/* 现代企业风格样式 */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --light-bg: #f8f9fa;
    --dark-bg: #2c3e50;
    --text-dark: #2c3e50;
    --text-light: #ecf0f1;
    --border-color: #dee2e6;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* 卡片样式 */
.card {
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 25px;
    margin-bottom: 25px;
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

/* 导航栏 */
.navbar {
    background: white;
    box-shadow: var(--shadow);
    padding: 15px 30px;
    border-radius: 10px;
    margin-bottom: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 15px;
}

.nav-brand h1 {
    color: var(--primary-color);
    font-size: 24px;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    gap: 20px;
    align-items: center;
}

.nav-link {
    color: var(--text-dark);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 6px;
    transition: var(--transition);
    font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
    background: var(--secondary-color);
    color: white;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--secondary-color);
}

/* 按钮样式 */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--secondary-color), #2980b9);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

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

.btn-danger {
    background: var(--accent-color);
    color: white;
}

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

/* 登录页面 */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.login-card {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 450px;
    overflow: hidden;
}

.login-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 40px 30px;
    text-align: center;
}

.login-header h2 {
    font-size: 28px;
    margin-bottom: 10px;
}

.login-form {
    padding: 40px 30px;
}

.form-group {
    margin-bottom: 25px;
}

.form-control {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 16px;
    transition: var(--transition);
}

.form-control:focus {
    border-color: var(--secondary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

/* 表格样式 */
.table-responsive {
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th {
    background: linear-gradient(135deg, var(--primary-color), #34495e);
    color: white;
    padding: 15px;
    text-align: left;
    font-weight: 600;
}

.data-table td {
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
}

.data-table tr:hover {
    background: #f8f9fa;
}

/* 排行榜样式 */
.ranking-list {
    display: grid;
    gap: 20px;
}

.ranking-item {
    display: flex;
    align-items: center;
    padding: 20px;
    background: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.ranking-item:hover {
    transform: translateX(10px);
}

.rank-number {
    font-size: 32px;
    font-weight: bold;
    color: var(--secondary-color);
    min-width: 60px;
}

.top-1 .rank-number { color: #ffd700; }
.top-2 .rank-number { color: #c0c0c0; }
.top-3 .rank-number { color: #cd7f32; }

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
    flex: 1;
}

.score-badge {
    background: linear-gradient(135deg, var(--success-color), #2ecc71);
    color: white;
    padding: 10px 20px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 18px;
}

/* 仪表板样式 */
.dashboard-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

.stat-card {
    background: white;
    padding: 25px;
    border-radius: 15px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-icon {
    font-size: 40px;
    margin-bottom: 15px;
}

.stat-value {
    font-size: 36px;
    font-weight: bold;
    color: var(--primary-color);
}

.stat-label {
    color: #666;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* 图表容器 */
.chart-container {
    height: 400px;
    position: relative;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .dashboard-stats {
        grid-template-columns: 1fr;
    }
}

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

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

/* 加载动画 */
.loading {
    display: inline-block;
    width: 50px;
    height: 50px;
    border: 3px solid rgba(52, 152, 219, 0.3);
    border-radius: 50%;
    border-top-color: var(--secondary-color);
    animation: spin 1s ease-in-out infinite;
}

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