/* ================================================================
   CNS Final Exam Quiz — Design System & Styles
   ================================================================ */

/* ---------- CSS Custom Properties (Design Tokens) ---------- */
:root {
    /* Colors — dark theme palette */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a27;
    --bg-card: #16162380;
    --bg-card-hover: #1e1e30;
    --bg-glass: rgba(22, 22, 35, 0.65);

    --text-primary: #eeeef5;
    --text-secondary: #9d9db5;
    --text-muted: #6b6b85;

    --accent-indigo: #6366f1;
    --accent-violet: #8b5cf6;
    --accent-purple: #a855f7;
    --accent-fuchsia: #d946ef;
    --accent-cyan: #22d3ee;

    --gradient-primary: linear-gradient(135deg, #6366f1, #a855f7);
    --gradient-accent: linear-gradient(135deg, #8b5cf6, #d946ef);
    --gradient-success: linear-gradient(135deg, #10b981, #34d399);
    --gradient-danger: linear-gradient(135deg, #ef4444, #f97066);
    --gradient-warm: linear-gradient(135deg, #f59e0b, #fbbf24);

    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.12);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.12);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.12);

    --border-color: rgba(255, 255, 255, 0.06);
    --border-active: rgba(99, 102, 241, 0.4);

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Radii */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 24px rgba(0,0,0,0.3);
    --shadow-lg: 0 8px 48px rgba(0,0,0,0.4);
    --shadow-glow-indigo: 0 0 40px rgba(99,102,241,0.15);
    --shadow-glow-success: 0 0 30px rgba(16,185,129,0.15);
    --shadow-glow-danger: 0 0 30px rgba(239,68,68,0.15);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    outline: none;
    background: none;
}

input {
    font-family: inherit;
    outline: none;
}

/* ---------- Screen Management ---------- */
.screen {
    display: none;
    min-height: 100vh;
    position: relative;
}

.screen.active {
    display: flex;
}

/* ---------- Backgrounds & Effects ---------- */
.landing-bg, .quiz-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.4;
    animation: float 8s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(99,102,241,0.3), transparent 70%);
    top: -10%;
    right: -5%;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(168,85,247,0.25), transparent 70%);
    bottom: -5%;
    left: -5%;
    animation-delay: -3s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(34,211,238,0.2), transparent 70%);
    top: 40%;
    left: 30%;
    animation-delay: -5s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -20px) scale(1.05); }
    66% { transform: translate(-20px, 15px) scale(0.95); }
}

/* ================================================================
   LANDING SCREEN
   ================================================================ */
#landing-screen {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
}

.landing-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 680px;
    width: 100%;
    animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.logo-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto var(--space-lg);
    animation: fadeInUp 0.6s ease-out;
}

.logo-icon svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 0 20px rgba(99,102,241,0.3));
}

.landing-title {
    margin-bottom: var(--space-md);
}

.title-line-1 {
    display: block;
    font-size: clamp(1.5rem, 4vw, 2.2rem);
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.title-line-2 {
    display: block;
    font-size: clamp(2.8rem, 7vw, 4.5rem);
    font-weight: 900;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

.landing-subtitle {
    color: var(--text-muted);
    font-size: 1.05rem;
    font-weight: 400;
    margin-bottom: var(--space-2xl);
}

/* Stats */
.landing-stats {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    margin-bottom: var(--space-2xl);
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    backdrop-filter: blur(12px);
    min-width: 110px;
    transition: var(--transition-base);
}

.stat-card:hover {
    border-color: var(--border-active);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow-indigo);
}

.stat-number {
    font-size: 1.8rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

/* Mode Selector */
.mode-selector {
    margin-bottom: var(--space-2xl);
}

.mode-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-md);
}

.mode-cards {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    flex-wrap: wrap;
}

.mode-card {
    background: var(--bg-card);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    cursor: pointer;
    transition: var(--transition-base);
    min-width: 140px;
    text-align: center;
}

.mode-card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(99,102,241,0.3);
    transform: translateY(-2px);
}

.mode-card.selected {
    border-color: var(--accent-indigo);
    background: rgba(99,102,241,0.08);
    box-shadow: 0 0 20px rgba(99,102,241,0.1);
}

.mode-icon {
    font-size: 1.6rem;
    margin-bottom: var(--space-xs);
}

.mode-name {
    font-weight: 700;
    font-size: 0.95rem;
    margin-bottom: 2px;
}

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

.custom-count-wrapper {
    margin-top: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-md);
    justify-content: center;
}

.custom-count-wrapper label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.custom-input {
    background: var(--bg-tertiary);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: var(--space-sm) var(--space-md);
    font-size: 1rem;
    width: 90px;
    text-align: center;
    font-weight: 600;
    transition: var(--transition-fast);
}

.custom-input:focus {
    border-color: var(--accent-indigo);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}

/* Buttons */
.btn-start {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--gradient-primary);
    color: white;
    font-size: 1.1rem;
    font-weight: 700;
    padding: 14px 40px;
    border-radius: var(--radius-full);
    transition: var(--transition-base);
    box-shadow: 0 4px 24px rgba(99,102,241,0.3);
    position: relative;
    overflow: hidden;
}

.btn-start::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.1), transparent);
    opacity: 0;
    transition: var(--transition-fast);
}

.btn-start:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(99,102,241,0.4);
}

.btn-start:hover::before {
    opacity: 1;
}

.btn-start:active {
    transform: translateY(0);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    padding: 12px 28px;
    border-radius: var(--radius-full);
    border: 1.5px solid var(--border-color);
    transition: var(--transition-base);
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-active);
    transform: translateY(-1px);
}

.hidden {
    display: none !important;
}

/* ================================================================
   QUIZ SCREEN
   ================================================================ */
#quiz-screen {
    flex-direction: column;
    height: 100vh;
}

/* Header */
.quiz-header {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.btn-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    border: 1px solid transparent;
}

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

.header-title {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-secondary);
}

.header-center {
    flex: 1;
    max-width: 400px;
    margin: 0 var(--space-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.progress-info {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.progress-divider {
    color: var(--text-muted);
    margin: 0 2px;
}

.progress-bar-wrapper {
    width: 100%;
    height: 4px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    width: 0%;
    transition: width var(--transition-slow);
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.score-badge, .timer-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 600;
    padding: 6px 12px;
    border-radius: var(--radius-full);
    border: 1px solid var(--border-color);
    background: var(--bg-card);
}

.score-badge {
    color: var(--success);
}

.timer-badge {
    color: var(--accent-cyan);
}

/* Quiz Main */
.quiz-main {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-xl) var(--space-lg);
    display: flex;
    justify-content: center;
    position: relative;
    z-index: 1;
}

.question-container {
    max-width: 780px;
    width: 100%;
    animation: slideIn 0.35s ease-out;
}

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

@keyframes slideOut {
    from { opacity: 1; transform: translateX(0); }
    to { opacity: 0; transform: translateX(-20px); }
}

.multi-select-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(139, 92, 246, 0.12);
    color: var(--accent-violet);
    font-size: 0.8rem;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-md);
    border: 1px solid rgba(139, 92, 246, 0.2);
}

.question-number {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-indigo);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-sm);
}

.question-text {
    font-size: 1.15rem;
    font-weight: 500;
    line-height: 1.7;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

/* Exhibit */
.exhibit-wrapper {
    margin-bottom: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition-base);
}

.exhibit-wrapper:hover {
    border-color: var(--border-active);
}

.exhibit-label {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: var(--space-sm) var(--space-md);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    border-bottom: 1px solid var(--border-color);
    background: rgba(255,255,255,0.02);
}

.exhibit-image {
    display: block;
    max-width: 100%;
    margin: 0 auto;
    padding: var(--space-md);
    cursor: zoom-in;
    transition: var(--transition-fast);
    background: #fafafa;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.exhibit-image:hover {
    opacity: 0.9;
}

/* Choices */
.choices-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.choice-btn {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-card);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition-base);
    text-align: left;
    width: 100%;
    position: relative;
    backdrop-filter: blur(8px);
}

.choice-btn:hover:not(.disabled) {
    background: var(--bg-card-hover);
    border-color: rgba(99,102,241,0.3);
    transform: translateX(4px);
}

.choice-btn.selected {
    border-color: var(--accent-indigo);
    background: rgba(99,102,241,0.08);
    box-shadow: 0 0 0 1px rgba(99,102,241,0.1);
}

.choice-btn.correct {
    border-color: var(--success);
    background: var(--success-bg);
    box-shadow: var(--shadow-glow-success);
}

.choice-btn.incorrect {
    border-color: var(--danger);
    background: var(--danger-bg);
    box-shadow: var(--shadow-glow-danger);
}

.choice-btn.correct-reveal {
    border-color: var(--success);
    background: var(--success-bg);
}

.choice-btn.disabled {
    cursor: default;
    pointer-events: none;
}

.choice-indicator {
    width: 28px;
    height: 28px;
    min-width: 28px;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-muted);
    transition: var(--transition-fast);
    margin-top: 2px;
    font-family: var(--font-mono);
}

.choice-btn.selected .choice-indicator {
    border-color: var(--accent-indigo);
    background: var(--accent-indigo);
    color: white;
}

.choice-btn.correct .choice-indicator {
    border-color: var(--success);
    background: var(--success);
    color: white;
}

.choice-btn.incorrect .choice-indicator {
    border-color: var(--danger);
    background: var(--danger);
    color: white;
}

.choice-btn.correct-reveal .choice-indicator {
    border-color: var(--success);
    background: var(--success);
    color: white;
}

.choice-text {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-primary);
    padding-top: 3px;
}

.choice-icon {
    margin-left: auto;
    display: none;
    min-width: 20px;
}

.choice-btn.correct .choice-icon,
.choice-btn.incorrect .choice-icon,
.choice-btn.correct-reveal .choice-icon {
    display: flex;
    align-items: center;
}

/* Explanation */
.explanation-card {
    background: rgba(99, 102, 241, 0.06);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    animation: fadeInUp 0.4s ease-out;
}

.explanation-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--accent-indigo);
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: var(--space-sm);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.explanation-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* Footer Navigation */
.quiz-footer {
    position: sticky;
    bottom: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    border-top: 1px solid var(--border-color);
}

.btn-nav {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    transition: var(--transition-base);
}

.btn-nav:hover:not(:disabled) {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    border-color: var(--border-active);
}

.btn-nav:disabled {
    opacity: 0.35;
    cursor: not-allowed;
}

.btn-submit {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 24px;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 0.9rem;
    color: white;
    background: var(--gradient-primary);
    box-shadow: 0 4px 16px rgba(99,102,241,0.25);
    transition: var(--transition-base);
}

.btn-submit:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 24px rgba(99,102,241,0.35);
}

/* ================================================================
   RESULTS SCREEN
   ================================================================ */
#results-screen {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
}

.results-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 600px;
    width: 100%;
    animation: fadeInUp 0.8s ease-out;
}

.results-header {
    margin-bottom: var(--space-2xl);
}

.results-icon {
    font-size: 3.5rem;
    margin-bottom: var(--space-md);
    animation: bounce 0.6s ease-out;
}

@keyframes bounce {
    0% { transform: scale(0); }
    60% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

.results-title {
    font-size: 2.2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-sm);
}

.results-subtitle {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Score Circle */
.score-circle-wrapper {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto var(--space-2xl);
}

.score-circle {
    width: 200px;
    height: 200px;
    transform: rotate(-90deg);
}

.score-circle-bg {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 8;
}

.score-circle-fill {
    fill: none;
    stroke: url(#scoreGrad);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 534;
    stroke-dashoffset: 534;
    transition: stroke-dashoffset 1.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.score-circle-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.score-percent {
    font-size: 2.8rem;
    font-weight: 900;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.score-fraction {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 600;
    font-family: var(--font-mono);
}

/* Result Stats */
.results-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-sm);
    margin-bottom: var(--space-2xl);
}

.result-stat {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    backdrop-filter: blur(8px);
}

.result-stat-icon {
    font-size: 1.3rem;
    font-weight: 800;
}

.result-stat.correct .result-stat-icon { color: var(--success); }
.result-stat.wrong .result-stat-icon { color: var(--danger); }
.result-stat.skipped .result-stat-icon { color: var(--text-muted); }
.result-stat.time .result-stat-icon { color: var(--accent-cyan); }

.result-stat-info {
    display: flex;
    flex-direction: column;
}

.result-stat-num {
    font-size: 1.4rem;
    font-weight: 800;
    font-family: var(--font-mono);
}

.result-stat-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
}

/* Results Actions */
.results-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
}

/* ================================================================
   IMAGE MODAL
   ================================================================ */
.image-modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.2s ease-out;
}

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

.image-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.85);
    backdrop-filter: blur(10px);
}

.image-modal-content {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
    animation: scaleIn 0.3s ease-out;
}

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

.image-modal-content img {
    max-width: 90vw;
    max-height: 85vh;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    background: white;
}

.image-modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.image-modal-close:hover {
    background: var(--danger);
    color: white;
    border-color: var(--danger);
}

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 768px) {
    .landing-stats {
        flex-wrap: wrap;
    }
    
    .stat-card {
        min-width: 90px;
        padding: var(--space-sm) var(--space-md);
    }

    .stat-number {
        font-size: 1.4rem;
    }

    .mode-cards {
        flex-direction: column;
        align-items: stretch;
    }

    .mode-card {
        min-width: unset;
    }

    .quiz-header {
        padding: var(--space-sm) var(--space-md);
    }

    .header-title {
        display: none;
    }

    .header-center {
        margin: 0 var(--space-sm);
    }

    .quiz-main {
        padding: var(--space-md);
    }

    .quiz-footer {
        padding: var(--space-sm) var(--space-md);
    }

    .btn-nav span {
        display: none;
    }

    .results-stats {
        grid-template-columns: repeat(2, 1fr);
    }

    .results-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .btn-start, .btn-secondary {
        justify-content: center;
    }

    .question-text {
        font-size: 1rem;
    }

    .score-circle-wrapper {
        width: 160px;
        height: 160px;
    }
    
    .score-circle {
        width: 160px;
        height: 160px;
    }

    .score-percent {
        font-size: 2.2rem;
    }
}

@media (max-width: 480px) {
    #landing-screen {
        padding: var(--space-md);
    }

    .title-line-2 {
        font-size: 2.4rem;
    }

    .custom-count-wrapper {
        flex-direction: column;
        gap: var(--space-sm);
    }
}

/* ================================================================
   SCROLLBAR
   ================================================================ */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(99,102,241,0.3);
}