/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9fdfb;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    outline: none;
}

.btn-primary {
    background-color: #4cd3aa;
    color: white;
}

.btn-primary:hover {
    background-color: #3bb896;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(76, 211, 170, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: #4cd3aa;
    border: 2px solid #4cd3aa;
}

.btn-secondary:hover {
    background-color: rgba(76, 211, 170, 0.1);
    transform: translateY(-3px);
}

.highlight {
    color: #4cd3aa;
    font-weight: 700;
}

/* 导航栏 */
.header {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: #4cd3aa;
    font-family: 'Quicksand', sans-serif;
}

.logo i {
    margin-right: 8px;
}

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

.nav-links a {
    font-weight: 500;
    color: #555;
    position: relative;
}

.nav-links a:hover {
    color: #4cd3aa;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #4cd3aa;
    transition: width 0.3s ease;
}

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

.search-container {
    display: flex;
    align-items: center;
}

.search-form {
    display: flex;
    align-items: center;
    background-color: #f5f9f8;
    border-radius: 30px;
    overflow: hidden;
    padding: 5px;
    border: 1px solid #e0f0ea;
}

.search-input {
    border: none;
    outline: none;
    padding: 10px 15px;
    background: transparent;
    width: 200px;
    font-family: 'Noto Sans SC', sans-serif;
}

.search-btn {
    background-color: #4cd3aa;
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.search-btn:hover {
    background-color: #3bb896;
    transform: rotate(15deg);
}

/* SEO关键词区域（对用户隐藏但搜索引擎可见） */
.seo-keywords {
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
    opacity: 0;
}

/* 主横幅 */
.hero {
    background: linear-gradient(135deg, #e6f7f1 0%, #c6f0e3 100%);
    padding: 150px 0 100px;
    margin-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    color: #2a5749;
    margin-bottom: 20px;
    line-height: 1.2;
    font-family: 'Quicksand', sans-serif;
}

.hero-subtitle {
    font-size: 18px;
    color: #558f7d;
    margin-bottom: 40px;
    max-width: 700px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    margin-bottom: 40px;
}

.wave-animation {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M321.39,56.44c58-10.79,114.16-30.13,172-41.86,82.39-16.72,168.19-17.73,250.45-.39C823.78,31,906.67,72,985.66,92.83c70.05,18.48,146.53,26.09,214.34,3V0H0V27.35A600.21,600.21,0,0,0,321.39,56.44Z" fill="%23f9fdfb"></path></svg>');
    background-size: cover;
    animation: wave 12s linear infinite;
}

@keyframes wave {
    0% { background-position-x: 0; }
    100% { background-position-x: 1200px; }
}

/* 内容区域 */
.section {
    padding: 80px 0;
}

.section-alt {
    background-color: #f0f9f5;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: #2a5749;
    margin-bottom: 15px;
    text-align: center;
    font-family: 'Quicksand', sans-serif;
}

.section-subtitle {
    font-size: 18px;
    color: #558f7d;
    text-align: center;
    max-width: 800px;
    margin: 0 auto 50px;
}

/* 关键词云 */
.keyword-cloud {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
}

.keyword-cloud span {
    padding: 8px 16px;
    background-color: rgba(76, 211, 170, 0.1);
    border-radius: 20px;
    color: #2a5749;
    font-weight: 500;
    transition: all 0.3s ease;
    cursor: pointer;
}

.keyword-cloud span:hover {
    background-color: #4cd3aa;
    color: white;
    transform: translateY(-3px);
}

/* 图片展示区域 */
.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}

.gallery-item {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
}

.gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(76, 211, 170, 0.15);
}

.image-box {
    height: 200px;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.image-info {
    padding: 25px;
}

.image-info h3 {
    font-size: 20px;
    font-weight: 700;
    color: #2a5749;
    margin-bottom: 10px;
}

.image-info p {
    color: #666;
    margin-bottom: 20px;
    font-size: 15px;
}

.image-link {
    color: #4cd3aa;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
}

.image-link::after {
    content: '→';
    margin-left: 5px;
    transition: transform 0.3s ease;
}

.image-link:hover::after {
    transform: translateX(5px);
}

/* 关键词列表 */
.keyword-list {
    background-color: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    margin-top: 30px;
}

.keyword-list h3 {
    font-size: 20px;
    color: #2a5749;
    margin-bottom: 15px;
}

.keyword-list p {
    color: #666;
    font-size: 14px;
    line-height: 1.8;
}

/* 视频展示区域 */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}

.video-card {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
}

.video-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(76, 211, 170, 0.15);
}

.video-thumb {
    height: 180px;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    position: relative;
}

.play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background-color: rgba(76, 211, 170, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.play-btn:hover {
    background-color: #4cd3aa;
    transform: translate(-50%, -50%) scale(1.1);
}

.video-info {
    padding: 20px;
}

.video-info h3 {
    font-size: 18px;
    font-weight: 700;
    color: #2a5749;
    margin-bottom: 10px;
}

.video-info p {
    color: #666;
    font-size: 14px;
    margin-bottom: 15px;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    font-size: 14px;
    color: #888;
}

.video-meta i {
    margin-right: 5px;
}

.video-link {
    display: inline-block;
    background-color: #4cd3aa;
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 14px;
}

.video-link:hover {
    background-color: #3bb896;
}

/* 高密度关键词区域 */
.density-area {
    background-color: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
}

.density-area h3 {
    font-size: 20px;
    color: #2a5749;
    margin-bottom: 15px;
}

.density-area p {
    color: #666;
    line-height: 1.8;
}

/* 分类区域 */
.categories {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.category-card {
    background-color: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
    text-align: center;
}

.category-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(76, 211, 170, 0.15);
}

.category-icon {
    width: 70px;
    height: 70px;
    background-color: rgba(76, 211, 170, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 28px;
    color: #4cd3aa;
}

.category-card h3 {
    font-size: 22px;
    color: #2a5749;
    margin-bottom: 15px;
    font-family: 'Quicksand', sans-serif;
}

.category-card p {
    color: #666;
    margin-bottom: 25px;
    font-size: 15px;
}

.category-link {
    display: inline-block;
    color: #4cd3aa;
    font-weight: 600;
    border-bottom: 2px solid transparent;
    padding-bottom: 5px;
}

.category-link:hover {
    border-bottom-color: #4cd3aa;
}

/* 页脚 */
.footer {
    background-color: #2a5749;
    color: #c6e6db;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo a {
    font-size: 24px;
    font-weight: 700;
    color: #fff;
    font-family: 'Quicksand', sans-serif;
    margin-bottom: 15px;
    display: block;
}

.footer-logo p {
    margin-top: 15px;
    font-size: 15px;
}

.footer-links h4 {
    font-size: 18px;
    color: white;
    margin-bottom: 20px;
    font-weight: 600;
}

.footer-links a {
    display: block;
    margin-bottom: 10px;
    color: #c6e6db;
}

.footer-links a:hover {
    color: #4cd3aa;
    padding-left: 5px;
}

.footer-search h4 {
    font-size: 18px;
    color: white;
    margin-bottom: 20px;
    font-weight: 600;
}

.footer-search-form {
    display: flex;
    margin-bottom: 15px;
}

.footer-search-input {
    flex: 1;
    padding: 12px 15px;
    border: none;
    border-radius: 5px 0 0 5px;
    outline: none;
    font-family: 'Noto Sans SC', sans-serif;
}

.footer-search-btn {
    background-color: #4cd3aa;
    color: white;
    border: none;
    width: 50px;
    border-radius: 0 5px 5px 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.footer-search-btn:hover {
    background-color: #3bb896;
}

.footer-search p {
    font-size: 14px;
    color: #a3d4c5;
}

.footer-bottom {
    border-top: 1px solid #3a7767;
    padding-top: 30px;
    text-align: center;
    font-size: 14px;
}

.footer-bottom p {
    margin-bottom: 10px;
    line-height: 1.6;
}

.footer-bottom a {
    color: #4cd3aa;
    font-weight: 600;
}

.footer-bottom a:hover {
    text-decoration: underline;
}

/* 浮动元素 */
.floating-elements {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 100;
}

.float-item {
    position: absolute;
    background-color: rgba(76, 211, 170, 0.9);
    color: white;
    padding: 8px 12px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: 0 5px 15px rgba(76, 211, 170, 0.3);
    animation: float 6s ease-in-out infinite;
    opacity: 0.9;
    cursor: pointer;
}

.float-item:hover {
    opacity: 1;
    transform: scale(1.1);
}

.float-item-1 {
    animation-delay: 0s;
    bottom: 0;
    right: 0;
}

.float-item-2 {
    animation-delay: 1.2s;
    bottom: 40px;
    right: 30px;
}

.float-item-3 {
    animation-delay: 2.4s;
    bottom: 80px;
    right: 10px;
}

.float-item-4 {
    animation-delay: 3.6s;
    bottom: 120px;
    right: 40px;
}

.float-item-5 {
    animation-delay: 4.8s;
    bottom: 160px;
    right: 20px;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero-title {
        font-size: 40px;
    }
    
    .nav-links {
        gap: 20px;
    }
    
    .search-input {
        width: 150px;
    }
    
    .gallery {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    
    .categories {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 20px;
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .section-subtitle {
        font-size: 16px;
    }
    
    .gallery {
        grid-template-columns: 1fr;
    }
    
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .categories {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .float-item-4, .float-item-5 {
        display: none;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .keyword-cloud {
        gap: 10px;
    }
    
    .keyword-cloud span {
        padding: 6px 12px;
        font-size: 14px;
    }
    
    .float-item-3 {
        display: none;
    }
}