* {
    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;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, #1a5fb4 0%, #3584e4 100%);
    color: white;
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.logo img {
    width: 60px;
    height: 60px;
    object-fit: contain;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

.logo-text h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 2px;
}

.logo-text p {
    font-size: 13px;
    opacity: 0.9;
}

.nav {
    display: flex;
    gap: 30px;
}

.nav a {
    color: white;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: opacity 0.3s;
    position: relative;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: white;
    transition: width 0.3s;
}

.nav a:hover::after {
    width: 100%;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #1a5fb4 0%, #3584e4 50%, #62a0ea 100%);
    color: white;
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></svg>');
    background-size: 100px 100px;
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.hero p {
    font-size: 20px;
    opacity: 0.95;
}

/* Section */
.section {
    padding: 80px 0;
}

.bg-light {
    background-color: #eef2f7;
}

.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    color: #1a5fb4;
    margin-bottom: 50px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #1a5fb4, #3584e4);
    border-radius: 2px;
}

/* About */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 18px;
    line-height: 1.8;
    color: #555;
}

/* Activity Gallery - 瀑布流布局 */
.activity-gallery h3 {
    text-align: center;
    font-size: 24px;
    color: #333;
    margin-bottom: 30px;
}

.gallery-masonry {
    column-count: 3;
    column-gap: 15px;
}

.gallery-item {
    break-inside: avoid;
    margin-bottom: 15px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    background: white;
}

.gallery-item:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 12px 30px rgba(0,0,0,0.15);
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
}

/* Achievements - 瀑布流布局 */
.achievements-masonry {
    column-count: 3;
    column-gap: 20px;
}

.achievement-card {
    break-inside: avoid;
    margin-bottom: 20px;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
}

.achievement-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.12);
}

.achievement-img img {
    width: 100%;
    height: auto;
    display: block;
}

.achievement-info {
    padding: 15px 18px;
}

.achievement-info h4 {
    font-size: 15px;
    font-weight: 600;
    color: #1a5fb4;
    margin-bottom: 6px;
    line-height: 1.4;
}

.achievement-info p {
    font-size: 13px;
    color: #666;
    margin-bottom: 8px;
}

.achievement-info .date {
    display: inline-block;
    background: linear-gradient(135deg, #1a5fb4, #3584e4);
    color: white;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 500;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, #1c1c1c 0%, #2d2d2d 100%);
    color: white;
    padding: 50px 0 20px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.footer-logo img {
    width: 50px;
    height: 50px;
    object-fit: contain;
}

.footer-logo p {
    font-size: 20px;
    font-weight: 600;
}

.footer-info {
    text-align: right;
}

.footer-info p {
    font-size: 14px;
    opacity: 0.8;
    margin-bottom: 5px;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.copyright p {
    font-size: 13px;
    opacity: 0.6;
}

/* Responsive */
@media (max-width: 992px) {
    .gallery-masonry {
        column-count: 2;
    }
    
    .achievements-masonry {
        column-count: 2;
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav {
        gap: 20px;
    }

    .hero h2 {
        font-size: 32px;
    }

    .hero p {
        font-size: 16px;
    }

    .section-title {
        font-size: 28px;
    }

    .gallery-masonry {
        column-count: 1;
    }

    .achievements-masonry {
        column-count: 1;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

    .footer-info {
        text-align: center;
    }
}