/* 渐进式黄色主题 */
:root {
    --primary-yellow: #ffde22;
    --secondary-yellow: #ffd700;
    --dark-accent: #33312e;
    --light-bg: #fffdf5;
    --text-dark: #2a2a2a;
    --text-light: #5a5a5a;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--light-bg);
    color: var(--text-dark);
    line-height: 1.7;
    overflow-x: hidden;
}

/* 渐进式加载动画 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.progressive-load {
    opacity: 0;
    animation: fadeIn 0.6s forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

/* 交互式按钮 */
.btn {
    display: inline-block;
    padding: 12px 24px;
    background: linear-gradient(135deg, var(--primary-yellow), var(--secondary-yellow));
    color: var(--text-dark);
    border: none;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    transform: scale(1);
}

.btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: scale(0.98);
}

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

/* 动态头部样式 */
header {
    background-color: white;
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.header-scrolled {
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

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

.logo {
    font-size: 28px;
    font-weight: 800;
    background: linear-gradient(to right, #ff8a00, #ffde22);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 25px;
}

nav ul li a {
    padding: 8px 16px;
    border-radius: 50px;
    font-weight: 500;
    transition: var(--transition);
}

nav ul li a:hover {
    background-color: var(--primary-yellow);
    color: var(--text-dark);
}

/* 动态内容卡片 */
.main-content {
    padding: 40px;
    margin: 40px 0;
    background-color: white;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.main-content:hover {
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 26px;
    margin-bottom: 30px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(to right, var(--primary-yellow), var(--secondary-yellow));
    border-radius: 2px;
}

/* 3D卡片效果 */
.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
    perspective: 1000px;
}

.article-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    transition: var(--transition);
    transform-style: preserve-3d;
    box-shadow: var(--shadow-sm);
    position: relative;
}

.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(to right, var(--primary-yellow), var(--secondary-yellow));
}

.article-card:hover {
    transform: translateY(-8px) rotateX(5deg);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

.article-card:hover .card-image {
    transform: scale(1.03);
}

.card-body {
    padding: 20px;
}

.card-title {
    font-size: 18px;
    margin-bottom: 12px;
    font-weight: 600;
    transition: var(--transition);
}

.article-card:hover .card-title {
    color: var(--primary-yellow);
}

.card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
    color: var(--text-light);
    margin-top: 15px;
}

/* 分类标签 */
.category-tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: rgba(255, 222, 34, 0.2);
    color: var(--text-dark);
    border-radius: 50px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 15px;
}

/* 文章详情页 */
.article-detail {
    max-width: 800px;
    margin: 0 auto;
}

.article-header {
    margin-bottom: 40px;
    text-align: center;
}

.article-title {
    font-size: 36px;
    margin-bottom: 20px;
    line-height: 1.3;
}

.article-meta {
    display: flex;
    justify-content: center;
    gap: 25px;
    color: var(--text-light);
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.article-image {
    width: 100%;
    max-height: 500px;
    object-fit: cover;
    border-radius: 16px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.article-image:hover {
    transform: scale(1.01);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.article-content {
    line-height: 1.8;
    font-size: 18px;
    color: var(--text-dark);
}

.article-content p {
    margin-bottom: 25px;
}

.article-content img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    margin: 25px 0;
    box-shadow: var(--shadow-sm);
}

/* 交互式分页 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 50px;
}

.pagination a {
    padding: 12px 24px;
    border-radius: 50px;
    background-color: white;
    color: var(--text-dark);
    font-weight: 600;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.pagination a:hover {
    background: linear-gradient(135deg, var(--primary-yellow), var(--secondary-yellow));
    color: var(--text-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* 友情链接 */
.friend-links {
    background-color: white;
    border-radius: 16px;
    padding: 30px;
    margin: 40px 0;
    box-shadow: var(--shadow-sm);
}

.friend-links h3 {
    margin-bottom: 20px;
    font-size: 22px;
}

.friend-links-container {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.friend-links-container a {
    padding: 8px 20px;
    background-color: rgba(255, 222, 34, 0.2);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
}

.friend-links-container a:hover {
    background-color: var(--primary-yellow);
    color: var(--text-dark);
    transform: translateY(-2px);
}

/* 动态页脚 */
footer {
    background-color: var(--dark-accent);
    color: white;
    padding: 40px 0;
    text-align: center;
    margin-top: 60px;
}

.copyright {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .main-content {
        padding: 30px 20px;
    }
    
    .article-title {
        font-size: 28px;
    }
    
    .article-grid {
        grid-template-columnons: 1fr;
    }
}

/* 滚动进度条 */
.progress-container {
    width: 100%;
    height: 5px;
    background: transparent;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1001;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(to right, var(--primary-yellow), var(--secondary-yellow));
    width: 0%;
    transition: width 0.1s ease;
}