/* 渐进式交互主题 - 动态渐变风格 */
:root {
    --primary-gradient: linear-gradient(135deg, #4361ee, #3a0ca3);
    --secondary-gradient: linear-gradient(135deg, #f72585, #b5179e);
    --dark-bg: #1a1a2e;
    --light-text: #e6e6e6;
    --accent-color: #4cc9f0;
    --card-bg: rgba(255, 255, 255, 0.08);
    --transition-speed: 0.4s;
}

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

@supports (font-variation-settings: normal) {
    * {
        font-family: 'Inter var', -apple-system, BlinkMacSystemFont, sans-serif;
    }
}

body {
    background-color: var(--dark-bg);
    color: var(--light-text);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(67, 97, 238, 0.1) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(247, 37, 133, 0.1) 0%, transparent 20%);
}

/* 动态渐变头部 */
header {
    background: linear-gradient(90deg, rgba(26, 26, 46, 0.9), rgba(58, 12, 163, 0.7));
    backdrop-filter: blur(10px);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-speed) ease;
}

.header-scrolled {
    background: rgba(26, 26, 46, 0.95);
    padding: 1rem 0;
}

.container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 800;
    background: linear-gradient(to right, #4cc9f0, #f72585);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

/* 渐进式导航菜单 */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--light-text);
    font-size: 1.5rem;
    cursor: pointer;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

nav ul li a {
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-weight: 500;
    position: relative;
    overflow: hidden;
}

nav ul li a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width var(--transition-speed) ease;
}

nav ul li a:hover::before {
    width: 100%;
}

/* 渐进式卡片 */
.article-card {
    background: var(--card-bg);
    border-radius: 1rem;
    overflow: hidden;
    transition: all var(--transition-speed) ease;
    border: 1px solid rgba(255, 255, 255, 0.05);
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
}

.article-card:hover {
    transform: translateY(-0.5rem);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.4);
    background: rgba(255, 255, 255, 0.12);
}

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

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

.card-body {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
    line-height: 1.4;
    transition: color var(--transition-speed) ease;
}

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

.card-excerpt {
    color: rgba(230, 230, 230, 0.8);
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: rgba(230, 230, 230, 0.6);
    margin-top: auto;
}

/* 渐进式网格布局 */
.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.featured-grid {
    grid-template-columns: repeat(2, 1fr);
}

.featured-grid .article-card {
    grid-column: span 1;
}

.featured-grid .article-card:first-child {
    grid-column: span 2;
}

.featured-grid .article-card:first-child .card-image {
    height: 300px;
}

/* 渐进式加载动画 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.article-card {
    animation: fadeIn 0.6s ease forwards;
    opacity: 0;
}

.article-card:nth-child(1) { animation-delay: 0.1s; }
.article-card:nth-child(2) { animation-delay: 0.2s; }
.article-card:nth-child(3) { animation-delay: 0.3s; }
/* 继续根据需要添加更多延迟 */

/* 文章详情页 */
.article-hero {
    position: relative;
    height: 60vh;
    min-height: 400px;
    display: flex;
    align-items: flex-end;
    margin-bottom: 3rem;
    overflow: hidden;
    border-radius: 1rem;
}

.hero-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(26, 26, 46, 0.9), transparent);
    z-index: 2;
}

.hero-content {
    position: relative;
    z-index: 3;
    padding: 3rem;
    width: 100%;
}

.article-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.article-meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.article-content {
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
    font-size: 1.1rem;
}

.article-content p {
    margin-bottom: 1.5rem;
}

.article-content img {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    margin: 2rem 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

/* 渐进式分页 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 3rem;
}

.pagination a {
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    background: rgba(255, 255, 255, 0.1);
    transition: all var(--transition-speed) ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.pagination a:hover {
    background: var(--primary-gradient);
    color: white;
    transform: translateY(-2px);
}

/* 渐进式页脚 */
footer {
    background: rgba(0, 0, 0, 0.3);
    padding: 3rem 0 1.5rem;
    margin-top: auto;
    backdrop-filter: blur(5px);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-column h3 {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    color: var(--accent-color);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(230, 230, 230, 0.7);
    transition: color var(--transition-speed) ease;
    display: inline-block;
    padding: 0.25rem 0;
}

.footer-links a:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}

.copyright {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(230, 230, 230, 0.5);
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .featured-grid {
        grid-template-columns: 1fr;
    }
    
    .featured-grid .article-card:first-child {
        grid-column: span 1;
    }
    
    .featured-grid .article-card:first-child .card-image {
        height: 200px;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }
    
    nav {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: var(--dark-bg);
        padding: 1rem;
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
        transform: translateY(-150%);
        opacity: 0;
        transition: all var(--transition-speed) ease;
        z-index: 999;
    }
    
    nav.active {
        transform: translateY(0);
        opacity: 1;
    }
    
    nav ul {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .container {
        padding: 0 1.5rem;
    }
    
    .article-title {
        font-size: 2rem;
    }
}

@media (max-width: 576px) {
    .article-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-content {
        padding: 2rem 1.5rem;
    }
    
    .article-title {
        font-size: 1.8rem;
    }
}