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

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #e8eef5 100%);
    color: #2c3e50;
    line-height: 1.6;
    min-height: 100vh;
}

.site-container {
    max-width: 1400px;
    margin: 0 auto;
    background: #fff;
    box-shadow: 0 0 30px rgba(0,0,0,0.08);
}

.top-header {
    background: linear-gradient(to right, #1e3c72, #2a5298);
    color: white;
    padding: 15px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    animation: slideDown 0.6s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.site-logo h1 {
    font-size: 28px;
    font-weight: 600;
    letter-spacing: 1px;
}

.site-logo h1 a {
    color: white;
    text-decoration: none;
}

.user-actions {
    display: flex;
    gap: 15px;
}

.user-actions a {
    color: white;
    text-decoration: none;
    padding: 8px 20px;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 20px;
    transition: all 0.3s;
}

.user-actions a:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.main-nav {
    background: #34495e;
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav-menu {
    display: flex;
    list-style: none;
    justify-content: center;
    flex-wrap: wrap;
}

.nav-menu li {
    position: relative;
}

.nav-menu a {
    display: block;
    color: white;
    text-decoration: none;
    padding: 18px 25px;
    transition: all 0.3s;
    font-size: 15px;
    position: relative;
    overflow: hidden;
}

.nav-menu a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: #3498db;
    transition: all 0.3s;
    transform: translateX(-50%);
}

.nav-menu a:hover::before {
    width: 80%;
}

.nav-menu a:hover {
    background: rgba(255,255,255,0.1);
    transform: translateY(-2px);
}

.page-content {
    padding: 40px;
    animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-header {
    text-align: center;
    margin-bottom: 50px;
    padding-bottom: 30px;
    border-bottom: 2px solid #ecf0f1;
}

.content-header h2 {
    font-size: 36px;
    color: #2c3e50;
    margin-bottom: 15px;
    animation: titlePulse 1s ease-out;
}

@keyframes titlePulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.content-header p {
    font-size: 16px;
    color: #7f8c8d;
    max-width: 800px;
    margin: 0 auto;
}

.forum-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.forum-card {
    background: white;
    border: 1px solid #e8ecef;
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    animation: cardSlideUp 0.6s ease-out backwards;
}

@keyframes cardSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.forum-card:nth-child(1) { animation-delay: 0.1s; }
.forum-card:nth-child(2) { animation-delay: 0.2s; }
.forum-card:nth-child(3) { animation-delay: 0.3s; }
.forum-card:nth-child(4) { animation-delay: 0.4s; }
.forum-card:nth-child(5) { animation-delay: 0.5s; }
.forum-card:nth-child(6) { animation-delay: 0.6s; }

.forum-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.15);
    border-color: #3498db;
}

.forum-card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    position: relative;
}

.forum-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.forum-card:hover .forum-card-image img {
    transform: scale(1.1);
}

.forum-card-content {
    padding: 20px;
}

.forum-card h3 {
    font-size: 18px;
    color: #2c3e50;
    margin-bottom: 10px;
    line-height: 1.4;
}

.forum-card h3 a {
    color: #2c3e50;
    text-decoration: none;
    transition: color 0.3s;
}

.forum-card h3 a:hover {
    color: #3498db;
}

.forum-meta {
    display: flex;
    justify-content: space-between;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid #ecf0f1;
    font-size: 13px;
    color: #7f8c8d;
}

.forum-meta span {
    display: flex;
    align-items: center;
    gap: 5px;
}

.topic-list {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 15px rgba(0,0,0,0.05);
}

.topic-item {
    display: flex;
    align-items: center;
    padding: 25px 30px;
    border-bottom: 1px solid #ecf0f1;
    transition: all 0.3s;
    animation: listFadeIn 0.5s ease-out backwards;
}

@keyframes listFadeIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

.topic-item:hover {
    background: #f8f9fa;
    transform: translateX(5px);
}

.topic-item:last-child {
    border-bottom: none;
}

.topic-image {
    width: 100px;
    height: 70px;
    border-radius: 8px;
    overflow: hidden;
    margin-right: 20px;
    flex-shrink: 0;
}

.topic-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.topic-item:hover .topic-image img {
    transform: scale(1.1);
}

.topic-info {
    flex: 1;
}

.topic-info h4 {
    font-size: 16px;
    margin-bottom: 8px;
}

.topic-info h4 a {
    color: #2c3e50;
    text-decoration: none;
    transition: color 0.3s;
}

.topic-info h4 a:hover {
    color: #3498db;
}

.topic-info p {
    color: #7f8c8d;
    font-size: 14px;
}

.topic-stats {
    display: flex;
    gap: 20px;
    color: #7f8c8d;
    font-size: 14px;
}

.site-footer {
    background: #2c3e50;
    color: #ecf0f1;
    padding: 40px;
    margin-top: 60px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 25px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #ecf0f1;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #3498db;
}

.copyright {
    color: #95a5a6;
    font-size: 14px;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

@media (max-width: 768px) {
    .top-header {
        flex-direction: column;
        gap: 15px;
        padding: 20px;
    }

    .nav-menu {
        flex-direction: column;
    }

    .page-content {
        padding: 20px;
    }

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

    .topic-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .topic-image {
        width: 100%;
        height: 150px;
        margin-right: 0;
        margin-bottom: 15px;
    }
}