/**
 * 学生成绩管理系统 v5.0 - 精美主题样式
 * 设计理念：现代、清新、专业
 * 主色调：深蓝紫渐变 + 翡翠绿点缀
 */

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #10b981;
    --secondary-dark: #059669;
    --accent: #f59e0b;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    --dark: #1e293b;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --success: #10b981;
    --border-radius: 16px;
    --border-radius-sm: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.05);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(135deg, #f0f4ff 0%, #e0e7ff 50%, #f5f3ff 100%);
    min-height: 100vh;
    color: var(--gray-800);
    line-height: 1.6;
}

/* ===== 导航栏 ===== */
.navbar {
    background: linear-gradient(135deg, #1e3a5f 0%, #2d4a6f 50%, #1e3a5f 100%);
    box-shadow: var(--shadow-lg);
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 3px solid var(--primary);
}

.navbar-brand {
    font-size: 1.4rem;
    font-weight: 700;
    color: #ffffff !important;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.navbar-brand i {
    font-size: 1.6rem;
    color: #60a5fa;
}

.nav-link {
    color: #e2e8f0 !important;
    padding: 1rem 1.2rem !important;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover, .nav-link.active {
    color: #ffffff !important;
    background: rgba(99, 102, 241, 0.3);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 20%;
    right: 20%;
    height: 3px;
    background: #60a5fa;
    border-radius: 3px 3px 0 0;
}

/* ===== 卡片组件 ===== */
.card {
    background: rgba(255,255,255,0.95);
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    overflow: hidden;
}

.card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}

.card-header {
    background: transparent;
    border-bottom: 1px solid var(--gray-100);
    padding: 1.25rem 1.5rem;
    font-weight: 600;
}

.card-body {
    padding: 1.5rem;
}

/* ===== 统计卡片 ===== */
.stat-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--primary);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.stat-card.success::before { background: var(--success); }
.stat-card.warning::before { background: var(--warning); }
.stat-card.danger::before { background: var(--danger); }
.stat-card.info::before { background: var(--info); }

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.stat-icon.primary { background: linear-gradient(135deg, var(--primary-light), var(--primary)); color: white; }
.stat-icon.success { background: linear-gradient(135deg, #34d399, var(--secondary)); color: white; }
.stat-icon.warning { background: linear-gradient(135deg, #fbbf24, var(--warning)); color: white; }
.stat-icon.danger { background: linear-gradient(135deg, #f87171, var(--danger)); color: white; }

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--gray-800);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-top: 0.25rem;
}

/* ===== 按钮 ===== */
.btn {
    border-radius: var(--border-radius-sm);
    font-weight: 500;
    padding: 0.5rem 1.25rem;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-success {
    background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger), #dc2626);
    box-shadow: 0 4px 14px rgba(239, 68, 68, 0.4);
}

.btn-outline-primary {
    border: 2px solid var(--primary);
    color: var(--primary);
    background: transparent;
}

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

/* ===== 表单 ===== */
.form-control, .form-select {
    border-radius: var(--border-radius-sm);
    border: 2px solid var(--gray-200);
    padding: 0.625rem 1rem;
    transition: var(--transition);
    background: white;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary-light);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.form-label {
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
}

/* ===== 表格 ===== */
.table {
    border-radius: var(--border-radius-sm);
    overflow: hidden;
}

.table thead th {
    background: linear-gradient(135deg, var(--gray-50), var(--gray-100));
    font-weight: 600;
    color: var(--gray-700);
    border-bottom: 2px solid var(--gray-200);
    padding: 1rem;
}

.table tbody td {
    padding: 1rem;
    vertical-align: middle;
    border-bottom: 1px solid var(--gray-100);
}

.table tbody tr:hover {
    background: var(--gray-50);
}

/* ===== 徽章 ===== */
.badge {
    padding: 0.35em 0.75em;
    border-radius: 20px;
    font-weight: 500;
    font-size: 0.75rem;
}

.badge-primary { background: linear-gradient(135deg, var(--primary-light), var(--primary)); }
.badge-success { background: linear-gradient(135deg, #34d399, var(--secondary)); }
.badge-warning { background: linear-gradient(135deg, #fbbf24, var(--warning)); }
.badge-danger { background: linear-gradient(135deg, #f87171, var(--danger)); }

/* ===== 登录页面 ===== */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    position: relative;
    overflow: hidden;
}

.login-page::before {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    animation: float 20s linear infinite;
}

@keyframes float {
    0% { transform: translate(0, 0); }
    100% { transform: translate(-50%, -50%); }
}

.login-card {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
    padding: 2.5rem;
    width: 100%;
    max-width: 420px;
    position: relative;
    z-index: 1;
}

.login-logo {
    text-align: center;
    margin-bottom: 2rem;
}

.login-logo i {
    font-size: 3.5rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.login-logo h2 {
    font-weight: 700;
    color: var(--gray-800);
    margin-top: 0.5rem;
}

.login-logo p {
    color: var(--gray-500);
}

/* ===== 仪表盘 ===== */
.dashboard-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 2rem 0;
    margin-bottom: 2rem;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
}

.welcome-text {
    font-size: 1.5rem;
    font-weight: 600;
}

.welcome-sub {
    opacity: 0.85;
    margin-top: 0.25rem;
}

/* ===== 成绩卡片 ===== */
.score-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-left: 4px solid var(--primary);
}

.score-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

.score-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.score-card-title {
    font-weight: 600;
    color: var(--gray-800);
    font-size: 1.1rem;
}

.score-card-meta {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-top: 0.25rem;
}

.score-card-score {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.score-card-full {
    font-size: 1rem;
    color: var(--gray-400);
}

/* ===== 科目选择卡片 ===== */
.subject-select-card {
    background: white;
    border: 2px solid var(--gray-200);
    border-radius: var(--border-radius-sm);
    padding: 1rem;
    transition: var(--transition);
    cursor: pointer;
}

.subject-select-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow);
}

.subject-select-card.active {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(99,102,241,0.05), rgba(99,102,241,0.1));
}

/* ===== 进度条 ===== */
.progress {
    height: 8px;
    border-radius: 4px;
    background: var(--gray-200);
    overflow: hidden;
}

.progress-bar {
    border-radius: 4px;
    transition: width 0.6s ease;
}

.progress-bar.primary { background: linear-gradient(90deg, var(--primary-light), var(--primary)); }
.progress-bar.success { background: linear-gradient(90deg, #34d399, var(--secondary)); }
.progress-bar.warning { background: linear-gradient(90deg, #fbbf24, var(--warning)); }
.progress-bar.danger { background: linear-gradient(90deg, #f87171, var(--danger)); }

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

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .stat-value { font-size: 1.5rem; }
    .login-card { margin: 1rem; padding: 1.5rem; }
    .navbar-brand { font-size: 1.1rem; }
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

/* ===== 模态框 ===== */
.modal-content {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
}

.modal-header {
    border-bottom: 1px solid var(--gray-100);
    padding: 1.25rem 1.5rem;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid var(--gray-100);
    padding: 1rem 1.5rem;
}

/* ===== 分页 ===== */
.pagination .page-link {
    border: none;
    color: var(--gray-600);
    border-radius: var(--border-radius-sm);
    margin: 0 0.25rem;
    padding: 0.5rem 0.875rem;
}

.pagination .page-item.active .page-link {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.pagination .page-link:hover {
    background: var(--gray-100);
    color: var(--primary);
}

/* ===== 提示框 ===== */
.alert {
    border: none;
    border-radius: var(--border-radius-sm);
    padding: 1rem 1.25rem;
}

.alert-primary { background: linear-gradient(135deg, rgba(99,102,241,0.1), rgba(99,102,241,0.05)); color: var(--primary-dark); }
.alert-success { background: linear-gradient(135deg, rgba(16,185,129,0.1), rgba(16,185,129,0.05)); color: var(--secondary-dark); }
.alert-warning { background: linear-gradient(135deg, rgba(245,158,11,0.1), rgba(245,158,11,0.05)); color: #b45309; }
.alert-danger { background: linear-gradient(135deg, rgba(239,68,68,0.1), rgba(239,68,68,0.05)); color: #dc2626; }

/* ===== 下拉菜单 ===== */
.dropdown-menu {
    border: none;
    border-radius: var(--border-radius-sm);
    box-shadow: var(--shadow-lg);
    padding: 0.5rem;
}

.dropdown-item {
    border-radius: var(--border-radius-sm);
    padding: 0.5rem 1rem;
    transition: var(--transition);
}

.dropdown-item:hover {
    background: var(--gray-100);
    color: var(--primary);
}

/* ===== 管理员后台 ===== */
.admin-sidebar {
    background: linear-gradient(180deg, var(--gray-800), var(--gray-900));
    min-height: 100vh;
    color: white;
    padding: 1.5rem 0;
}

.admin-sidebar .nav-link {
    color: rgba(255,255,255,0.7) !important;
    padding: 0.75rem 1.5rem !important;
    border-radius: 0;
}

.admin-sidebar .nav-link:hover, .admin-sidebar .nav-link.active {
    background: rgba(255,255,255,0.1);
    color: white !important;
}

.admin-sidebar .nav-link.active {
    border-left: 3px solid var(--primary);
}

.admin-content {
    background: var(--gray-50);
    min-height: 100vh;
    padding: 2rem;
}

/* ===== 图表容器 ===== */
.chart-container {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

/* ===== 空状态 ===== */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--gray-400);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h4 {
    color: var(--gray-600);
    margin-bottom: 0.5rem;
}

/* ===== 加载动画 ===== */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== 工具提示 ===== */
.tooltip-inner {
    background: var(--gray-800);
    border-radius: var(--border-radius-sm);
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
}