/* 关于页面专用样式 */
.intro-section {
    padding: 80px 0;
    background: #f8f9fa;
}

.intro-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 40px;
    max-width: 1000px;
    margin: 0 auto;
}

.intro-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    color: #333;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #e9ecef;
}

.intro-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.intro-card h3 {
    color: #667eea;
    font-size: 1.5rem;
    margin-bottom: 20px;
    font-weight: 700;
    text-align: center;
}

.intro-card p {
    line-height: 1.8;
    color: #444;
    text-align: justify;
    font-size: 1rem;
}

.stats-section {
    padding: 100px 0;
    background: white;
    text-align: center;
}

.stats-title {
    font-size: 2.5rem;
    color: #333;
    margin-bottom: 60px;
    font-weight: 700;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 60px;
    max-width: 800px;
    margin: 0 auto;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 4rem;
    font-weight: 900;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
    display: block;
}

.stat-label {
    font-size: 1.2rem;
    color: #666;
    font-weight: 600;
}

.history-section {
    padding: 100px 0;
    background: #f8f9fa;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    color: #333;
    margin-bottom: 80px;
    font-weight: 700;
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(to bottom, #667eea, #764ba2);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
    width: 100%;
    display: flex;
    align-items: center;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-content {
    background: white;
    border-radius: 15px;
    padding: 25px 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    width: 40%;
    position: relative;
    border: 1px solid #e9ecef;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-right: 15%;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: 15%;
}

.timeline-content::before {
    content: '';
    position: absolute;
    top: 50%;
    width: 0;
    height: 0;
    border: 12px solid transparent;
    transform: translateY(-50%);
}

.timeline-item:nth-child(odd) .timeline-content::before {
    right: -24px;
    border-left-color: white;
}

.timeline-item:nth-child(even) .timeline-content::before {
    left: -24px;
    border-right-color: white;
}

.timeline-date {
    color: #667eea;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.timeline-event {
    color: #333;
    font-size: 1rem;
    font-weight: 600;
}

.timeline-dot {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 20px;
    height: 20px;
    background: #667eea;
    border-radius: 50%;
    transform: translate(-50%, -50%);
    border: 4px solid white;
    box-shadow: 0 0 0 4px #667eea;
    z-index: 2;
}

.rankings-section {
    padding: 100px 0;
    background: white;
}

.rankings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    margin-top: 60px;
}

.ranking-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #e9ecef;
}

.ranking-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
}

.ranking-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 25px;
    text-align: center;
    font-size: 1.3rem;
    font-weight: 700;
}

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

.ranking-table th,
.ranking-table td {
    padding: 15px 20px;
    text-align: left;
    border-bottom: 1px solid #f1f3f4;
}

.ranking-table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #495057;
    font-size: 0.9rem;
}

.ranking-table td {
    color: #333;
    font-size: 0.9rem;
}

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

/* 改进的排行榜配色 */
.ranking-table .rank-1 {
    background: linear-gradient(135deg, #fff8e1, #ffecb3);
    color: #e65100;
    font-weight: 700;
    border-left: 4px solid #ff9800;
}

.ranking-table .rank-2 {
    background: linear-gradient(135deg, #f3e5f5, #e1bee7);
    color: #6a1b9a;
    font-weight: 600;
    border-left: 4px solid #9c27b0;
}

.ranking-table .rank-3 {
    background: linear-gradient(135deg, #e8f5e8, #c8e6c9);
    color: #2e7d32;
    font-weight: 600;
    border-left: 4px solid #4caf50;
}

.ranking-table .rank-1:hover {
    background: linear-gradient(135deg, #fff3c4, #ffe082);
    transform: scale(1.02);
}

.ranking-table .rank-2:hover {
    background: linear-gradient(135deg, #f8bbd9, #f48fb1);
    transform: scale(1.02);
}

.ranking-table .rank-3:hover {
    background: linear-gradient(135deg, #dcedc8, #aed581);
    transform: scale(1.02);
}

@media (max-width: 768px) {
    .intro-section {
        padding: 60px 0;
    }
    
    .intro-cards {
        grid-template-columns: 1fr;
        gap: 30px;
        margin: 0 20px;
    }
    
    .intro-card {
        padding: 30px 25px;
    }
    
    .stats-title {
        font-size: 2rem;
    }
    
    .stat-number {
        font-size: 3rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .timeline::before {
        left: 30px;
    }
    
    .timeline-item {
        flex-direction: row !important;
        padding-left: 70px;
    }
    
    .timeline-content {
        width: 100% !important;
        margin: 0 !important;
    }
    
    .timeline-content::before {
        left: -24px !important;
        border-right-color: white !important;
        border-left-color: transparent !important;
        border-width: 12px !important;
    }
    
    .timeline-dot {
        left: 30px;
    }
    
    .rankings-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    .intro-cards {
        margin: 0 10px;
    }
    
    .intro-card {
        padding: 20px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .ranking-table th,
    .ranking-table td {
        padding: 10px 15px;
        font-size: 0.8rem;
    }
}