/* ============================================
   糖心vlog - 完全原创CSS设计
   配色方案：深紫渐变 + 玫瑰金 + 暗夜蓝
   ============================================ */

/* CSS变量 */
:root {
    --primary-color: #6C2BD9;
    --primary-light: #8B5CF6;
    --primary-dark: #4C1D95;
    --secondary-color: #E8A87C;
    --accent-color: #F72585;
    --accent-light: #FF5DA2;
    --text-primary: #1A1A2E;
    --text-secondary: #4A4A6A;
    --text-light: #8888A8;
    --text-white: #F5F5FF;
    --bg-primary: #0F0F1A;
    --bg-secondary: #1A1A2E;
    --bg-card: #222240;
    --bg-card-hover: #2A2A50;
    --bg-gradient-start: #0F0F1A;
    --bg-gradient-end: #1A1035;
    --border-color: #333360;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 20px;
    --shadow: 0 4px 24px rgba(108, 43, 217, 0.15);
    --shadow-hover: 0 8px 40px rgba(108, 43, 217, 0.25);
    --shadow-card: 0 2px 16px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-main: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    --max-width: 1280px;
    --glow-purple: 0 0 20px rgba(108, 43, 217, 0.4);
    --glow-pink: 0 0 20px rgba(247, 37, 133, 0.4);
}

/* 全局重置 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-white);
    line-height: 1.7;
    overflow-x: hidden;
    min-height: 100vh;
}

a {
    color: var(--primary-light);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--accent-color);
}

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

ul, ol {
    list-style: none;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================================
   导航栏 - 毛玻璃效果
   ============================================ */
.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 15, 26, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(108, 43, 217, 0.2);
    padding: 0 24px;
    height: 68px;
    transition: var(--transition);
}

.site-nav.scrolled {
    background: rgba(15, 15, 26, 0.95);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-white);
    text-decoration: none;
}

.nav-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: #fff;
    font-weight: 800;
}

.nav-logo:hover {
    color: var(--primary-light);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-menu a {
    color: var(--text-white);
    padding: 8px 16px;
    border-radius: var(--border-radius-sm);
    font-size: 0.92rem;
    font-weight: 500;
    position: relative;
    overflow: hidden;
    transition: var(--transition);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
    transition: transform 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    transform: translateX(-50%) scaleX(1);
}

.nav-menu a:hover {
    color: var(--accent-light);
    background: rgba(108, 43, 217, 0.1);
}

.nav-download-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 22px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: #fff !important;
    border-radius: 50px;
    font-size: 0.88rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.nav-download-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--glow-purple);
    color: #fff !important;
}

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
    background: none;
    border: none;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-white);
    border-radius: 2px;
    transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   主内容区
   ============================================ */
main {
    padding-top: 68px;
}

.section-block {
    padding: 80px 0;
    position: relative;
}

.section-block:nth-child(even) {
    background: linear-gradient(180deg, var(--bg-secondary), var(--bg-primary));
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text-white), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1rem;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   欢迎区域 - 渐变背景 + 粒子感
   ============================================ */
.welcome-section {
    padding: 120px 0 100px;
    text-align: center;
    background: linear-gradient(160deg, var(--bg-primary) 0%, var(--primary-dark) 40%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.welcome-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(247, 37, 133, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.welcome-section::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -15%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(108, 43, 217, 0.2) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.welcome-section .container {
    position: relative;
    z-index: 1;
}

.welcome-title {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    background: linear-gradient(135deg, #fff 30%, var(--primary-light) 70%, var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-text {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 720px;
    margin: 0 auto 40px;
    line-height: 1.9;
}

.welcome-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 36px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: #fff;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--glow-purple);
    color: #fff;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 36px;
    background: transparent;
    color: var(--text-white);
    border: 2px solid rgba(108, 43, 217, 0.5);
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-secondary:hover {
    border-color: var(--primary-light);
    background: rgba(108, 43, 217, 0.1);
    color: var(--primary-light);
}

/* ============================================
   精选视频区
   ============================================ */
.featured-video-wrapper {
    max-width: 900px;
    margin: 0 auto;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    position: relative;
    background: var(--bg-card);
    box-shadow: var(--shadow);
}

.featured-video-cover {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
}

.featured-video-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(0deg, rgba(15, 15, 26, 0.9) 0%, transparent 50%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 40px;
}

.featured-video-overlay h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    color: #fff;
}

.featured-video-overlay p {
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.95rem;
    line-height: 1.7;
}

.play-btn-circle {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 72px;
    height: 72px;
    background: rgba(108, 43, 217, 0.8);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    border: 3px solid rgba(255, 255, 255, 0.3);
}

.play-btn-circle::after {
    content: '';
    display: block;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 12px 0 12px 22px;
    border-color: transparent transparent transparent #fff;
    margin-left: 4px;
}

.play-btn-circle:hover {
    background: var(--accent-color);
    transform: translate(-50%, -50%) scale(1.1);
    box-shadow: var(--glow-pink);
}

/* ============================================
   关于我们
   ============================================ */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}

.about-text {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.9;
}

.about-text p {
    margin-bottom: 16px;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.stat-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 28px 24px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.stat-card:hover {
    border-color: var(--primary-light);
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.stat-number {
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-light), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 6px;
}

.stat-label {
    font-size: 0.88rem;
    color: var(--text-light);
}

/* ============================================
   视频卡片网格
   ============================================ */
.video-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.video-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
}

.video-card:hover {
    transform: translateY(-6px);
    border-color: var(--primary-light);
    box-shadow: var(--shadow-hover);
}

.video-card-cover {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16 / 10;
}

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

.video-card:hover .video-card-cover img {
    transform: scale(1.08);
}

.video-card-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    color: #fff;
    font-size: 0.72rem;
    padding: 3px 10px;
    border-radius: 20px;
    font-weight: 600;
}

.video-card-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0, 0, 0, 0.75);
    color: #fff;
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 4px;
}

.video-card-body {
    padding: 16px;
}

.video-card-body h3 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 8px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
    font-size: 0.82rem;
}

.rating {
    color: #FFD700;
    font-weight: 600;
}

.views {
    color: var(--text-light);
}

.video-desc {
    font-size: 0.82rem;
    color: var(--text-light);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ============================================
   资质认证
   ============================================ */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.cert-item {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 32px 24px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.cert-item:hover {
    border-color: var(--primary-light);
    transform: translateY(-4px);
}

.cert-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.cert-item h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
    color: var(--text-white);
}

.cert-item p {
    font-size: 0.85rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   支付方式
   ============================================ */
.payment-grid {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.payment-item {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 24px 36px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    min-width: 120px;
}

.payment-item:hover {
    border-color: var(--primary-light);
    transform: translateY(-3px);
}

.payment-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, rgba(108, 43, 217, 0.2), rgba(247, 37, 133, 0.2));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary-light);
}

.payment-item span {
    font-size: 0.88rem;
    color: var(--text-light);
}

/* ============================================
   客户支持
   ============================================ */
.support-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.support-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 32px 28px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.support-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow);
}

.support-icon {
    width: 52px;
    height: 52px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
}

.support-card h3 {
    font-size: 1.05rem;
    margin-bottom: 10px;
    color: var(--text-white);
}

.support-card p {
    font-size: 0.88rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   负责任观影
   ============================================ */
.responsible-content {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 48px;
    border: 1px solid var(--border-color);
}

.responsible-item {
    display: flex;
    gap: 20px;
    margin-bottom: 28px;
    align-items: flex-start;
}

.responsible-item:last-child {
    margin-bottom: 0;
}

.responsible-icon {
    width: 44px;
    height: 44px;
    min-width: 44px;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: #fff;
}

.responsible-item h3 {
    font-size: 1.05rem;
    margin-bottom: 6px;
    color: var(--text-white);
}

.responsible-item p {
    font-size: 0.88rem;
    color: var(--text-light);
    line-height: 1.7;
}

/* ============================================
   FAQ 手风琴
   ============================================ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    margin-bottom: 12px;
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: var(--primary-light);
}

.faq-question {
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.98rem;
    color: var(--text-white);
    user-select: none;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--primary-light);
}

.faq-arrow {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
    color: var(--text-light);
    font-size: 0.9rem;
}

.faq-item.active .faq-arrow {
    transform: rotate(180deg);
    color: var(--accent-color);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer-inner {
    padding: 0 24px 20px;
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.8;
}

/* ============================================
   用户评价
   ============================================ */
.review-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.review-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 28px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
}

.review-card:hover {
    border-color: var(--primary-light);
    transform: translateY(-4px);
}

.review-card::before {
    content: '\201C';
    position: absolute;
    top: 16px;
    right: 24px;
    font-size: 3rem;
    color: rgba(108, 43, 217, 0.2);
    font-family: Georgia, serif;
    line-height: 1;
}

.review-header {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 14px;
}

.review-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
}

.review-info h4 {
    font-size: 0.92rem;
    color: var(--text-white);
    margin-bottom: 2px;
}

.review-info span {
    font-size: 0.78rem;
    color: var(--text-light);
}

.review-stars {
    color: #FFD700;
    font-size: 0.85rem;
    margin-bottom: 12px;
}

.review-text {
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
    margin-bottom: 12px;
}

.review-date {
    font-size: 0.78rem;
    color: var(--text-light);
}

/* ============================================
   热门标签云
   ============================================ */
.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    max-width: 900px;
    margin: 0 auto;
}

.tag-cloud a {
    display: inline-block;
    padding: 8px 20px;
    background: var(--bg-card);
    color: var(--text-white);
    border-radius: 50px;
    font-size: 0.88rem;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    white-space: nowrap;
}

.tag-cloud a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-color: transparent;
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--glow-purple);
}

/* ============================================
   页脚
   ============================================ */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand p {
    font-size: 0.88rem;
    color: var(--text-light);
    line-height: 1.7;
    margin-top: 12px;
}

.footer-col h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 16px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.footer-col ul li {
    margin-bottom: 8px;
}

.footer-col ul li a {
    font-size: 0.88rem;
    color: var(--text-light);
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--primary-light);
    padding-left: 4px;
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.82rem;
    color: var(--text-light);
    margin-bottom: 4px;
    line-height: 1.8;
}

/* ============================================
   面包屑导航
   ============================================ */
.breadcrumb {
    padding: 16px 0;
    font-size: 0.88rem;
    color: var(--text-light);
}

.breadcrumb a {
    color: var(--text-light);
}

.breadcrumb a:hover {
    color: var(--primary-light);
}

.breadcrumb span {
    margin: 0 8px;
    color: var(--text-light);
}

/* ============================================
   分类页头部
   ============================================ */
.category-header {
    padding: 100px 0 60px;
    text-align: center;
    background: linear-gradient(160deg, var(--bg-primary) 0%, var(--primary-dark) 50%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.category-header::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(247, 37, 133, 0.12) 0%, transparent 70%);
    border-radius: 50%;
}

.category-header h1 {
    font-size: 2.8rem;
    font-weight: 800;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #fff, var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    z-index: 1;
}

.category-header .subtitle {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.7);
    position: relative;
    z-index: 1;
}

/* ============================================
   分类页文章区
   ============================================ */
.article-content {
    max-width: 860px;
    margin: 0 auto;
    padding: 60px 0;
}

.article-content h2 {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-white);
    margin: 40px 0 16px;
    padding-left: 16px;
    border-left: 4px solid var(--primary-color);
}

.article-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-white);
    margin: 28px 0 12px;
}

.article-content p {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.9;
    margin-bottom: 16px;
}

.article-content a {
    color: var(--accent-color);
    border-bottom: 1px dashed var(--accent-color);
}

.article-content a:hover {
    color: var(--primary-light);
    border-bottom-color: var(--primary-light);
}

.article-image {
    width: 100%;
    border-radius: var(--border-radius);
    margin: 24px 0;
    border: 1px solid var(--border-color);
}

/* ============================================
   下载页
   ============================================ */
.download-hero {
    padding: 120px 0 80px;
    text-align: center;
    background: linear-gradient(160deg, var(--bg-primary) 0%, var(--primary-dark) 50%, var(--bg-secondary) 100%);
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    max-width: 960px;
    margin: 0 auto;
}

.download-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 40px 28px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.download-card:hover {
    border-color: var(--primary-light);
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.download-card-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
}

.download-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--text-white);
}

.download-card p {
    font-size: 0.88rem;
    color: var(--text-light);
    margin-bottom: 24px;
    line-height: 1.6;
}

/* ============================================
   返回顶部按钮
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--glow-purple);
}

/* ============================================
   响应式设计
   ============================================ */

/* 平板端 */
@media (max-width: 1200px) {
    .video-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

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

@media (max-width: 768px) {
    html {
        font-size: 15px;
    }

    .menu-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--bg-secondary);
        flex-direction: column;
        align-items: flex-start;
        padding: 80px 24px 24px;
        gap: 4px;
        transition: right 0.35s ease;
        box-shadow: -4px 0 30px rgba(0, 0, 0, 0.5);
        border-left: 1px solid var(--border-color);
        overflow-y: auto;
    }

    .nav-menu.open {
        right: 0;
    }

    .nav-menu a {
        width: 100%;
        padding: 12px 16px;
        font-size: 1rem;
    }

    .nav-download-btn {
        width: 100%;
        justify-content: center;
        margin-top: 12px;
    }

    .welcome-title {
        font-size: 2rem;
    }

    .welcome-text {
        font-size: 0.95rem;
    }

    .section-block {
        padding: 50px 0;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .video-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .review-grid {
        grid-template-columns: 1fr;
    }

    .support-grid {
        grid-template-columns: 1fr;
    }

    .cert-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .download-cards {
        grid-template-columns: 1fr;
    }

    .category-header h1 {
        font-size: 2rem;
    }

    .responsible-content {
        padding: 28px 20px;
    }

    .featured-video-overlay {
        padding: 20px;
    }

    .featured-video-overlay h3 {
        font-size: 1.2rem;
    }

    .payment-grid {
        gap: 16px;
    }

    .payment-item {
        padding: 16px 24px;
        min-width: 100px;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }

    .welcome-title {
        font-size: 1.7rem;
    }

    .welcome-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn-primary, .btn-secondary {
        width: 100%;
        justify-content: center;
    }

    .about-stats {
        grid-template-columns: 1fr;
    }

    .tag-cloud a {
        font-size: 0.8rem;
        padding: 6px 14px;
    }
}

/* ============================================
   动画效果
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

/* 渐变边框效果 */
.gradient-border {
    position: relative;
}

.gradient-border::before {
    content: '';
    position: absolute;
    inset: -1px;
    border-radius: inherit;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    z-index: -1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.gradient-border:hover::before {
    opacity: 1;
}