/* 重置和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-color: #1f2937;
    --light-color: #f8fafc;
    --border-color: #e5e7eb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: #ffffff;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.header {
    background: #ffffff;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-logo h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* 主要内容 */
.main {
    min-height: calc(100vh - 200px);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.9;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    max-width: 600px;
    margin: 0 auto;
}

.stat-card {
    background: rgba(255, 255, 255, 0.1);
    padding: 1.5rem;
    border-radius: 12px;
    backdrop-filter: blur(10px);
}

.stat-card h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

/* 指数概览 */
.indices-overview {
    padding: 4rem 0;
    background: var(--light-color);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.indices-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.index-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.index-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

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

.index-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-secondary);
    flex: 1;
}

.index-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
}

.index-change {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.index-change.positive {
    color: var(--success-color);
}

.index-change.negative {
    color: var(--danger-color);
}

.index-change.positive::before {
    content: '+';
}

.index-chart {
    height: 60px;
    background: linear-gradient(90deg, transparent 0%, var(--primary-color) 50%, transparent 100%);
    opacity: 0.1;
    border-radius: 8px;
    margin-bottom: 1rem;
    position: relative;
}

.index-link {
    display: inline-block;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.index-link:hover {
    color: var(--secondary-color);
}

/* 市场动态 */
.market-news {
    padding: 4rem 0;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.news-item {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.news-item:hover {
    transform: translateY(-3px);
}

.news-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.news-item p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.news-item time {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 页脚 */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #9ca3af;
}

/* 数据表格样式 */
.data-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    margin: 2rem 0;
}

.data-table th,
.data-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.data-table th {
    background: var(--light-color);
    font-weight: 600;
    color: var(--text-primary);
}

.data-table tr:hover {
    background: #f9fafb;
}

/* 图表容器 */
.chart-container {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin: 2rem 0;
}

.chart-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .indices-grid {
        grid-template-columns: 1fr;
    }

    .news-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 2rem 0;
    }

    .indices-overview,
    .market-news {
        padding: 2rem 0;
    }

    .index-card,
    .news-item {
        padding: 1.5rem;
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 工具提示 */
.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--dark-color);
    color: white;
    text-align: center;
    border-radius: 6px;
    padding: 8px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -100px;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.875rem;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/* 性能优化 */
.index-card,
.news-item {
    will-change: transform;
}

img {
    max-width: 100%;
    height: auto;
    loading: lazy;
}