: 1px solid var(--accent-text);
    background-color: transparent;
    color: var(--accent-text);
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

#login-btn:hover, #logout-btn:hover, #profile-btn:hover, #leaderboard-btn:hover {
    background-color: rgba(255, 255, 255, 0.15);
}

/* Small spinner for loading states (used inside header buttons) */
.spinner {
    display: inline-block;
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,0.5);
    border-top-color: rgba(255,255,255,1);
    border-radius: 50%;
    margin-right: 8px;
    vertical-align: middle;
    animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Overlay spinner for leaderboard list (larger, centered) */
.overlay-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(0,0,0,0.1);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    margin: 40px auto; /* center inside the list container */
    animation: spin 0.9s linear infinite;
}

/* --- Firebase Auth Modal --- */ .auth-overlay-hidden { display: none !important; }

#auth-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0, 0, 0, 0.6); display: flex; justify-content: center; align-items: center; z-index: 1000; backdrop-filter: blur(5px); }

#auth-modal { background-color: var(--bg-secondary); padding: 2.5rem; border-radius: 8px; box-shadow: 0 5px 15px rgba(0,0,0,0.3); width: 100%; max-width: 400px; text-align: center; }

#auth-modal form { display: flex; flex-direction: column; gap: 1rem; }

#auth-modal h2 { margin-bottom: 0.5rem; color: var(--text-primary); }

#auth-modal p { margin-bottom: 1rem; color: var(--text-secondary); }

#auth-modal input[type="text"],
#auth-modal input[type="email"],
#auth-modal input[type="password"] { padding: 12px; border: 1px solid var(--button-disabled-bg); border-radius: 5px; font-size: 1rem; background-color: var(--bg-primary); color: var(--text-primary); }

#auth-modal button[type="submit"] { padding: 12px; border: none; border-radius: 5px; background-color: var(--accent-primary); color: var(--accent-text); font-size: 1.1rem; font-weight: bold; cursor: pointer; transition: background-color 0.2s; }

#auth-modal button[type="submit"]:hover { background-color: var(--accent-hover); }

.auth-toggle-link { font-size: 0.9rem; color: var(--text-secondary); }

.auth-toggle-link a, #forgot-password-link, #back-to-login-link { color: var(--accent-primary); text-decoration: none; font-weight: bold; cursor: pointer; }

.auth-toggle-link a:hover, #forgot-password-link:hover, #back-to-login-link:hover { text-decoration: underline; }

/* --- Auth Error/Success Messages --- */
.auth-error { color: #dc3545; background-color: rgba(220, 53, 69, 0.1); padding: 10px; border-radius: 5px; display: none; /* Hidden by default */ }

.auth-success { color: #28a745; background-color: rgba(40, 167, 69, 0.1); padding: 10px; border-radius: 5px; display: none; /* Hidden by default */ }

/* --- Profile & Achievements Modal --- */
#profile-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

#profile-modal {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 12px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

/* Leaderboard modal already defined; ensure it's mobile-friendly */
#leaderboard-modal {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 12px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

.profile-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--button-disabled-bg);
    padding-bottom: 10px;
}

#close-profile-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    line-height: 1;
}

#achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 15px;
}

/* --- Individual Badge Styles --- */

.achievement-card {
    background-color: var(--bg-primary);
    border: 2px solid var(--button-disabled-bg);
    border-radius: 8px;
    padding: 15px 10px;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    transition: transform 0.2s;
}

.achievement-icon {
    font-size: 2.5rem;
    margin-bottom: 5px;
}

.achievement-title {
    font-weight: bold;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.achievement-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Locked State */

.achievement-card.locked {
    opacity: 0.6;
    filter: grayscale(1);
}

.achievement-card.locked .achievement-icon {
    filter: grayscale(1) contrast(0.5);
}

/* Unlocked State */

.achievement-card.unlocked {
    border-color: #ffd700; /* Gold border */
    background-color: rgba(255, 215, 0, 0.1); /* Slight gold tint */
}

.achievement-card.unlocked:hover {
    transform: scale(1.05);
}

/* --- Toast Notification --- */ #toast-container { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); z-index: 2000; display: flex; flex-direction: column; gap: 10px; }

.toast { background-color: #28a745; /* Success Green */ color: white; padding: 15px 25px; border-radius: 50px; box-shadow: 0 4px 12px rgba(0,0,0,0.3); display: flex; align-items: center; gap: 10px; font-weight: bold; animation: slideUpFade 0.5s ease-out, fadeOut 0.5s ease-in 3.5s forwards; }

@keyframes slideUpFade { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

@keyframes fadeOut { from { opacity: 1; } to { opacity: 0; } }

/* --- Theme Icon Logic --- */
/* Default (Light Mode): Show Moon, Hide Sun */
.icon-sun { display: none; }
.icon-moon { display: inline; }

/* Dark Mode: Show Sun, Hide Moon */
body.dark-mode .icon-sun { display: inline; }
body.dark-mode .icon-moon { display: none; }

/* --- Leaderboard Modal --- */
#leaderboard-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}
#leaderboard-modal {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

/* Leaderboard Rows */
.leaderboard-row { display: flex; justify-content: space-between; align-items: center; padding: 12px; border-bottom: 1px solid var(--button-disabled-bg); font-size: 1rem; }

.leaderboard-row:last-child { border-bottom: none; }

.rank-info { display: flex; align-items: center; gap: 15px; }

.rank-num { font-weight: bold; width: 25px; text-align: center; }
.rank-name { font-weight: 600; }
.rank-xp { color: var(--accent-primary); font-weight: bold; }

/* Special Ranks */
/* .rank-1 .rank-num { font-size: 1.5rem; } /* Gold */
/* .rank-2 .rank-num { font-size: 1.3rem; } /* Silver */
/* .rank-3 .rank-num { font-size: 1.2rem; } /* Bronze */

/* Highlight Current User */
.leaderboard-row.current-user { background-color: var(--explanation-bg); border-left: 4px solid var(--accent-primary); border-radius: 4px; }