/* ============================================
   KARIMEN QUIZ - Shared Styles & Theme System
   ============================================ */

/* CSS Variables for Theming */
:root {
    /* Light Mode (default) */
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-gradient: linear-gradient(135deg, #00cc44 0%, #009933 100%);
    --bg-gradient-hover: linear-gradient(135deg, #00b33d 0%, #00802b 100%);
    --text-primary: #1c1c1e;
    --text-secondary: #555;
    --text-muted: #888;
    --border-color: #e0e0e0;
    --border-light: #eee;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.3);
    --accent: #00cc44;
    --accent-hover: #00b33d;
    --success: #4CAF50;
    --success-bg: #e8f5e9;
    --success-text: #2e7d32;
    --danger: #f44336;
    --danger-bg: #ffebee;
    --danger-text: #c62828;
    --warning: #ff9800;
    --warning-bg: #fff3e0;
    --warning-text: #e65100;
    --info-bg: #e8f5e9;
    --card-bg-alt: #f1f8e9;
    --card-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --card-gradient-selected: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
    --option-bg: #ffffff;
    --option-border: #e0e0e0;
    --option-hover-bg: #e8f5e9;
    --option-hover-border: #00cc44;
    --nav-btn-bg: #f0f0f0;
    --nav-btn-color: #555;
    --timer-bg: #e8f5e9;
    --timer-border: #00cc44;
    --explanation-bg: #fff8e1;
    --question-bg: #f1f8e9;
    --question-border: #00cc44;
    --header-text: white;
    --lang-btn-border: #00cc44;
    --lang-btn-color: #00cc44;
    --lang-btn-active-bg: #00cc44;
    --lang-btn-active-color: white;
    --scrollbar-thumb: #c1c1c1;
    --scrollbar-track: #f1f1f1;
    --badge-bg: #e8f5e9;
    --badge-color: #00cc44;
    --input-bg: #ffffff;
    --input-border: #e0e0e0;
    --input-focus-border: #00cc44;
    --table-header-bg: #f1f8e9;
    --table-hover-bg: #f1f8e9;
    --table-border: #eee;
    --placas-card-bg: #f9f9fb;
    --placas-card-border: #e5e5ea;
    --flashcard-bg: #ffffff;
    --flashcard-border: #e0e0e0;
    --flashcard-shadow: 0 8px 30px rgba(0,0,0,0.12);
    --modal-overlay: rgba(0,0,0,0.5);
    --modal-bg: #ffffff;
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-primary: #1c1c1e;
    --bg-secondary: #2c2c2e;
    --bg-card: #2c2c2e;
    --bg-gradient: linear-gradient(135deg, #009933 0%, #006622 100%);
    --bg-gradient-hover: linear-gradient(135deg, #00802b 0%, #00551a 100%);
    --text-primary: #f5f5f7;
    --text-secondary: #a1a1a6;
    --text-muted: #8e8e93;
    --border-color: #3a3a3c;
    --border-light: #3a3a3c;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
    --accent: #00cc44;
    --accent-hover: #00b33d;
    --success: #66bb6a;
    --success-bg: #1b3a1d;
    --success-text: #81c784;
    --danger: #ef5350;
    --danger-bg: #3a1b1b;
    --danger-text: #ef9a9a;
    --warning: #ffa726;
    --warning-bg: #3a2e1b;
    --warning-text: #ffcc80;
    --info-bg: #1a3a1a;
    --card-bg-alt: #1a3a1a;
    --card-gradient: linear-gradient(135deg, #2c2c2e 0%, #3a3a3c 100%);
    --card-gradient-selected: linear-gradient(135deg, #1a3a1a 0%, #2a5a2a 100%);
    --option-bg: #2c2c2e;
    --option-border: #3a3a3c;
    --option-hover-bg: #1a3a1a;
    --option-hover-border: #00cc44;
    --nav-btn-bg: #3a3a3c;
    --nav-btn-color: #a1a1a6;
    --timer-bg: #1a3a1a;
    --timer-border: #00cc44;
    --explanation-bg: #2a2e1b;
    --question-bg: #1a3a1a;
    --question-border: #00cc44;
    --header-text: #f5f5f7;
    --lang-btn-border: #00cc44;
    --lang-btn-color: #00cc44;
    --lang-btn-active-bg: #00cc44;
    --lang-btn-active-color: #1c1c1e;
    --scrollbar-thumb: #555;
    --scrollbar-track: #2c2c2e;
    --badge-bg: #1a3a1a;
    --badge-color: #00cc44;
    --input-bg: #2c2c2e;
    --input-border: #3a3a3c;
    --input-focus-border: #00cc44;
    --table-header-bg: #3a3a3c;
    --table-hover-bg: #1a3a1a;
    --table-border: #3a3a3c;
    --placas-card-bg: #2c2c2e;
    --placas-card-border: #3a3a3c;
    --flashcard-bg: #2c2c2e;
    --flashcard-border: #3a3a3c;
    --flashcard-shadow: 0 8px 30px rgba(0,0,0,0.4);
    --modal-overlay: rgba(0,0,0,0.7);
    --modal-bg: #2c2c2e;
}

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

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background 0.3s, color 0.3s;
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--scrollbar-track); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #999; }

/* Container */
.container {
    max-width: 960px;
    margin: 0 auto;
    background: var(--bg-secondary);
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transition: background 0.3s, box-shadow 0.3s;
}

/* Header */
.header {
    background: var(--bg-gradient);
    color: var(--header-text);
    padding: 20px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}
.header h1 { font-size: 22px; }
.header .user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    flex-wrap: wrap;
}
.header .user-info a, .header .user-info button {
    color: var(--header-text);
    text-decoration: none;
    padding: 6px 15px;
    border: 2px solid rgba(255,255,255,0.5);
    border-radius: 20px;
    font-size: 13px;
    transition: all 0.3s;
    background: transparent;
    cursor: pointer;
    font-family: inherit;
}
.header .user-info a:hover, .header .user-info button:hover {
    background: rgba(255,255,255,0.2);
}

.content { padding: 30px; }

/* Language Selector */
.lang-selector {
    display: flex;
    gap: 8px;
    justify-content: center;
    margin-bottom: 25px;
    flex-wrap: wrap;
}
.lang-btn {
    padding: 8px 16px;
    border: 2px solid var(--lang-btn-border);
    background: transparent;
    color: var(--lang-btn-color);
    border-radius: 25px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
    transition: all 0.3s;
    font-family: inherit;
}
.lang-btn:hover, .lang-btn.active {
    background: var(--lang-btn-active-bg);
    color: var(--lang-btn-active-color);
}

/* Category Grid */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}
.category-card, .random-card {
    background: var(--card-gradient);
    border-radius: 15px;
    padding: 25px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    border: 3px solid transparent;
}
.category-card:hover, .random-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}
.category-card.selected {
    border-color: var(--accent);
    background: var(--card-gradient-selected);
}
.category-card .icon, .random-card .icon { font-size: 48px; margin-bottom: 10px; }
.category-card h3, .random-card h3 { color: var(--text-primary); margin-bottom: 5px; }
.category-card p, .random-card p { color: var(--text-muted); font-size: 13px; }

/* Placas Card */
.placas-card {
    background: var(--card-gradient);
    border-radius: 15px;
    padding: 25px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    border: 3px solid transparent;
    text-decoration: none;
    display: block;
    color: inherit;
}
.placas-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}
.placas-card .icon { font-size: 48px; margin-bottom: 10px; }
.placas-card h3 { color: var(--text-primary); margin-bottom: 5px; font-size: 18px; }
.placas-card p { color: var(--text-muted); font-size: 13px; }
.placas-card .badge {
    display: inline-block;
    background: var(--accent);
    color: white;
    padding: 3px 12px;
    border-radius: 12px;
    font-size: 11px;
    margin-top: 8px;
    font-weight: 600;
}

/* Exam Grid */
.exam-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 10px;
    margin-bottom: 25px;
}
.exam-btn {
    padding: 12px;
    border: 2px solid var(--border-color);
    background: var(--option-bg);
    border-radius: 10px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    color: var(--text-secondary);
    font-family: inherit;
}
.exam-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}
.exam-btn.selected {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

/* Quiz Area */
.quiz-area { display: none; }
.quiz-area.active { display: block; }

.back-btn {
    padding: 10px 20px;
    border: 2px solid var(--accent);
    background: transparent;
    color: var(--accent);
    border-radius: 10px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    margin-bottom: 20px;
    font-family: inherit;
}
.back-btn:hover { background: var(--accent); color: white; }

/* Timer */
.timer-container {
    display: none;
    text-align: center;
    margin-bottom: 15px;
    padding: 10px;
    background: var(--timer-bg);
    border-radius: 10px;
    border: 2px solid var(--timer-border);
}
.timer-container.show { display: block; }
.timer-container .timer-label { font-size: 12px; color: var(--text-muted); margin-bottom: 3px; }
.timer-container .timer-display {
    font-size: 28px;
    font-weight: 800;
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
}
.timer-container .timer-display.warning {
    color: var(--danger);
    animation: blink 1s infinite;
}
@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

/* Progress Bar */
.progress-bar-container {
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    margin-bottom: 20px;
    overflow: hidden;
}
.progress-bar {
    height: 100%;
    background: var(--bg-gradient);
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 0%;
}

/* Question Header */
.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--border-light);
}
.question-number { font-size: 18px; font-weight: 700; color: var(--accent); }
.progress-text { color: var(--text-muted); font-size: 14px; }

/* Question Text */
.question-text {
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding: 20px;
    background: var(--question-bg);
    border-radius: 10px;
    border-left: 4px solid var(--question-border);
}

/* Question Image */
.question-image {
    text-align: center;
    margin-bottom: 20px;
}
.question-image img {
    max-width: 100%;
    max-height: 300px;
    border-radius: 10px;
    border: 2px solid var(--border-color);
}

/* Options */
.options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 25px;
}
.options:has(.choice-btn) {
    grid-template-columns: 1fr;
}
.option-btn {
    padding: 20px;
    border: 3px solid var(--option-border);
    background: var(--option-bg);
    border-radius: 15px;
    cursor: pointer;
    font-size: 18px;
    font-weight: 700;
    transition: all 0.3s;
    color: var(--text-secondary);
    font-family: inherit;
}
.option-btn:hover:not(.disabled) {
    border-color: var(--option-hover-border);
    background: var(--option-hover-bg);
    transform: scale(1.02);
}
.option-btn.correct {
    border-color: var(--success);
    background: var(--success-bg);
    color: var(--success-text);
}
.option-btn.wrong {
    border-color: var(--danger);
    background: var(--danger-bg);
    color: var(--danger-text);
}
.option-btn.disabled { cursor: default; opacity: 0.7; }
.option-btn.selected-answer {
    border-color: var(--warning);
    background: var(--warning-bg);
}

/* Choice Buttons (Multiple Choice) */
.choice-btn {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 15px 20px;
    text-align: left;
    font-weight: 600;
    font-size: 15px;
    line-height: 1.4;
}
.choice-btn .choice-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent);
    color: white;
    font-size: 14px;
    font-weight: 800;
    flex-shrink: 0;
}
.choice-btn .choice-text {
    flex: 1;
    padding-top: 3px;
}
.choice-btn.correct .choice-number {
    background: var(--success);
}
.choice-btn.wrong .choice-number {
    background: var(--danger);
}

/* Wrong Warning */
.wrong-warning {
    display: none;
    padding: 15px 20px;
    background: var(--danger-bg);
    border-radius: 10px;
    border: 3px solid var(--danger);
    margin-bottom: 15px;
    text-align: center;
    font-size: 20px;
    font-weight: 800;
    color: var(--danger-text);
    animation: pulse 0.5s ease-in-out;
}
.wrong-warning.show { display: block; }
@keyframes pulse {
    0% { transform: scale(0.8); opacity: 0; }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); opacity: 1; }
}

/* Explanation */
.explanation {
    display: none;
    padding: 20px;
    background: var(--explanation-bg);
    border-radius: 10px;
    border-left: 4px solid var(--warning);
    margin-bottom: 25px;
}
.explanation.show { display: block; }
.explanation h4 { color: var(--warning-text); margin-bottom: 8px; }
.explanation p { color: var(--text-secondary); line-height: 1.5; }

/* Navigation Buttons */
.nav-buttons {
    display: flex;
    justify-content: space-between;
    gap: 15px;
    flex-wrap: wrap;
}
.nav-btn {
    padding: 12px 30px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    font-family: inherit;
}
.nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.nav-btn.prev { background: var(--nav-btn-bg); color: var(--nav-btn-color); }
.nav-btn.prev:hover:not(:disabled) { background: var(--border-color); }
.nav-btn.next { background: var(--accent); color: white; }
.nav-btn.next:hover:not(:disabled) { background: var(--accent-hover); }
.nav-btn.finish { background: var(--success); color: white; }
.nav-btn.finish:hover { background: #43a047; }
.nav-btn.review { background: var(--warning); color: white; }
.nav-btn.review:hover { background: #f57c00; }

/* Results */
.results {
    display: none;
    text-align: center;
    padding: 30px;
}
.results.show { display: block; }
.results .score { font-size: 72px; font-weight: 800; color: var(--accent); margin: 20px 0; }
.results .score-label { font-size: 18px; color: var(--text-muted); }
.results .result-message {
    font-size: 20px;
    margin: 20px 0;
    padding: 15px;
    border-radius: 10px;
}
.results .result-message.pass { background: var(--success-bg); color: var(--success-text); }
.results .result-message.fail { background: var(--danger-bg); color: var(--danger-text); }
.results .stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin: 25px 0;
}
.results .stat-item {
    padding: 15px;
    background: var(--card-bg-alt);
    border-radius: 10px;
}
.results .stat-item .number { font-size: 28px; font-weight: 700; color: var(--text-primary); }
.results .stat-item .label { font-size: 13px; color: var(--text-muted); margin-top: 5px; }

/* Result Buttons */
.result-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 20px;
}
.restart-btn, .history-btn {
    padding: 15px 40px;
    border: none;
    background: var(--bg-gradient);
    color: white;
    border-radius: 10px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s;
    font-family: inherit;
    text-decoration: none;
    display: inline-block;
}
.restart-btn:hover, .history-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0, 204, 68, 0.4);
}
.history-btn {
    background: var(--success);
}
.history-btn:hover {
    box-shadow: 0 5px 20px rgba(76, 175, 80, 0.4);
}

/* Review Section */
.review-section {
    display: none;
    text-align: left;
    padding: 20px;
}
.review-section.show { display: block; }
.review-section h2 {
    text-align: center;
    color: var(--danger-text);
    margin-bottom: 20px;
    font-size: 22px;
}
.review-item {
    background: var(--card-bg-alt);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 15px;
    border-left: 4px solid var(--danger);
}
.review-item .review-question {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}
.review-item .review-answers {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}
.review-item .review-answers .user-answer {
    color: var(--danger-text);
    font-weight: 600;
}
.review-item .review-answers .correct-answer {
    color: var(--success-text);
    font-weight: 600;
}
.review-item .review-explanation {
    padding: 12px;
    background: var(--explanation-bg);
    border-radius: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    border-left: 3px solid var(--warning);
}

/* Random Mode Button */
.random-btn {
    padding: 15px 30px;
    border: 3px solid var(--warning);
    background: var(--warning-bg);
    color: var(--warning-text);
    border-radius: 15px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 700;
    transition: all 0.3s;
    font-family: inherit;
    width: 100%;
    margin-bottom: 20px;
}
.random-btn:hover {
    background: var(--warning);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(255, 152, 0, 0.3);
}

/* Dark Mode Toggle */
.dark-mode-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background: var(--bg-gradient);
    color: white;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.dark-mode-toggle:hover {
    transform: scale(1.1);
}

/* Flashcard Styles */
.flashcard-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}
.flashcard-controls {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.flashcard-btn {
    padding: 10px 20px;
    border: 2px solid var(--accent);
    background: transparent;
    color: var(--accent);
    border-radius: 10px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    font-family: inherit;
}
.flashcard-btn:hover, .flashcard-btn.active {
    background: var(--accent);
    color: white;
}
.flashcard {
    width: 100%;
    height: 350px;
    perspective: 1000px;
    cursor: pointer;
    margin-bottom: 20px;
}
.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}
.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}
.flashcard-front, .flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 15px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 30px;
    background: var(--flashcard-bg);
    border: 2px solid var(--flashcard-border);
    box-shadow: var(--flashcard-shadow);
}
.flashcard-front {
    background: var(--bg-gradient);
    color: white;
}
.flashcard-front .card-icon { font-size: 64px; margin-bottom: 15px; }
.flashcard-front .card-hint { font-size: 14px; opacity: 0.8; }
.flashcard-back {
    transform: rotateY(180deg);
    text-align: center;
}
.flashcard-back .card-image {
    max-width: 150px;
    max-height: 150px;
    margin-bottom: 15px;
    border-radius: 8px;
}
.flashcard-back .card-meaning {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}
.flashcard-back .card-category {
    font-size: 13px;
    color: var(--text-muted);
    padding: 4px 12px;
    background: var(--badge-bg);
    color: var(--badge-color);
    border-radius: 20px;
    display: inline-block;
}
.flashcard-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 15px;
}
.flashcard-nav-btn {
    padding: 12px 25px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    font-family: inherit;
}
.flashcard-nav-btn.prev { background: var(--nav-btn-bg); color: var(--nav-btn-color); }
.flashcard-nav-btn.prev:hover { background: var(--border-color); }
.flashcard-nav-btn.next { background: var(--accent); color: white; }
.flashcard-nav-btn.next:hover { background: var(--accent-hover); }
.flashcard-nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.flashcard-counter {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 600;
}

/* History Page */
.history-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}
.history-card {
    background: var(--bg-card);
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
    cursor: pointer;
}
.history-card:hover {
    box-shadow: var(--shadow);
    transform: translateY(-2px);
}
.history-card .history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    flex-wrap: wrap;
    gap: 10px;
}
.history-card .history-exam {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
}
.history-card .history-date {
    font-size: 13px;
    color: var(--text-muted);
}
.history-card .history-stats {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}
.history-card .history-stat {
    font-size: 14px;
    color: var(--text-secondary);
}
.history-card .history-stat strong {
    color: var(--text-primary);
}
.history-card .history-errors {
    margin-top: 10px;
    padding: 10px;
    background: var(--danger-bg);
    border-radius: 8px;
    display: none;
}
.history-card .history-errors.show { display: block; }
.history-card .history-errors .error-item {
    font-size: 13px;
    color: var(--danger-text);
    padding: 3px 0;
}
.history-empty {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}
.history-empty .icon { font-size: 64px; margin-bottom: 15px; }
.history-empty h3 { color: var(--text-primary); margin-bottom: 10px; }

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--modal-overlay);
    z-index: 999;
    justify-content: center;
    align-items: center;
    padding: 20px;
}
.modal-overlay.show { display: flex; }
.modal-content {
    background: var(--modal-bg);
    border-radius: 20px;
    padding: 30px;
    max-width: 600px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}
.modal-content h2 {
    color: var(--text-primary);
    margin-bottom: 20px;
    text-align: center;
}
.modal-close {
    float: right;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-muted);
    padding: 5px;
}
.modal-close:hover { color: var(--text-primary); }

/* Responsive */
@media (max-width: 768px) {
    .container { border-radius: 0; }
    .content { padding: 20px 15px; }
    .header { padding: 15px 20px; }
    .header h1 { font-size: 18px; }
    .header .user-info { font-size: 13px; }
    .category-grid { grid-template-columns: 1fr; }
    .exam-grid { grid-template-columns: repeat(auto-fill, minmax(65px, 1fr)); }
    .options { grid-template-columns: 1fr; }
    .option-btn { padding: 18px; font-size: 16px; }
    .results .stats { grid-template-columns: 1fr; }
    .results .score { font-size: 56px; }
    .nav-buttons { flex-direction: column; }
    .nav-btn { width: 100%; text-align: center; }
    .flashcard { height: 300px; }
    .flashcard-front .card-icon { font-size: 48px; }
    .dark-mode-toggle { width: 44px; height: 44px; font-size: 20px; bottom: 15px; right: 15px; }
    .result-buttons { flex-direction: column; }
    .result-buttons .restart-btn, .result-buttons .history-btn { width: 100%; text-align: center; }
}

@media (max-width: 480px) {
    .header { flex-direction: column; text-align: center; }
    .header .user-info { justify-content: center; }
    .lang-selector { gap: 5px; }
    .lang-btn { padding: 6px 12px; font-size: 12px; }
    .question-text { font-size: 16px; padding: 15px; }
    .option-btn { padding: 15px; font-size: 15px; }
    .exam-grid { grid-template-columns: repeat(auto-fill, minmax(55px, 1fr)); }
    .exam-btn { padding: 10px; font-size: 12px; }
    .flashcard { height: 280px; }
    .flashcard-back .card-meaning { font-size: 16px; }
}