@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=Syne:wght@500;600;700;800&display=swap');

:root {
    /* Accent Colors — tidak berubah antar tema */
    --primary-green: #10b981;
    --primary-gold: #fbbf24;
    --primary-gradient: linear-gradient(135deg, #10b981 0%, #fbbf24 100%);
    --primary-gradient-hover: linear-gradient(135deg, #059669 0%, #f59e0b 100%);

    --correct-main: #10b981;
    --incorrect-main: #ef4444;
    --persimmon: #cc5038;
    --persimmon-hover: #b8432d;

    /* Box Shadows */
    --shadow-elegant: 0 10px 40px rgba(0, 0, 0, 0.5);
    --glow-gold: 0 0 20px rgba(251, 191, 36, 0.15);

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);

    /* Typography */
    --font-heading: 'Syne', sans-serif;
    --font-body: 'Outfit', sans-serif;

    /* Dynamic variables */
    --score-percent: 0;
}

/* ================== THEMES ================== */

/* ORIGINAL — deep forest green / dark emerald */
.theme-original {
    --bg-main:       #020f0a;
    --bg-card:       rgba(255, 255, 255, 0.03);
    --bg-glass:      rgba(16, 185, 129, 0.05);
    --text-main:     #f8fafc;
    --text-muted:    #94a3b8;
    --border-color:  rgba(251, 191, 36, 0.2);
    --glass-border:  1px solid rgba(255, 255, 255, 0.08);
    --input-bg:      rgba(0, 0, 0, 0.3);
    --input-border:  rgba(255, 255, 255, 0.1);
    --option-bg:     rgba(255, 255, 255, 0.03);
    --option-border: rgba(255, 255, 255, 0.08);
    --option-hover:  rgba(255, 255, 255, 0.06);
    --saved-bg:      rgba(255, 255, 255, 0.03);
    --saved-border:  rgba(255, 255, 255, 0.05);
    --orb-opacity:   0.25;
    --ambient-grad:  radial-gradient(circle at 50% 0%, #06241a 0%, #020f0a 60%);
    --start-btn-color: #020f0a;
}

/* DARK — hitam dominan */
.theme-dark {
    --bg-main:       #0a0a0a;
    --bg-card:       rgba(255, 255, 255, 0.04);
    --bg-glass:      rgba(255, 255, 255, 0.02);
    --text-main:     #ffffff;
    --text-muted:    #8899aa;
    --border-color:  rgba(255, 255, 255, 0.12);
    --glass-border:  1px solid rgba(255, 255, 255, 0.06);
    --input-bg:      rgba(255, 255, 255, 0.05);
    --input-border:  rgba(255, 255, 255, 0.08);
    --option-bg:     rgba(255, 255, 255, 0.04);
    --option-border: rgba(255, 255, 255, 0.07);
    --option-hover:  rgba(255, 255, 255, 0.08);
    --saved-bg:      rgba(255, 255, 255, 0.04);
    --saved-border:  rgba(255, 255, 255, 0.06);
    --orb-opacity:   0.08;
    --ambient-grad:  radial-gradient(circle at 50% 0%, #111111 0%, #0a0a0a 60%);
    --start-btn-color: #0a0a0a;
}

/* LIGHT — putih dominan */
.theme-light {
    --bg-main:       #f0f4f8;
    --bg-card:       rgba(255, 255, 255, 0.75);
    --bg-glass:      rgba(16, 185, 129, 0.04);
    --text-main:     #1a202c;
    --text-muted:    #4a5568;
    --border-color:  rgba(16, 185, 129, 0.2);
    --glass-border:  1px solid rgba(0, 0, 0, 0.08);
    --input-bg:      rgba(255, 255, 255, 0.9);
    --input-border:  rgba(0, 0, 0, 0.12);
    --option-bg:     rgba(255, 255, 255, 0.8);
    --option-border: rgba(0, 0, 0, 0.08);
    --option-hover:  rgba(255, 255, 255, 0.95);
    --saved-bg:      rgba(255, 255, 255, 0.7);
    --saved-border:  rgba(0, 0, 0, 0.06);
    --orb-opacity:   0.12;
    --ambient-grad:  radial-gradient(circle at 50% 0%, #d1fae5 0%, #f0f4f8 60%);
    --start-btn-color: #020f0a;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    position: relative;
    overflow-x: hidden;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* Background Effects */
.ambient-background {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    z-index: -1;
    overflow: hidden;
    background: var(--ambient-grad, radial-gradient(circle at 50% 0%, #06241a 0%, #020f0a 60%));
    transition: background 0.5s ease;
}

.ambient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: var(--orb-opacity, 0.25);
    animation: floatOrb 15s ease-in-out infinite alternate;
    transition: opacity 0.5s ease;
}

.orb-green {
    width: 60vw;
    height: 60vw;
    max-width: 600px; max-height: 600px;
    background: var(--primary-green);
    top: -20%; left: -10%;
}

.orb-gold {
    width: 50vw;
    height: 50vw;
    max-width: 500px; max-height: 500px;
    background: var(--primary-gold);
    bottom: -10%; right: -10%;
    animation-delay: -5s;
}

.glass-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: url('data:image/svg+xml;utf8,<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><filter id="noiseFilter"><feTurbulence type="fractalNoise" baseFrequency="0.65" numOctaves="3" stitchTiles="stitch"/></filter><rect width="100%" height="100%" filter="url(%23noiseFilter)" opacity="0.03"/></svg>');
    opacity: 0.5;
    mix-blend-mode: overlay;
}

@keyframes floatOrb {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(5%, 10%) scale(1.1); }
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.5px;
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.app-container {
    width: 100%;
    max-width: 600px;
    margin: 2rem auto;
    padding: 0 1rem;
    position: relative;
    z-index: 1;
}

/* ================== SCREENS & ANIMATIONS ================== */
.screen {
    display: none;
    width: 100%;
    opacity: 0;
    transform: translateY(15px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.screen.active {
    display: block;
    animation: fadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes fadeIn {
    0% { opacity: 0; transform: translateY(15px); }
    100% { opacity: 1; transform: translateY(0); }
}

/* ================== REUSABLE COMPONENTS ================== */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 20px;
    padding: 2.5rem;
    border: var(--glass-border);
    box-shadow: var(--shadow-elegant);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
}

.glass-card {
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-card:hover {
    box-shadow: 0 20px 40px rgba(0,0,0,0.6), var(--glow-gold);
}

/* Base button sizing */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    font-family: var(--font-body);
    font-weight: 600;
    padding: 1.1rem 2rem;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    transition: all var(--transition-normal);
    font-size: 1.05rem;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.gradient-btn {
    background: var(--primary-gradient);
    color: #020f0a; /* Dark text for contrast */
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.2);
}

.gradient-btn:hover:not(:disabled) {
    background: var(--primary-gradient-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(251, 191, 36, 0.3);
}

.gradient-btn:disabled {
    background: #1e293b;
    color: var(--text-muted);
    cursor: not-allowed;
    box-shadow: none;
}

.btn-large {
    width: 100%;
    padding: 1.25rem;
    font-size: 1.15rem;
}

.glass-btn {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
    border: 1px solid rgba(255,255,255,0.1);
    backdrop-filter: blur(5px);
}

.glass-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.btn-text {
    background: none;
    border: none;
    color: var(--primary-gold);
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.btn-text:hover {
    color: var(--primary-green);
}

/* ================== HOME SCREEN ================== */
.hero-section {
    text-align: center;
    margin-bottom: 3rem;
}

.hero-section h1 {
    font-size: 3.5rem;
    color: #fff;
    margin-bottom: 0.5rem;
}

.ai-badge {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: var(--font-heading);
    font-size: 3.5rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.15rem;
    font-weight: 300;
    max-width: 90%;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
}

.form-group label {
    display: block;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    color: var(--primary-gold);
    letter-spacing: 1px;
}

.form-group input {
    width: 100%;
    padding: 1.25rem;
    background: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: 12px;
    font-family: var(--font-body);
    font-size: 1.1rem;
    color: var(--text-main);
    transition: all var(--transition-normal);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-green);
    background: rgba(16, 185, 129, 0.05);
    box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.1);
}

.error-text {
    display: none;
    color: var(--incorrect-main);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* ================== DIFFICULTY SELECTOR ================== */
.difficulty-selector {
    display: flex;
    gap: 0.5rem;
}

.diff-btn {
    flex: 1;
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 600;
    padding: 0.7rem 0.5rem;
    border-radius: 10px;
    border: 1px solid var(--input-border);
    background: var(--input-bg);
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-align: center;
}

.diff-btn:hover {
    border-color: var(--primary-green);
    color: var(--text-main);
    transform: translateY(-1px);
}

.diff-btn.active {
    background: var(--primary-gradient);
    color: #020f0a;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
}

/* Saved Quizzes */
.saved-quizzes {
    margin-top: 3.5rem;
}

.saved-quizzes.hidden {
    display: none;
}

.saved-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.saved-header h3 {
    font-size: 1.2rem;
    color: var(--text-main);
}

.saved-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.saved-item {
    background: var(--saved-bg);
    border: 1px solid var(--saved-border);
    padding: 1.25rem 1.5rem;
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: var(--transition-normal);
}

.saved-item:hover {
    border-color: rgba(251, 191, 36, 0.3);
    background: rgba(255, 255, 255, 0.06);
    transform: translateY(-2px);
}

.saved-item-info strong {
    display: block;
    color: var(--text-main);
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
    font-family: var(--font-heading);
}

.saved-item-info small {
    color: var(--text-muted);
}

.saved-item-score {
    background: var(--primary-gradient);
    color: #020f0a;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-weight: 700;
    box-shadow: 0 4px 10px rgba(16,185,129,0.2);
}

/* ================== LOADING SCREEN ================== */
#loading-screen .loader-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 50vh;
    text-align: center;
}

.elegant-loader {
    position: relative;
    width: 80px;
    height: 80px;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.gradient-ring {
    position: absolute;
    width: 100%; height: 100%;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: var(--primary-green);
    border-right-color: var(--primary-gold);
    animation: spinSmooth 1.5s cubic-bezier(0.68, -0.55, 0.265, 1.55) infinite;
}

.core-icon {
    font-size: 1.5rem;
    animation: pulseIcon 2s infinite alternate;
}

@keyframes spinSmooth {
    to { transform: rotate(360deg); }
}
@keyframes pulseIcon {
    0% { transform: scale(0.9); opacity: 0.7; }
    100% { transform: scale(1.1); opacity: 1; }
}

#loading-title {
    margin-bottom: 0.5rem;
}

#loading-desc {
    color: var(--text-muted);
}

/* ================== QUIZ SCREEN ================== */
.quiz-header {
    margin-bottom: 2.5rem;
}

.progress-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 10px;
}

/* === BACK BUTTON RED === */
.btn-cancel {
    background: transparent;
    color: var(--text-muted);
    border: 1px solid rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-cancel:hover {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--incorrect-main);
    border-color: rgba(239, 68, 68, 0.3);
}

.btn-cancel:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    pointer-events: none;
}

/* Tombol Batal di footer */
.btn-cancel-footer {
    color: var(--text-muted);
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    font-size: 0.95rem;
}

.btn-cancel-footer:hover {
    color: var(--incorrect-main);
    border-color: rgba(239, 68, 68, 0.3);
    background: rgba(239, 68, 68, 0.07);
}

.topic-badge {
    background: rgba(251, 191, 36, 0.1);
    color: var(--primary-gold);
    border: 1px solid rgba(251, 191, 36, 0.2);
    padding: 0.35rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.progress-text {
    color: var(--text-muted);
    font-weight: 500;
}

.progress-track {
    height: 8px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    width: 0%;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.question-card {
    margin-bottom: 2rem;
}

/* ================== QUESTION IMAGE ================== */
.question-image-container {
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 1.25rem;
    background: var(--bg-card);
    border: var(--glass-border);
    position: relative;
    min-height: 180px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
}

.image-type-badge {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-gold);
    background: rgba(251, 191, 36, 0.08);
    border-bottom: 1px solid rgba(251, 191, 36, 0.12);
    padding: 0.5rem 1rem;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.image-shimmer {
    width: 100%;
    height: 260px;
    background: var(--bg-card);
    position: relative;
    overflow: hidden;
}

.image-shimmer::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(90deg,
        transparent,
        rgba(255, 255, 255, 0.06),
        transparent);
    animation: shimmer 1.8s infinite;
}

.question-image {
    width: 100%;
    max-height: 340px;
    object-fit: contain;
    background: rgba(0, 0, 0, 0.2);
    display: block;
    animation: fadeIn 0.4s ease;
}

.theme-light .question-image {
    background: rgba(0, 0, 0, 0.05);
}

.image-error {
    min-height: 140px;
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    padding: 2rem;
}

#question-text {
    font-size: 1.4rem;
    margin-bottom: 2.5rem;
    color: var(--text-main);
    line-height: 1.5;
    font-weight: 600;
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.option-btn {
    width: 100%;
    text-align: left;
    padding: 1.25rem 1.5rem;
    background: var(--option-bg);
    border: 1px solid var(--option-border);
    border-radius: 12px;
    font-family: var(--font-body);
    font-size: 1.05rem;
    color: var(--text-main);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
}

.option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: rgba(255,255,255,0.05);
    color: var(--text-muted);
    border-radius: 8px;
    margin-right: 1.25rem;
    font-weight: 600;
    font-size: 0.9rem;
    flex-shrink: 0;
    transition: all 0.3s ease;
}

.option-btn:hover:not(:disabled) {
    background: var(--option-hover);
    border-color: var(--option-border);
    transform: translateY(-2px);
}

.option-btn:hover:not(:disabled) .option-letter {
    background: rgba(255,255,255,0.1);
    color: #fff;
}

.option-btn.selected {
    border-color: var(--primary-green);
    background: rgba(16, 185, 129, 0.05);
}

.option-btn.selected .option-letter {
    background: var(--primary-green);
    color: #020f0a;
}

.quiz-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

/* ================== THEME SWITCHER ================== */
.theme-switcher {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    background: var(--bg-card);
    border: var(--glass-border);
    border-radius: 12px;
    padding: 0.35rem;
    width: fit-content;
}

.theme-btn {
    font-family: var(--font-body);
    font-size: 0.82rem;
    font-weight: 600;
    padding: 0.45rem 0.9rem;
    border-radius: 8px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition-normal);
    letter-spacing: 0.3px;
}

.theme-btn:hover {
    color: var(--text-main);
    background: var(--option-bg);
}

.theme-btn.active {
    background: var(--primary-gradient);
    color: #020f0a;
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.25);
}

/* ================== TOMBOL BATAL MERAH ================== */
.btn-batal-red {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.9rem 1.5rem;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    background: var(--persimmon);
    color: #ffffff;
    transition: all var(--transition-normal);
    letter-spacing: 0.3px;
}

.btn-batal-red:hover {
    background: var(--persimmon-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(204, 80, 56, 0.3);
}

/* ================== RESULT SCREEN ================== */
.result-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.score-container {
    display: flex;
    justify-content: center;
    margin: 2.5rem 0;
}

.score-circle {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    background: conic-gradient(var(--primary-green) calc(var(--score-percent) * 1%), rgba(255,255,255,0.05) 0);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: 0 0 30px rgba(16,185,129,0.1);
}

.score-circle::before {
    content: '';
    position: absolute;
    width: 140px;
    height: 140px;
    background: var(--bg-main);
    border-radius: 50%;
}

.score-number {
    position: relative;
    font-family: var(--font-heading);
    font-size: 3.5rem;
    color: #fff;
}

.score-message {
    font-size: 1.1rem;
    color: var(--text-muted);
}

.stats-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: rgba(255,255,255,0.02);
    border-radius: 16px;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.stat-icon-wrapper {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.stat-card.correct .stat-icon-wrapper {
    background: rgba(16, 185, 129, 0.1);
    color: var(--primary-green);
}

.stat-card.incorrect .stat-icon-wrapper {
    background: rgba(239, 68, 68, 0.1);
    color: var(--incorrect-main);
}

.stat-value {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    color: #fff;
    line-height: 1;
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.study-tips-card {
    background: linear-gradient(145deg, rgba(255,255,255,0.03), rgba(251,191,36,0.03));
    border-color: rgba(251,191,36,0.15);
    margin-bottom: 3rem;
}

.study-tips-card .card-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.study-tips-card .card-header h3 {
    color: var(--primary-gold);
    font-size: 1.25rem;
}

#study-tips-content {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--text-main);
}

.elegant-shimmer {
    height: 12px;
    background: rgba(255,255,255,0.05);
    margin-bottom: 12px;
    border-radius: 6px;
    position: relative;
    overflow: hidden;
}
.elegant-shimmer.w-75 { width: 75%; }
.elegant-shimmer.w-50 { width: 50%; }

.elegant-shimmer::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.08), transparent);
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.review-section {
    margin-bottom: 3rem;
}

.review-section h3 {
    margin-bottom: 1.5rem;
    color: #fff;
    font-size: 1.3rem;
}

.review-item {
    background: rgba(255,255,255,0.02);
    border: 1px solid rgba(255,255,255,0.05);
    border-left: 3px solid transparent;
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    transition: var(--transition-fast);
}

.review-item:hover {
    background: rgba(255,255,255,0.04);
}

.review-item.correct {
    border-left-color: var(--primary-green);
}

.review-item.incorrect {
    border-left-color: var(--incorrect-main);
}

.review-question {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    color: #fff;
    margin-bottom: 1rem;
}

.review-answers {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.25rem;
    font-size: 0.95rem;
}

.user-answer { color: var(--text-muted); }
.correct-answer { color: var(--primary-green); font-weight: 500; }
.review-item.incorrect .user-answer { color: var(--incorrect-main); text-decoration: line-through; }

.review-explanation {
    background: rgba(0,0,0,0.2);
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.95rem;
    color: var(--text-muted);
}

.result-footer {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.result-footer .btn {
    flex: 1;
}

/* ================== TOAST NOTIFICATION ================== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(2, 15, 10, 0.9);
    backdrop-filter: blur(10px);
    color: #fff;
    padding: 1rem 2rem;
    border-radius: 30px;
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 10px 25px rgba(0,0,0,0.5);
    font-weight: 500;
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* ================== MEDIA QUERIES ================== */
@media (max-width: 600px) {
    .app-container {
        margin: 0;
        padding: 1rem;
    }
    
    .hero-section h1 { font-size: 2.5rem; }
    
    .card {
        padding: 1.5rem;
        border-radius: 16px;
    }
    
    .btn { padding: 1rem; font-size: 1rem; }
    
    .result-footer {
        flex-direction: column-reverse;
    }
}