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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fafafa;
}

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

/* 头部样式 */
.header {
    background: linear-gradient(135deg, #f7931a 0%, #ffa500 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
}

.logo {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.subtitle {
    font-size: 1.2rem;
    font-weight: 400;
    margin-bottom: 15px;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* 导航样式 */
.nav {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-list {
    display: flex;
    justify-content: center;
    list-style: none;
    padding: 20px 0;
}

.nav-list li {
    margin: 0 15px;
}

.nav-list a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
    padding: 8px 16px;
    border-radius: 20px;
}

.nav-list a:hover {
    color: #f7931a;
    background: rgba(247, 147, 26, 0.1);
}

/* 主要内容区域 */
.main {
    min-height: 100vh;
}

.section {
    padding: 40px 0;
    margin-bottom: 60px;
}

.section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 40px;
    color: #333;
    position: relative;
}

.section h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: #f7931a;
    border-radius: 2px;
}

/* 概览卡片 */
.overview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.overview-card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.overview-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.overview-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: #f7931a;
}

/* 时间线样式 */
.timeline-container {
    position: relative;
    padding: 40px 0;
}

.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #f7931a;
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
    opacity: 0;
    transform: translateX(-20px);
    animation: slideIn 0.6s forwards;
}

.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.2s; }
.timeline-item:nth-child(3) { animation-delay: 0.3s; }
.timeline-item:nth-child(4) { animation-delay: 0.4s; }
.timeline-item:nth-child(5) { animation-delay: 0.5s; }

@keyframes slideIn {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -25px;
    top: 5px;
    width: 12px;
    height: 12px;
    background: #f7931a;
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 3px rgba(247, 147, 26, 0.3);
}

.timeline-content {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.timeline-date {
    font-weight: 600;
    color: #f7931a;
    margin-bottom: 8px;
}

.timeline-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.timeline-description {
    line-height: 1.6;
    color: #666;
}

/* 里程碑样式 */
.milestones-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.milestone-card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    border-left: 4px solid #f7931a;
    transition: transform 0.3s;
}

.milestone-card:hover {
    transform: translateY(-3px);
}

.milestone-year {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: #f7931a;
}

.milestone-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: #333;
}

.milestone-description {
    line-height: 1.6;
    color: #666;
}

/* 技术发展时间线 */
.tech-timeline {
    display: grid;
    gap: 20px;
    margin-top: 40px;
}

.tech-item {
    background: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.tech-icon {
    font-size: 2rem;
    min-width: 60px;
    text-align: center;
}

.tech-content h4 {
    color: #f7931a;
    margin-bottom: 10px;
}

.tech-date {
    font-weight: 500;
    color: #666;
    margin-bottom: 10px;
}

/* 价格历史 */
.price-timeline {
    display: grid;
    gap: 20px;
    margin-top: 40px;
}

.price-item {
    background: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.price-amount {
    flex: 1;
    font-size: 1.8rem;
    font-weight: 700;
    color: #f7931a;
    margin-bottom: 5px;
}

.price-date {
    font-weight: 600;
    color: #666;
    margin-bottom: 10px;
}

.price-details {
    flex: 2;
    line-height: 1.6;
}

/* 新闻网格 */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.news-card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

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

.news-date {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: #f7931a;
}

.news-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 15px;
    line-height: 1.6;
}

.news-description {
    line-height: 1.6;
    color: #666;
}

/* 标签样式 */
.tags {
    margin-top: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    background: rgba(247, 147, 26, 0.1);
    color: #f7931a;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* 页脚 */
.footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 40px 0;
}

.footer p {
    margin-bottom: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .logo {
        font-size: 2rem;
    }
    
    .section h2 {
        font-size: 2rem;
    }
    
    .nav-list {
        flex-wrap: wrap;
        gap: 10px;
    }
    
    .nav-list li {
        margin: 5px;
    }
    
    .timeline {
        padding-left: 30px;
    }
    
    .timeline::before {
        left: 10px;
    }
    
    .timeline-item::before {
        left: -20px;
    }
    
    .price-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .overview-grid,
    .milestones-grid,
    .news-grid {
        grid-template-columns: 1fr;
    }
}

/* 滚动动画 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s, transform 0.6s;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 加载动画 */
.loading {
    text-align: center;
    padding: 40px;
    color: #666;
}

.loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid #f7931a;
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s linear infinite;
    margin-left: 10px;
}

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