/* 重置和基本样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    overflow-x: hidden;
    position: relative;
}

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

a {
    text-decoration: none;
    color: #4a6fa5;
    transition: all 0.3s ease;
}

a:hover {
    color: #2c4a7a;
}

h1, h2, h3, h4 {
    font-family: 'Quicksand', sans-serif;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #2c3e50;
}

p {
    margin-bottom: 1rem;
}

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

/* 动态背景 */
.dynamic-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.bg-circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(74, 111, 165, 0.05);
    animation: float 20s infinite linear;
}

.circle-1 {
    width: 300px;
    height: 300px;
    top: 10%;
    left: 5%;
    animation-delay: 0s;
}

.circle-2 {
    width: 200px;
    height: 200px;
    top: 60%;
    right: 10%;
    animation-delay: 5s;
    background: rgba(86, 204, 242, 0.05);
}

.circle-3 {
    width: 250px;
    height: 250px;
    bottom: 10%;
    left: 15%;
    animation-delay: 10s;
    background: rgba(155, 89, 182, 0.05);
}

.circle-4 {
    width: 180px;
    height: 180px;
    top: 20%;
    right: 20%;
    animation-delay: 15s;
    background: rgba(46, 204, 113, 0.05);
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(0deg);
    }
    33% {
        transform: translateY(-30px) rotate(120deg);
    }
    66% {
        transform: translateY(20px) rotate(240deg);
    }
}

/* 头部样式 */
.header {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(74, 111, 165, 0.1);
}

.logo-area {
    padding: 1.5rem 0;
    text-align: center;
    border-bottom: 1px solid rgba(74, 111, 165, 0.1);
}

.logo-area h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.logo-area h1 a {
    color: #4a6fa5;
}

.logo-area h1 span {
    color: #56ccf2;
}

.tagline {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.search-area {
    padding: 1.5rem 0;
    border-bottom: 1px solid rgba(74, 111, 165, 0.1);
}

.search-form {
    display: flex;
    max-width: 600px;
    margin: 0 auto 1rem;
    border-radius: 50px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(74, 111, 165, 0.1);
}

.search-input {
    flex: 1;
    padding: 15px 25px;
    border: none;
    font-size: 1.1rem;
    background-color: #fff;
}

.search-btn {
    padding: 0 30px;
    background: linear-gradient(135deg, #4a6fa5, #56ccf2);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.search-btn:hover {
    background: linear-gradient(135deg, #3a5a85, #46bcd2);
}

.search-keywords {
    text-align: center;
    color: #7f8c8d;
}

.search-keywords a {
    margin: 0 5px;
    font-weight: 500;
}

.main-nav {
    padding: 1rem 0;
}

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

.main-nav li {
    margin: 0 1rem;
}

.main-nav a {
    display: flex;
    align-items: center;
    padding: 10px 15px;
    border-radius: 30px;
    font-weight: 500;
    color: #4a6fa5;
    transition: all 0.3s ease;
}

.main-nav a:hover {
    background-color: rgba(74, 111, 165, 0.1);
    color: #2c4a7a;
}

.main-nav i {
    margin-right: 8px;
}

/* 主要内容区域 */
.main-content {
    padding: 3rem 0;
}

/* 高密度关键词展示区 */
.high-density-section {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9), rgba(248, 249, 250, 0.9));
    border-radius: 15px;
    padding: 2.5rem;
    margin-bottom: 3rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(74, 111, 165, 0.1);
    position: relative;
    overflow: hidden;
}

.high-density-section::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, #4a6fa5, #56ccf2);
}

.high-density-section h2 {
    color: #4a6fa5;
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
}

.keywords-cloud {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-bottom: 2rem;
}

.keyword-large, .keyword-medium, .keyword-small {
    padding: 12px 20px;
    border-radius: 30px;
    font-weight: 700;
    transition: all 0.3s ease;
    display: inline-block;
}

.keyword-large {
    font-size: 1.3rem;
    background: linear-gradient(135deg, #4a6fa5, #56ccf2);
    color: white;
    box-shadow: 0 5px 15px rgba(74, 111, 165, 0.3);
}

.keyword-medium {
    font-size: 1.1rem;
    background-color: rgba(86, 204, 242, 0.15);
    color: #2c4a7a;
    border: 2px solid #56ccf2;
}

.keyword-small {
    font-size: 1rem;
    background-color: rgba(155, 89, 182, 0.1);
    color: #8e44ad;
    border: 2px solid rgba(155, 89, 182, 0.3);
}

.keyword-large:hover, .keyword-medium:hover, .keyword-small:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.keywords-description {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #555;
    text-align: justify;
}

/* 图片展示区 */
.image-gallery {
    margin-bottom: 3rem;
}

.image-gallery h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #4a6fa5;
    position: relative;
    padding-bottom: 15px;
}

.image-gallery h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: linear-gradient(to right, #4a6fa5, #56ccf2);
}

.gallery-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.gallery-item {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.4s ease;
    border: 1px solid rgba(74, 111, 165, 0.1);
}

.gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.gallery-item img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.image-info {
    padding: 1.5rem;
}

.image-info h3 {
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
}

.image-info h3 a {
    color: #2c3e50;
}

.image-info h3 a:hover {
    color: #4a6fa5;
}

.image-info p {
    color: #666;
    margin-bottom: 1.2rem;
    font-size: 1rem;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tags a {
    padding: 5px 12px;
    background-color: rgba(86, 204, 242, 0.1);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #2c4a7a;
}

.tags a:hover {
    background-color: rgba(86, 204, 242, 0.3);
}

/* 视频展示区 */
.video-section {
    margin-bottom: 3rem;
}

.video-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #4a6fa5;
    position: relative;
    padding-bottom: 15px;
}

.video-section h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: linear-gradient(to right, #56ccf2, #4a6fa5);
}

.video-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.video-item {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.4s ease;
    border: 1px solid rgba(74, 111, 165, 0.1);
}

.video-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.video-thumbnail {
    position: relative;
    overflow: hidden;
}

.video-thumbnail img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.video-item:hover .video-thumbnail img {
    transform: scale(1.05);
}

.play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(86, 204, 242, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.video-item:hover .play-btn {
    background: rgba(74, 111, 165, 0.9);
    transform: translate(-50%, -50%) scale(1.1);
}

.video-info {
    padding: 1.5rem;
}

.video-info h3 {
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
}

.video-info h3 a {
    color: #2c3e50;
}

.video-info h3 a:hover {
    color: #4a6fa5;
}

.video-info p {
    color: #666;
    margin-bottom: 1.2rem;
    font-size: 1rem;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    color: #7f8c8d;
    font-size: 0.9rem;
}

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

/* 关键词列表区 */
.keywords-list-section {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9), rgba(248, 249, 250, 0.9));
    border-radius: 15px;
    padding: 2.5rem;
    margin-bottom: 3rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(74, 111, 165, 0.1);
}

.keywords-list-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #4a6fa5;
}

.keywords-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
}

.keywords-list a {
    padding: 8px 16px;
    background-color: rgba(155, 89, 182, 0.1);
    border-radius: 20px;
    font-weight: 500;
    color: #8e44ad;
    transition: all 0.3s ease;
}

.keywords-list a:hover {
    background-color: rgba(155, 89, 182, 0.3);
    transform: translateY(-3px);
}

/* 页脚样式 */
.footer {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: #56ccf2;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 10px;
}

.footer-section h3::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 2px;
    background-color: #56ccf2;
}

.footer-section p {
    color: #bdc3c7;
    line-height: 1.7;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: #bdc3c7;
    transition: all 0.3s ease;
}

.footer-section ul li a:hover {
    color: #56ccf2;
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(236, 240, 241, 0.1);
    color: #95a5a6;
    font-size: 0.9rem;
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #4a6fa5, #56ccf2);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    box-shadow: 0 5px 15px rgba(74, 111, 165, 0.4);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 99;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: linear-gradient(135deg, #3a5a85, #46bcd2);
    transform: translateY(-5px);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .gallery-container, .video-container {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
    
    .logo-area h1 {
        font-size: 2rem;
    }
    
    .high-density-section, .keywords-list-section {
        padding: 2rem;
    }
}

@media (max-width: 768px) {
    .main-nav ul {
        flex-direction: column;
        align-items: center;
    }
    
    .main-nav li {
        margin: 0.5rem 0;
    }
    
    .gallery-container, .video-container {
        grid-template-columns: 1fr;
    }
    
    .search-form {
        flex-direction: column;
        border-radius: 15px;
    }
    
    .search-input {
        border-radius: 15px 15px 0 0;
        padding: 12px 20px;
    }
    
    .search-btn {
        border-radius: 0 0 15px 15px;
        padding: 12px;
    }
    
    .keyword-large, .keyword-medium, .keyword-small {
        padding: 10px 15px;
        font-size: 0.9rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .logo-area h1 {
        font-size: 1.8rem;
    }
    
    .high-density-section, .keywords-list-section {
        padding: 1.5rem;
    }
    
    .keywords-cloud {
        gap: 10px;
    }
    
    .keywords-list {
        gap: 8px;
    }
    
    .keywords-list a {
        padding: 6px 12px;
        font-size: 0.85rem;
    }
}