/* GESP编程能力等级考试真题练习平台 - 样式表 v2 */

/* ===== CSS Reset & Variables ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #4F46E5;
    --primary-light: #6366F1;
    --primary-dark: #3730A3;
    --primary-bg: #EEF2FF;
    --secondary: #0EA5E9;
    --accent: #F59E0B;
    --success: #10B981;
    --success-bg: #ECFDF5;
    --danger: #EF4444;
    --danger-bg: #FEF2F2;
    --warning: #F59E0B;
    --warning-bg: #FFFBEB;
    --info: #3B82F6;
    --info-bg: #EFF6FF;
    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-300: #D1D5DB;
    --gray-400: #9CA3AF;
    --gray-500: #6B7280;
    --gray-600: #4B5563;
    --gray-700: #374151;
    --gray-800: #1F2937;
    --gray-900: #111827;
    --text: #1F2937;
    --text-light: #6B7280;
    --text-muted: #9CA3AF;
    --border: #E5E7EB;
    --bg: #F9FAFB;
    --white: #FFFFFF;
    --radius: 12px;
    --radius-sm: 8px;
    --radius-xs: 6px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.1), 0 8px 10px rgba(0,0,0,0.05);
    --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Base ===== */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    font-size: 15px;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover {
    color: var(--primary-dark);
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header ===== */
.header {
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border);
}
.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}
.logo a {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.3px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.logo a:hover { color: var(--primary-dark); }
.logo a::before {
    content: '🐍';
    font-size: 22px;
}
.nav {
    display: flex;
    gap: 4px;
}
.nav a {
    color: var(--gray-600);
    padding: 8px 16px;
    border-radius: var(--radius-xs);
    font-size: 14px;
    font-weight: 500;
    transition: all var(--transition);
}
.nav a:hover {
    background: var(--primary-bg);
    color: var(--primary);
    text-decoration: none;
}
.nav a.active {
    background: var(--primary-bg);
    color: var(--primary);
}
.user-area {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
}
.user-area .username {
    color: var(--gray-700);
    font-weight: 500;
}
.user-area .btn { font-size: 13px; }

/* Hamburger */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 32px;
    height: 32px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    z-index: 1002;
    border-radius: var(--radius-xs);
}
.menu-toggle:hover { background: var(--gray-100); }
.menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--gray-600);
    border-radius: 2px;
    transition: all 0.3s;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 22px;
    border: none;
    border-radius: var(--radius-xs);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    text-align: center;
    transition: all var(--transition);
    white-space: nowrap;
    line-height: 1.4;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 1px 3px rgba(79,70,229,0.3);
}
.btn-primary:hover {
    background: var(--primary-light);
    color: #fff;
    box-shadow: 0 4px 12px rgba(79,70,229,0.35);
}

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-700);
    border: 1px solid var(--gray-200);
}
.btn-secondary:hover {
    background: var(--gray-200);
    color: var(--gray-800);
}

.btn-outline {
    background: transparent;
    border: 1.5px solid var(--primary);
    color: var(--primary);
}
.btn-outline:hover {
    background: var(--primary);
    color: #fff;
}

.btn-success {
    background: var(--success);
    color: #fff;
    box-shadow: 0 1px 3px rgba(16,185,129,0.3);
}
.btn-success:hover { background: #059669; color: #fff; }

.btn-warning {
    background: var(--warning);
    color: #fff;
    box-shadow: 0 1px 3px rgba(245,158,11,0.3);
}
.btn-warning:hover { background: #D97706; color: #fff; }

.btn-danger {
    background: var(--danger);
    color: #fff;
    box-shadow: 0 1px 3px rgba(239,68,68,0.3);
}
.btn-danger:hover { background: #DC2626; color: #fff; }

.btn-sm { padding: 6px 14px; font-size: 13px; border-radius: var(--radius-xs); }
.btn-xs { padding: 4px 10px; font-size: 12px; border-radius: 4px; }
.btn-lg { padding: 14px 32px; font-size: 16px; border-radius: var(--radius-sm); }
.btn-block { width: 100%; }

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* ===== Forms ===== */
.form-group { margin-bottom: 18px; }
.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    font-size: 14px;
    color: var(--gray-700);
}
.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 14px 18px;
    border: 2px solid var(--gray-200);
    border-radius: 9999px;
    font-size: 14px;
    font-family: inherit;
    color: var(--text);
    background: #fff;
    transition: all var(--transition);
}
.form-input::placeholder,
.form-textarea::placeholder,
.form-select::placeholder {
    color: var(--text-muted);
    opacity: 0.7;
}
.form-input:hover,
.form-select:hover,
.form-textarea:hover {
    border-color: var(--gray-300);
    background: var(--gray-50);
}
.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.12);
}
.form-textarea {
    resize: vertical;
    min-height: 100px;
    line-height: 1.6;
}

/* ===== Cards ===== */
.card {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    margin-bottom: 20px;
    transition: box-shadow var(--transition);
}
.card:hover { box-shadow: var(--shadow); }
.card-header {
    padding: 18px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.card-header h3 { font-size: 16px; font-weight: 600; margin: 0; }
.card-body { padding: 24px; }

/* ===== Tables ===== */
.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}
.data-table th,
.data-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--gray-100);
}
.data-table th {
    background: var(--gray-50);
    font-weight: 600;
    color: var(--gray-600);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}
.data-table tr:hover { background: var(--gray-50); }
.data-table tr:last-child td { border-bottom: none; }

/* ===== Tags ===== */
.tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}
.tag-primary { background: var(--primary-bg); color: var(--primary); }
.tag-success { background: var(--success-bg); color: #059669; }
.tag-warning { background: var(--warning-bg); color: #B45309; }
.tag-danger { background: var(--danger-bg); color: #DC2626; }
.tag-info { background: var(--info-bg); color: #2563EB; }
.tag-gray { background: var(--gray-100); color: var(--gray-600); }

/* Type tags */
.type-tag {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}
.type-single { background: #DBEAFE; color: #1D4ED8; }
.type-judge { background: #D1FAE5; color: #047857; }
.type-programming { background: #FCE7F3; color: #BE185D; }

.lang-tag {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
    background: var(--primary-bg);
    color: var(--primary);
}

/* ===== Alerts ===== */
.alert {
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    margin: 16px 0;
    font-size: 14px;
    border-left: 4px solid;
}
.alert-success {
    background: var(--success-bg);
    color: #065F46;
    border-left-color: var(--success);
}
.alert-error {
    background: var(--danger-bg);
    color: #991B1B;
    border-left-color: var(--danger);
}
.alert-warning {
    background: var(--warning-bg);
    color: #92400E;
    border-left-color: var(--warning);
}
.alert-info {
    background: var(--info-bg);
    color: #1E40AF;
    border-left-color: var(--info);
}

/* ===== Pagination ===== */
.pagination-wrapper {
    display: flex;
    justify-content: center;
    gap: 4px;
    padding: 24px;
}
.pagination-wrapper a {
    padding: 8px 14px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xs);
    color: var(--gray-600);
    font-size: 14px;
    font-weight: 500;
    transition: all var(--transition);
}
.pagination-wrapper a:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-bg);
    text-decoration: none;
}
.pagination-wrapper a.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ===== Hero ===== */
.hero {
    background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 50%, #0EA5E9 100%);
    color: #fff;
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.08) 0%, transparent 50%);
    pointer-events: none;
}
.hero h1 {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
    position: relative;
}
.hero .subtitle {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 36px;
    position: relative;
    font-weight: 400;
}
.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    position: relative;
}
.hero .btn {
    padding: 14px 36px;
    font-size: 16px;
    border-radius: var(--radius-sm);
    font-weight: 600;
}
.hero .btn-primary {
    background: #fff;
    color: var(--primary);
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}
.hero .btn-primary:hover {
    background: #F8FAFC;
    box-shadow: 0 6px 20px rgba(0,0,0,0.2);
}
.hero .btn-outline {
    border-color: rgba(255,255,255,0.6);
    color: #fff;
}
.hero .btn-outline:hover {
    background: rgba(255,255,255,0.15);
    border-color: #fff;
    color: #fff;
}

/* ===== Page Header ===== */
.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 32px 0 24px;
    gap: 12px;
    flex-wrap: wrap;
}
.page-header h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--gray-900);
}

.question-nav {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-top: 18px;
    flex-wrap: wrap;
}
.question-nav .btn { min-width: 110px; justify-content: center; }

/* ===== Question Detail (new!) ===== */
.question-detail { overflow: hidden; }

.question-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 16px 24px;
    background: var(--gray-50);
    border-bottom: 1px solid var(--border);
}

.question-body {
    padding: 28px 24px;
}

.question-title {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.8;
    color: var(--gray-900);
    margin-bottom: 20px;
    word-break: break-word;
}
.question-title pre { background: #1e1e1e; color: #d4d4d4; border-radius: 8px; padding: 16px 20px; font-family: Consolas, 'Courier New', monospace; font-size: 13px; line-height: 1.6; overflow-x: auto; margin: 10px 0; }
.question-title code { background: #f1f5f9; color: #334155; border-radius: 4px; padding: 2px 6px; font-family: Consolas, 'Courier New', monospace; font-size: 13px; }
.question-title pre code { background: transparent; color: inherit; padding: 0; border-radius: 0; font-size: inherit; }

.question-image {
    margin: 16px 0 24px;
    text-align: center;
}
.question-image img {
    max-width: 100%;
    max-height: 400px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
}

/* Option items in detail page */
.option-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin: 20px 0;
}
.option-item {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 18px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition);
    background: #fff;
    font-size: 15px;
}
.option-item:hover {
    border-color: var(--primary-light);
    background: var(--primary-bg);
}
.option-item.selected {
    border-color: var(--primary);
    background: var(--primary-bg);
    box-shadow: 0 0 0 2px rgba(79,70,229,0.15);
}
.option-item .opt-letter {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--gray-100);
    color: var(--gray-600);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 15px;
    flex-shrink: 0;
    transition: all var(--transition);
}
.option-item.selected .opt-letter {
    background: var(--primary);
    color: #fff;
}
.option-item .opt-text { flex: 1; }

/* Judge buttons */
.judge-buttons {
    display: flex;
    gap: 16px;
    margin: 24px 0;
}
.judge-btn {
    flex: 1;
    padding: 20px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    background: #fff;
    cursor: pointer;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    transition: all var(--transition);
}
.judge-btn:hover {
    border-color: var(--primary-light);
    background: var(--primary-bg);
}
.judge-btn.selected {
    border-color: var(--primary);
    background: var(--primary-bg);
    color: var(--primary);
    box-shadow: 0 0 0 2px rgba(79,70,229,0.15);
}
.judge-btn.correct-btn { color: var(--success); }
.judge-btn.correct-btn.selected {
    border-color: var(--success);
    background: var(--success-bg);
    color: #059669;
}
.judge-btn.wrong-btn { color: var(--danger); }
.judge-btn.wrong-btn.selected {
    border-color: var(--danger);
    background: var(--danger-bg);
    color: #DC2626;
}

/* Answer area */
.answer-area {
    margin: 24px 0;
    padding: 24px;
    background: var(--gray-50);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
}
.answer-area.hidden { display: none; }

.answer-bar {
    padding: 16px 20px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.answer-bar.correct {
    background: var(--success-bg);
    color: #065F46;
    border: 1px solid #A7F3D0;
}
.answer-bar.incorrect {
    background: var(--danger-bg);
    color: #991B1B;
    border: 1px solid #FECACA;
}
.answer-bar .icon { font-size: 20px; }

.answer-section {
    background: #fff;
    padding: 16px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--gray-200);
    margin-bottom: 12px;
}
.answer-section h3 {
    font-size: 13px;
    font-weight: 600;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}
.answer-value {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}

.explanation-section {
    background: #fff;
    padding: 16px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--gray-200);
}
.explanation-section h3 {
    font-size: 13px;
    font-weight: 600;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}
.explanation-content {
    font-size: 14px;
    line-height: 1.8;
    color: var(--gray-700);
}

/* Submit button area */
.submit-area {
    display: flex;
    justify-content: center;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}
.submit-area .btn-lg {
    min-width: 200px;
}

/* Login prompt */
.login-prompt {
    text-align: center;
    padding: 40px 24px;
}
.login-prompt p {
    font-size: 16px;
    color: var(--gray-500);
    margin-bottom: 20px;
}
.login-prompt .btn-group {
    display: flex;
    gap: 12px;
    justify-content: center;
}

/* ===== Exam ===== */
.exam-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 24px;
}
.exam-header {
    background: #fff;
    border-radius: var(--radius);
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}
.exam-timer {
    font-size: 28px;
    font-weight: 700;
    color: var(--danger);
    font-variant-numeric: tabular-nums;
}
.questions-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 20px;
    padding: 12px;
    background: #fff;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
}
.nav-btn {
    width: 38px;
    height: 38px;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius-xs);
    background: #fff;
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    color: var(--gray-600);
    transition: all var(--transition);
}
.nav-btn:hover { border-color: var(--primary); color: var(--primary); }
.nav-btn.active {
    border-color: var(--primary);
    background: var(--primary);
    color: #fff;
}
.nav-btn.answered {
    background: var(--success-bg);
    border-color: var(--success);
    color: #059669;
}
.nav-btn.current { box-shadow: 0 0 0 3px rgba(79,70,229,0.2); }
.question-panel {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}
.question-number {
    font-size: 16px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}
.question-type {
    color: var(--text-light);
    margin-bottom: 20px;
    font-size: 13px;
}
.question-title {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 28px;
    color: var(--gray-900);
    word-break: break-word;
}
.question-title pre { background: #1e1e1e; color: #d4d4d4; border-radius: 8px; padding: 16px 20px; font-family: Consolas, 'Courier New', monospace; font-size: 13px; line-height: 1.6; overflow-x: auto; margin: 10px 0; }
.question-title code { background: #f1f5f9; color: #334155; border-radius: 4px; padding: 2px 6px; font-family: Consolas, 'Courier New', monospace; font-size: 13px; }
.question-title pre code { background: transparent; color: inherit; padding: 0; border-radius: 0; font-size: inherit; }
.question-options { display: flex; flex-direction: column; gap: 12px; }
.option-label {
    display: flex;
    align-items: flex-start;
    padding: 14px 18px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition);
}
.option-label:hover { border-color: var(--primary-light); background: var(--primary-bg); }
.option-label input { margin-right: 12px; margin-top: 3px; }
.option-letter {
    font-weight: 700;
    margin-right: 10px;
    color: var(--gray-400);
}
.question-actions {
    display: flex;
    justify-content: space-between;
    margin-top: 32px;
}
.exam-footer {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-top: 28px;
}

/* ===== Score Report ===== */
.score-overview {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px;
    display: flex;
    align-items: center;
    gap: 48px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}
.score-circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #fff;
    box-shadow: 0 8px 24px rgba(79,70,229,0.25);
    flex-shrink: 0;
}
.score-value { font-size: 42px; font-weight: 800; line-height: 1; }
.score-label { font-size: 15px; opacity: 0.9; }
.score-details {
    flex: 1;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.detail-item { display: flex; flex-direction: column; }
.detail-item .label { color: var(--text-light); font-size: 13px; }
.detail-item .value { font-size: 22px; font-weight: 600; color: var(--gray-900); }

/* ===== Stats ===== */
.stats-section { padding: 60px 0; }
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.stat-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 28px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all var(--transition);
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.stat-icon { font-size: 36px; margin-bottom: 12px; }
.stat-value { font-size: 32px; font-weight: 800; color: var(--primary); }
.stat-label { color: var(--text-light); margin-top: 6px; font-size: 14px; }

/* ===== Features ===== */
.features { padding: 60px 0; background: #fff; }
.section-title {
    text-align: center;
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 48px;
    color: var(--gray-900);
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.feature-card {
    text-align: center;
    padding: 32px 24px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: #fff;
    transition: all var(--transition);
}
.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}
.feature-icon { font-size: 44px; margin-bottom: 16px; }
.feature-card h3 { font-size: 17px; margin-bottom: 8px; color: var(--gray-900); }
.feature-card p { font-size: 14px; color: var(--text-light); }

/* ===== Categories ===== */
.categories-section { padding: 60px 0; }
.categories-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.category-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}
.category-card:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
    text-decoration: none;
}
.category-number {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 16px;
    flex-shrink: 0;
}
.category-name { font-size: 16px; font-weight: 500; color: var(--gray-800); }

/* ===== Auth ===== */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: calc(100vh - 200px);
    padding: 60px 24px;
    background: linear-gradient(135deg, #EEF2FF 0%, #E0E7FF 50%, #F0F9FF 100%);
}
.auth-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 48px 40px;
    width: 100%;
    max-width: 440px;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}
.auth-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
}
.auth-header {
    text-align: center;
    margin-bottom: 36px;
}
.auth-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-bg), #fff);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    margin: 0 auto 16px;
    box-shadow: 0 4px 12px rgba(79,70,229,0.15);
}
.auth-card h2 {
    text-align: center;
    margin-bottom: 8px;
    font-size: 26px;
    font-weight: 800;
    color: var(--gray-900);
    letter-spacing: -0.3px;
}
.auth-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 14px;
    margin: 0;
}
.auth-footer {
    text-align: center;
    margin-top: 24px;
    font-size: 14px;
    color: var(--text-light);
}
.auth-footer a {
    font-weight: 600;
}
.test-account, .notice {
    background: var(--warning-bg);
    padding: 16px;
    border-radius: var(--radius-sm);
    margin-top: 20px;
    font-size: 13px;
    border: 1px solid #FDE68A;
}
.password-rules {
    margin-top: 10px;
    font-size: 12px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    color: var(--text-muted);
}
.password-rules span { transition: color 0.2s; }
.auth-form .form-group { margin-bottom: 22px; }
.auth-form .form-group label { margin-bottom: 8px; color: var(--gray-800); font-weight: 600; }
.auth-form .btn { border-radius: 9999px; padding: 14px 24px; font-weight: 600; letter-spacing: 0.2px; }

/* ===== User Center ===== */
.user-stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 28px;
}
.stat-box {
    background: #fff;
    border-radius: var(--radius);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all var(--transition);
}
.stat-box:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.stat-box .stat-icon { font-size: 32px; margin: 0; }
.stat-info .stat-value { font-size: 26px; }
.user-content-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.quick-actions { display: flex; gap: 16px; margin-top: 28px; }

/* ===== Wrong Book ===== */
.wrongbook-stats {
    display: flex;
    align-items: center;
    gap: 32px;
    background: #fff;
    padding: 24px;
    border-radius: var(--radius);
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
}
.stat-item { text-align: center; flex: 1; }
.stat-item .stat-value { font-size: 28px; font-weight: 800; color: var(--primary); }
.stat-item .stat-label { color: var(--text-light); font-size: 13px; }

/* ===== Admin ===== */
.admin-container { display: flex; min-height: calc(100vh - 64px); }
.admin-sidebar {
    width: 240px;
    background: var(--gray-800);
    color: #fff;
    padding: 24px 0;
}
.admin-sidebar h3 {
    padding: 0 24px;
    margin-bottom: 24px;
    font-size: 16px;
    font-weight: 600;
    color: rgba(255,255,255,0.6);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 12px;
}
.admin-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 24px;
    color: rgba(255,255,255,0.65);
    font-size: 14px;
    transition: all var(--transition);
    border-left: 3px solid transparent;
}
.admin-nav a:hover,
.admin-nav a.active {
    background: rgba(255,255,255,0.08);
    color: #fff;
    text-decoration: none;
    border-left-color: var(--primary-light);
}
.admin-content { flex: 1; padding: 32px; background: var(--bg); }

/* ===== Modals ===== */
.modal {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}
.modal-content {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px;
    width: 90%;
    max-width: 520px;
    box-shadow: var(--shadow-xl);
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}
.modal-header h3 { font-size: 18px; font-weight: 600; }
.close { font-size: 24px; cursor: pointer; color: var(--gray-400); }
.close:hover { color: var(--gray-600); }

/* ===== Empty State ===== */
.empty-state, .empty-tip {
    text-align: center;
    padding: 60px 24px;
    color: var(--text-light);
}
.empty-state p, .empty-tip p { font-size: 15px; margin-top: 8px; }

/* ===== Footer ===== */
.footer {
    background: var(--gray-800);
    color: rgba(255,255,255,0.6);
    padding: 32px 0;
    text-align: center;
    font-size: 13px;
    margin-top: 60px;
}
.footer p { margin: 6px 0; }
.footer .features { font-size: 12px; margin-top: 12px; opacity: 0.5; }

/* ===== Score Color ===== */
.score.pass { color: var(--success); }
.score.fail { color: var(--danger); }
.text-success { color: var(--success) !important; }
.text-error { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-muted { color: var(--text-muted) !important; }
.text-primary { color: var(--primary) !important; }

/* ===== Exam Select ===== */
.exam-modes {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 28px;
}
.exam-mode-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 28px 20px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all var(--transition);
}
.exam-mode-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}
.mode-icon { font-size: 44px; margin-bottom: 14px; }
.exam-mode-card h3 { font-size: 16px; margin-bottom: 8px; }
.exam-mode-card p { font-size: 13px; color: var(--text-light); margin-bottom: 16px; }
.custom-select { padding: 28px; }
.custom-select h3 { margin-bottom: 24px; font-size: 18px; }
.form-section { margin-bottom: 20px; }
.form-section h4 { font-size: 14px; margin-bottom: 12px; color: var(--gray-700); }
.category-checkboxes { display: flex; flex-wrap: wrap; gap: 14px; }
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 14px;
    padding: 8px 14px;
    border: 1.5px solid var(--gray-200);
    border-radius: 20px;
    transition: all var(--transition);
}
.checkbox-label:hover { border-color: var(--gray-300); background: var(--gray-50); }
.checkbox-label:has(input:checked) {
    border-color: var(--primary);
    background: var(--primary-bg);
    color: var(--primary);
}
.difficulty-range { display: flex; align-items: center; gap: 12px; font-size: 14px; }
.count-options { display: flex; flex-wrap: wrap; gap: 10px; }
.radio-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 8px 16px;
    border: 1.5px solid var(--gray-200);
    border-radius: 20px;
    font-size: 14px;
    transition: all var(--transition);
}
.radio-label:hover { border-color: var(--gray-300); }
.radio-label:has(input:checked) {
    border-color: var(--primary);
    background: var(--primary-bg);
    color: var(--primary);
}
.smart-select { padding: 32px; text-align: center; }
.smart-select h3 { margin-bottom: 10px; }
.smart-select p { color: var(--text-light); margin-bottom: 20px; font-size: 14px; }

/* ===== Guide ===== */
.guide-section { padding: 60px 0; background: #fff; }
.guide-steps { display: flex; gap: 32px; justify-content: center; }
.guide-step {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    flex: 1;
    max-width: 260px;
}
.step-number {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}
.step-content h4 { font-size: 16px; margin-bottom: 6px; }
.step-content p { font-size: 14px; color: var(--text-light); }

/* ===== Language Cards ===== */
.language-card {
    text-align: center;
    padding: 32px 24px;
    text-decoration: none;
    color: inherit;
    transition: all var(--transition);
    border: 1.5px solid var(--border);
}
.language-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}
.lang-icon { font-size: 48px; margin-bottom: 12px; }
.language-card h3 { font-size: 18px; margin-bottom: 4px; color: var(--gray-900); }
.language-card .lang-count {
    display: inline-block;
    margin-top: 10px;
    padding: 4px 14px;
    background: var(--primary-bg);
    color: var(--primary);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

/* ===== Score Chart ===== */
.score-chart {
    display: flex;
    align-items: flex-end;
    gap: 10px;
    height: 160px;
    padding: 10px 0;
}
.score-bar {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    height: 100%;
}
.score-fill {
    width: 100%;
    background: linear-gradient(to top, var(--primary), var(--secondary));
    border-radius: 6px 6px 0 0;
    transition: height 0.5s ease;
    min-height: 4px;
}
.score-bar .score-value { font-size: 11px; color: var(--text-light); }
.score-bar .score-label { font-size: 11px; color: var(--text-muted); white-space: nowrap; }

/* ===== Progress ===== */
.progress-list { display: flex; flex-direction: column; gap: 16px; }
.progress-item { display: flex; flex-direction: column; gap: 6px; }
.progress-label {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    color: var(--gray-600);
}
.progress-bar {
    height: 8px;
    background: var(--gray-200);
    border-radius: 4px;
    overflow: hidden;
}
.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 4px;
    transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Admin Stats ===== */
.admin-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 28px;
}
.admin-stat-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    border-left: 4px solid var(--primary);
    transition: all var(--transition);
}
.admin-stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.admin-stat-card .icon { font-size: 36px; }
.admin-stat-card .value { font-size: 28px; font-weight: 800; color: var(--gray-900); }
.admin-stat-card .label { font-size: 13px; color: var(--text-light); }

.quick-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 28px;
}
.quick-link {
    background: #fff;
    padding: 28px;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all var(--transition);
}
.quick-link:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
}
.quick-link .link-icon { font-size: 36px; margin-bottom: 8px; }
.quick-link h4 { font-size: 15px; color: var(--gray-800); }

/* ===== Stats Overview ===== */
.stats-overview {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    padding: 10px 0;
}
.overview-item {
    text-align: center;
    padding: 20px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: all var(--transition);
}
.overview-item:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.overview-value { font-size: 28px; font-weight: 800; color: var(--primary); line-height: 1.2; }
.overview-label { font-size: 13px; color: var(--text-light); margin-top: 6px; }

/* ===== Suggestions ===== */
.suggestions-card {
    background: linear-gradient(135deg, var(--info-bg) 0%, #fff 100%);
    border: none;
    border-left: 4px solid var(--info);
}
.suggestions-list { display: flex; flex-direction: column; gap: 12px; }
.suggestion-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    background: #fff;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}
.suggestion-icon { font-size: 24px; flex-shrink: 0; }
.suggestion-content h4 { font-size: 14px; margin-bottom: 4px; }
.suggestion-content p { font-size: 13px; color: var(--text-light); margin: 0; }

/* ===== Difficulty Bars ===== */
.difficulty-bars { display: flex; flex-direction: column; gap: 16px; }
.diff-item {
    background: var(--gray-50);
    padding: 14px 16px;
    border-radius: var(--radius-sm);
}
.diff-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-size: 14px;
}
.diff-label .diff-percent { font-weight: 700; color: var(--primary); }
.diff-bar {
    height: 10px;
    background: var(--gray-200);
    border-radius: 5px;
    overflow: hidden;
}
.diff-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 5px;
    transition: width 0.8s ease;
}
.diff-count { font-size: 12px; color: var(--text-light); margin-top: 6px; }

/* ===== Legend ===== */
.mastery-legend { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 12px; }
.legend-item { display: flex; align-items: center; gap: 10px; font-size: 13px; }
.legend-color { width: 12px; height: 12px; border-radius: 3px; flex-shrink: 0; }
.legend-name { flex: 1; }
.legend-value { font-weight: 700; color: var(--primary); }

/* ===== Content Header ===== */
.content-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}
.content-header h2 { margin: 0; font-size: 20px; font-weight: 700; }
.header-actions { display: flex; gap: 10px; }

/* ===== Tab Nav ===== */
.tab-nav { display: flex; gap: 4px; margin-top: 6px; }
.tab-nav a {
    padding: 7px 18px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-light);
    border: 1.5px solid var(--gray-200);
    transition: all var(--transition);
}
.tab-nav a:hover {
    border-color: var(--gray-300);
    color: var(--gray-700);
    text-decoration: none;
}
.tab-nav a.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ===== Filter ===== */
.filter-card { padding: 16px 24px; }
.filter-toggle { margin-bottom: 12px; }
.filter-form { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.filter-form .form-select { width: auto; min-width: 140px; }
.filter-form .form-input { width: auto; min-width: 180px; }
.filter-actions { display: flex; gap: 10px; align-items: center; }

/* Question list */
.question-list { display: flex; flex-direction: column; gap: 12px; }
.question-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 14px 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: inherit;
    transition: all var(--transition);
}
.question-card:hover {
    border-color: var(--primary-light);
    background: var(--primary-bg);
}
.question-card-main { display: flex; align-items: flex-start; gap: 12px; min-width: 0; }
.question-card-index {
    width: 32px; height: 32px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: 999px;
    background: var(--gray-100);
    color: var(--gray-600);
    font-weight: 700;
    font-size: 13px;
    flex-shrink: 0;
}
.question-card-body { min-width: 0; display: flex; flex-direction: column; justify-content: space-between; }
.question-card-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-900);
    line-height: 1.5;
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.question-card-meta { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.question-card-action { flex-shrink: 0; }

/* ===== Content Area ===== */
.main {
    min-height: calc(100vh - 64px - 100px);
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
    padding: 14px 24px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease;
    max-width: 400px;
}
.toast-success { background: var(--success); color: #fff; }
.toast-error { background: var(--danger); color: #fff; }
.toast-info { background: var(--info); color: #fff; }
@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* ===== Image Upload ===== */
.image-upload-group { display: flex; flex-direction: column; gap: 10px; }
.image-preview {
    min-height: 40px;
    padding: 12px;
    background: var(--gray-50);
    border: 1.5px dashed var(--gray-300);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}
.form-help { font-size: 12px; color: var(--text-muted); margin: 0; }

/* ===== Navigation Overlay ===== */
.nav-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(2px);
    z-index: 1000;
}
.nav-overlay.active { display: block; }

/* ===== Difficulty star ===== */
.tag.difficulty { color: var(--accent); font-weight: 600; letter-spacing: 1px; }

/* ============================================ */
/* ===== RESPONSIVE ===== */
/* ============================================ */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .categories-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .container { padding: 0 16px; }

    .header .container > .user-area { display: none; }
    .menu-toggle { display: flex; }

    .nav {
        position: fixed;
        top: 0; right: -280px;
        width: 280px;
        height: 100vh;
        background: #fff;
        flex-direction: column;
        gap: 0;
        box-shadow: -8px 0 30px rgba(0,0,0,0.12);
        transition: right 0.3s ease;
        z-index: 1001;
        padding-top: 72px;
        overflow-y: auto;
    }
    .nav.open { right: 0; }
    .nav a {
        padding: 14px 24px;
        border-bottom: 1px solid var(--gray-100);
        color: var(--gray-700);
        font-size: 15px;
        border-radius: 0;
    }
    .nav a:hover { background: var(--gray-50); }
    body.nav-open { overflow: hidden; }
    .header .container { position: relative; z-index: 1003; }
    .header .logo,
    .header .user-area { position: relative; z-index: 1003; }

    .hero { padding: 60px 0; }
    .hero h1 { font-size: 28px; }
    .hero .subtitle { font-size: 15px; }
    .hero-buttons { flex-direction: column; align-items: center; gap: 12px; }
    .hero .btn-lg { width: 220px; }

    .stats-grid,
    .features-grid,
    .user-stats-grid,
    .admin-stats { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .categories-grid { grid-template-columns: 1fr; }
    .user-content-grid { grid-template-columns: 1fr; }

    .page-header { flex-direction: column; align-items: flex-start; gap: 12px; }
    .page-header h1 { font-size: 20px; }

    .question-detail .question-body { padding: 20px 16px; }
    .question-title { font-size: 16px; }
    .option-item { padding: 12px 14px; font-size: 14px; }
    .judge-btn { padding: 16px; font-size: 16px; }
    .answer-area { padding: 16px; }

    .exam-container { padding: 12px; }
    .exam-header { flex-direction: column; gap: 12px; align-items: flex-start; padding: 16px; }
    .exam-timer { font-size: 22px; }
    .exam-modes { grid-template-columns: repeat(2, 1fr); }
    .question-panel { padding: 20px 16px; }
    .question-title { font-size: 15px; }
    .option-label { padding: 12px; }
    .question-actions { flex-direction: column; gap: 10px; }
    .question-actions .btn { width: 100%; }
    .exam-footer { flex-direction: column; }
    .exam-footer .btn { width: 100%; }

    .score-overview { flex-direction: column; gap: 24px; padding: 24px; }
    .score-circle { width: 120px; height: 120px; }
    .score-value { font-size: 32px; }
    .score-details { grid-template-columns: 1fr; gap: 16px; }

    .auth-container { padding: 30px 16px; }
    .auth-card { padding: 28px 20px; }

    .admin-container { flex-direction: column; }
    .admin-sidebar {
        width: 100%; height: auto;
        display: flex; flex-wrap: wrap;
        padding: 12px 0;
    }
    .admin-sidebar h3 { display: none; }
    .admin-nav { display: flex; flex-wrap: wrap; width: 100%; }
    .admin-nav a { padding: 10px 14px; font-size: 13px; border: none; border-right: 1px solid rgba(255,255,255,0.1); }
    .admin-content { padding: 16px; }
    .admin-stats { grid-template-columns: 1fr 1fr; gap: 12px; }
    .quick-links { grid-template-columns: 1fr 1fr; gap: 12px; }

    .data-table { font-size: 13px; }
    .data-table th, .data-table td { padding: 8px 10px; }
    .pagination-wrapper a { padding: 6px 10px; font-size: 13px; }

    .guide-steps { flex-wrap: wrap; gap: 20px; }
    .guide-step { max-width: 100%; }

    .wrongbook-stats { flex-wrap: wrap; gap: 16px; }
    .stat-item { flex: 1; min-width: 80px; }

    .modal-content { padding: 24px 16px; width: 95%; }
    .footer { padding: 24px 0; font-size: 12px; }
    .nav-btn { width: 32px; height: 32px; font-size: 12px; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 24px; }
    .hero .subtitle { font-size: 14px; }
    .hero .btn-lg { width: 180px; font-size: 14px; }

    .stats-grid,
    .user-stats-grid,
    .admin-stats,
    .exam-modes { grid-template-columns: 1fr; }
    .quick-links { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }

    .score-details { grid-template-columns: 1fr; }
    .option-item { padding: 10px 12px; }
    .option-item .opt-letter { width: 32px; height: 32px; font-size: 14px; }
}

/* ===== 考试完整翻页控制器 ===== */
.full-pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 20px;
    padding: 16px;
    background: var(--gray-50);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
}

.full-pagination .btn {
    padding: 8px 14px;
    font-size: 13px;
    border-radius: var(--radius-xs);
    border: 1px solid var(--gray-200);
    background: #fff;
    color: var(--gray-600);
    cursor: pointer;
    transition: all var(--transition);
}

.full-pagination .btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-bg);
}

.page-info {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--gray-600);
}

.page-input {
    width: 60px;
    padding: 6px 8px;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius-xs);
    font-size: 14px;
    text-align: center;
    color: var(--primary);
    font-weight: 600;
}

.page-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}

.pagination-wrapper a.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.pagination-ellipsis {
    padding: 8px 4px;
    color: var(--gray-400);
}

.pagination-info {
    padding: 8px 12px;
    color: var(--gray-500);
    font-size: 14px;
}

@media (max-width: 768px) {
    .full-pagination {
        flex-wrap: wrap;
        gap: 6px;
    }
    
    .full-pagination .btn {
        padding: 6px 10px;
        font-size: 12px;
    }
    
    .page-input {
        width: 50px;
        padding: 5px 6px;
        font-size: 13px;
    }
}