* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Dark Theme (Default) */
.dark-theme {
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #1a1a1a;
    --bg-quaternary: #0f0f0f;
    --bg-hover: #141414;
    --bg-selected: #222222;
    --border-primary: #333333;
    --border-secondary: #666666;
    --border-hover: #444444;
    --text-primary: #ffffff;
    --text-secondary: #888888;
    --text-tertiary: #666666;
    --text-muted: #aaaaaa;
    --text-disabled: #555555;
    --button-bg: #ffffff;
    --button-text: #000000;
    --button-hover: #cccccc;
    --accent-correct: #00ff00;
    --accent-correct-bg: #001a00;
    --accent-incorrect: #ff0000;
    --accent-incorrect-bg: #1a0000;
    --accent-warning: #ffd700;
    --accent-warning-bg: #1a1a00;
    --accent-challenge: #ff6600;
    --accent-challenge-bg: #1a0a00;
    --accent-extreme: #ff0000;
    --accent-extreme-bg: #1a0000;
    --progress-bg: #1a1a1a;
    --progress-fill: #ffffff;
    --timer-gradient: linear-gradient(90deg, #ff6600 0%, #ff3300 100%);
    --score-gradient: linear-gradient(90deg, #00ff00 0%, #00cc00 100%);
    --shadow-light: rgba(255, 255, 255, 0.05);
    --shadow-dark: rgba(0, 0, 0, 0.5);
    --removed-text: #666666;
    --explanation-bg: #1a1a1a;
    --explanation-border: #333333;
    --explanation-text: #cccccc;
}

/* Light Theme */
.light-theme {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f8f8;
    --bg-tertiary: #e8e8e8;
    --bg-quaternary: #f0f0f0;
    --bg-hover: #ebebeb;
    --bg-selected: #dddddd;
    --border-primary: #dddddd;
    --border-secondary: #999999;
    --border-hover: #bbbbbb;
    --text-primary: #000000;
    --text-secondary: #666666;
    --text-tertiary: #888888;
    --text-muted: #555555;
    --text-disabled: #aaaaaa;
    --button-bg: #000000;
    --button-text: #ffffff;
    --button-hover: #333333;
    --accent-correct: #008800;
    --accent-correct-bg: #e8f5e8;
    --accent-incorrect: #cc0000;
    --accent-incorrect-bg: #ffe8e8;
    --accent-warning: #cc9900;
    --accent-warning-bg: #fff9e6;
    --accent-challenge: #cc4400;
    --accent-challenge-bg: #fff0e6;
    --accent-extreme: #cc0000;
    --accent-extreme-bg: #ffe6e6;
    --progress-bg: #e8e8e8;
    --progress-fill: #000000;
    --timer-gradient: linear-gradient(90deg, #cc4400 0%, #cc0000 100%);
    --score-gradient: linear-gradient(90deg, #008800 0%, #006600 100%);
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-dark: rgba(0, 0, 0, 0.15);
    --removed-text: #999999;
    --explanation-bg: #f5f5f5;
    --explanation-border: #dddddd;
    --explanation-text: #333333;
} 

/* Hacker Theme */
.hacker-theme {
    --bg-primary: #000000;
    --bg-secondary: #000000;
    --bg-tertiary: #001100;
    --bg-quaternary: #000000;
    --bg-hover: #001100;
    --bg-selected: #002200;
    --border-primary: #00ff00;
    --border-secondary: #00cc00;
    --border-hover: #00ff00;
    --text-primary: #00ff00;
    --text-secondary: #00cc00;
    --text-tertiary: #008800;
    --text-muted: #00aa00;
    --text-disabled: #006600;
    --button-bg: #00ff00;
    --button-text: #000000;
    --button-hover: #00cc00;
    --accent-correct: #00ff00;
    --accent-correct-bg: #002200;
    --accent-incorrect: #ff0000;
    --accent-incorrect-bg: #220000;
    --accent-warning: #ffff00;
    --accent-warning-bg: #222200;
    --accent-challenge: #ff6600;
    --accent-challenge-bg: #221100;
    --accent-extreme: #ff0000;
    --accent-extreme-bg: #220000;
    --progress-bg: #001100;
    --progress-fill: #00ff00;
    --timer-gradient: linear-gradient(90deg, #ff6600 0%, #ff0000 100%);
    --score-gradient: linear-gradient(90deg, #00ff00 0%, #00cc00 100%);
    --shadow-light: rgba(0, 255, 0, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.8);
    --removed-text: #006600;
    --explanation-bg: #001100;
    --explanation-border: #00ff00;
    --explanation-text: #00cc00;
}

/* Ruby Theme */
.ruby-theme {
    --bg-primary: #1a0000;
    --bg-secondary: #220000;
    --bg-tertiary: #330000;
    --bg-quaternary: #2a0000;
    --bg-hover: #440000;
    --bg-selected: #550000;
    --border-primary: #660000;
    --border-secondary: #cc0000;
    --border-hover: #880000;
    --text-primary: #ffcccc;
    --text-secondary: #cc8888;
    --text-tertiary: #aa6666;
    --text-muted: #dd9999;
    --text-disabled: #774444;
    --button-bg: #cc0000;
    --button-text: #ffffff;
    --button-hover: #aa0000;
    --accent-correct: #00ff00;
    --accent-correct-bg: #001a00;
    --accent-incorrect: #ff6666;
    --accent-incorrect-bg: #330000;
    --accent-warning: #ffaa00;
    --accent-warning-bg: #332200;
    --accent-challenge: #ff4444;
    --accent-challenge-bg: #330000;
    --accent-extreme: #ff0000;
    --accent-extreme-bg: #440000;
    --progress-bg: #330000;
    --progress-fill: #cc0000;
    --timer-gradient: linear-gradient(90deg, #ff4444 0%, #cc0000 100%);
    --score-gradient: linear-gradient(90deg, #ff6666 0%, #cc0000 100%);
    --shadow-light: rgba(204, 0, 0, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.8);
    --removed-text: #774444;
    --explanation-bg: #330000;
    --explanation-border: #660000;
    --explanation-text: #dd9999;
}

/* Cloudy Theme */
.cloudy-theme {
    --bg-primary: #f5f5f5;
    --bg-secondary: #eeeeee;
    --bg-tertiary: #e0e0e0;
    --bg-quaternary: #f0f0f0;
    --bg-hover: #e8e8e8;
    --bg-selected: #d8d8d8;
    --border-primary: #c0c0c0;
    --border-secondary: #a0a0a0;
    --border-hover: #b0b0b0;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-tertiary: #888888;
    --text-muted: #555555;
    --text-disabled: #aaaaaa;
    --button-bg: #777777;
    --button-text: #ffffff;
    --button-hover: #555555;
    --accent-correct: #4a934a;
    --accent-correct-bg: #f0f8f0;
    --accent-incorrect: #cc6666;
    --accent-incorrect-bg: #f8f0f0;
    --accent-warning: #b8860b;
    --accent-warning-bg: #f8f8f0;
    --accent-challenge: #cd853f;
    --accent-challenge-bg: #f8f4f0;
    --accent-extreme: #a0522d;
    --accent-extreme-bg: #f8f0f0;
    --progress-bg: #d0d0d0;
    --progress-fill: #777777;
    --timer-gradient: linear-gradient(90deg, #cd853f 0%, #a0522d 100%);
    --score-gradient: linear-gradient(90deg, #4a934a 0%, #2d5a2d 100%);
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-dark: rgba(0, 0, 0, 0.15);
    --removed-text: #aaaaaa;
    --explanation-bg: #f8f8f8;
    --explanation-border: #d0d0d0;
    --explanation-text: #555555;
}

/* Kitty Theme */
.kitty-theme {
    --bg-primary: #ffffff;
    --bg-secondary: #fefefe;
    --bg-tertiary: #fff0f8;
    --bg-quaternary: #fff5fa;
    --bg-hover: #ffeef6;
    --bg-selected: #ffe6f2;
    --border-primary: #ff6ec7;
    --border-secondary: #ff3eb8;
    --border-hover: #ff8fd1;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-tertiary: #888888;
    --text-muted: #555555;
    --text-disabled: #cccccc;
    --button-bg: #ff6ec7;
    --button-text: #ffffff;
    --button-hover: #ff3eb8;
    --accent-correct: #00cc66;
    --accent-correct-bg: #f0fff8;
    --accent-incorrect: #ff6666;
    --accent-incorrect-bg: #fff0f0;
    --accent-warning: #ffaa00;
    --accent-warning-bg: #fff8f0;
    --accent-challenge: #ff6600;
    --accent-challenge-bg: #fff4f0;
    --accent-extreme: #ff3366;
    --accent-extreme-bg: #fff0f4;
    --progress-bg: #ffe6f2;
    --progress-fill: #ff6ec7;
    --timer-gradient: linear-gradient(90deg, #ff6600 0%, #ff3366 100%);
    --score-gradient: linear-gradient(90deg, #ff6ec7 0%, #ff3eb8 100%);
    --shadow-light: rgba(255, 110, 199, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.1);
    --removed-text: #cccccc;
    --explanation-bg: #fff8fc;
    --explanation-border: #ff6ec7;
    --explanation-text: #555555;
}

/* Astro Theme */
.astro-theme {
    --bg-primary: #0a0a0f;
    --bg-secondary: #0f0f1a;
    --bg-tertiary: #1a1a2e;
    --bg-quaternary: #141420;
    --bg-hover: #1f1f35;
    --bg-selected: #252540;
    --border-primary: #4a4a7a;
    --border-secondary: #6666aa;
    --border-hover: #5555aa;
    --text-primary: #e6e6ff;
    --text-secondary: #b3b3dd;
    --text-tertiary: #8888bb;
    --text-muted: #ccccee;
    --text-disabled: #666699;
    --button-bg: #6666cc;
    --button-text: #ffffff;
    --button-hover: #5555aa;
    --accent-correct: #66ff66;
    --accent-correct-bg: #1a2e1a;
    --accent-incorrect: #ff6666;
    --accent-incorrect-bg: #2e1a1a;
    --accent-warning: #ffcc66;
    --accent-warning-bg: #2e2e1a;
    --accent-challenge: #cc66ff;
    --accent-challenge-bg: #2e1a2e;
    --accent-extreme: #ff66cc;
    --accent-extreme-bg: #2e1a25;
    --progress-bg: #1a1a2e;
    --progress-fill: #6666cc;
    --timer-gradient: linear-gradient(90deg, #cc66ff 0%, #ff66cc 100%);
    --score-gradient: linear-gradient(90deg, #6666cc 0%, #4444aa 100%);
    --shadow-light: rgba(102, 102, 204, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.8);
    --removed-text: #666699;
    --explanation-bg: #1a1a2e;
    --explanation-border: #4a4a7a;
    --explanation-text: #b3b3dd;
}

/* Cyberpunk Theme */
.cyberpunk-theme {
    --bg-primary: #0d0d0d;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2d2d2d;
    --bg-quaternary: #262626;
    --bg-hover: #333333;
    --bg-selected: #404040;
    --border-primary: #00ffff;
    --border-secondary: #ff00ff;
    --border-hover: #66ffff;
    --text-primary: #00ffff;
    --text-secondary: #ff00ff;
    --text-tertiary: #9966ff;
    --text-muted: #66ffcc;
    --text-disabled: #666666;
    --button-bg: #ff00ff;
    --button-text: #000000;
    --button-hover: #cc00cc;
    --accent-correct: #00ff66;
    --accent-correct-bg: #002d1a;
    --accent-incorrect: #ff0066;
    --accent-incorrect-bg: #2d001a;
    --accent-warning: #ffff00;
    --accent-warning-bg: #2d2d00;
    --accent-challenge: #ff6600;
    --accent-challenge-bg: #2d1a00;
    --accent-extreme: #ff0099;
    --accent-extreme-bg: #2d0020;
    --progress-bg: #2d2d2d;
    --progress-fill: #00ffff;
    --timer-gradient: linear-gradient(90deg, #ff6600 0%, #ff0099 100%);
    --score-gradient: linear-gradient(90deg, #00ffff 0%, #0099cc 100%);
    --shadow-light: rgba(0, 255, 255, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.9);
    --removed-text: #666666;
    --explanation-bg: #2d2d2d;
    --explanation-border: #00ffff;
    --explanation-text: #66ffcc;
}

/* FIXED: Ensure notes container is visible when needed */
#notes-container {
    display: none;
    opacity: 1;
    visibility: visible;
}

#notes-container.show {
    display: block !important;
}

/* Ensure body doesn't hide overflow */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    margin: 0;
    padding: 0;
    transition: all 0.3s ease;
}

/* Wrapper for centering quiz container */
body.quiz-view {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

/* When showing notes, remove centering */
body.notes-view {
    display: block;
    padding: 0;
}

/* Hacker theme specific styling */
.hacker-theme body {
    font-family: 'Courier New', monospace;
    text-shadow: 0 0 5px var(--text-primary);
}

.hacker-theme .brand {
    text-shadow: 0 0 10px var(--text-primary);
    animation: flicker 2s infinite alternate;
}

@keyframes flicker {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

/* Cyberpunk theme specific styling */
.cyberpunk-theme body {
    font-family: 'Courier New', monospace;
    text-shadow: 0 0 3px var(--text-primary);
}

.cyberpunk-theme .brand {
    text-shadow: 0 0 15px var(--text-primary);
    animation: cyberpunkGlow 3s infinite alternate;
}

@keyframes cyberpunkGlow {
    0%, 100% { 
        text-shadow: 0 0 15px var(--text-primary), 0 0 25px var(--text-secondary);
    }
    50% { 
        text-shadow: 0 0 20px var(--text-primary), 0 0 35px var(--text-secondary), 0 0 45px var(--border-primary);
    }
}

.cyberpunk-theme .quiz-container {
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.3), inset 0 0 30px rgba(255, 0, 255, 0.1);
}

/* Ruby theme special effects */
.ruby-theme .brand {
    text-shadow: 0 0 8px var(--text-primary);
    animation: rubyShimmer 4s infinite ease-in-out;
}

@keyframes rubyShimmer {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.9; }
}

.ruby-theme .quiz-container {
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 20px rgba(204, 0, 0, 0.2);
}

/* Kitty theme special effects */
.kitty-theme .brand {
    color: var(--border-primary);
    animation: kittyBounce 2s infinite ease-in-out;
}

@keyframes kittyBounce {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-2px); }
}

.kitty-theme .quiz-container {
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 25px rgba(255, 110, 199, 0.15);
}

/* Astro theme special effects */
.astro-theme .brand {
    text-shadow: 0 0 10px var(--text-primary);
    animation: astroFloat 6s infinite ease-in-out;
}

@keyframes astroFloat {
    0%, 100% { transform: translateY(0px); opacity: 1; }
    50% { transform: translateY(-3px); opacity: 0.9; }
}

.astro-theme .quiz-container {
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 30px rgba(102, 102, 204, 0.2), inset 0 0 20px rgba(102, 102, 170, 0.05);
}

.quiz-container {
    max-width: 800px;
    width: 100%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.hacker-theme .quiz-container {
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 20px rgba(0, 255, 0, 0.3);
}

.quiz-header {
    padding: 24px 16px;
    text-align: center;
    border-bottom: 1px solid var(--border-primary);
    position: relative;
    background-color: var(--bg-secondary);
}

.brand {
    font-size: 24px;
    font-weight: 300;
    letter-spacing: 4px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.theme-button {
    position: absolute;
    top: 20px;
    right: 16px;
    background: none;
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.3s ease;
    z-index: 10;
}

.theme-button:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--border-secondary);
}

.hacker-theme .theme-button:hover {
    box-shadow: 0 0 10px var(--border-primary);
}

.theme-icon {
    position: absolute;
    transition: all 0.3s ease;
}

/* Theme icon visibility rules */
.dark-theme .sun-icon,
.dark-theme .hacker-icon,
.dark-theme .gem-icon,
.dark-theme .cloud-icon,
.dark-theme .cat-icon,
.dark-theme .nebula-icon,
.dark-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(180deg);
}

.dark-theme .moon-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.light-theme .moon-icon,
.light-theme .hacker-icon,
.light-theme .gem-icon,
.light-theme .cloud-icon,
.light-theme .cat-icon,
.light-theme .nebula-icon,
.light-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.light-theme .sun-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.hacker-theme .moon-icon,
.hacker-theme .sun-icon,
.hacker-theme .gem-icon,
.hacker-theme .cloud-icon,
.hacker-theme .cat-icon,
.hacker-theme .nebula-icon,
.hacker-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.hacker-theme .hacker-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.ruby-theme .moon-icon,
.ruby-theme .sun-icon,
.ruby-theme .hacker-icon,
.ruby-theme .cloud-icon,
.ruby-theme .cat-icon,
.ruby-theme .nebula-icon,
.ruby-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.ruby-theme .gem-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.cloudy-theme .moon-icon,
.cloudy-theme .sun-icon,
.cloudy-theme .hacker-icon,
.cloudy-theme .gem-icon,
.cloudy-theme .cat-icon,
.cloudy-theme .nebula-icon,
.cloudy-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.cloudy-theme .cloud-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.kitty-theme .moon-icon,
.kitty-theme .sun-icon,
.kitty-theme .hacker-icon,
.kitty-theme .gem-icon,
.kitty-theme .cloud-icon,
.kitty-theme .nebula-icon,
.kitty-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.kitty-theme .cat-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.astro-theme .moon-icon,
.astro-theme .sun-icon,
.astro-theme .hacker-icon,
.astro-theme .gem-icon,
.astro-theme .cloud-icon,
.astro-theme .cat-icon,
.astro-theme .mohawk-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.astro-theme .nebula-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.cyberpunk-theme .moon-icon,
.cyberpunk-theme .sun-icon,
.cyberpunk-theme .hacker-icon,
.cyberpunk-theme .gem-icon,
.cyberpunk-theme .cloud-icon,
.cyberpunk-theme .cat-icon,
.cyberpunk-theme .nebula-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

.cyberpunk-theme .mohawk-icon {
    opacity: 1;
    transform: rotate(0deg);
}

.subtitle {
    font-size: 12px;
    color: var(--text-secondary);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.quiz-content {
    padding: 24px 16px;
    background-color: var(--bg-secondary);
}

.question-number {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.question h2 {
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
}

.option {
    padding: 16px;
    background-color: var(--bg-quaternary);
    border: 2px solid var(--border-primary);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.hacker-theme .option {
    border-radius: 0;
}

.option:hover:not(.selected):not(.disabled) {
    border-color: var(--border-hover);
    background-color: var(--bg-hover);
}

.hacker-theme .option:hover:not(.selected):not(.disabled) {
    box-shadow: 0 0 5px var(--border-primary);
}

.option-content {
    display: flex;
    align-items: center;
}

.option-letter {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    margin-right: 12px;
    flex-shrink: 0;
    font-weight: 500;
    font-size: 14px;
    color: var(--text-primary);
}

.hacker-theme .option-letter {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.option-text {
    flex: 1;
    font-size: 14px;
    line-height: 1.4;
    color: var(--text-primary);
}

.explanation {
    display: none;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--explanation-border);
    font-size: 12px;
    color: var(--explanation-text);
    line-height: 1.5;
    background-color: var(--explanation-bg);
    padding: 12px;
    border-radius: 4px;
    margin-top: 8px;
}

.hacker-theme .explanation {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.option.selected .explanation {
    display: block;
}

.option.correct {
    border-color: var(--accent-correct);
    background-color: var(--accent-correct-bg);
}

.option.correct .option-letter {
    background-color: var(--accent-correct);
    color: var(--bg-primary);
    border-color: var(--accent-correct);
}

.option.incorrect {
    border-color: var(--accent-incorrect);
    background-color: var(--accent-incorrect-bg);
}

.option.incorrect .option-letter {
    background-color: var(--accent-incorrect);
    color: var(--bg-primary);
    border-color: var(--accent-incorrect);
}

.option.disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.option.removed {
    color: var(--removed-text);
    text-decoration: line-through;
    border-color: var(--border-primary);
    background-color: var(--bg-tertiary);
}

.option.removed .option-letter {
    background-color: var(--border-primary);
    color: var(--text-disabled);
    border-color: var(--border-primary);
}

.next-button {
    display: none;
    width: 100%;
    padding: 14px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hacker-theme .next-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.next-button:hover {
    background-color: var(--button-hover);
}

.hacker-theme .next-button:hover {
    box-shadow: 0 0 10px var(--button-bg);
}

.next-button.show {
    display: block;
}

.back-button {
    margin-top: 16px;
    padding: 8px 12px;
    background: none;
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.hacker-theme .back-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.back-button:hover {
    border-color: var(--border-secondary);
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
}

.hacker-theme .back-button:hover {
    box-shadow: 0 0 5px var(--border-primary);
}

#back-to-grades {
    display: block;
    margin: 12px auto 0;
}

.quiz-navigation {
    display: flex;
    justify-content: space-between;
    gap: 12px;
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.hint-button, .cheat-button {
    background: none;
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.hacker-theme .hint-button,
.hacker-theme .cheat-button {
    border-radius: 0;
}

.hint-button:hover, .cheat-button:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--border-secondary);
}

.hacker-theme .hint-button:hover,
.hacker-theme .cheat-button:hover {
    box-shadow: 0 0 5px var(--border-primary);
}

.hint-button.used, .cheat-button.used {
    opacity: 0.5;
    cursor: not-allowed;
}

.snapshot-button {
    background: none;
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.3s ease;
    margin: 0 auto 16px;
}

.hacker-theme .snapshot-button {
    border-radius: 0;
}

.snapshot-button:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--border-secondary);
}

.hacker-theme .snapshot-button:hover {
    box-shadow: 0 0 5px var(--border-primary);
}

.hint-box {
    display: none;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 16px;
}

.hacker-theme .hint-box {
    border-radius: 0;
    border: 2px solid var(--border-primary);
}

.hint-box.show {
    display: block;
}

.hint-text {
    font-size: 13px;
    color: var(--accent-warning);
    line-height: 1.4;
    display: flex;
    align-items: flex-start;
}

.hacker-theme .hint-text {
    font-family: 'Courier New', monospace;
}

.hint-text::before {
    content: "💡";
    margin-right: 8px;
    font-size: 16px;
}

.hacker-theme .hint-text::before {
    content: ">";
    color: var(--text-primary);
}

.progress-bar {
    height: 4px;
    background-color: var(--progress-bg);
    position: relative;
}

.progress-fill {
    height: 100%;
    background-color: var(--progress-fill);
    transition: width 0.3s ease;
}

/* Selection screen styles */
.selection-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 20px;
}

.selection-button {
    padding: 14px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.hacker-theme .selection-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.selection-button:hover {
    background-color: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .selection-button:hover {
    box-shadow: 0 0 10px var(--button-bg);
}

.select-title {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
    text-align: center;
}

/* Category Selection - NEW (uses same styling as other selections) */
#category-selection {
    /* Inherits all styling from existing selection screens */
}

.category-button {
    /* Same styling as .selection-button */
    padding: 14px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.hacker-theme .category-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.category-button:hover {
    background-color: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .category-button:hover {
    box-shadow: 0 0 10px var(--button-bg);
}

/* Quiz Type Selection Cards */
.quiz-type-cards {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.quiz-type-card {
    background-color: var(--bg-quaternary);
    border: 2px solid var(--border-primary);
    border-radius: 12px;
    padding: 24px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
    opacity: 0;
}

.hacker-theme .quiz-type-card {
    border-radius: 0;
}

.quiz-type-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, var(--shadow-light) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.quiz-type-card:hover::before {
    opacity: 1;
}

.quiz-type-card:hover {
    transform: translateY(-2px);
    border-color: var(--border-secondary);
    background-color: var(--bg-hover);
}

.hacker-theme .quiz-type-card:hover {
    box-shadow: 0 0 15px var(--border-primary);
}

/* Special styling for Past Papers card */
.past-papers-card {
    background: linear-gradient(135deg, var(--bg-quaternary) 0%, var(--bg-tertiary) 100%);
    border: 2px solid;
    border-image: linear-gradient(135deg, var(--accent-warning) 0%, var(--accent-challenge) 100%) 1;
    position: relative;
    padding: 28px 24px;
}

.dark-theme .past-papers-card::after,
.hacker-theme .past-papers-card::after {
    content: '';
    position: absolute;
    inset: -2px;
    background: linear-gradient(135deg, #ffaa0020 0%, #ff660020 100%);
    border-radius: 12px;
    z-index: -1;
    filter: blur(10px);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.hacker-theme .past-papers-card {
    border-radius: 0;
}

.hacker-theme .past-papers-card::after {
    border-radius: 0;
}

.past-papers-card:hover::after {
    opacity: 1;
}

.past-papers-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px rgba(255, 170, 0, 0.15);
}

.past-papers-card .card-icon {
    background: linear-gradient(135deg, var(--accent-warning) 0%, var(--accent-challenge) 100%);
    width: 56px;
    height: 56px;
}

.past-papers-card .card-icon svg {
    color: var(--bg-primary);
}

.past-papers-card .card-title {
    font-size: 20px;
    font-weight: 600;
    background: linear-gradient(135deg, var(--accent-warning) 0%, var(--accent-challenge) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.past-papers-card .card-badge.aesthetic {
    background: linear-gradient(135deg, var(--accent-warning) 0%, var(--accent-challenge) 100%);
    color: var(--bg-primary);
    border: none;
    font-weight: 700;
    letter-spacing: 1.5px;
    padding: 6px 12px;
}

.card-icon {
    width: 48px;
    height: 48px;
    background-color: var(--bg-tertiary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    transition: all 0.3s ease;
}

.hacker-theme .card-icon {
    border-radius: 0;
    border: 1px solid var(--border-primary);
}

.quiz-type-card:hover .card-icon {
    background-color: var(--bg-selected);
}

.card-icon svg {
    color: var(--text-primary);
}

.card-title {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
    color: var(--text-primary);
}

.card-description {
    font-size: 13px;
    color: var(--text-tertiary);
    line-height: 1.5;
    margin-bottom: 12px;
}

.card-badge {
    display: inline-block;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 4px 8px;
    border-radius: 4px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
}

.hacker-theme .card-badge {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.quiz-type-card:nth-child(2) .card-badge {
    background-color: var(--accent-warning-bg);
    color: var(--accent-warning);
    border-color: var(--accent-warning);
}

/* Quiz Mode Selection Styles */
#quiz-mode-selection {
    max-width: 900px;
    margin: 0 auto;
}

.quiz-mode-cards {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.quiz-mode-card {
    background-color: var(--bg-quaternary);
    border: 2px solid var(--border-primary);
    border-radius: 12px;
    padding: 24px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.hacker-theme .quiz-mode-card {
    border-radius: 0;
}

.quiz-mode-card:hover {
    transform: translateY(-2px);
    border-color: var(--border-secondary);
    background-color: var(--bg-hover);
}

.hacker-theme .quiz-mode-card:hover {
    box-shadow: 0 0 15px var(--border-primary);
}

.quiz-mode-card.selected {
    border-color: var(--border-secondary);
    background-color: var(--bg-hover);
}

.quiz-mode-card.selected::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--shadow-light) 0%, transparent 50%);
    pointer-events: none;
}

.mode-icon {
    width: 48px;
    height: 48px;
    background-color: var(--bg-tertiary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    transition: all 0.3s ease;
}

.hacker-theme .mode-icon {
    border-radius: 0;
    border: 1px solid var(--border-primary);
}

.quiz-mode-card:hover .mode-icon,
.quiz-mode-card.selected .mode-icon {
    background-color: var(--bg-selected);
}

.mode-icon svg {
    color: var(--text-primary);
}

.mode-title {
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
    color: var(--text-primary);
}

.mode-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 16px;
}

.mode-features {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 16px;
}

.feature {
    font-size: 13px;
    color: var(--text-tertiary);
}

.mode-badge {
    display: inline-block;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 4px 10px;
    border-radius: 4px;
    position: absolute;
    top: 20px;
    right: 20px;
}

.hacker-theme .mode-badge {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.mode-badge.default {
    background-color: var(--accent-warning-bg);
    color: var(--accent-warning);
    border: 1px solid var(--accent-warning);
}

.mode-badge.challenge {
    background-color: var(--accent-challenge-bg);
    color: var(--accent-challenge);
    border: 1px solid var(--accent-challenge);
}

.mode-badge.extreme {
    background-color: var(--accent-extreme-bg);
    color: var(--accent-extreme);
    border: 1px solid var(--accent-extreme);
}

.start-quiz-button {
    width: 100%;
    padding: 16px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
}

.hacker-theme .start-quiz-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.start-quiz-button:hover {
    background-color: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .start-quiz-button:hover {
    box-shadow: 0 0 15px var(--button-bg);
}

/* Quiz Mode Indicators */
.quiz-mode-indicator {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 4px 12px;
    border-radius: 4px;
    margin-bottom: 16px;
}

.hacker-theme .quiz-mode-indicator {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.quiz-mode-indicator.normal {
    background-color: var(--accent-warning-bg);
    color: var(--accent-warning);
    border: 1px solid var(--accent-warning);
}

.quiz-mode-indicator.rapid {
    background-color: var(--accent-challenge-bg);
    color: var(--accent-challenge);
    border: 1px solid var(--accent-challenge);
}

.quiz-mode-indicator.sudden {
    background-color: var(--accent-extreme-bg);
    color: var(--accent-extreme);
    border: 1px solid var(--accent-extreme);
}

/* Timer Bar for Rapid Fire Mode */
.timer-bar {
    position: relative;
    width: 100%;
    height: 32px;
    background-color: var(--bg-tertiary);
    border-radius: 16px;
    margin-bottom: 20px;
    overflow: hidden;
}

.hacker-theme .timer-bar {
    border-radius: 0;
    border: 1px solid var(--border-primary);
}

.timer-fill {
    height: 100%;
    background: var(--timer-gradient);
    transition: width 0.1s linear;
    border-radius: 16px;
}

.hacker-theme .timer-fill {
    border-radius: 0;
}

.timer-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    text-shadow: 0 0 4px var(--shadow-dark);
}

.hacker-theme .timer-text {
    font-family: 'Courier New', monospace;
}

/* Results Screen Styles */
.results-container {
    max-width: 400px;
    margin: 0 auto;
}

.results-score {
    margin-bottom: 24px;
}

.score-bar {
    width: 100%;
    height: 6px;
    background-color: var(--progress-bg);
    border-radius: 3px;
    overflow: hidden;
    margin-top: 16px;
}

.hacker-theme .score-bar {
    border-radius: 0;
    border: 1px solid var(--border-primary);
}

.score-fill {
    height: 100%;
    background: var(--score-gradient);
    transition: width 1s ease-out;
    border-radius: 3px;
}

.hacker-theme .score-fill {
    border-radius: 0;
}

.results-actions {
    display: flex;
    flex-direction: column;
    gap: 16px;
    align-items: stretch;
    width: 100%;
}

.retry-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px 32px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    width: 100%;
}

.hacker-theme .retry-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.retry-button:hover {
    background-color: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .retry-button:hover {
    box-shadow: 0 0 15px var(--button-bg);
}

.secondary-actions {
    display: flex;
    flex-direction: column;
    gap: 16px;
    width: 100%;
}

.topics-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px 32px;
    background: none;
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    width: 100%;
}

.hacker-theme .topics-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.topics-button:hover {
    border-color: var(--border-secondary);
    background-color: var(--shadow-light);
}

.hacker-theme .topics-button:hover {
    box-shadow: 0 0 10px var(--border-primary);
}

.menu-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px 32px;
    background: none;
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    width: 100%;
}

.hacker-theme .menu-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.menu-button:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
}

.hacker-theme .menu-button:hover {
    box-shadow: 0 0 10px var(--border-primary);
}

/* Notes Specific Styles - FIXED */
.notes-container {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--bg-secondary);
    min-height: 100vh;
    border-left: 1px solid var(--border-primary);
    border-right: 1px solid var(--border-primary);
}

.hacker-theme .notes-container {
    border-left: 2px solid var(--border-primary);
    border-right: 2px solid var(--border-primary);
}

.notes-header {
    padding: 32px 24px;
    text-align: center;
    border-bottom: 1px solid var(--border-primary);
    background-color: var(--bg-secondary);
}

.topic-breadcrumb {
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 13px;
    border-bottom: 1px solid var(--border-primary);
    background-color: var(--bg-secondary);
}

.hacker-theme .topic-breadcrumb {
    font-family: 'Courier New', monospace;
}

.breadcrumb-item {
    color: var(--text-tertiary);
    transition: color 0.2s ease;
}

.breadcrumb-item:not(.active):hover {
    color: var(--text-secondary);
    cursor: pointer;
}

.breadcrumb-item.active {
    color: var(--text-primary);
    cursor: default;
}

.breadcrumb-separator {
    color: var(--border-primary);
}

.notes-content {
    padding: 40px 24px 100px;
    background-color: var(--bg-secondary);
}

.note-article {
    max-width: 650px;
    margin: 0 auto;
}

.note-title {
    font-size: 36px;
    font-weight: 300;
    margin-bottom: 32px;
    letter-spacing: -1px;
    line-height: 1.2;
    color: var(--text-primary);
}

.note-section {
    margin-bottom: 48px;
}

.note-section h2 {
    font-size: 24px;
    font-weight: 400;
    margin-bottom: 16px;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.lead-text {
    font-size: 18px;
    line-height: 1.7;
    color: var(--text-muted);
    font-weight: 300;
}

.note-section p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.key-points {
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.point {
    padding: 16px 20px;
    background-color: var(--bg-quaternary);
    border-left: 3px solid var(--border-primary);
    border-radius: 4px;
    font-size: 15px;
    color: var(--text-muted);
    transition: all 0.2s ease;
}

.hacker-theme .point {
    border-radius: 0;
    border-left: 3px solid var(--border-primary);
    font-family: 'Courier New', monospace;
}

.point:hover {
    background-color: var(--bg-hover);
    border-left-color: var(--border-secondary);
}

.hacker-theme .point:hover {
    box-shadow: 0 0 5px var(--border-primary);
}

.organelle-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 16px;
    margin-top: 24px;
}

.organelle-card {
    padding: 24px;
    background-color: var(--bg-quaternary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.hacker-theme .organelle-card {
    border-radius: 0;
    border: 2px solid var(--border-primary);
}

.organelle-card:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-secondary);
    transform: translateY(-2px);
}

.hacker-theme .organelle-card:hover {
    box-shadow: 0 0 10px var(--border-primary);
}

.organelle-card h3 {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.organelle-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin: 0;
}

.notes-footer {
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 800px;
    padding: 20px 24px;
    background: linear-gradient(to top, var(--bg-secondary) 80%, transparent);
    border-top: 1px solid var(--border-primary);
}

.notes-footer .back-button {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--bg-quaternary);
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 0 auto;
}

.hacker-theme .notes-footer .back-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.notes-footer .back-button:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-secondary);
    transform: translateX(-2px);
}

.hacker-theme .notes-footer .back-button:hover {
    box-shadow: 0 0 10px var(--border-primary);
}

/* Past Paper Specific Styles */
.exam-info {
    background: var(--bg-quaternary);
    padding: 16px;
    border-radius: 8px;
    margin: 16px 0;
    border-left: 4px solid var(--border-primary);
    font-size: 14px;
    color: var(--text-secondary);
}

.question-section {
    border-bottom: 2px solid var(--border-primary);
    padding-bottom: 32px;
    margin-bottom: 32px;
}

.question-section:last-child {
    border-bottom: none;
}

.sub-question {
    margin: 24px 0;
    padding: 20px;
    background: var(--bg-quaternary);
    border-radius: 8px;
    border: 1px solid var(--border-primary);
    position: relative;
}

.hacker-theme .sub-question {
    border-radius: 0;
    border: 2px solid var(--border-primary);
}

.sub-question h3 {
    color: var(--text-primary);
    font-size: 18px;
    margin-bottom: 12px;
    font-weight: 600;
}

.sub-question p {
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.reveal-btn {
    background: var(--button-bg);
    color: var(--button-text);
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    margin-bottom: 16px;
}

.hacker-theme .reveal-btn {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.reveal-btn:hover {
    background: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .reveal-btn:hover {
    box-shadow: 0 0 10px var(--button-bg);
}

.reveal-btn.revealed {
    background: var(--accent-warning);
    color: var(--bg-primary);
}

.answer-box {
    background: var(--accent-correct-bg);
    border: 2px solid var(--accent-correct);
    border-radius: 8px;
    padding: 20px;
    margin-top: 16px;
    transition: all 0.4s ease;
}

.hacker-theme .answer-box {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.answer-box h4 {
    color: var(--accent-correct);
    margin-bottom: 16px;
    font-size: 16px;
    font-weight: 600;
}

.mark-point {
    margin: 8px 0;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
}

.mark {
    color: var(--accent-correct);
    font-weight: bold;
    font-size: 16px;
}

.exam-footer {
    text-align: center;
    padding: 24px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    border: 1px solid var(--border-primary);
}

.hacker-theme .exam-footer {
    border-radius: 0;
    border: 2px solid var(--border-primary);
}

.exam-footer p {
    margin: 8px 0;
    color: var(--text-secondary);
}

/* Game Over Screen for Sudden Death */
.game-over-screen {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 80vh;
    background-color: var(--bg-primary);
    flex-direction: column;
    text-align: center;
}

.game-over .skull {
    font-size: 64px;
    margin-bottom: 16px;
}

.game-over h1 {
    font-size: 32px;
    margin-bottom: 24px;
    letter-spacing: 2px;
    color: var(--text-primary);
}

.hacker-theme .game-over h1 {
    font-family: 'Courier New', monospace;
    text-shadow: 0 0 10px var(--text-primary);
}

.game-over .retry-button {
    margin-bottom: 16px;
}

/* Tablet and Desktop styles */
@media (min-width: 768px) {
    body {
        padding: 20px;
    }

    .quiz-header {
        padding: 40px;
    }

    .theme-button {
        top: 36px;
        right: 40px;
        width: 44px;
        height: 44px;
    }

    .brand {
        font-size: 36px;
        letter-spacing: 8px;
    }

    .subtitle {
        font-size: 14px;
        letter-spacing: 2px;
    }

    .quiz-content {
        padding: 40px;
    }

    .question-header {
        margin-bottom: 24px;
    }

    .question-number {
        font-size: 14px;
    }

    .question h2 {
        font-size: 20px;
        line-height: 1.6;
        margin-bottom: 32px;
    }

    .options {
        gap: 16px;
        margin-bottom: 40px;
    }

    .option {
        padding: 20px;
    }

    .option-letter {
        width: 32px;
        height: 32px;
        margin-right: 16px;
        font-size: 16px;
    }

    .option-text {
        font-size: 16px;
    }

    .explanation {
        font-size: 14px;
    }

    .hint-button, .cheat-button {
        width: 40px;
        height: 40px;
    }

    .hint-box {
        padding: 16px;
        margin-bottom: 24px;
    }

    .hint-text {
        font-size: 14px;
    }

    .next-button {
        padding: 16px;
        font-size: 16px;
    }

    /* Quiz Type Cards - Desktop */
    .quiz-type-cards {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    /* Past Papers card spans full width on desktop */
    .past-papers-card {
        grid-column: 1 / -1;
    }

    .quiz-type-card {
        padding: 32px 24px;
    }

    .quiz-type-card:hover {
        transform: translateY(-4px);
    }

    .card-icon {
        width: 56px;
        height: 56px;
    }

    .card-title {
        font-size: 18px;
    }

    .card-description {
        font-size: 14px;
    }

    .select-title {
        font-size: 14px;
        margin-bottom: 24px;
    }

    .selection-button:hover {
        transform: translateY(-2px);
    }

    .notes-header {
        padding: 40px;
    }
    .notes-content {
        padding: 60px 40px 120px;
    }
    .note-title {
        font-size: 40px;
    }
    .note-section h2 {
        font-size: 28px;
    }
}

/* Loading state for topic selection */
#topic-buttons .lead-text {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

/* Mobile styles */
@media (max-width: 767px) {
    .notes-header {
        padding: 24px 16px;
    }
    .topic-breadcrumb {
        padding: 16px;
        font-size: 12px;
        gap: 8px;
    }
    .notes-content {
        padding: 24px 16px 100px;
    }
    .note-title {
        font-size: 28px;
        margin-bottom: 24px;
    }
    .note-section {
        margin-bottom: 36px;
    }
    .note-section h2 {
        font-size: 20px;
    }
    .lead-text {
        font-size: 16px;
    }
    .note-section p {
        font-size: 15px;
    }
    .point {
        padding: 14px 16px;
        font-size: 14px;
    }
    .organelle-grid {
        grid-template-columns: 1fr;
    }
    .organelle-card {
        padding: 20px;
    }
    .notes-footer {
        padding: 16px;
    }
    
    /* Past Paper mobile styles */
    .sub-question {
        padding: 16px;
        margin: 16px 0;
    }
    
    .answer-box {
        padding: 16px;
    }
    
    .mark-point {
        font-size: 13px;
    }
}

/* Animation for card entrance */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.quiz-type-card {
    animation: fadeInUp 0.5s ease-out forwards;
}

.quiz-type-card:nth-child(1) {
    animation-delay: 0.1s;
}

.quiz-type-card:nth-child(2) {
    animation-delay: 0.2s;
}

.quiz-type-card:nth-child(3) {
    animation-delay: 0.3s;
}

.quiz-type-card:nth-child(4) {
    animation-delay: 0.4s;
}

/* Past Papers card special styling for different themes */
.light-theme .past-papers-card {
    background: linear-gradient(135deg, #fff8f0 0%, #fff0e6 100%);
    box-shadow: 0 4px 16px rgba(255, 170, 0, 0.1);
}

.hacker-theme .past-papers-card {
    background: linear-gradient(135deg, #001100 0%, #002200 100%);
    border-color: #00ff00;
}

.hacker-theme .past-papers-card .card-title {
    text-shadow: 0 0 10px #00ff00;
}

.ruby-theme .past-papers-card {
    background: linear-gradient(135deg, #440000 0%, #550000 100%);
}

.cloudy-theme .past-papers-card {
    background: linear-gradient(135deg, #f8f8f8 0%, #f0f0f0 100%);
}

.kitty-theme .past-papers-card {
    background: linear-gradient(135deg, #fff5fc 0%, #ffebf7 100%);
}

.astro-theme .past-papers-card {
    background: linear-gradient(135deg, #2e2e4a 0%, #3a3a5a 100%);
}

.cyberpunk-theme .past-papers-card {
    background: linear-gradient(135deg, #1a001a 0%, #2d002d 100%);
    border-image: linear-gradient(135deg, #ff00ff 0%, #00ffff 100%) 1;
}

.cyberpunk-theme .past-papers-card .card-title {
    background: linear-gradient(135deg, #ff00ff 0%, #00ffff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Theme transition animation */
* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* Loading state for topic selection */
#topic-buttons .lead-text {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

/* Snapshot Overlay Styles */
.snapshot-view {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.snapshot-container {
    background: #000;
    color: #fff;
    width: 400px;
    height: 600px;
    border-radius: 30px;
    padding: 40px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}

.snapshot-container::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.05) 0%, transparent 70%);
    pointer-events: none;
}

.snapshot-header {
    text-align: center;
    margin-bottom: 40px;
}

.app-name {
    font-size: 28px;
    font-weight: 300;
    letter-spacing: 4px;
    margin-bottom: 10px;
    background: linear-gradient(45deg,#fff,#ccc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.decorative-line {
    width: 80px;
    height: 2px;
    background: linear-gradient(90deg,transparent,#fff,transparent);
    margin: 0 auto;
}

.topic-section {
    margin-bottom: 40px;
}

.topic-label {
    font-size: 12px;
    color: #666;
    letter-spacing: 2px;
    margin-bottom: 8px;
}

.topic-name {
    font-size: 20px;
    font-weight: 500;
    color: #fff;
}

.result-section {
    display: flex;
    align-items: center;
    justify-content: space-around;
    margin: 60px 0;
}

.grade-circle {
    width: 120px;
    height: 120px;
    border: 3px solid var(--grade-color, #ff0000);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: radial-gradient(circle, rgba(255,255,255,0.05), transparent);
    box-shadow: 0 0 30px rgba(0,0,0,0.5), inset 0 0 20px rgba(0,0,0,0.3);
}

.grade-circle::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 1px solid var(--grade-color, #ff0000);
    opacity: 0.3;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 0.3; }
    100% { transform: scale(1.2); opacity: 0; }
}

.grade {
    font-size: 48px;
    font-weight: bold;
    color: var(--grade-color, #ff0000);
    text-shadow: 0 0 20px var(--grade-color, #ff0000);
}

.score-details { text-align: center; }

.big-percentage {
    font-size: 64px;
    font-weight: 200;
    margin-bottom: 10px;
    background: linear-gradient(180deg,#ffffff 0%,#666666 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.5));
}

.score-breakdown {
    font-size: 16px;
    color: #aaa;
}

.app-promotion {
    position: absolute;
    bottom: 30px;
    left: 0;
    right: 0;
    text-align: center;
}

.download-text {
    font-size: 12px;
    color: #666;
    letter-spacing: 0.5px;
    font-weight: 300;
}

.close-snapshot {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.close-snapshot:hover {
    background: rgba(255,255,255,0.2);
    transform: rotate(90deg);
}

/* Authentication Screen Styles */
.auth-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.auth-card {
    max-width: 400px;
    width: 90%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 12px;
    padding: 48px 32px;
    text-align: center;
    box-shadow: 0 4px 16px var(--shadow-dark);
}

.hacker-theme .auth-card {
    border-radius: 0;
    border: 2px solid var(--border-primary);
    box-shadow: 0 0 20px var(--border-primary);
}

.auth-brand {
    font-size: 36px;
    font-weight: 300;
    letter-spacing: 8px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.hacker-theme .auth-brand {
    text-shadow: 0 0 10px var(--text-primary);
    animation: flicker 2s infinite alternate;
}

.auth-subtitle {
    font-size: 18px;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.auth-description {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.google-signin-button {
    width: 100%;
    padding: 14px 24px;
    background-color: #fff;
    color: #3c4043;
    border: 1px solid #dadce0;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.google-signin-button:hover {
    background-color: #f8f9fa;
    box-shadow: 0 1px 3px rgba(0,0,0,0.15);
}

.hacker-theme .google-signin-button {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
    border-radius: 0;
}

.hacker-theme .google-signin-button:hover {
    background-color: var(--bg-tertiary);
    box-shadow: 0 0 10px var(--border-primary);
}

/* Sign Out Button Styles */
.signout-button {
    position: absolute;
    bottom: 24px;
    right: 24px;
    padding: 8px 16px;
    background: none;
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.hacker-theme .signout-button {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.signout-button:hover {
    border-color: var(--border-secondary);
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
}

.hacker-theme .signout-button:hover {
    box-shadow: 0 0 5px var(--border-primary);
}

/* Ensure grade selection has relative positioning */
#grade-selection {
    position: relative;
    padding-bottom: 60px; /* Space for sign-out button */
}

/* Online Counter Pill */
.online-counter-pill {
    position: fixed;
    bottom: 24px;
    left: 24px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: 20px;
    padding: 8px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    z-index: 100;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px var(--shadow-dark);
}

/* Glow effect when number changes */
.online-counter-pill.glowing {
    box-shadow: 0 0 20px rgba(50, 255, 0, 0.5), 0 2px 8px var(--shadow-dark);
    border-color: rgba(50, 255, 0, 0.5);
}

/* The green dot */
.online-dot {
    width: 8px;
    height: 8px;
    background-color: #32ff00;
    border-radius: 50%;
    position: relative;
    box-shadow: 0 0 4px #32ff00;
}

/* Pulsing animation for the dot */
.online-dot::after {
    content: '';
    position: absolute;
    top: -4px;
    left: -4px;
    width: 16px;
    height: 16px;
    border: 2px solid #32ff00;
    border-radius: 50%;
    opacity: 0.3;
    animation: pulse-ring 2s infinite;
}

@keyframes pulse-ring {
    0% {
        transform: scale(0.5);
        opacity: 0.5;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* Online text */
.online-text {
    font-size: 13px;
    white-space: nowrap;
}

#online-count {
    font-weight: 500;
    color: var(--text-primary);
}

/* Counter animations */
@keyframes countUp {
    from {
        opacity: 0;
        transform: translateY(5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.online-counter-pill.animating #online-count {
    animation: countUp 0.3s ease;
}

/* Mobile responsive */
@media (max-width: 767px) {
    .online-counter-pill {
        bottom: 16px;
        left: 16px;
        padding: 6px 12px;
        font-size: 12px;
    }
    
    .online-text {
        font-size: 11px;
    }
    
    .online-dot {
        width: 6px;
        height: 6px;
    }
}

/* Theme-specific styles */
.hacker-theme .online-counter-pill {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.hacker-theme .online-counter-pill.glowing {
    box-shadow: 0 0 20px #32ff00, 0 0 40px #32ff00;
}

.kitty-theme .online-dot {
    background-color: #ff6ec7;
    box-shadow: 0 0 4px #ff6ec7;
}

.kitty-theme .online-dot::after {
    border-color: #ff6ec7;
}

.cyberpunk-theme .online-counter-pill.glowing {
    box-shadow: 0 0 30px #00ffff, 0 0 20px #ff00ff;
}

/* Past paper Styling */

/* ==============================================
   PAST PAPER STYLING - CLEAN FLOW DESIGN
   ============================================== */

/* Enhanced exam info styling */
.notes-view .exam-info {
    background: var(--bg-quaternary);
    padding: 20px;
    border-radius: 8px;
    margin: 24px 0;
    border-left: 4px solid var(--border-secondary);
    font-size: 14px;
    color: var(--text-secondary);
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: center;
}

.hacker-theme .notes-view .exam-info {
    border-radius: 0;
    border-left: 4px solid var(--border-primary);
    font-family: 'Courier New', monospace;
}

/* Question section styling - remove card backgrounds */
.notes-view .question-section {
    border-bottom: 1px solid var(--border-primary);
    padding-bottom: 40px;
    margin-bottom: 40px;
    background: none;
    border-radius: 0;
}

.notes-view .question-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.notes-view .question-section h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 32px;
    color: var(--text-primary);
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-primary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Individual sub-questions - no cards, just clean spacing */
.notes-view .sub-question {
    margin: 32px 0;
    padding: 0;
    background: none;
    border: none;
    border-radius: 0;
    position: relative;
}

/* Add subtle divider between sub-questions */
.notes-view .sub-question:not(:last-child)::after {
    content: '';
    position: absolute;
    bottom: -16px;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, var(--border-primary) 20%, var(--border-primary) 80%, transparent 100%);
    opacity: 0.5;
}

/* Question number and title styling */
.notes-view .sub-question h3 {
    color: var(--text-primary);
    font-size: 20px;
    margin-bottom: 16px;
    font-weight: 700;
    display: inline-block;
    background: var(--bg-tertiary);
    padding: 8px 16px;
    border-radius: 6px;
    border: 1px solid var(--border-primary);
}

.hacker-theme .notes-view .sub-question h3 {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

/* Question text styling */
.notes-view .sub-question p {
    font-size: 16px;
    line-height: 1.7;
    margin-bottom: 20px;
    color: var(--text-primary);
    font-weight: 400;
}

/* Enhanced reveal button styling */
.notes-view .reveal-btn {
    background: var(--button-bg);
    color: var(--button-text);
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.hacker-theme .notes-view .reveal-btn {
    border-radius: 0;
    font-family: 'Courier New', monospace;
    border: 1px solid var(--button-bg);
}

.notes-view .reveal-btn:hover {
    background: var(--button-hover);
    transform: translateY(-1px);
}

.hacker-theme .notes-view .reveal-btn:hover {
    box-shadow: 0 0 10px var(--button-bg);
}

.notes-view .reveal-btn.revealed {
    background: var(--accent-warning);
    color: var(--bg-primary);
}

/* Answer box styling - clean and elegant */
.notes-view .answer-box {
    background: var(--accent-correct-bg);
    border: 1px solid var(--accent-correct);
    border-radius: 8px;
    padding: 24px;
    margin-top: 20px;
    transition: all 0.4s ease;
    border-left: 4px solid var(--accent-correct);
}

.hacker-theme .notes-view .answer-box {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.notes-view .answer-box h4 {
    color: var(--accent-correct);
    margin-bottom: 16px;
    font-size: 16px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Mark points styling */
.notes-view .mark-point {
    margin: 12px 0;
    padding: 8px 0;
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
}

.notes-view .mark {
    color: var(--accent-correct);
    font-weight: bold;
    font-size: 16px;
    margin-left: 8px;
}

/* Exam footer styling */
.notes-view .exam-footer {
    text-align: center;
    padding: 32px 24px;
    margin-top: 48px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    border: 1px solid var(--border-primary);
    border-top: 3px solid var(--border-secondary);
}

.hacker-theme .notes-view .exam-footer {
    border-radius: 0;
    border-top: 3px solid var(--border-primary);
}

.notes-view .exam-footer p {
    margin: 8px 0;
    color: var(--text-secondary);
    font-size: 14px;
}

.notes-view .exam-footer p:first-child {
    color: var(--text-primary);
    font-weight: 600;
    font-size: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Mobile responsiveness */
@media (max-width: 767px) {
    .notes-view .exam-info {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
    
    .notes-view .question-section h2 {
        font-size: 20px;
    }
    
    .notes-view .sub-question h3 {
        font-size: 18px;
        padding: 6px 12px;
    }
    
    .notes-view .answer-box {
        padding: 20px 16px;
    }
    
    .notes-view .exam-footer {
        padding: 24px 16px;
        margin-top: 32px;
    }
}

/* PaperBrain Boost Button Styles - Updated */
.paperbrain-boost-btn {
    width: 100%;
    padding: 12px 24px;
    background-color: #000000;
    color: #ffffff;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 8px;
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    position: relative;
    overflow: hidden;
}

/* PaperBrain Boost Button Styles - Fixed */
.paperbrain-boost-btn {
    width: 60%;
    padding: 10px 20px; /* Match reveal button padding */
    background-color: #000000;
    color: #ffffff;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 8px;
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

/* Animated gradient border using conic gradient */
.paperbrain-boost-btn::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    width: calc(100% + 4px);
    height: calc(100% + 4px);
    background: conic-gradient(
        from var(--angle),
        #00ffff 0deg,     /* Cyan */
        #00ff00 72deg,    /* Green */
        #0080ff 144deg,   /* Blue */
        #ff00ff 216deg,   /* Pink */
        #ffff00 288deg,   /* Yellow */
        #00ffff 360deg    /* Back to cyan */
    );
    border-radius: 6px;
    z-index: -1;
    animation: spinGradient 4s linear infinite;
}

/* Inner black background */
.paperbrain-boost-btn::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: calc(100% - 4px);
    height: calc(100% - 4px);
    background: #000000;
    border-radius: 4px;
    z-index: -1;
}

/* Smooth rotation animation */
@keyframes spinGradient {
    from {
        --angle: 0deg;
    }
    to {
        --angle: 360deg;
    }
}

/* Support for CSS custom properties in animations */
@property --angle {
    syntax: '<angle>';
    initial-value: 0deg;
    inherits: false;
}

/* Text and icon container to stay above the background */
.paperbrain-boost-btn svg,
.paperbrain-boost-btn span {
    position: relative;
    z-index: 2;
}

/* Glow effect on hover */
.paperbrain-boost-btn:hover {
    transform: translateY(-1px);
    box-shadow: 
        0 0 20px rgba(0, 255, 255, 0.4),
        0 0 30px rgba(0, 255, 0, 0.3),
        0 0 40px rgba(255, 0, 255, 0.2);
}

/* Fallback for browsers that don't support @property */
@supports not (background: conic-gradient(from var(--angle), red, blue)) {
    .paperbrain-boost-btn::before {
        background: linear-gradient(
            90deg,
            #00ffff 0%,
            #00ff00 20%,
            #0080ff 40%,
            #ff00ff 60%,
            #ffff00 80%,
            #00ffff 100%
        );
        background-size: 300% 100%;
        animation: slideGradient 3s linear infinite;
    }
    
    @keyframes slideGradient {
        0% {
            background-position: 0% 50%;
        }
        100% {
            background-position: 100% 50%;
        }
    }
}

/* Disabled state */
.paperbrain-boost-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.paperbrain-boost-btn.disabled::before {
    animation: none;
    opacity: 0.3;
}

.paperbrain-boost-btn.disabled:hover {
    transform: none;
    box-shadow: none;
}

/* Hacker theme adjustments */
.hacker-theme .paperbrain-boost-btn {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

.hacker-theme .paperbrain-boost-btn::before,
.hacker-theme .paperbrain-boost-btn::after {
    border-radius: 0;
}

/* Ensure it matches reveal button in past papers */
.notes-view .paperbrain-boost-btn {
    padding: 10px 20px; /* Same as reveal button */
    margin-bottom: 4px;
}

/* Boost usage text */
.boost-usage-text {
    font-size: 11px;
    color: var(--text-tertiary);
    text-align: center;
    margin-bottom: 16px;
    margin-top: 2px;
}

/* PaperBrain Boost Content Box */
.paperbrain-boost-box {
    background-color: #000000;
    border: 2px solid #ffffff;
    border-radius: 8px;
    padding: 24px;
    margin-top: 16px;
    transition: all 0.4s ease;
    color: #ffffff;
}

.hacker-theme .paperbrain-boost-box {
    border-radius: 0;
    border-color: #00ff00;
    color: #00ff00;
}

.paperbrain-boost-box h4 {
    color: #ffffff;
    margin-bottom: 16px;
    font-size: 16px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.hacker-theme .paperbrain-boost-box h4 {
    color: #00ff00;
}

.boost-content {
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 12px;
}

.boost-tip {
    background-color: #1a1a1a;
    padding: 12px;
    border-left: 3px solid #666666;
    margin: 12px 0;
    font-size: 14px;
}

.hacker-theme .boost-tip {
    background-color: #001100;
    border-left-color: #00ff00;
}

/* PaperBrain Boost Counter Pill */
.boost-counter-pill {
    position: fixed;
    bottom: 24px;
    left: 170px; /* Position next to online counter */
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: 20px;
    padding: 8px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    z-index: 100;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px var(--shadow-dark);
}

.boost-counter-pill.low-boosts {
    border-color: #ff6600;
    box-shadow: 0 0 10px rgba(255, 102, 0, 0.3);
}

.boost-counter-pill.no-boosts {
    border-color: #ff0000;
    box-shadow: 0 0 10px rgba(255, 0, 0, 0.3);
}

.boost-text {
    font-size: 13px;
    white-space: nowrap;
}

#boost-count {
    font-weight: 500;
    color: var(--text-primary);
}

/* Mobile responsive for boost counter */
@media (max-width: 767px) {
    .boost-counter-pill {
        bottom: 16px;
        left: 140px;
        padding: 6px 12px;
        font-size: 12px;
    }
    
    .boost-text {
        font-size: 11px;
    }
}

/* Theme-specific boost counter styles */
.hacker-theme .boost-counter-pill {
    border-radius: 0;
    font-family: 'Courier New', monospace;
}

/* No boosts modal */
.no-boosts-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.no-boosts-modal.show {
    opacity: 1;
    visibility: visible;
}

.no-boosts-content {
    background: var(--bg-secondary);
    border: 2px solid var(--border-primary);
    border-radius: 12px;
    padding: 32px;
    max-width: 400px;
    text-align: center;
}

.hacker-theme .no-boosts-content {
    border-radius: 0;
    border-color: #00ff00;
}

.no-boosts-content h3 {
    font-size: 24px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.no-boosts-content p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.boost-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.watch-ad-btn, .upgrade-btn {
    padding: 14px 24px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.watch-ad-btn {
    background-color: #00cc00;
    color: #000000;
}

.upgrade-btn {
    background-color: #666666;
    color: #ffffff;
}

.close-modal-btn {
    margin-top: 16px;
    background: none;
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

/* Animation for reveal effect */
@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.answer-box.animate {
    animation: slideInDown 0.4s ease;
}

@media (max-width: 480px) {
    .snapshot-container { width: 90%; height: 80vh; padding: 30px; }
    .big-percentage { font-size: 48px; }
    .grade-circle { width: 100px; height: 100px; }
    .grade { font-size: 36px; }
}