@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;600;700&display=swap');

/* 모바일 터치 최적화 */
* {
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* 텍스트는 선택 가능하게 */
p, span, h1, h2, h3, h4, h5, h6, .question-text, .option-text, #explanation-container {
    -webkit-user-select: text;
    -moz-user-select: text;
    -ms-user-select: text;
    user-select: text;
}

/* 강력한 볼드체 스타일 적용 */
#explanation-container strong,
#explanation-container b {
    font-weight: bold !important;
    font-family: inherit !important;
}

#explanation-container em,
#explanation-container i {
    font-style: italic !important;
}

/* 모바일 스크롤 개선 */
body {
    -webkit-overflow-scrolling: touch;
}

:root {
    /* Light mode colors */
    --primary-color: #16a085;
    --primary-dark: #138d75;
    --primary-light: #48c9b0;
    --secondary-color: #ecf0f1;
    --secondary-dark: #d5dbdb;
    --accent-color: #f39c12;
    --accent-dark: #e67e22;
    --success-color: #27ae60;
    --success-light: #d5f4e6;
    --error-color: #e74c3c;
    --error-light: #fadbd8;
    --warning-color: #e67e22;
    --warning-light: #fdeaa7;
    --text-color: #2c3e50;
    --text-light: #7f8c8d;
    --text-muted: #95a5a6;
    --text-white: #ffffff;
    --bg-color: #ffffff;
    --bg-alt: #f8f9fa;
    --bg-dark: #2c3e50;
    --border-color: #dee2e6;
    --border-light: #e9ecef;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Border radius */
    --border-radius-sm: 6px;
    --border-radius: 12px;
    --border-radius-lg: 18px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.06);
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 32px rgba(0, 0, 0, 0.16);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 통일된 디자인 시스템 확장 */
    --primary-gradient: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    --accent-gradient: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    --success-gradient: linear-gradient(135deg, var(--success-color), #2ecc71);
    --error-gradient: linear-gradient(135deg, var(--error-color), #c0392b);
    
    --glass-bg: rgba(255, 255, 255, 0.2);
    --glass-bg-dark: rgba(0, 0, 0, 0.2);
    --glass-border: rgba(255, 255, 255, 0.3);
    
    --text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    --text-shadow-strong: 0 3px 6px rgba(0, 0, 0, 0.6);
    
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #1abc9c;
        --primary-dark: #16a085;
        --primary-light: #48c9b0;
        --secondary-color: #34495e;
        --secondary-dark: #2c3e50;
        --success-light: #1e3a2e;
        --error-light: #3a1e1e;
        --warning-light: #3a2e1e;
        --text-color: #ecf0f1;
        --text-light: #bdc3c7;
        --text-white: #ffffff;
        --bg-color: #2c3e50;
        --bg-alt: #34495e;
        --bg-dark: #1a252f;
        --border-color: #4a5f7a;
        --border-light: #5a6f8a;
        
        /* 다크모드용 그라데이션 재정의 */
        --primary-gradient: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
        --accent-gradient: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
        
        /* 다크모드용 글래스 효과 */
        --glass-bg: rgba(255, 255, 255, 0.1);
        --glass-bg-dark: rgba(0, 0, 0, 0.3);
        --glass-border: rgba(255, 255, 255, 0.2);
    }
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-alt);
    color: var(--text-color);
    line-height: 1.6;
    margin: 0;
    padding: var(--spacing-lg);
    min-height: 100vh;
    font-weight: 400;
    transition: background-color var(--transition), color var(--transition);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-color);
    padding: var(--spacing-xxl);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    backdrop-filter: blur(10px);
    transition: background-color var(--transition), box-shadow var(--transition);
}

/* 새로운 헤더 디자인 */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--bg-dark), #8e44ad);
    background-size: 300% 300%;
    animation: headerGradient 8s ease infinite;
    color: white;
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
}

/* 헤더 배경 애니메이션 */
@keyframes headerGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* 헤더에 은은한 패턴 오버레이 */
header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/><circle cx="25" cy="25" r="0.5" fill="white" opacity="0.05"/><circle cx="75" cy="75" r="0.5" fill="white" opacity="0.05"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
    pointer-events: none;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
    z-index: 1;
}

.title-section {
    position: relative;
    z-index: 1;
}

.title-section h1 {
    font-size: 2rem;
    font-weight: var(--font-weight-bold);
    margin: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-shadow: var(--text-shadow);
}

.title-section .subtitle {
    font-size: 1rem;
    font-weight: var(--font-weight-medium);
    opacity: 0.9;
    margin: var(--spacing-xs) 0 0 0;
    text-shadow: var(--text-shadow);
}

.header-stats {
    text-align: center;
    background: var(--glass-bg-dark);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    backdrop-filter: blur(15px);
    border: 2px solid var(--glass-border);
    position: relative;
    z-index: 1;
    box-shadow: var(--shadow-lg);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.stat-number {
    font-size: 1.8rem;
    font-weight: 900;
    color: var(--accent-color);
    text-shadow: 0 3px 6px rgba(0, 0, 0, 0.6);
}

.stat-label {
    font-size: 1rem;
    font-weight: 700;
    color: #ffffff;
    text-shadow: 0 3px 6px rgba(0, 0, 0, 0.7);
    letter-spacing: 0.5px;
    background: rgba(0, 0, 0, 0.3);
    padding: 4px 8px;
    border-radius: var(--border-radius);
    margin-top: 4px;
}

.feature-highlights {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--glass-bg);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 20px;
    backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    font-size: 0.9rem;
    font-weight: var(--font-weight-medium);
    color: var(--text-white);
    text-shadow: var(--text-shadow);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.35);
    box-shadow: var(--shadow);
}

.feature-item i {
    font-size: 1.1rem;
    color: var(--accent-color);
    text-shadow: var(--text-shadow);
}

/* Banner styles */
.notice-banner, .info-banner {
    margin: var(--spacing-lg) auto var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    max-width: 800px;
    font-size: 0.95rem;
    line-height: 1.4;
}

.notice-banner {
    background: var(--success-light);
    border-left: 4px solid var(--success-color);
    color: var(--success-color);
}

.info-banner {
    background: #e8f4fd;
    border-left: 4px solid #2196f3;
    color: #1565c0;
}

.info-banner.quiz-banner {
    background: #fff3e0;
    border-left: 4px solid #ff9800;
    color: #e65100;
}

.notice-banner i, .info-banner i {
    font-size: 1.1rem;
    flex-shrink: 0;
}

/* Dark mode support for banners */
@media (prefers-color-scheme: dark) {
    .notice-banner {
        background: var(--success-light);
        color: #81c784;
    }
    
    .info-banner {
        background: #1a2332;
        color: #64b5f6;
    }
}

/* 새로운 섹션 스타일 */
.filter-section,
.study-modes-section {
    margin-bottom: var(--spacing-lg);
    background: var(--bg-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-light);
}

.section-header h2 {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.3rem;
    margin: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.question-counter {
    background: rgba(44, 62, 80, 0.1);
    color: #2c3e50;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    padding: 6px 12px;
    border-radius: 8px;
}

.question-counter #question-count {
    font-size: 1.3rem;
    font-weight: 700;
    color: #27ae60;
    margin-right: 4px;
}

/* Section styles */
section {
    margin-bottom: var(--spacing-xl);
}

section h2 {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

section h2::before {
    content: '';
    width: 4px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 2px;
}

.filter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

/* 년도 필터 특별 스타일 */
.year-filter {
    background: linear-gradient(135deg, rgba(243, 156, 18, 0.1), rgba(230, 126, 34, 0.1));
    border: 2px solid rgba(243, 156, 18, 0.6);
    font-weight: 600;
    color: #e67e22;
    box-shadow: 0 4px 16px rgba(243, 156, 18, 0.15);
    transition: all var(--transition);
}

.year-filter:focus {
    border-color: #e67e22;
    box-shadow: 0 0 0 3px rgba(243, 156, 18, 0.2);
    background: linear-gradient(135deg, rgba(243, 156, 18, 0.15), rgba(230, 126, 34, 0.15));
}

.filter-select {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-lg);
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-color);
    font-size: 1rem;
    font-family: inherit;
    font-weight: 500;
    transition: all var(--transition);
    cursor: pointer;
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    min-height: 44px;
    display: flex;
    align-items: center;
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(22, 160, 133, 0.2), 0 8px 24px rgba(22, 160, 133, 0.15);
    background: rgba(255, 255, 255, 0.12);
}

/* filter-select 자연스러운 호버 효과 */
.filter-select:hover {
    border-color: rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.1);
}



.start-box {
    text-align: center;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-alt);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
}

#question-count {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
    font-weight: 600;
}

.mode-selection {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* Button styles */
button {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
    min-height: 44px; /* Touch-friendly size */
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    color: inherit;
    -webkit-appearance: none;
    appearance: none;
}

button:hover:not(:disabled) {
    box-shadow: var(--shadow-lg);
    filter: brightness(0.95);
}

button:disabled {
    background-color: var(--text-muted);
    color: var(--bg-color);
    cursor: not-allowed;
    transform: none;
    opacity: 0.6;
}

button:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(22, 160, 133, 0.3);
}

/* 새로운 버튼 스타일 */
.primary-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-height: 52px;
    width: 100%;
    line-height: 1.2;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.primary-btn:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.secondary-btn {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    font-weight: 500;
    font-size: 0.9rem;
    transition: var(--transition);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    min-height: 52px;
    line-height: 1.2;
}

.secondary-btn:hover:not(:disabled) {
    background: var(--primary-color);
    color: white;
}

.button-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.button-group.vertical {
    flex-direction: column;
}

/* 랜덤 퀴즈 카드의 버튼 그룹 특별 처리 */
.secondary-card .button-group {
    display: flex;
    flex-direction: row;
    gap: var(--spacing-sm);
    align-items: stretch;
}

.secondary-card .button-group .primary-btn {
    flex: 2;
    min-height: 52px;
    padding: var(--spacing-md) var(--spacing-lg);
}

.secondary-card .button-group .secondary-btn {
    flex: 1;
    font-size: 0.85rem;
    min-height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-sm);
}

.secondary-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-top: var(--spacing-md);
    align-items: center;
    flex-wrap: wrap;
}

.icon-btn {
    min-width: 88px;
    height: 48px;
    border-radius: 24px;
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    transition: var(--transition);
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: var(--font-weight-medium);
    line-height: 1;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
    text-decoration: none;
    padding: 0 var(--spacing-sm);
    white-space: nowrap;
}

.icon-btn i {
    font-size: 1rem;
    line-height: 1;
    display: inline-block;
    margin: 0;
    padding: 0;
    flex-shrink: 0;
}

.icon-btn span {
    font-weight: 500;
    font-size: 0.85rem;
}

.icon-btn:hover:not(:disabled) {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
    transform: scale(1.1);
}

.icon-btn.danger:hover:not(:disabled) {
    background: var(--error-color);
    border-color: var(--error-color);
}

/* 설정 버튼 그리드 */
.settings-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.setting-btn {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all var(--transition);
    cursor: pointer;
    color: var(--text-color);
    font-weight: 500;
    box-shadow: var(--shadow-sm);
}

.setting-btn:hover {
    border-color: var(--primary-color);
    background: var(--primary-light);
    color: white;
    transform: translateY(-2px);
}

.setting-btn i {
    font-size: 1.2rem;
}

.setting-btn span {
    font-size: 0.8rem;
    font-weight: 500;
}

/* Primary buttons */
#start-sequential-btn {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow);
}

#start-quiz-btn, #restart-btn {
    background: var(--accent-color);
    color: white;
    box-shadow: var(--shadow);
}

#new-random-quiz-btn {
    background: linear-gradient(135deg, #9b59b6, #8e44ad);
    color: white;
    box-shadow: var(--shadow);
    font-size: 0.9rem;
}

/* new-random-quiz-btn 호버 효과 제거 - 페이지 깊이 없음 */

/* Danger button */
#stop-btn {
    background: var(--error-color);
    color: white;
    box-shadow: var(--shadow);
}

/* Secondary buttons */
.secondary-btn {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    color: var(--text-color);
    font-size: 0.9rem;
    padding: var(--spacing-sm) var(--spacing-md);
}

.secondary-btn:hover:not(:disabled) {
    background: var(--bg-alt);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Special buttons */
#study-wrong-btn {
    background: var(--warning-color);
    color: white;
    box-shadow: var(--shadow);
}

#undo-wrong-btn {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow);
}

#undo-wrong-btn:hover:not(:disabled) {
    background: var(--primary-dark);
}

.remove-btn {
    background: var(--error-color);
    color: white;
    font-weight: 700;
    box-shadow: var(--shadow);
}

.remove-btn:hover:not(:disabled) {
    background: var(--error-color);
    filter: brightness(0.9);
}

/* Section-specific styles */
#review-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--warning-light), #fdf2e9);
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid rgba(243, 156, 18, 0.2);
}

#review-section h3 {
    margin-bottom: var(--spacing-lg);
    color: var(--warning-color);
    font-size: 1.3rem;
    font-weight: 600;
}

.result-actions button {
    margin: var(--spacing-sm);
}

/* Quiz container styles */
#quiz-container { 
    margin-top: var(--spacing-xl); 
}

#quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
    padding: var(--spacing-md) 0;
    border-bottom: 2px solid var(--border-light);
}

#quiz-progress {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
}

#question-card {
    background: var(--bg-color);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    transition: all var(--transition);
}

/* question-card 호버 효과 제거 - 페이지 깊이 없음 */

#question-classification {
    font-size: 0.95rem;
    color: white;
    background: var(--primary-color);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    text-align: center;
    font-weight: 500;
}

#question-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto var(--spacing-lg) auto;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-light);
    box-shadow: var(--shadow);
    transition: all var(--transition);
}

/* question-image 호버 효과 제거 - 페이지 깊이 없음 */

#question-text {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
    color: var(--text-color);
    line-height: 1.7;
}

#options-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.option-btn {
    display: block;
    width: 100%;
    padding: var(--spacing-md);
    text-align: left;
    background: var(--bg-color);
    border: 2px solid var(--border-light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition);
    font-size: 1rem;
    line-height: 1.5;
    min-height: 50px;
    color: var(--text-color);
    font-family: inherit;
    -webkit-appearance: none;
    appearance: none;
}

.option-btn:not(:disabled):hover {
    background-color: var(--bg-alt);
    border-color: var(--primary-light);
    box-shadow: var(--shadow);
}

.option-btn.selected-correct {
    background: var(--success-light) !important;
    border: 2px solid var(--success-color) !important;
    color: #155724 !important;
}

.option-btn.selected-incorrect {
    background: var(--error-light) !important;
    border: 2px solid var(--error-color) !important;
    color: #721c24 !important;
}

.option-btn.correct-answer {
    background: var(--success-light) !important;
    border: 2px solid var(--success-color) !important;
    color: #155724 !important;
}

/* Navigation and feedback styles */
#navigation-btns {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

#prev-btn, #next-btn {
    background: var(--primary-color);
    color: white;
    flex: 1;
    max-width: 200px;
    box-shadow: var(--shadow);
}

.feedback {
    display: none !important;
}

.feedback.correct {
    color: #155724;
    background: var(--success-light);
    border: 2px solid var(--success-color);
    text-align: center;
}

.feedback.incorrect {
    color: #721c24;
    background: var(--error-light);
    border: 2px solid var(--error-color);
    text-align: center;
}

/* Results container */
#results-container { 
    text-align: center; 
    padding: var(--spacing-xl);
}

#score-text {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xl);
}

.stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
    flex-wrap: wrap;
}

.stat {
    background: var(--bg-alt);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    min-width: 120px;
    border: 1px solid var(--border-light);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-xs);
}

.stat span:last-child {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.results-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-top: var(--spacing-xl);
}

/* Special action buttons */
#add-to-wrong-note, #remove-from-wrong-note {
    text-align: center;
    margin: var(--spacing-lg) 0;
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
}

#add-to-wrong-btn {
    background: var(--warning-color);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 0.95rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: all var(--transition);
}

#add-to-wrong-btn:hover:not(:disabled) {
    background: var(--warning-color);
    filter: brightness(0.9);
    box-shadow: var(--shadow-lg);
}

#add-to-wrong-btn:disabled {
    background: var(--text-muted);
    color: var(--bg-color);
    cursor: not-allowed;
    opacity: 0.6;
}

#undo-from-quiz-btn {
    background: var(--primary-color);
    color: white;
    font-size: 0.9rem;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition);
}

#undo-from-quiz-btn:hover:not(:disabled) {
    background: var(--primary-dark);
    box-shadow: var(--shadow);
}

#progress-info {
    background: #e8f4f8;
    border: 2px solid var(--primary-light);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    margin: var(--spacing-lg) 0;
    color: var(--primary-dark);
    font-size: 0.95rem;
    box-shadow: var(--shadow-sm);
    position: relative;
}

#progress-info p {
    margin-left: var(--spacing-xl);
    margin-bottom: 0;
}

/* Notification system */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--success-color);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    z-index: 1000;
    max-width: 300px;
    font-weight: 500;
}

.notification.error {
    background: var(--error-color);
}

/* Backup section */
.backup-btn {
    background: var(--text-muted);
    color: white;
    border: none;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow);
}

.backup-btn:hover {
    background: var(--text-color);
    box-shadow: var(--shadow-lg);
}

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

.backup-info {
    font-size: 0.9rem;
    color: var(--text-light);
    margin: 0;
    font-style: italic;
    line-height: 1.5;
}

/* Explanation Styles */
.quiz-actions-container {
    text-align: center;
    margin: var(--spacing-lg) 0;
}

#explanation-btn {
    background: var(--primary-light);
    color: white;
    box-shadow: var(--shadow);
}

/* explanation-btn 호버 효과 제거 - 페이지 깊이 없음 */

#explanation-container {
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0 0 0;
    background: var(--bg-alt);
    border: 1px solid var(--border-light);
    border-left: 4px solid var(--primary-color);
    border-radius: var(--border-radius);
    line-height: 1.7;
    font-size: 1rem;
    word-wrap: break-word;
    color: var(--text-color);
}

/* 새로운 해설 형식 스타일 */
.explanation-answer {
    background: linear-gradient(135deg, var(--success-color), #2ecc71);
    color: white;
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
    font-size: 1.1rem;
    text-align: center;
    box-shadow: var(--shadow);
}

.explanation-reason {
    background: var(--bg-color);
    border: 2px solid var(--primary-light);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.explanation-reason::before {
    content: '💡';
    position: absolute;
    top: -10px;
    left: var(--spacing-md);
    background: var(--bg-color);
    padding: 0 var(--spacing-sm);
    font-size: 1.2rem;
}

.explanation-concept {
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    border-left: 4px solid var(--accent-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.explanation-concept::before {
    content: '●';
    color: var(--accent-color);
    font-weight: bold;
    font-size: 1.2rem;
    margin-right: var(--spacing-sm);
}

.explanation-concept-title {
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.explanation-analysis {
    background: var(--bg-color);
    border: 1px solid var(--border-light);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.explanation-analysis-title {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
    border-bottom: 2px solid var(--border-light);
    padding-bottom: var(--spacing-sm);
}

.choice-analysis-item {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--border-color);
    background: var(--bg-alt);
    transition: all var(--transition);
}

.choice-analysis-item:hover {
    border-left-color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.choice-analysis-item.correct {
    border-left-color: var(--success-color);
    background: linear-gradient(90deg, rgba(39, 174, 96, 0.1), var(--bg-alt));
}

.choice-analysis-item.incorrect {
    border-left-color: var(--text-muted);
    background: var(--bg-alt);
}

.choice-text {
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: var(--spacing-xs);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.choice-text .choice-icon {
    font-size: 1.1rem;
}

.choice-text .choice-icon.correct {
    color: var(--success-color);
}

.choice-text .choice-icon.incorrect {
    color: var(--text-muted);
}

.choice-explanation {
    color: var(--text-light);
    line-height: 1.6;
    margin-left: var(--spacing-lg);
}

/* Markdown Content Styles */
#explanation-container h1,
#explanation-container h2,
#explanation-container h3 {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--primary-dark);
    border-bottom: 2px solid var(--border-light);
    padding-bottom: var(--spacing-xs);
}

#explanation-container ul,
#explanation-container ol {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

#explanation-container li {
    margin-bottom: var(--spacing-xs);
}

#explanation-container p:last-child {
    margin-bottom: 0;
}

#explanation-container code {
    background-color: var(--border-light);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', Courier, monospace;
}

#explanation-container blockquote {
    border-left: 4px solid var(--border-color);
    padding-left: var(--spacing-md);
    margin-left: 0;
    color: var(--text-light);
    font-style: italic;
}

#explanation-container hr {
    margin: var(--spacing-lg) 0;
    border: none;
    border-top: 2px solid var(--border-light);
}

#explanation-container pre {
    background-color: var(--bg-dark);
    color: #fff;
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

#explanation-container pre code {
    background: transparent;
    padding: 0;
    color: inherit;
}

#explanation-container strong,
#explanation-container b {
    font-weight: 700 !important;
    color: var(--primary-dark) !important;
    font-family: inherit;
    display: inline;
}

#explanation-container em,
#explanation-container i {
    font-style: italic !important;
    color: var(--text-color);
    display: inline;
}

#explanation-container p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}


/* Utility classes */
.hidden { 
    display: none !important; 
}

/* Responsive design */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-sm);
        background: var(--bg-alt);
    }
    
    /* 헤더 모바일 최적화 */
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .title-section h1 {
        font-size: 1.5rem;
    }
    
    .feature-highlights {
        gap: var(--spacing-md);
    }
    
    .feature-item {
        font-size: 0.8rem;
        padding: var(--spacing-xs) var(--spacing-sm);
    }
    
    /* 섹션 모바일 최적화 */
    .filter-section,
    .study-modes-section {
        padding: 0;
        margin-bottom: var(--spacing-sm);
        background: transparent;
        border-radius: 0;
        box-shadow: none;
        border: none;
    }
    
    .section-header {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
    
    .section-header h2 {
        font-size: 1.1rem;
    }
    
    /* 모바일에서 카드형식 제거하고 심플한 버튼형식으로 대체 */
    .cards-container {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-sm);
        padding: 0 var(--spacing-sm);
    }
    
    .card {
        background: transparent;
        border: none;
        border-radius: 0;
        padding: var(--spacing-md);
        box-shadow: none;
        text-align: left;
        position: relative;
        overflow: visible;
    }
    
    .card::before {
        display: none;
    }
    
    .card:hover {
        transform: none;
        box-shadow: none;
        border-color: transparent;
    }
    
    .card-icon {
        width: 48px;
        height: 48px;
        border-radius: 12px;
        background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
        display: inline-flex;
        align-items: center;
        justify-content: center;
        margin: 0 var(--spacing-sm) 0 0;
        color: white;
        font-size: 1.2rem;
        box-shadow: none;
        flex-shrink: 0;
        vertical-align: middle;
    }
    
    .card-icon i {
        font-size: 1.2rem;
        line-height: 1;
        display: inline-block;
        margin: 0;
        padding: 0;
        font-style: normal;
    }
    
    .card h3 {
        font-size: 1.1rem;
        margin: 0;
        display: inline-block;
        vertical-align: middle;
        color: var(--text-color);
    }
    
    .card p {
        font-size: 0.9rem;
        margin: var(--spacing-sm) 0 0 0;
        color: var(--text-muted);
        line-height: 1.4;
    }
    
    /* 버튼 모바일 최적화 */
    .button-group {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    /* 랜덤 퀴즈 카드를 모바일에서 세로 배치로 변경 */
    .secondary-card .button-group {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .secondary-card .button-group .primary-btn {
        flex: none;
        width: 100%;
        font-size: 1rem;
        padding: var(--spacing-md) var(--spacing-lg);
        min-height: 56px;
    }
    
    .secondary-card .button-group .secondary-btn {
        flex: none;
        width: 100%;
        font-size: 0.9rem;
        padding: var(--spacing-md) var(--spacing-lg);
        min-height: 56px;
    }
    
    .secondary-buttons {
        gap: var(--spacing-xs);
        margin-top: var(--spacing-md);
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .icon-btn {
        min-width: 80px;
        height: 44px;
        font-size: 0.8rem;
        border-radius: 22px;
        gap: var(--spacing-xs);
        padding: 0 var(--spacing-sm);
        flex-shrink: 0;
    }
    
    .icon-btn i {
        font-size: 0.9rem;
        line-height: 1;
        display: inline-block;
        margin: 0;
        padding: 0;
        flex-shrink: 0;
    }
    
    .icon-btn span {
        font-size: 0.8rem;
        font-weight: 500;
    }
    
    .settings-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .setting-btn {
        padding: var(--spacing-lg);
        min-height: 70px;
        width: 100%;
        font-size: 1rem;
        gap: var(--spacing-sm);
    }
    
    .setting-btn i {
        font-size: 1.4rem;
    }
    
    .setting-btn span {
        font-size: 0.95rem;
        font-weight: 600;
        text-align: center;
        line-height: 1.2;
    }
    
    /* 필터 모바일 최적화 */
    .filter-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding: var(--spacing-sm);
        margin: 0 var(--spacing-sm) var(--spacing-md) var(--spacing-sm);
        background: transparent;
        border-radius: 0;
        border: none;
        backdrop-filter: none;
    }
    
    .filter-select {
        padding: var(--spacing-md);
        font-size: 1rem;
        min-height: 48px;
        border-radius: 12px;
    }
    

    
    /* 새로운 해설 형식 모바일 최적화 */
    .explanation-answer {
        font-size: 1rem;
        padding: var(--spacing-md);
    }
    
    .explanation-reason,
    .explanation-concept,
    .explanation-analysis {
        padding: var(--spacing-md);
        margin-bottom: var(--spacing-md);
    }
    
    .explanation-concept-title,
    .explanation-analysis-title {
        font-size: 1rem;
    }
    
    .choice-analysis-item {
        padding: var(--spacing-sm) var(--spacing-md);
        margin-bottom: var(--spacing-sm);
    }
    
    .choice-text {
        font-size: 0.9rem;
    }
    
    .choice-explanation {
        font-size: 0.85rem;
        margin-left: var(--spacing-md);
    }
    
    .container {
        padding: var(--spacing-md);
        margin: 0;
        background: transparent; /* 배경 카드 제거 */
        border-radius: 0;
        box-shadow: none;
        min-height: 100vh;
    }
    
    header h1 {
        font-size: 1.6rem;
        line-height: 1.3;
    }
    
    .filter-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding: var(--spacing-sm);
        margin: 0 var(--spacing-sm) var(--spacing-md) var(--spacing-sm);
        background: transparent;
        border-radius: 0;
        border: none;
        backdrop-filter: none;
    }
    
    .cards-container {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-sm);
        padding: 0 var(--spacing-sm);
    }
    
    .card {
        background: transparent;
        border: none;
        border-radius: 0;
        padding: var(--spacing-md);
        box-shadow: none;
        text-align: left;
    }
    
    .card-header {
        padding: 0;
        margin-bottom: var(--spacing-sm);
    }
    
    .card-header h3 {
        font-size: 1.1rem;
        margin: 0;
        color: var(--text-color);
    }
    
    .card-content {
        padding: 0;
    }
    
    /* 모바일 터치 타겟 최적화 */
    button {
        min-height: 48px;
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: 1rem;
        border-radius: 8px;
    }
    
    .tree-toggle {
        width: 40px;
        height: 40px;
        border-radius: 10px;
    }
    
    .option-button {
        min-height: 56px;
        padding: var(--spacing-lg);
        font-size: 1rem;
        margin-bottom: var(--spacing-md);
        border-radius: 12px;
    }
    
    .question-count-display {
        flex-direction: row;
        gap: var(--spacing-xs);
        text-align: center;
        flex-wrap: nowrap;
        align-items: center;
    }
    
    /* 사파리 iOS 특화 수정 */
    .count-number {
        font-size: 1.8rem;
        line-height: 1;
        margin: 0;
        padding: 0;
    }
    
    .count-label, .count-unit {
        font-size: 0.9rem;
        line-height: 1.1;
    }
    
    .count-number {
        font-size: 1.8rem;
    }
    
    .progress-display {
        padding: var(--spacing-sm);
        font-size: 0.85rem;
        text-align: center;
    }
    
    .backup-card .backup-controls {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .backup-card .backup-btn {
        width: 100%;
        justify-content: center;
    }
    
    .mode-selection {
        gap: var(--spacing-sm);
    }
    
    .mode-selection button {
        font-size: 0.9rem;
        padding: var(--spacing-md);
    }
    
    #quiz-container {
        margin-top: var(--spacing-md);
        padding-bottom: 80px; /* 네비게이션 버튼 공간 확보 */
    }
    
    #question-card {
        background: transparent; /* 문제창 카드 배경 제거 */
        border: none;
        box-shadow: none;
        padding: var(--spacing-sm) 0;
        margin: 0;
        transition: none; /* 애니메이션 제거 */
        transform: none; /* 플로팅 효과 제거 */
    }
    
    #question-card:hover {
        transform: none; /* 호버 애니메이션 제거 */
        box-shadow: none;
    }
    
    /* 모바일에서 해설창 카드형식 제거 */
    #explanation-container {
        padding: var(--spacing-sm);
        margin: var(--spacing-md) 0 0 0;
        background: transparent;
        border: none;
        border-left: none;
        border-radius: 0;
        line-height: 1.6;
        font-size: 0.95rem;
    }
    
    /* 모바일에서 해설 섹션들 카드형식 제거 */
    .explanation-answer {
        background: linear-gradient(135deg, var(--success-color), #2ecc71);
        color: white;
        padding: var(--spacing-sm);
        border-radius: 8px;
        margin-bottom: var(--spacing-md);
        font-weight: 600;
        font-size: 1rem;
        text-align: center;
        box-shadow: none;
    }
    
    .explanation-reason {
        background: transparent;
        border: none;
        border-radius: 0;
        padding: var(--spacing-sm);
        margin-bottom: var(--spacing-md);
        position: relative;
        border-left: 3px solid var(--primary-light);
    }
    
    .explanation-reason::before {
        content: '💡';
        position: static;
        background: transparent;
        padding: 0;
        font-size: 1rem;
        margin-right: var(--spacing-sm);
        display: inline-block;
    }
    
    .explanation-concept {
        background: transparent;
        border-left: 3px solid var(--accent-color);
        border-radius: 0;
        padding: var(--spacing-sm);
        margin-bottom: var(--spacing-md);
        position: relative;
    }
    
    .explanation-concept::before {
        content: '●';
        color: var(--accent-color);
        font-weight: bold;
        font-size: 1rem;
        margin-right: var(--spacing-sm);
    }
    
    .explanation-analysis {
        background: transparent;
        border: none;
        border-radius: 0;
        padding: var(--spacing-sm);
        margin-bottom: var(--spacing-md);
        border-left: 3px solid var(--border-color);
    }
    
    .choice-analysis-item {
        padding: var(--spacing-sm);
        margin-bottom: var(--spacing-sm);
        border-radius: 0;
        border-left: 3px solid var(--border-color);
        background: transparent;
    }
    
    #navigation-btns {
        position: -webkit-sticky;
        position: sticky;
        bottom: 0;
        background: white;
        padding: var(--spacing-md);
        margin: var(--spacing-md) -var(--spacing-md) 0;
        box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
        border-top: 1px solid var(--border-light);
        flex-direction: row;
        gap: var(--spacing-sm);
    }
    }
    
    #prev-btn, #next-btn {
        max-width: none;
        width: 100%;
        min-height: 48px;
        font-size: 1rem;
    }
    
    .stats {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-md);
    }
    
    .stat {
        width: 200px;
        text-align: center;
    }
    
    .results-actions {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .results-actions button {
        width: 100%;
    }
    
    .notification {
        top: 10px;
        right: 10px;
        left: 10px;
        max-width: none;
        font-size: 0.9rem;
    }
}

/* Missing closing bracket fix */

@media (max-width: 480px) {
    body {
        padding: 8px;
    }
    
    .container {
        padding: var(--spacing-sm);
    }
    
    header h1 {
        font-size: 1.4rem;
        line-height: 1.2;
    }
    
    header p {
        font-size: 0.9rem;
    }
    
    /* 더 큰 터치 타겟 */
    button {
        min-height: 52px;
        font-size: 1.1rem;
        padding: var(--spacing-lg);
    }
    
    /* 랜덤 퀴즈 카드 세로 배치 (480px 이하) */
    .secondary-card .button-group {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .secondary-card .button-group .primary-btn {
        flex: none;
        width: 100%;
        font-size: 1.1rem;
        padding: var(--spacing-lg);
        min-height: 60px;
    }
    
    .secondary-card .button-group .secondary-btn {
        flex: none;
        width: 100%;
        font-size: 1rem;
        padding: var(--spacing-lg);
        min-height: 60px;
    }
    
    .tree-toggle {
        width: 44px;
        height: 44px;
    }
    
    /* 설정 버튼 480px 이하 최적화 */
    .settings-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .setting-btn {
        padding: var(--spacing-xl);
        min-height: 80px;
        width: 100%;
        font-size: 1.1rem;
        gap: var(--spacing-md);
    }
    
    .setting-btn i {
        font-size: 1.6rem;
    }
    
    .setting-btn span {
        font-size: 1.1rem;
        font-weight: 600;
        text-align: center;
        line-height: 1.2;
    }
    
    .option-button {
        min-height: 64px;
        padding: var(--spacing-xl);
        font-size: 1.1rem;
        margin-bottom: var(--spacing-lg);
    }
    
    /* 작은 화면에서도 가로 배치 유지 */
    .question-count-display {
        flex-direction: row;
        gap: var(--spacing-xs);
        flex-wrap: nowrap;
        align-items: center;
        justify-content: center;
    }
    
    .progress-display {
        font-size: 0.8rem;
        padding: var(--spacing-sm);
        margin: var(--spacing-xs) 0;
    }
    
    #sequential-progress-info span,
    #random-progress-info span {
        font-size: 0.8rem;
    }
    
    .count-label, .count-unit {
        font-size: 0.85rem;
        white-space: nowrap;
    }
    
    .count-number {
        font-size: 1.6rem;
        min-width: auto;
        margin: 0 4px;
    }
    
    /* 텍스트 크기 최적화 */
    #question-text {
        font-size: 1.1rem;
        line-height: 1.5;
    }
    
    /* 네비게이션 버튼 고정 */
    #quiz-container {
        padding-bottom: 90px; /* 더 큰 여백 */
        min-height: 100vh;
        position: relative;
    }
    
    #navigation-btns {
        position: fixed !important;
        bottom: 0 !important;
        left: 0 !important;
        right: 0 !important;
        background: transparent !important;
        padding: var(--spacing-md) !important;
        box-shadow: none !important;
        border: none !important;
        z-index: 99999 !important;
        /* 사파리 강제 고정 */
        -webkit-transform: translate3d(0, 0, 0) !important;
        transform: translate3d(0, 0, 0) !important;
        width: 100% !important;
        margin: 0 !important;
        display: flex !important;
        flex-direction: row !important;
        gap: var(--spacing-sm) !important;
        box-sizing: border-box !important;
    }
    
    #prev-btn, #next-btn {
        min-height: 52px;
        font-size: 1.1rem;
        font-weight: 600;
    }
    
    .option-btn {
        font-size: 1rem;
    }
    
    #score-text {
        font-size: 2rem;
    }
}

/* 새로운 카드 디자인 */
.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.card {
    background: var(--bg-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow);
    border: 2px solid var(--border-light);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
    text-align: center;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-color);
    transition: all var(--transition);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.card:hover::before {
    height: 6px;
}

/* 카드 타입별 색상 */
.primary-card::before {
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
}

.secondary-card::before {
    background: linear-gradient(90deg, var(--accent-color), #e67e22);
}

.warning-card::before {
    background: linear-gradient(90deg, var(--warning-color), #f39c12);
}

.settings-card::before {
    background: linear-gradient(90deg, var(--text-muted), #7f8c8d);
}

.card-icon {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    color: white;
    font-size: 1.6rem;
    box-shadow: var(--shadow);
    flex-shrink: 0;
    text-decoration: none;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.card-icon i {
    font-size: 1.6rem;
    line-height: 1;
    display: inline-block;
    margin: 0;
    padding: 0;
    font-style: normal;
}

.secondary-card .card-icon {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
}

.warning-card .card-icon {
    background: linear-gradient(135deg, var(--warning-color), #e67e22);
}

.settings-card .card-icon {
    background: linear-gradient(135deg, var(--text-muted), var(--text-light));
}

.card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-color);
    margin: 0 0 var(--spacing-sm) 0;
}

.card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0 0 var(--spacing-lg) 0;
    line-height: 1.5;
}

/* 진행 정보 스타일 */
.progress-info {
    background: rgba(22, 160, 133, 0.1);
    border: 1px solid rgba(22, 160, 133, 0.2);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm) var(--spacing-md);
    margin: var(--spacing-md) 0;
    font-size: 0.85rem;
    color: var(--primary-dark);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    justify-content: center;
    font-weight: 500;
}

/* 오답 카운트 표시 */
.wrong-count-display {
    background: linear-gradient(135deg, #fff3e0, #ffeaa7);
    color: #d35400;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    font-weight: 600;
    margin: var(--spacing-md) 0;
    font-size: 0.9rem;
}

/* Card Layout Styles */
.cards-container-old {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.card-old {
    background: var(--bg-color);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    border: 2px solid var(--border-light);
    overflow: hidden;
    transition: all var(--transition);
    position: relative;
}

.card-header {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    position: relative;
    overflow: hidden;
}

.card-header i {
    font-size: 1.5rem;
}

.card-header h3 {
    margin: 0;
    font-size: 1.3rem;
    font-weight: 600;
}

.card-content {
    padding: var(--spacing-xl);
}

.card-content p {
    margin-bottom: var(--spacing-lg);
    color: var(--text-light);
    font-size: 1rem;
    line-height: 1.6;
}

/* Study Card Specific Styles */
.study-card .card-header {
    background: var(--primary-color);
}

.question-info {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.question-count-display {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-alt);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
    /* 사파리 호환성 개선 */
    -webkit-box-align: center;
    -webkit-box-pack: center;
}

.count-label {
    font-size: 1rem;
    color: var(--text-light);
    font-weight: 500;
    /* 사파리에서 텍스트 정렬 개선 */
    line-height: 1.2;
}

.count-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    transition: all var(--transition);
    /* 사파리 호환성 개선 */
    line-height: 1;
    display: inline-block;
    min-width: 2em;
    text-align: center;
}

.count-unit {
    font-size: 1.1rem;
    color: var(--text-light);
    font-weight: 500;
    /* 사파리에서 텍스트 정렬 개선 */
    line-height: 1.2;
}

.progress-display {
    background: #e8f4f8;
    border: 1px solid var(--primary-light);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    margin: var(--spacing-sm) 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--primary-dark);
}

#sequential-progress-info {
    background: #e8f4f8;
    border-color: var(--primary-color);
}

#sequential-progress-info i {
    color: var(--primary-color);
}

#random-progress-info {
    background: #fff3e0;
    border-color: var(--accent-color);
    color: #e65100;
}

#random-progress-info i {
    color: var(--accent-color);
}

.progress-display i {
    color: var(--primary-color);
    font-size: 1rem;
}

.study-card #question-count {
    font-size: 1.4rem;
    color: var(--primary-color);
    font-weight: 700;
    display: block;
    text-align: center;
    margin: var(--spacing-lg) 0;
}

/* Review Card Specific Styles */
.review-card .card-header {
    background: var(--warning-color);
}

.review-card .card-content {
    text-align: center;
}

.review-card button {
    display: block;
    width: 100%;
    margin-bottom: var(--spacing-md);
}

/* Backup Card Specific Styles */
.backup-card .card-header {
    background: var(--text-muted);
}

.backup-card .backup-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.backup-card .backup-group {
    padding: var(--spacing-md);
    background: var(--bg-alt);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
}

.backup-card .backup-group h4 {
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-color);
    font-size: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.backup-card .backup-group .backup-btn {
    width: 100%;
    margin-bottom: var(--spacing-sm);
}

.backup-card .backup-group .backup-btn:last-child {
    margin-bottom: 0;
}

.backup-card .text-backup {
    background: var(--primary-light);
}

/* text-backup 호버 효과 제거 - 페이지 깊이 없음 */

.backup-card .backup-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

/* Update existing styles for card compatibility */
.mode-selection {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

/* Print styles */
@media print {
    body {
        background: white;
        color: black;
    }
    
    .container {
        box-shadow: none;
        max-width: none;
    }
    
    button, .notification {
        display: none;
    }
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--bg-color);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.modal-header h3 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-fast);
}

/* close-btn 호버 효과 제거 - 페이지 깊이 없음 */

.modal-body {
    padding: var(--spacing-lg);
    flex: 1;
    overflow-y: auto;
}

.modal-body p {
    margin: 0 0 var(--spacing-lg) 0;
    color: var(--text-light);
    line-height: 1.5;
}

#backup-textarea {
    width: 100%;
    min-height: 200px;
    max-height: 300px;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.4;
    resize: vertical;
    background: var(--bg-alt);
    color: var(--text-color);
    transition: border-color var(--transition-fast);
}

#backup-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(22, 160, 133, 0.1);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    justify-content: flex-end;
    flex-wrap: wrap;
}

.modal-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    min-width: 120px;
    justify-content: center;
}

.modal-btn.primary {
    background: var(--primary-color);
    color: white;
}

.modal-btn.primary:hover {
    background: var(--primary-dark);
    box-shadow: var(--shadow-lg);
}

.modal-btn.secondary {
    background: var(--secondary-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

/* modal-btn.secondary 호버 효과 제거 - 페이지 깊이 없음 */

/* Mobile responsiveness for modal */
@media (max-width: 768px) {
    .modal-content {
        width: 95%;
        max-height: 90vh;
        margin: 5vh auto;
        border-radius: 12px;
    }
    
    .modal-header {
        padding: var(--spacing-lg);
        border-radius: 12px 12px 0 0;
    }
    
    .modal-header h3 {
        font-size: 1.2rem;
    }
    
    .modal-body {
        padding: var(--spacing-md);
        max-height: 70vh;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    .modal-actions {
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
    }
    
    .modal-btn {
        width: 100%;
        min-height: 48px;
        font-size: 1.1rem;
    }
    
    .close-btn {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
    
    /* 트리 모바일 최적화 */
    .tree-item {
        padding: var(--spacing-md);
    }
    
    .tree-header {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }
    
    .tree-children {
        margin-left: var(--spacing-md);
        padding-left: var(--spacing-sm);
    }
    
    .category-details {
        flex-wrap: wrap;
        gap: var(--spacing-xs);
    }
    
    #backup-textarea {
        min-height: 150px;
        font-size: 0.85rem;
    }
}

/* Analysis Modal Styles */
.analysis-section {
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: var(--bg-alt);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
}

.analysis-section h4 {
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
    font-size: 1.2rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.score-display {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
}

.score-circle {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: var(--shadow-lg);
}

.score-number {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
}

.score-label {
    font-size: 1rem;
    font-weight: 500;
    opacity: 0.9;
}

.score-details {
    flex: 1;
    min-width: 200px;
}

.score-details p {
    margin: var(--spacing-sm) 0;
    font-size: 1rem;
    color: var(--text-color);
}

.category-analysis {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.category-tree {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.tree-node {
    margin-bottom: var(--spacing-xs);
}

.tree-item {
    background: var(--bg-color);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
    transition: border-color var(--transition);
    position: relative;
}

.tree-item:hover {
    border-color: var(--primary-color);
}

.tree-item.high-priority {
    border-left: 4px solid var(--error-color);
    background: linear-gradient(90deg, rgba(231, 76, 60, 0.05), var(--bg-color));
}

.tree-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xs);
}

.tree-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
}

.tree-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.tree-toggle {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.tree-toggle:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.toggle-icon {
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.tree-bullet {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.priority-icon {
    font-size: 1.2rem;
    margin-right: var(--spacing-xs);
}

.category-name {
    font-weight: 600;
    color: var(--text-color);
    font-size: 1rem;
    flex: 1;
}

.progress-bar {
    width: 80px;
    height: 8px;
    background: var(--border-light);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--success-color), var(--warning-color), var(--error-color));
    transition: width 0.3s ease;
}

.category-ratio {
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 0.85rem;
    font-weight: 700;
    color: white;
    min-width: 50px;
    text-align: center;
}

.category-details {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 0.85rem;
    color: var(--text-light);
}

.priority-label {
    background: var(--error-color);
    color: white;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.tree-children {
    margin-left: var(--spacing-xl);
    margin-top: var(--spacing-md);
    border-left: 2px solid var(--border-light);
    padding-left: var(--spacing-md);
    overflow: hidden;
    transition: all 0.3s ease;
}

.tree-level-0 .tree-item {
    border-left: 4px solid var(--primary-color);
    background: linear-gradient(90deg, rgba(22, 160, 133, 0.08), var(--bg-color));
    font-size: 1.05rem;
}

.tree-level-1 .tree-item {
    border-left: 3px solid var(--accent-color);
    background: linear-gradient(90deg, rgba(243, 156, 18, 0.06), var(--bg-color));
}

.tree-level-2 .tree-item {
    border-left: 2px solid var(--success-color);
    background: linear-gradient(90deg, rgba(39, 174, 96, 0.04), var(--bg-color));
    font-size: 0.95rem;
}

.tree-level-3 .tree-item {
    border-left: 2px solid var(--warning-color);
    background: linear-gradient(90deg, rgba(230, 126, 34, 0.03), var(--bg-color));
    font-size: 0.9rem;
}

.tree-level-4 .tree-item {
    border-left: 1px solid var(--text-light);
    background: linear-gradient(90deg, rgba(149, 165, 166, 0.02), var(--bg-color));
    font-size: 0.85rem;
}

.ratio-high {
    background-color: var(--error-color);
}

.ratio-medium {
    background-color: var(--warning-color);
}

.ratio-low {
    background-color: var(--success-color);
}

/* Font Awesome 아이콘 색상 클래스 */
.text-danger {
    color: #e74c3c !important;
}

.text-warning {
    color: #f39c12 !important;
}

.text-info {
    color: #3498db !important;
}

.text-success {
    color: #27ae60 !important;
}

.priority-icon {
    font-size: 1.2rem;
    margin-right: var(--spacing-xs);
    display: flex;
    align-items: center;
}

.tree-bullet {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    color: var(--text-light);
}

/* 카드 헤더 아이콘 스타일 */
.card-header i {
    margin-right: var(--spacing-sm);
    font-size: 1.2rem;
}

/* 버튼 아이콘 스타일 */
button i {
    margin-right: var(--spacing-xs);
    display: inline-block;
    line-height: 1;
    font-style: normal;
    text-rendering: auto;
    -webkit-font-smoothing: antialiased;
}

button i:last-child {
    margin-right: 0;
    margin-left: var(--spacing-xs);
}

/* Font Awesome 아이콘 정규화 */
.fas, .far, .fab, .fal, .fad, .fass, .fasr, .fasl {
    font-family: "Font Awesome 6 Free", "Font Awesome 6 Pro", "Font Awesome 5 Free", "Font Awesome 5 Pro" !important;
    font-style: normal !important;
    font-variant: normal !important;
    text-rendering: auto !important;
    line-height: 1 !important;
    -webkit-font-smoothing: antialiased !important;
    -moz-osx-font-smoothing: grayscale !important;
    display: inline-block !important;
    vertical-align: middle !important;
    transform: none !important;
    -webkit-transform: none !important;
}

/* 특별히 아이콘 버튼과 카드 아이콘에 대한 추가 안정화 */
.icon-btn .fas, .icon-btn .far, .icon-btn .fab,
.card-icon .fas, .card-icon .far, .card-icon .fab {
    width: auto !important;
    height: auto !important;
    aspect-ratio: auto !important;
}

/* 모달 헤더 아이콘 */
.modal-header h3 i {
    margin-right: var(--spacing-sm);
    color: var(--primary-color);
}

/* 우선순위 아이콘 애니메이션 */
.priority-icon .fa-fire {
    animation: fire-flicker 1.5s infinite alternate;
}

@keyframes fire-flicker {
    0% { opacity: 0.8; transform: scale(1); }
    100% { opacity: 1; transform: scale(1.1); }
}

.priority-icon .fa-exclamation-triangle {
    animation: warning-pulse 2s infinite;
}

@keyframes warning-pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

/* iOS Safari 특화 수정 */
.ios-safari .question-count-display {
    display: -webkit-box;
    display: -webkit-flex;
    display: flex;
    -webkit-box-align: center;
    -webkit-align-items: center;
    align-items: center;
    -webkit-box-pack: center;
    -webkit-justify-content: center;
    justify-content: center;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

.ios-safari .count-number {
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    font-variant-numeric: tabular-nums;
}

.category-item {
    background: var(--bg-color);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
    transition: all var(--transition);
}

.category-item:hover {
    box-shadow: var(--shadow);
    transform: translateY(-1px);
}

.category-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.category-name {
    font-weight: 600;
    color: var(--text-color);
    font-size: 0.95rem;
}

.category-ratio {
    font-weight: 700;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    font-size: 0.9rem;
}

.ratio-high {
    background: #ffebee;
    color: #c62828;
}

.ratio-medium {
    background: #fff3e0;
    color: #ef6c00;
}

.ratio-low {
    background: #e8f5e8;
    color: #2e7d32;
}

.category-stats {
    color: var(--text-light);
    font-size: 0.85rem;
}

@media (max-width: 768px) {
    .score-display {
        flex-direction: column;
        text-align: center;
    }
    
    .score-circle {
        width: 100px;
        height: 100px;
    }
    
    .score-number {
        font-size: 2rem;
    }
    
    .category-header {
        flex-direction: column;
        gap: var(--spacing-xs);
        align-items: flex-start;
    }
}

/* 기능 안내 섹션 스타일 */
.feature-guide {
    margin: var(--spacing-md) 0;
    text-align: center;
}

.simple-guide {
    padding: var(--spacing-md);
    background: var(--secondary-color);
    border-radius: var(--border-radius-md);
    font-size: 0.95rem;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.quiz-info {
    margin-top: var(--spacing-sm);
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
}

.guide-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.guide-item {
    background: white;
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(22, 160, 133, 0.1);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.guide-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.guide-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
}

.guide-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 1.2rem;
}

.guide-content h3 {
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
    font-weight: 600;
}

.guide-content p {
    color: var(--text-medium);
    margin-bottom: var(--spacing-md);
    line-height: 1.5;
    font-size: 0.95rem;
}

.guide-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.guide-content li {
    color: var(--text-medium);
    margin-bottom: var(--spacing-xs);
    position: relative;
    padding-left: var(--spacing-md);
    font-size: 0.9rem;
}

.guide-content li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

@media (max-width: 768px) {
    .feature-guide {
        margin: var(--spacing-md) 0;
        padding: var(--spacing-md);
    }
    
    .guide-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .guide-item {
        padding: var(--spacing-md);
    }
    
    .guide-icon {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
    
    .feature-guide h2 {
        font-size: 1.3rem;
    }
}