/* ================================================================
   AI体育教学平台 — 自定义样式表
   覆盖 Bootstrap 5 默认样式，统一视觉风格
   ================================================================ */

/* ===== 1. CSS 变量 ===== */
:root {
    --primary: #2563EB;
    --primary-dark: #1D4ED8;
    --primary-light: #3B82F6;
    --primary-rgb: 37, 99, 235;
    --accent: #F97316;
    --accent-dark: #EA580C;
    --success: #10B981;
    --success-light: #D1FAE5;
    --danger: #EF4444;
    --danger-light: #FEE2E2;
    --warning: #F59E0B;
    --warning-light: #FEF3C7;
    --info: #0EA5E9;
    --bg-light: #F8FAFC;
    --bg-dark: #0F172A;
    --bg-white: #FFFFFF;
    --text-primary: #1E293B;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --text-light: #CBD5E1;
    --border-color: #E2E8F0;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.15);
    --card-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.12);
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    --border-radius-pill: 50px;
    --sidebar-width: 240px;
    --navbar-height: 56px;
    --font-family-base: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei",
        "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
    --transition-slow: 0.35s ease;
}


/* ===== 2. 全局样式 ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-base);
    background-color: var(--bg-light);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
    color: var(--primary-dark);
}

::selection {
    background: rgba(var(--primary-rgb), 0.15);
    color: var(--primary-dark);
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 700;
}

.text-muted {
    color: var(--text-muted) !important;
}


/* ===== 3. 导航栏美化 ===== */
.top-navbar {
    background: var(--bg-white) !important;
    height: var(--navbar-height);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
    border-bottom: 1px solid var(--border-color);
    z-index: 1030;
    transition: box-shadow var(--transition-normal);
}

.top-navbar .navbar-brand {
    color: var(--primary) !important;
    font-weight: 800;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
}

.top-navbar .navbar-brand i {
    color: var(--accent);
}

.top-navbar .nav-link {
    color: var(--text-secondary) !important;
    font-weight: 500;
    font-size: 0.92rem;
    padding: 0.5rem 0.85rem !important;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.top-navbar .nav-link:hover {
    color: var(--primary) !important;
    background: rgba(var(--primary-rgb), 0.06);
    opacity: 1 !important;
}

.top-navbar .nav-link.active {
    color: var(--primary) !important;
    background: rgba(var(--primary-rgb), 0.1);
}

.top-navbar .dropdown-toggle {
    color: var(--text-secondary) !important;
}

.top-navbar .badge {
    font-size: 0.7rem;
    font-weight: 600;
}

/* 退出按钮白底导航适配 */
.top-navbar .btn-outline-light {
    color: var(--text-secondary);
    border-color: var(--border-color);
}

.top-navbar .btn-outline-light:hover {
    color: var(--danger);
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.06);
}

/* 用户名区域 */
.top-navbar .ms-auto .text-white {
    color: var(--text-secondary) !important;
}

/* 移动端汉堡按钮适配白底 */
.top-navbar #sidebarToggle {
    color: var(--text-secondary) !important;
}

.top-navbar .navbar-toggler {
    color: var(--text-secondary) !important;
}

.top-navbar .navbar-toggler .bi {
    color: var(--text-secondary);
}


/* ===== 4. 侧边栏美化 ===== */
.sidebar {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-white);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    z-index: 1020;
    transition: transform 0.25s ease;
    padding-top: 0.5rem;
}

/* 侧边栏滚动条美化 */
.sidebar::-webkit-scrollbar {
    width: 4px;
}

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

.sidebar::-webkit-scrollbar-thumb {
    background: var(--text-light);
    border-radius: 4px;
}

.sidebar .nav-link {
    color: var(--text-secondary);
    padding: 0.7rem 1.25rem;
    margin: 2px 10px;
    border-radius: var(--border-radius-sm);
    font-size: 0.92rem;
    font-weight: 500;
    position: relative;
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.sidebar .nav-link .bi {
    margin-right: 0.6rem;
    font-size: 1.1rem;
    vertical-align: -1px;
}

.sidebar .nav-link:hover {
    background: rgba(var(--primary-rgb), 0.06);
    color: var(--primary);
    border-left-color: rgba(var(--primary-rgb), 0.3);
}

.sidebar .nav-link.active {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary);
    font-weight: 600;
    border-left-color: var(--primary);
}

/* 内容区域 — 教师端 */
.main-with-sidebar {
    margin-left: var(--sidebar-width);
    padding: 1.5rem 2rem;
    min-height: calc(100vh - var(--navbar-height));
}

/* 内容区域 — 学生端 */
.main-no-sidebar {
    padding: 1.5rem 2rem;
    min-height: calc(100vh - var(--navbar-height));
}


/* ===== 5. 卡片样式 ===== */
.card {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    overflow: hidden;
}

.card:hover {
    box-shadow: var(--card-shadow-hover);
}

.card-header {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.25rem;
    font-weight: 600;
}

.card-body {
    padding: 1.25rem;
}

/* 统计卡片 */
.stat-card {
    border-radius: var(--border-radius) !important;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal) !important;
    cursor: default;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1) !important;
}

.stat-card .fs-3 {
    font-size: 1.85rem !important;
    font-weight: 800 !important;
    letter-spacing: -0.03em;
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    flex-shrink: 0;
}

/* 图表卡片 */
.chart-card {
    border-radius: var(--border-radius) !important;
    transition: box-shadow var(--transition-normal) !important;
}

.chart-card:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08) !important;
}


/* ===== 6. 表格美化 ===== */
.table {
    margin-bottom: 0;
}

.table-card {
    border-radius: var(--border-radius);
    overflow: hidden;
}

.table thead th {
    background: #F1F5F9;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    border-bottom: 2px solid var(--border-color);
    padding: 0.85rem 1rem;
    white-space: nowrap;
}

.table tbody tr {
    transition: background var(--transition-fast);
}

.table tbody tr:nth-child(even) {
    background-color: #FAFBFD;
}

.table tbody tr:hover {
    background-color: rgba(var(--primary-rgb), 0.04) !important;
}

.table tbody td {
    padding: 0.75rem 1rem;
    vertical-align: middle;
    border-bottom: 1px solid #F1F5F9;
    font-size: 0.92rem;
}

.table-light {
    --bs-table-bg: #F1F5F9;
    --bs-table-border-color: var(--border-color);
}


/* ===== 7. 按钮样式 ===== */
.btn {
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    font-size: 0.9rem;
    padding: 0.45rem 1rem;
    transition: all var(--transition-fast);
    border: none;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 1px 3px rgba(var(--primary-rgb), 0.3);
}

.btn-primary:hover,
.btn-primary:focus {
    background: var(--primary-dark);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.35);
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: 0 1px 3px rgba(var(--primary-rgb), 0.3);
}

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

.btn-success:hover {
    background: #059669;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.35);
    transform: translateY(-1px);
}

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

.btn-danger:hover {
    background: #DC2626;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.35);
    transform: translateY(-1px);
}

.btn-warning {
    background: var(--warning);
    color: #fff;
}

.btn-warning:hover {
    background: #D97706;
    color: #fff;
}

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

.btn-outline-primary:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-1px);
}

.btn-outline-secondary {
    color: var(--text-secondary);
    border: 1.5px solid var(--border-color);
    background: transparent;
}

.btn-outline-secondary:hover {
    background: var(--text-secondary);
    border-color: var(--text-secondary);
    color: #fff;
    transform: translateY(-1px);
}

.btn-outline-success {
    color: var(--success);
    border: 1.5px solid var(--success);
    background: transparent;
}

.btn-outline-success:hover {
    background: var(--success);
    color: #fff;
}

.btn-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.82rem;
    border-radius: 6px;
}

.btn-lg {
    padding: 0.65rem 1.5rem;
    font-size: 1.05rem;
    border-radius: var(--border-radius);
}


/* ===== 8. 上传区域 ===== */
.upload-zone {
    border: 2px dashed var(--text-light);
    border-radius: var(--border-radius-lg);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--bg-light);
    position: relative;
}

.upload-zone:hover,
.upload-zone.drag-over {
    border-color: var(--primary);
    background: rgba(var(--primary-rgb), 0.04);
    box-shadow: 0 0 0 4px rgba(var(--primary-rgb), 0.08);
}

.upload-zone .upload-icon {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
    transition: color var(--transition-normal);
}

.upload-zone:hover .upload-icon {
    color: var(--primary);
}

.upload-zone.has-file {
    border-color: var(--success);
    background: #F0FDF4;
    border-style: solid;
}


/* ===== 9. AI 分析结果样式 ===== */

/* 报告区域左侧蓝色竖线 */
.report-content {
    border-left: 4px solid var(--primary);
    padding-left: 1.5rem;
    min-height: 300px;
    padding: 2rem;
    padding-left: 2rem;
    font-size: 0.95rem;
    line-height: 1.8;
    white-space: pre-wrap;
    word-wrap: break-word;
    position: relative;
}

.report-content h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 1rem 0 0.5rem;
    color: var(--primary-dark);
}

.report-content h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 1.2rem 0 0.4rem;
    color: #1E3A5F;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.3rem;
}

.report-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 1rem 0 0.3rem;
    color: var(--text-secondary);
}

.report-content strong {
    color: var(--primary);
}

.report-card {
    border-radius: var(--border-radius) !important;
    border: 2px solid var(--border-color) !important;
    transition: border-color 0.3s;
}

.report-card.active {
    border-color: var(--primary) !important;
    box-shadow: 0 0 0 4px rgba(var(--primary-rgb), 0.1);
}

/* 评分圆环配色 */
.score-ring-fill {
    fill: none;
    stroke-width: 10;
    stroke-linecap: round;
    transition: stroke-dashoffset 1.5s ease;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.score-ring-text .score-num {
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    background-clip: text;
}


/* ===== 10. 动画 ===== */

/* 数字滚动动画 */
@keyframes countUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.count-up {
    animation: countUp 0.6s ease-out;
}

/* 打字机光标 */
@keyframes blink {
    0%, 50% {
        opacity: 1;
    }
    51%, 100% {
        opacity: 0;
    }
}

.typing-cursor::after {
    content: '\2502';
    animation: blink 1s infinite;
    color: var(--primary);
    font-weight: 400;
    margin-left: 1px;
}

/* 淡入上移动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.5s ease-out;
}

/* 淡入动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.fade-in {
    animation: fadeIn 0.4s ease-out;
}

/* 从左滑入 */
@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-left {
    animation: slideInLeft 0.4s ease-out;
}

/* 缩放弹入 */
@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.scale-in {
    animation: scaleIn 0.3s ease-out;
}

/* 骨架屏闪烁 */
@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: 4px;
    height: 20px;
}

.skeleton-text {
    height: 14px;
    margin-bottom: 8px;
}

.skeleton-title {
    height: 24px;
    width: 60%;
    margin-bottom: 12px;
}

.skeleton-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
}

/* 脉冲动画 — 用于通知点 */
@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(var(--primary-rgb), 0.5);
    }
    70% {
        box-shadow: 0 0 0 10px rgba(var(--primary-rgb), 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(var(--primary-rgb), 0);
    }
}

.pulse {
    animation: pulse 2s infinite;
}


/* ===== 11. 响应式调整 ===== */
@media (max-width: 991.98px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.show {
        transform: translateX(0);
        box-shadow: var(--card-shadow-lg);
    }

    .main-with-sidebar {
        margin-left: 0 !important;
        padding: 1rem !important;
    }

    .main-no-sidebar {
        padding: 1rem !important;
    }
}

@media (max-width: 767.98px) {
    .stat-card .fs-3 {
        font-size: 1.5rem !important;
    }

    .card-body {
        padding: 1rem;
    }

    .table thead th {
        font-size: 0.78rem;
        padding: 0.65rem 0.5rem;
    }

    .table tbody td {
        font-size: 0.85rem;
        padding: 0.6rem 0.5rem;
    }

    h4 {
        font-size: 1.15rem;
    }
}

@media (max-width: 575.98px) {
    .main-with-sidebar,
    .main-no-sidebar {
        padding: 0.75rem !important;
    }

    .btn-lg {
        padding: 0.55rem 1rem;
        font-size: 0.95rem;
    }
}


/* ===== 12. 登录页特殊样式 ===== */
.login-wrapper {
    display: flex;
    min-height: 100vh;
}

.login-hero {
    flex: 1;
    background: linear-gradient(135deg, #2563EB 0%, #1E40AF 40%, #1E3A8A 100%);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 3rem;
    color: #fff;
    position: relative;
    overflow: hidden;
}

.login-hero::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.04);
    bottom: -200px;
    left: -150px;
}

.login-hero::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.06);
    top: -80px;
    right: -120px;
}

.login-hero h1 {
    font-size: 2.4rem;
    font-weight: 800;
    margin-bottom: 0.75rem;
    color: #fff;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.login-hero p {
    font-size: 1.1rem;
    opacity: 0.85;
    max-width: 340px;
    text-align: center;
    line-height: 1.7;
}

.login-hero .hero-icon {
    font-size: 5rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.login-form-panel {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    background: #F9FAFB;
}

.login-card {
    width: 100%;
    max-width: 420px;
}

.login-card h2 {
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
}

/* 角色切换 Tab */
.role-tabs {
    display: flex;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    border: 2px solid var(--primary);
    margin-bottom: 1.5rem;
}

.role-tab {
    flex: 1;
    text-align: center;
    padding: 0.55rem 0;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-fast);
    background: #fff;
    color: var(--primary);
    border: none;
}

.role-tab.active {
    background: var(--primary);
    color: #fff;
}

.role-tab:not(.active):hover {
    background: rgba(var(--primary-rgb), 0.08);
}

.btn-login {
    background: var(--primary);
    border: none;
    padding: 0.65rem;
    font-size: 1.05rem;
    font-weight: 600;
    border-radius: var(--border-radius-sm);
    width: 100%;
    color: #fff;
    transition: all var(--transition-fast);
    box-shadow: 0 2px 8px rgba(var(--primary-rgb), 0.3);
}

.btn-login:hover {
    background: var(--primary-dark);
    color: #fff;
    box-shadow: 0 4px 16px rgba(var(--primary-rgb), 0.4);
    transform: translateY(-1px);
}

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

/* 登录页输入框美化 */
.login-card .form-control {
    border-radius: var(--border-radius-sm);
    border: 1.5px solid var(--border-color);
    padding: 0.55rem 0.85rem;
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.login-card .form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.12);
}

.login-card .input-group-text {
    background: #F8FAFC;
    border: 1.5px solid var(--border-color);
    border-right: none;
    border-radius: var(--border-radius-sm) 0 0 var(--border-radius-sm);
    color: var(--text-muted);
}

.login-card .input-group .form-control {
    border-left: none;
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
}

@media (max-width: 767.98px) {
    .login-hero {
        display: none;
    }

    .login-form-panel {
        flex: unset;
        width: 100%;
    }
}


/* ===== 13. 空状态样式 ===== */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: var(--text-light);
}

.empty-state h5 {
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: var(--text-muted);
    font-size: 0.92rem;
}


/* ===== 14. 状态标签 ===== */
.badge-pending {
    background: var(--warning) !important;
    color: #fff;
}

.badge-ai-scored {
    background: var(--primary) !important;
    color: #fff;
}

.badge-graded {
    background: var(--success) !important;
    color: #fff;
}

/* 提交卡片状态标签 */
.status-pending {
    background: var(--warning-light);
    color: #92400E;
}

.status-ai_scored {
    background: #DBEAFE;
    color: #1E40AF;
}

.status-graded {
    background: var(--success-light);
    color: #166534;
}

/* 成绩分数标签 */
.score-badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: var(--border-radius-pill);
    font-weight: 600;
    font-size: 0.85rem;
}

.score-excellent {
    background: var(--success-light);
    color: #16A34A;
}

.score-good {
    background: #DBEAFE;
    color: var(--primary);
}

.score-pass {
    background: var(--warning-light);
    color: #D97706;
}

.score-fail {
    background: var(--danger-light);
    color: #DC2626;
}


/* ===== 15. 表单元素 ===== */
.form-control,
.form-select {
    border-radius: var(--border-radius-sm);
    border: 1.5px solid var(--border-color);
    padding: 0.5rem 0.85rem;
    font-size: 0.92rem;
    transition: all var(--transition-fast);
    color: var(--text-primary);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.1);
}

.form-label {
    font-weight: 600;
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 0.35rem;
}

.input-group-text {
    background: #F8FAFC;
    border: 1.5px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}


/* ===== 16. 模态框美化 ===== */
.modal-content {
    border: none;
    border-radius: var(--border-radius-lg);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.modal-header {
    border-bottom: 1px solid var(--border-color);
    padding: 1.15rem 1.5rem;
}

.modal-title {
    font-weight: 700;
    font-size: 1.1rem;
}

.modal-footer {
    border-top: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
}


/* ===== 17. 分页样式 ===== */
.pagination .page-link {
    border-radius: var(--border-radius-sm);
    margin: 0 2px;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.85rem;
    padding: 0.35rem 0.65rem;
    transition: all var(--transition-fast);
}

.pagination .page-link:hover {
    background: rgba(var(--primary-rgb), 0.08);
    border-color: var(--primary);
    color: var(--primary);
}

.pagination .page-item.active .page-link {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
    box-shadow: 0 2px 4px rgba(var(--primary-rgb), 0.3);
}

.pagination .page-item.disabled .page-link {
    color: var(--text-light);
    background: transparent;
}


/* ===== 18. Alert 样式 ===== */
.alert {
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.75rem 1rem;
}

.alert-success {
    background: #ECFDF5;
    color: #065F46;
    border-left: 4px solid var(--success);
}

.alert-danger {
    background: #FEF2F2;
    color: #991B1B;
    border-left: 4px solid var(--danger);
}

.alert-warning {
    background: #FFFBEB;
    color: #92400E;
    border-left: 4px solid var(--warning);
}

.alert-info {
    background: #EFF6FF;
    color: #1E40AF;
    border-left: 4px solid var(--primary);
}


/* ===== 19. 筛选栏 ===== */
.filter-bar {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 1rem 1.25rem;
    box-shadow: var(--card-shadow);
}


/* ===== 20. 提交卡片（作业批改页） ===== */
.submission-card {
    border-radius: var(--border-radius) !important;
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal) !important;
    cursor: pointer;
}

.submission-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1) !important;
}

.submission-thumb {
    height: 180px;
    background: #F3F4F6;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}


/* ===== 21. 状态筛选标签（作业批改页） ===== */
.status-tabs .nav-link {
    color: var(--text-muted);
    border: none;
    padding: 0.5rem 1.25rem;
    border-radius: var(--border-radius-pill);
    font-size: 0.9rem;
    font-weight: 500;
    margin-right: 0.5rem;
    transition: all var(--transition-fast);
}

.status-tabs .nav-link:hover {
    background: #F3F4F6;
    color: var(--text-secondary);
}

.status-tabs .nav-link.active {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 8px rgba(var(--primary-rgb), 0.3);
}


/* ===== 22. 学生个人信息卡片 ===== */
.profile-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(var(--primary-rgb), 0.3);
}

.profile-card .stat-value {
    font-size: 1.8rem;
    font-weight: 800;
}

.profile-card .stat-label {
    font-size: 0.85rem;
    opacity: 0.85;
}


/* ===== 23. 历史记录时间线 ===== */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--border-color));
}

.history-card {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: all var(--transition-normal);
    cursor: pointer;
}

.history-card:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.1);
}


/* ===== 24. Footer ===== */
.site-footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8rem;
    padding: 1.5rem 0;
    border-top: 1px solid var(--border-color);
    margin-top: 1rem;
}


/* ===== 25. 杂项工具类 ===== */

/* 文字截断 */
.text-truncate-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 渐变文字 */
.text-gradient {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* 玻璃效果 */
.glass {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 隐藏滚动条（美观） */
.hide-scrollbar {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.hide-scrollbar::-webkit-scrollbar {
    display: none;
}


/* ===== 26. 深色模式 ===== */
[data-theme="dark"] {
    --bg-light: #0F172A;
    --bg-white: #1E293B;
    --text-primary: #E2E8F0;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    --text-light: #475569;
    --border-color: #334155;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    --card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
    --card-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] body {
    background-color: var(--bg-light);
    color: var(--text-primary);
}

[data-theme="dark"] .top-navbar {
    background: var(--bg-white) !important;
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .sidebar {
    background: var(--bg-white);
    border-right-color: var(--border-color);
}

[data-theme="dark"] .card {
    background: var(--bg-white);
    border-color: var(--border-color);
}

[data-theme="dark"] .card-header {
    background: var(--bg-white);
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .table thead th {
    background: #1E293B;
    color: var(--text-secondary);
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .table tbody tr:nth-child(even) {
    background-color: rgba(255, 255, 255, 0.02);
}

[data-theme="dark"] .table tbody tr:hover {
    background-color: rgba(var(--primary-rgb), 0.08) !important;
}

[data-theme="dark"] .table tbody td {
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .form-control,
[data-theme="dark"] .form-select {
    background: #0F172A;
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .form-control:focus,
[data-theme="dark"] .form-select:focus {
    background: #0F172A;
    border-color: var(--primary);
}

[data-theme="dark"] .input-group-text {
    background: #1E293B;
    border-color: var(--border-color);
    color: var(--text-muted);
}

[data-theme="dark"] .modal-content {
    background: var(--bg-white);
}

[data-theme="dark"] .filter-bar {
    background: var(--bg-white);
}

[data-theme="dark"] .alert-info {
    background: rgba(37, 99, 235, 0.15);
    color: #93C5FD;
}

[data-theme="dark"] .alert-success {
    background: rgba(16, 185, 129, 0.15);
    color: #6EE7B7;
}

[data-theme="dark"] .alert-danger {
    background: rgba(239, 68, 68, 0.15);
    color: #FCA5A5;
}

[data-theme="dark"] .alert-warning {
    background: rgba(245, 158, 11, 0.15);
    color: #FCD34D;
}

[data-theme="dark"] .login-form-panel {
    background: var(--bg-light);
}

[data-theme="dark"] .login-card h2 {
    color: var(--text-primary);
}

[data-theme="dark"] .upload-zone {
    background: rgba(255, 255, 255, 0.03);
    border-color: var(--border-color);
}

[data-theme="dark"] .skeleton {
    background: linear-gradient(90deg, #1e293b 25%, #334155 50%, #1e293b 75%);
    background-size: 200% 100%;
}

[data-theme="dark"] .site-footer {
    border-top-color: var(--border-color);
}

[data-theme="dark"] .table-light {
    --bs-table-bg: #1E293B;
}

[data-theme="dark"] .pagination .page-link {
    background: transparent;
    border-color: var(--border-color);
    color: var(--text-secondary);
}

[data-theme="dark"] .pagination .page-link:hover {
    background: rgba(var(--primary-rgb), 0.15);
}

[data-theme="dark"] .status-tabs .nav-link:hover {
    background: rgba(255, 255, 255, 0.05);
}

[data-theme="dark"] .role-tab {
    background: var(--bg-white);
    color: var(--primary-light);
}

[data-theme="dark"] .role-tab:not(.active):hover {
    background: rgba(var(--primary-rgb), 0.1);
}

[data-theme="dark"] .btn-outline-light {
    color: var(--text-secondary);
    border-color: var(--border-color);
}