/* 
 * 大奶 - 官方样式表
 * 主色调: 粉红 #FF69B4, 深紫 #6B2D5C
 */

:root {
    --primary-color: #FF69B4;
    --primary-dark: #E0529C;
    --secondary-color: #6B2D5C;
    --text-main: #333333;
    --text-muted: #666666;
    --bg-light: #F9F9F9;
    --bg-dark: #1A1A1A;
    --white: #FFFFFF;
    --border-color: #EEEEEE;
    --shadow: 0 4px 12px rgba(0,0,0,0.08);
    --transition: all 0.3s ease;
}

/* 基础重置 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: 'Microsoft YaHei', 'PingFang SC', sans-serif;
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--white);
}
a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }

/* 布局类 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 50px; }
.section-header h2 { font-size: 32px; color: var(--secondary-color); margin-bottom: 15px; }
.section-header p { color: var(--text-muted); font-size: 18px; }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.flex-row { display: flex; }
.flex-col-6 { flex: 0 0 50%; padding: 0 15px; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.text-center { text-align: center; }

/* 辅助类 */
.bg-light { background-color: var(--bg-light); }
.bg-dark { background-color: var(--bg-dark); }
.text-white { color: var(--white); }
.text-muted { color: var(--text-muted); }
.text-pink { color: var(--primary-color); }
.mb-2 { margin-bottom: 10px; }
.mb-3 { margin-bottom: 15px; }
.mb-4 { margin-bottom: 20px; }
.mb-5 { margin-bottom: 30px; }
.mt-2 { margin-top: 10px; }
.mt-3 { margin-top: 15px; }
.mt-4 { margin-top: 20px; }
.mt-5 { margin-top: 30px; }
.p-4 { padding: 20px; }
.p-5 { padding: 30px; }
.rounded { border-radius: 8px; }
.rounded-circle { border-radius: 50%; }
.shadow { box-shadow: var(--shadow); }
.shadow-sm { box-shadow: 0 2px 8px rgba(0,0,0,0.05); }
.w-100 { width: 100%; }
.d-block { display: block; }

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    border: 2px solid transparent;
    text-align: center;
}
.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
}
.btn-primary:hover {
    background-color: var(--primary-dark);
    color: var(--white);
}
.btn-outline {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: transparent;
}
.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--white);
}
.btn-sm { padding: 8px 20px; font-size: 14px; }
.btn-lg { padding: 15px 40px; font-size: 18px; }

/* 头部导航 */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    z-index: 1000;
    height: 70px;
}
.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}
.logo { display: flex; align-items: center; gap: 10px; }
.logo h1 { font-size: 24px; color: var(--secondary-color); }
.nav-menu ul { display: flex; gap: 25px; }
.nav-menu a {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-main);
    position: relative;
}
.nav-menu a:hover { color: var(--primary-color); }
.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px; left: 0;
    width: 0; height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}
.nav-menu a:hover::after { width: 100%; }

.header-actions { display: flex; gap: 15px; align-items: center; }
.search-toggle, .mobile-menu-btn {
    background: none; border: none; cursor: pointer;
    color: var(--text-main);
}
.mobile-menu-btn { display: none; flex-direction: column; gap: 5px; }
.mobile-menu-btn span { width: 25px; height: 3px; background: var(--text-main); border-radius: 2px; }

/* 搜索框 */
.search-bar {
    position: absolute;
    top: 70px; left: 0; right: 0;
    background: var(--white);
    padding: 20px 0;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: -1;
}
.search-bar.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
}
.search-form { display: flex; max-width: 800px; margin: 0 auto; }
.search-form input {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid var(--primary-color);
    border-radius: 30px 0 0 30px;
    font-size: 16px;
    outline: none;
}
.search-form button {
    padding: 0 30px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 0 30px 30px 0;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
}

/* 面包屑 */
.breadcrumb {
    padding: 90px 20px 20px;
    font-size: 14px;
    color: var(--text-muted);
}
.breadcrumb a { color: var(--primary-color); }

/* Hero Banner */
.hero {
    position: relative;
    height: 80vh;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
    margin-top: 70px;
    overflow: hidden;
}
.hero-bg {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: -1;
}
.hero-bg img {
    width: 100%; height: 100%;
    object-fit: cover;
}
.hero-bg::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
}
.hero-content { position: relative; z-index: 1; }
.hero-title { font-size: 48px; margin-bottom: 20px; }
.hero-title span { color: var(--primary-color); }
.hero-subtitle { font-size: 24px; margin-bottom: 40px; opacity: 0.9; }
.hero-actions { display: flex; gap: 20px; justify-content: center; }

/* 视频卡片 */
.card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}
.card:hover { transform: translateY(-10px); box-shadow: 0 10px 25px rgba(0,0,0,0.15); }
.card-img { position: relative; overflow: hidden; aspect-ratio: 16/9; }
.card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.card:hover .card-img img { transform: scale(1.05); }

/* 视频播放按钮特效 */
.play-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}
.card:hover .play-overlay { opacity: 1; }
.play-btn {
    width: 60px; height: 60px;
    background: var(--primary-color);
    border-radius: 50%;
    position: relative;
    box-shadow: 0 0 15px rgba(255,105,180,0.5);
}
.play-btn::after {
    content: '';
    position: absolute;
    top: 50%; left: 55%;
    transform: translate(-50%, -50%);
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-left: 15px solid var(--white);
}

.card-body { padding: 20px; }
.card-body h3 { font-size: 18px; margin-bottom: 10px; color: var(--secondary-color); }
.card-body p { color: var(--text-muted); font-size: 14px; margin-bottom: 15px; }
.card-meta {
    display: flex; justify-content: space-between;
    font-size: 12px; color: #999;
    border-top: 1px solid var(--border-color);
    padding-top: 15px;
}

/* 标签 */
.tag-list { display: flex; gap: 10px; flex-wrap: wrap; }
.tag {
    background: rgba(255,105,180,0.1);
    color: var(--primary-color);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 12px;
}

/* 专家卡片 */
.expert-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}
.expert-img { flex: 0 0 40%; }
.expert-img img { width: 100%; height: 100%; object-fit: cover; }
.expert-info { padding: 30px; flex: 1; }
.expert-title { color: var(--primary-color); font-weight: bold; margin-bottom: 15px; }
.expert-actions { display: flex; gap: 10px; margin-top: 20px; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: var(--white);
    border-radius: 8px;
    margin-bottom: 15px;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}
.faq-q {
    padding: 20px;
    display: flex; justify-content: space-between; align-items: center;
    cursor: pointer;
    font-weight: bold;
}
.faq-q h3 { font-size: 16px; margin: 0; }
.toggle-icon { font-size: 24px; color: var(--primary-color); transition: transform 0.3s; }
.faq-item.active .toggle-icon { transform: rotate(45deg); }
.faq-a {
    padding: 0 20px;
    max-height: 0;
    opacity: 0;
    transition: all 0.3s ease;
}
.faq-item.active .faq-a {
    padding: 0 20px 20px;
    max-height: 200px;
    opacity: 1;
}

/* 评论卡片 */
.review-card {
    background: var(--white);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    position: relative;
}
.review-stars { color: #FFD700; font-size: 20px; margin-bottom: 15px; }
.review-text { font-style: italic; margin-bottom: 20px; }
.review-author { font-weight: bold; color: var(--secondary-color); text-align: right; }

/* 底部 */
.footer {
    background: var(--bg-dark);
    color: #ccc;
    padding: 60px 0 20px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}
.footer-logo { display: flex; align-items: center; gap: 10px; margin-bottom: 20px; color: var(--white); }
.footer-desc { margin-bottom: 20px; font-size: 14px; }
.footer h3 { color: var(--white); margin-bottom: 20px; font-size: 18px; }
.footer ul li { margin-bottom: 10px; }
.footer ul a:hover { color: var(--primary-color); }
.social-share { display: flex; align-items: center; gap: 10px; }
.share-icon {
    width: 36px; height: 36px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    display: flex; align-items: center; justify-content: center;
    font-size: 12px; color: var(--white);
}
.share-icon:hover { background: var(--primary-color); }
.qrcode-col { display: flex; flex-direction: column; gap: 20px; }
.qrcode-item { text-align: center; }
.qrcode-item img { border-radius: 8px; margin-bottom: 5px; background: white; padding: 5px; }
.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 14px;
}

/* 返回顶部 */
.back-to-top {
    position: fixed;
    bottom: 30px; right: 30px;
    width: 50px; height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none; border-radius: 50%;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    opacity: 0; visibility: hidden;
    transition: var(--transition);
    z-index: 99;
    box-shadow: 0 4px 10px rgba(255,105,180,0.4);
}
.back-to-top.show { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--secondary-color); transform: translateY(-5px); }

/* 响应式 */
@media (max-width: 992px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .flex-row { flex-direction: column; }
    .flex-col-6 { flex: 0 0 100%; margin-bottom: 30px; }
    .expert-card { flex-direction: column; }
}

@media (max-width: 768px) {
    .nav-menu {
        position: absolute;
        top: 70px; left: 0; right: 0;
        background: var(--white);
        padding: 20px;
        box-shadow: 0 10px 10px rgba(0,0,0,0.1);
        display: none;
    }
    .nav-menu.active { display: block; }
    .nav-menu ul { flex-direction: column; gap: 15px; }
    .mobile-menu-btn { display: flex; }
    
    .grid-3, .grid-2 { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .hero-title { font-size: 32px; }
    .hero-subtitle { font-size: 18px; }
}