/* ============================================
   index.html 专属增强样式
   说明: 基于 main.css 设计系统，覆盖主色调为蓝色系，
         保留首页专属动画和视觉效果
   ============================================ */

/* 覆盖 main.css 变量 - 与全站统一蓝紫色系 */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #ec4899;
    --secondary-dark: #db2777;
    --accent: #06b6d4;
}

[data-theme="dark"] {
    --primary: #818cf8;
    --primary-dark: #6366f1;
    --primary-light: #a5b4fc;
    --secondary: #f472b6;
    --secondary-dark: #ec4899;
    --accent: #22d3ee;
}

/* ============================================
   Skip Link - 只在键盘聚焦时显示
   ============================================ */
.skip-link {
    position: fixed;
    top: -100px;
    left: 1rem;
    z-index: 10000;
    padding: 0.6rem 1.2rem;
    background: var(--primary);
    color: #fff !important;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    transition: top 0.3s ease;
    box-shadow: var(--shadow-md);
}

.skip-link:focus {
    top: 0;
}

/* ============================================
   Hero 浮动粒子
   ============================================ */
.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 1;
}

.hero-particles span {
    position: absolute;
    width: 6px;
    height: 6px;
    background: rgba(99, 102, 241, 0.2);
    border-radius: 50%;
    animation: heroFloat 8s ease-in-out infinite;
}

.hero-particles span:nth-child(1) { left: 10%; top: 20%; animation-delay: 0s; animation-duration: 7s; }
.hero-particles span:nth-child(2) { left: 20%; top: 60%; animation-delay: 1s; animation-duration: 9s; }
.hero-particles span:nth-child(3) { left: 35%; top: 30%; animation-delay: 2s; animation-duration: 8s; width: 4px; height: 4px; }
.hero-particles span:nth-child(4) { left: 50%; top: 70%; animation-delay: 0.5s; animation-duration: 10s; }
.hero-particles span:nth-child(5) { left: 65%; top: 25%; animation-delay: 1.5s; animation-duration: 7.5s; width: 5px; height: 5px; }
.hero-particles span:nth-child(6) { left: 75%; top: 55%; animation-delay: 3s; animation-duration: 9s; }
.hero-particles span:nth-child(7) { left: 85%; top: 35%; animation-delay: 2.5s; animation-duration: 8.5s; width: 3px; height: 3px; }
.hero-particles span:nth-child(8) { left: 90%; top: 75%; animation-delay: 1s; animation-duration: 7s; }

@keyframes heroFloat {
    0%, 100% { transform: translateY(0) scale(1); opacity: 0.3; }
    50% { transform: translateY(-30px) scale(1.3); opacity: 0.6; }
}

/* ============================================
   Hero 区域增强
   ============================================ */
.hero-section {
    position: relative;
    min-height: 480px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: linear-gradient(135deg, 
        rgba(99, 102, 241, 0.04) 0%, 
        rgba(236, 72, 153, 0.05) 50%, 
        rgba(6, 182, 212, 0.03) 100%
    );
}

/* Hero 渐变光斑装饰 */
.hero-section::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.12), transparent 70%);
    border-radius: 50%;
    z-index: 0;
    animation: heroBlob 12s ease-in-out infinite;
}

.hero-section::after {
    content: '';
    position: absolute;
    bottom: -20%;
    left: -10%;
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.08), transparent 70%);
    border-radius: 50%;
    z-index: 0;
    animation: heroBlob 15s ease-in-out infinite reverse;
}

@keyframes heroBlob {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -20px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

[data-theme="dark"] .hero-section {
    background: linear-gradient(135deg, 
        rgba(129, 140, 248, 0.04) 0%, 
        rgba(244, 114, 182, 0.05) 50%, 
        rgba(34, 211, 238, 0.03) 100%
    );
}

[data-theme="dark"] .hero-section::before {
    background: radial-gradient(circle, rgba(129, 140, 248, 0.1), transparent 70%);
}

[data-theme="dark"] .hero-section::after {
    background: radial-gradient(circle, rgba(244, 114, 182, 0.08), transparent 70%);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 4rem 1.5rem;
    max-width: 720px;
}

/* Hero 标题增强 */
.hero-title {
    font-size: clamp(1.8rem, 5vw, 3rem);
    font-weight: 800;
    line-height: 1.3;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

/* ============================================
   Hero 标题渐变文字
   ============================================ */
.hero-title .gradient-text {
    background: linear-gradient(135deg, var(--primary-dark), var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% 200%;
    animation: heroTextGradient 4s ease infinite;
}

@keyframes heroTextGradient {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* Hero 副标题 */
.hero-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 2rem;
    max-width: 580px;
    margin-left: auto;
    margin-right: auto;
}

/* Hero 按钮增强 */
.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-buttons .btn {
    padding: 0.7rem 2rem;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    transition: all 0.3s ease;
}

.hero-buttons .btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    border: none;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}

.hero-buttons .btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.hero-buttons .btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    backdrop-filter: blur(8px);
}

.hero-buttons .btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-3px);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.1);
}

/* ============================================
   头像呼吸光环
   ============================================ */
.about-avatar {
    position: relative;
}

.about-avatar::after {
    content: '';
    position: absolute;
    top: -6px;
    left: -6px;
    right: -6px;
    bottom: -6px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary), var(--accent));
    z-index: -1;
    animation: avatarRing 3s ease-in-out infinite;
    opacity: 0.6;
}

@keyframes avatarRing {
    0%, 100% { transform: scale(1); opacity: 0.6; }
    50% { transform: scale(1.05); opacity: 0.3; }
}

/* ============================================
   博客卡片缩略图
   ============================================ */
.blog-card .blog-thumbnail {
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    font-size: 2.5rem;
    position: relative;
    overflow: hidden;
}

.blog-card .blog-thumbnail::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.6s ease;
}

.blog-card:hover .blog-thumbnail::after {
    left: 100%;
}

/* ============================================
   分类图标彩色覆盖
   ============================================ */
.category-card:nth-child(1) .category-icon { background: linear-gradient(135deg, #3b82f6, #06b6d4); }
.category-card:nth-child(2) .category-icon { background: linear-gradient(135deg, #ec4899, #f59e0b); }
.category-card:nth-child(3) .category-icon { background: linear-gradient(135deg, #10b981, #3b82f6); }
.category-card:nth-child(4) .category-icon { background: linear-gradient(135deg, #f59e0b, #ec4899); }
.category-card:nth-child(5) .category-icon { background: linear-gradient(135deg, #8b5cf6, #3b82f6); }
.category-card:nth-child(6) .category-icon { background: linear-gradient(135deg, #06b6d4, #10b981); }

/* ============================================
   卡片滚动入场过渡
   ============================================ */
.blog-grid .blog-card,
.categories-grid .category-card {
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* ============================================
   标签呼吸效果
   ============================================ */
.tags-container .tag {
    animation: tagPulse 3s ease-in-out infinite;
}

.tags-container .tag:nth-child(2n) { animation-delay: 0.5s; }
.tags-container .tag:nth-child(3n) { animation-delay: 1s; }

@keyframes tagPulse {
    0%, 100% { box-shadow: 0 0 0 rgba(99, 102, 241, 0); }
    50% { box-shadow: 0 0 12px rgba(99, 102, 241, 0.15); }
}

/* ============================================
   加载进度条
   ============================================ */
.loading-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--border-color);
    z-index: 9999;
}

.loading-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    width: 0%;
    transition: width 0.3s ease;
}

/* ============================================
   响应式减弱动画
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    .hero-particles span,
    .hero-title .gradient-text,
    .about-avatar::after,
    .tags-container .tag,
    .hero-section::before,
    .hero-section::after {
        animation: none !important;
    }
}

/* ============================================
   Footer 底部美化
   ============================================ */
.footer-bottom {
    padding-top: var(--space-lg, 1.5rem);
}

.footer-tech {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm, 0.5rem);
    margin-bottom: var(--space-md, 1rem);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.tech-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.2rem 0.6rem;
    background: rgba(99, 102, 241, 0.08);
    color: var(--primary);
    border-radius: var(--radius-full, 9999px);
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid rgba(99, 102, 241, 0.15);
    transition: all 0.25s ease;
}

.tech-badge:hover {
    background: rgba(99, 102, 241, 0.15);
    transform: translateY(-1px);
}

.tech-badge i {
    font-size: 0.9em;
}

.footer-sep {
    color: var(--border-color);
    margin: 0 0.25rem;
    user-select: none;
}

.footer-brand {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.25s ease;
}

.footer-brand:hover {
    color: var(--secondary);
}

.footer-copyright {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.1rem;
    font-size: 0.8rem;
    line-height: 2;
    color: var(--text-muted);
}

.footer-copyright i {
    margin-right: 0.15rem;
    font-size: 0.85em;
    opacity: 0.7;
}

.footer-icp {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.25s ease;
}

.footer-icp:hover {
    color: var(--primary);
}

/* ============================================
   区块标题装饰增强
   ============================================ */
.section-header {
    position: relative;
    padding-bottom: var(--space-lg);
}

.section-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: var(--radius-full);
}

.section-title {
    position: relative;
    display: inline-block;
}

.section-title::before {
    content: '';
    position: absolute;
    left: -18px;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background: var(--secondary);
    border-radius: 50%;
    opacity: 0.7;
}

.section-title::after {
    content: '';
    position: absolute;
    right: -18px;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    opacity: 0.7;
}

/* ============================================
   分类卡片 - 玻璃拟态 + 独特渐变
   ============================================ */
.category-card {
    position: relative;
    overflow: hidden;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.category-card:nth-child(1)::before { background: linear-gradient(90deg, #3b82f6, #06b6d4); }
.category-card:nth-child(2)::before { background: linear-gradient(90deg, #ec4899, #f59e0b); }
.category-card:nth-child(3)::before { background: linear-gradient(90deg, #10b981, #3b82f6); }
.category-card:nth-child(4)::before { background: linear-gradient(90deg, #f59e0b, #ec4899); }
.category-card:nth-child(5)::before { background: linear-gradient(90deg, #8b5cf6, #3b82f6); }
.category-card:nth-child(6)::before { background: linear-gradient(90deg, #06b6d4, #10b981); }

.category-card:hover::before {
    opacity: 1;
}

.category-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(99, 102, 241, 0.12);
    border-color: transparent;
}

.category-icon {
    position: relative;
    z-index: 1;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.category-card:hover .category-icon {
    transform: scale(1.15) rotate(-5deg);
    box-shadow: 0 12px 32px rgba(99, 102, 241, 0.25);
}

/* 分类卡片序号角标 */
.category-card {
    counter-increment: category;
}

.category-card::after {
    content: counter(category, decimal-leading-zero);
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-muted);
    opacity: 0.06;
    line-height: 1;
    z-index: 0;
    pointer-events: none;
}

/* ============================================
   博客卡片 - 现代杂志风
   ============================================ */
.blog-card {
    position: relative;
    background: var(--bg-primary);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.blog-card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 2px;
    background: linear-gradient(135deg, var(--primary), var(--secondary), var(--accent));
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.blog-card:hover::before {
    opacity: 0.4;
}

.blog-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.1);
}

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

.blog-thumbnail i {
    transition: transform 0.4s ease, filter 0.4s ease;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.2));
}

.blog-card:hover .blog-thumbnail i {
    transform: scale(1.15);
    filter: drop-shadow(0 6px 16px rgba(0, 0, 0, 0.3));
}

.blog-category {
    position: relative;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    transition: all 0.25s ease;
}

.blog-category::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--primary);
    border-radius: 50%;
    display: inline-block;
}

.blog-card:hover .blog-category {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(236, 72, 153, 0.1));
    transform: translateX(4px);
}

/* 博客卡片 meta 图标颜色 */
.blog-meta span i {
    color: var(--primary-light);
    transition: color 0.25s ease;
}

.blog-card:hover .blog-meta span i {
    color: var(--secondary);
}

/* ============================================
   关于区域 - 精美卡片
   ============================================ */
.about-card {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    border: 1px solid var(--border-color);
    transition: all 0.4s ease;
}

.about-card::before {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 250px;
    height: 250px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.06), transparent 70%);
    pointer-events: none;
}

.about-card::after {
    content: '';
    position: absolute;
    bottom: -80px;
    left: -80px;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.05), transparent 70%);
    pointer-events: none;
}

.about-card:hover {
    box-shadow: 0 20px 50px rgba(99, 102, 241, 0.1);
    border-color: rgba(99, 102, 241, 0.2);
}

.about-info h3 {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1.6rem;
}

.about-info p:first-of-type {
    display: inline-block;
    padding: 0.2rem 0.8rem;
    background: rgba(99, 102, 241, 0.08);
    color: var(--primary);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: var(--space-md);
}

/* 社交链接彩色效果 */
.social-links {
    display: flex;
    gap: var(--space-sm);
    margin-top: var(--space-md);
}

.social-link {
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 1.1rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    opacity: 0;
    transition: opacity 0.3s ease;
    border-radius: inherit;
}

.social-link:hover::before {
    opacity: 1;
}

.social-link:hover {
    color: #fff;
    border-color: transparent;
    transform: translateY(-4px) scale(1.1);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
}

.social-link i {
    position: relative;
    z-index: 1;
}

/* ============================================
   技术栈标签 - 彩虹渐变
   ============================================ */
.tags-container {
    position: relative;
    padding: var(--space-xl);
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
}

.tags-container .tag {
    position: relative;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-full);
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: default;
    transition: all 0.3s ease;
}

.tags-container .tag:hover {
    color: #fff;
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
    animation: none;
}

/* 每个标签独特的hover颜色 */
.tags-container .tag:nth-child(1):hover { background: linear-gradient(135deg, #e34c26, #f06529); }
.tags-container .tag:nth-child(2):hover { background: linear-gradient(135deg, #264de4, #2965f1); }
.tags-container .tag:nth-child(3):hover { background: linear-gradient(135deg, #f7df1e, #f0db4f); color: #323330 !important; }
.tags-container .tag:nth-child(4):hover { background: linear-gradient(135deg, #3776ab, #ffd43b); color: #fff !important; }
.tags-container .tag:nth-child(5):hover { background: linear-gradient(135deg, #306998, #ffd43b); color: #fff !important; }
.tags-container .tag:nth-child(6):hover { background: linear-gradient(135deg, #00d4aa, #00b894); }
.tags-container .tag:nth-child(7):hover { background: linear-gradient(135deg, #4b8bbe, #ffe873); color: #fff !important; }
.tags-container .tag:nth-child(8):hover { background: linear-gradient(135deg, #6366f1, #ec4899); }
.tags-container .tag:nth-child(9):hover { background: linear-gradient(135deg, #06b6d4, #3b82f6); }

/* ============================================
   统计卡片增强
   ============================================ */
.stat-card {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--secondary), var(--accent));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.stat-card:hover::before {
    opacity: 1;
}

.stat-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(99, 102, 241, 0.1);
}

.stat-icon {
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.25);
}

.stat-card:hover .stat-icon {
    transform: scale(1.15) rotate(-5deg);
    box-shadow: 0 12px 32px rgba(99, 102, 241, 0.35);
}

/* ============================================
   容器增强 - 微妙背景纹理
   ============================================ */
.container {
    position: relative;
}

/* ============================================
   卡片交错入场动画
   ============================================ */
.blog-grid .blog-card:nth-child(1),
.categories-grid .category-card:nth-child(1) { transition-delay: 0s; }
.blog-grid .blog-card:nth-child(2),
.categories-grid .category-card:nth-child(2) { transition-delay: 0.08s; }
.blog-grid .blog-card:nth-child(3),
.categories-grid .category-card:nth-child(3) { transition-delay: 0.16s; }
.blog-grid .blog-card:nth-child(4),
.categories-grid .category-card:nth-child(4) { transition-delay: 0.24s; }
.blog-grid .blog-card:nth-child(5),
.categories-grid .category-card:nth-child(5) { transition-delay: 0.32s; }
.blog-grid .blog-card:nth-child(6),
.categories-grid .category-card:nth-child(6) { transition-delay: 0.40s; }

/* ============================================
   响应式减弱动画
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    .hero-particles span,
    .hero-title .gradient-text,
    .about-avatar::after,
    .tags-container .tag,
    .hero-section::before,
    .hero-section::after,
    .blog-card,
    .category-card,
    .stat-card {
        animation: none !important;
        transition: none !important;
    }
}

/* ============================================
   学习社群卡片 (community-card)
   ============================================ */
.community-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.community-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    text-align: center;
    transition: all 0.4s ease;
}

.community-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 40px rgba(99, 102, 241, 0.12);
    border-color: rgba(99, 102, 241, 0.2);
}

.community-card__icon {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 0.85rem;
    color: #fff;
    font-size: 1.35rem;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.community-card__icon--download {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
}

.community-card__icon--qq {
    background: linear-gradient(135deg, #12b7f5, #0099ff);
}

.community-card__icon--rocket {
    background: linear-gradient(135deg, var(--accent), #0891b2);
}

.community-card:hover .community-card__icon {
    transform: scale(1.1) rotate(-5deg);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.25);
}

.community-card__title {
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
}

.community-card__desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.85rem;
    line-height: 1.5;
}

.community-card__btn {
    font-size: 0.85rem;
    padding: 0.5rem 1.25rem;
}

.community-card__badge {
    font-size: 0.85rem;
    display: inline-block;
}

/* QQ 群二维码响应式容器 */
.community-card--qq {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.community-card__info {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.community-card__qr {
    width: 100%;
    max-width: 180px;
    margin-bottom: 0.85rem;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.community-card__qr-img {
    width: 100%;
    height: auto;
    object-fit: contain;
    display: block;
}

/* ============================================
   移动端适配
   ============================================ */
@media (max-width: 768px) {
    .section-title::before,
    .section-title::after {
        display: none;
    }

    .about-card {
        flex-direction: column;
        text-align: center;
        gap: var(--space-xl);
    }

    .social-links {
        justify-content: center;
    }

    .category-card:hover,
    .blog-card:hover,
    .stat-card:hover {
        transform: translateY(-4px) scale(1.01);
    }

    /* 社群卡片移动端 */
    .community-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .community-card {
        padding: 1.25rem;
    }

    .community-card:hover {
        transform: translateY(-3px);
    }

    /* QQ 群卡片移动端横向布局：左信息右二维码 */
    .community-card--qq {
        flex-direction: row;
        text-align: left;
        align-items: stretch;
        gap: 1rem;
    }

    .community-card__info {
        flex: 1;
        min-width: 0;
        align-items: flex-start;
    }

    .community-card--qq .community-card__icon {
        margin: 0;
        width: 40px;
        height: 40px;
        font-size: 1.1rem;
        flex-shrink: 0;
    }

    .community-card--qq .community-card__title {
        font-size: 1rem;
        margin-bottom: 0.2rem;
    }

    .community-card--qq .community-card__desc {
        font-size: 0.8rem;
        margin-bottom: 0.5rem;
        line-height: 1.4;
    }

    .community-card--qq .community-card__btn {
        font-size: 0.8rem;
        padding: 0.4rem 1rem;
    }

    /* 右侧二维码 - 横向布局时固定宽度，高度按图片比例自适应 */
    .community-card--qq .community-card__qr {
        max-width: 130px;
        width: 130px;
        flex-shrink: 0;
        margin-bottom: 0;
        align-self: center;
    }

    .community-card--qq .community-card__qr-img {
        width: 100%;
        height: auto;
        object-fit: contain;
    }
}

/* 小屏手机 - 改为垂直布局，二维码居中完整显示 */
@media (max-width: 480px) {
    .community-card--qq {
        flex-direction: column;
        text-align: center;
        align-items: center;
        gap: 0.75rem;
        padding: 1rem;
    }

    .community-card--qq .community-card__info {
        align-items: center;
        text-align: center;
        width: 100%;
    }

    .community-card--qq .community-card__icon {
        width: 36px;
        height: 36px;
        font-size: 1rem;
        margin: 0 auto;
    }

    .community-card--qq .community-card__title {
        font-size: 0.95rem;
    }

    .community-card--qq .community-card__desc {
        font-size: 0.75rem;
    }

    .community-card--qq .community-card__btn {
        font-size: 0.75rem;
        padding: 0.35rem 0.85rem;
    }

    /* 二维码垂直居中，宽度限制确保完整显示 */
    .community-card--qq .community-card__qr {
        width: 140px;
        max-width: 140px;
        margin-bottom: 0;
    }

    .community-card--qq .community-card__qr-img {
        width: 100%;
        height: auto;
        object-fit: contain;
    }

    .community-card__icon {
        width: 44px;
        height: 44px;
        font-size: 1.15rem;
    }

    .community-card__title {
        font-size: 1rem;
    }

    .community-card__desc {
        font-size: 0.8rem;
    }
}

/* 超大屏 - 二维码显示更大 */
@media (min-width: 1200px) {
    .community-card__qr {
        max-width: 200px;
    }
}