/* ============================================
   黑丝 - 汽车改装视频社区 原创CSS
   配色方案：深邃午夜蓝 + 香槟金 + 碳纤维灰
   ============================================ */
:root {
    --ph-primary: #1A1A2E;
    --ph-secondary: #16213E;
    --ph-accent: #C8A96E;
    --ph-accent-light: #D4BC8A;
    --ph-text: #E8E8E8;
    --ph-text-muted: #9A9AB0;
    --ph-bg: #0F0F1A;
    --ph-card: #1E1E32;
    --ph-card-hover: #252542;
    --ph-border: #2A2A45;
    --ph-success: #4CAF50;
    --ph-danger: #E74C3C;
    --ph-gradient: linear-gradient(135deg, #1A1A2E 0%, #16213E 50%, #0F0F1A 100%);
    --ph-gold-gradient: linear-gradient(135deg, #C8A96E 0%, #D4BC8A 50%, #B8944E 100%);
    --ph-radius: 12px;
    --ph-shadow: 0 8px 32px rgba(0,0,0,0.4);
    --ph-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    background: var(--ph-bg);
    color: var(--ph-text);
    line-height: 1.7;
    overflow-x: hidden;
}
a { color: var(--ph-accent); text-decoration: none; transition: var(--ph-transition); }
a:hover { color: var(--ph-accent-light); }
img { max-width: 100%; height: auto; display: block; }
.ph-container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }

/* === Header / 导航栏 === */
.ph-header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: rgba(15, 15, 26, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--ph-border);
    transition: var(--ph-transition);
}
.ph-header-inner {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1280px; margin: 0 auto; padding: 0 20px; height: 68px;
}
.ph-logo { display: flex; align-items: center; gap: 10px; }
.ph-logo img { height: 44px; width: auto; }
.ph-logo-text { font-size: 1.3rem; font-weight: 700; color: var(--ph-accent); letter-spacing: 1px; }
.ph-nav { display: flex; align-items: center; gap: 6px; }
.ph-nav a {
    padding: 8px 16px; border-radius: 8px; font-size: 0.9rem;
    color: var(--ph-text-muted); font-weight: 500;
    transition: var(--ph-transition);
}
.ph-nav a:hover, .ph-nav a.active {
    color: var(--ph-accent); background: rgba(200, 169, 110, 0.1);
}
.ph-mobile-toggle {
    display: none; background: none; border: none; color: var(--ph-text);
    font-size: 1.5rem; cursor: pointer;
}

/* === 搜索框 === */
.ph-search-bar {
    background: var(--ph-primary);
    padding: 12px 0;
    border-bottom: 1px solid var(--ph-border);
    margin-top: 68px;
}
.ph-search-wrap {
    max-width: 680px; margin: 0 auto; display: flex; gap: 10px; padding: 0 20px;
}
.ph-search-input {
    flex: 1; padding: 10px 18px; border-radius: 24px;
    border: 1px solid var(--ph-border); background: var(--ph-card);
    color: var(--ph-text); font-size: 0.95rem; outline: none;
    transition: var(--ph-transition);
}
.ph-search-input:focus { border-color: var(--ph-accent); box-shadow: 0 0 0 3px rgba(200,169,110,0.15); }
.ph-search-input::placeholder { color: var(--ph-text-muted); }
.ph-search-btn {
    padding: 10px 28px; border-radius: 24px; border: none;
    background: var(--ph-gold-gradient); color: var(--ph-primary);
    font-weight: 600; cursor: pointer; font-size: 0.95rem;
    transition: var(--ph-transition);
}
.ph-search-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 15px rgba(200,169,110,0.3); }

/* === Hero 轮播 === */
.ph-hero {
    position: relative; overflow: hidden;
    height: 520px;
}
.ph-hero-slides { display: flex; transition: transform 0.7s ease; height: 100%; }
.ph-hero-slide {
    min-width: 100%; height: 100%; position: relative;
    background-size: cover; background-position: center;
}
.ph-hero-overlay {
    position: absolute; inset: 0;
    background: linear-gradient(to right, rgba(15,15,26,0.9) 0%, rgba(15,15,26,0.4) 60%, transparent 100%);
    display: flex; align-items: center; padding: 0 60px;
}
.ph-hero-content { max-width: 560px; }
.ph-hero-content h1 {
    font-size: 2.6rem; font-weight: 800; line-height: 1.25;
    margin-bottom: 16px; color: #fff;
}
.ph-hero-content h1 span { color: var(--ph-accent); }
.ph-hero-content p { font-size: 1.05rem; color: var(--ph-text-muted); margin-bottom: 24px; line-height: 1.7; }
.ph-hero-btns { display: flex; gap: 14px; flex-wrap: wrap; }
.ph-btn-primary {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 30px; border-radius: 30px; border: none;
    background: var(--ph-gold-gradient); color: var(--ph-primary);
    font-weight: 700; font-size: 1rem; cursor: pointer;
    transition: var(--ph-transition);
}
.ph-btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(200,169,110,0.35); color: var(--ph-primary); }
.ph-btn-outline {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 30px; border-radius: 30px;
    border: 2px solid var(--ph-accent); color: var(--ph-accent);
    font-weight: 600; font-size: 1rem; background: transparent;
    cursor: pointer; transition: var(--ph-transition);
}
.ph-btn-outline:hover { background: var(--ph-accent); color: var(--ph-primary); }
.ph-hero-dots {
    position: absolute; bottom: 24px; left: 50%; transform: translateX(-50%);
    display: flex; gap: 10px;
}
.ph-hero-dot {
    width: 10px; height: 10px; border-radius: 50%;
    background: rgba(255,255,255,0.3); cursor: pointer;
    transition: var(--ph-transition);
}
.ph-hero-dot.active { background: var(--ph-accent); width: 28px; border-radius: 5px; }

/* === 通用区块 === */
.ph-section { padding: 70px 0; }
.ph-section-header { text-align: center; margin-bottom: 48px; }
.ph-section-header h2 {
    font-size: 2rem; font-weight: 700; margin-bottom: 12px;
    background: var(--ph-gold-gradient); -webkit-background-clip: text;
    -webkit-text-fill-color: transparent; background-clip: text;
}
.ph-section-header p { color: var(--ph-text-muted); font-size: 1rem; max-width: 600px; margin: 0 auto; }
.ph-section-alt { background: var(--ph-primary); }

/* === 视频卡片网格 === */
.ph-video-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
}
.ph-video-card {
    background: var(--ph-card);
    border-radius: var(--ph-radius);
    overflow: hidden;
    transition: var(--ph-transition);
    border: 1px solid var(--ph-border);
}
.ph-video-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--ph-shadow);
    border-color: var(--ph-accent);
}
.ph-video-thumb {
    position: relative; overflow: hidden;
    aspect-ratio: 16/9;
}
.ph-video-thumb img {
    width: 100%; height: 100%; object-fit: cover;
    transition: transform 0.5s ease;
}
.ph-video-card:hover .ph-video-thumb img { transform: scale(1.08); }
.ph-play-btn {
    position: absolute; top: 50%; left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    width: 56px; height: 56px; border-radius: 50%;
    background: rgba(200, 169, 110, 0.9);
    display: flex; align-items: center; justify-content: center;
    opacity: 0; transition: var(--ph-transition);
    box-shadow: 0 4px 20px rgba(200,169,110,0.4);
}
.ph-play-btn::after {
    content: '';
    border-style: solid;
    border-width: 10px 0 10px 18px;
    border-color: transparent transparent transparent var(--ph-primary);
    margin-left: 3px;
}
.ph-video-card:hover .ph-play-btn { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.ph-video-duration {
    position: absolute; bottom: 8px; right: 8px;
    background: rgba(0,0,0,0.75); color: #fff;
    padding: 2px 8px; border-radius: 4px; font-size: 0.8rem;
}
.ph-video-info { padding: 14px; }
.ph-video-info h3 {
    font-size: 0.95rem; font-weight: 600; margin-bottom: 8px;
    color: var(--ph-text); line-height: 1.4;
    display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.ph-video-meta {
    display: flex; align-items: center; gap: 12px;
    font-size: 0.8rem; color: var(--ph-text-muted);
}
.ph-video-meta span { display: flex; align-items: center; gap: 4px; }
.ph-video-tags { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }
.ph-video-tag {
    padding: 2px 10px; border-radius: 12px; font-size: 0.75rem;
    background: rgba(200,169,110,0.1); color: var(--ph-accent);
    border: 1px solid rgba(200,169,110,0.2);
}

/* === 分类标签栏 === */
.ph-tabs { display: flex; gap: 10px; justify-content: center; margin-bottom: 32px; flex-wrap: wrap; }
.ph-tab {
    padding: 8px 22px; border-radius: 20px; font-size: 0.9rem;
    background: var(--ph-card); color: var(--ph-text-muted);
    border: 1px solid var(--ph-border); cursor: pointer;
    transition: var(--ph-transition);
}
.ph-tab:hover, .ph-tab.active {
    background: var(--ph-accent); color: var(--ph-primary);
    border-color: var(--ph-accent);
}

/* === 专家团队 === */
.ph-expert-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.ph-expert-card {
    background: var(--ph-card); border-radius: var(--ph-radius);
    padding: 28px 20px; text-align: center;
    border: 1px solid var(--ph-border);
    transition: var(--ph-transition);
}
.ph-expert-card:hover { border-color: var(--ph-accent); transform: translateY(-4px); box-shadow: var(--ph-shadow); }
.ph-expert-avatar {
    width: 80px; height: 80px; border-radius: 50%;
    background: var(--ph-gold-gradient);
    margin: 0 auto 16px; display: flex; align-items: center; justify-content: center;
    font-size: 2rem; color: var(--ph-primary); font-weight: 700;
}
.ph-expert-card h4 { font-size: 1.05rem; margin-bottom: 6px; color: var(--ph-text); }
.ph-expert-card .ph-expert-role { color: var(--ph-accent); font-size: 0.85rem; margin-bottom: 10px; }
.ph-expert-card p { font-size: 0.85rem; color: var(--ph-text-muted); line-height: 1.6; }
.ph-expert-btns { display: flex; gap: 8px; justify-content: center; margin-top: 14px; }
.ph-expert-btn {
    padding: 6px 16px; border-radius: 16px; font-size: 0.8rem;
    border: 1px solid var(--ph-accent); color: var(--ph-accent);
    background: transparent; cursor: pointer; transition: var(--ph-transition);
}
.ph-expert-btn:hover { background: var(--ph-accent); color: var(--ph-primary); }

/* === FAQ === */
.ph-faq-list { max-width: 800px; margin: 0 auto; }
.ph-faq-item {
    background: var(--ph-card); border-radius: var(--ph-radius);
    margin-bottom: 12px; border: 1px solid var(--ph-border);
    overflow: hidden; transition: var(--ph-transition);
}
.ph-faq-item:hover { border-color: var(--ph-accent); }
.ph-faq-q {
    padding: 18px 24px; cursor: pointer;
    display: flex; justify-content: space-between; align-items: center;
    font-weight: 600; font-size: 0.95rem; color: var(--ph-text);
}
.ph-faq-q::after { content: '+'; font-size: 1.4rem; color: var(--ph-accent); transition: var(--ph-transition); }
.ph-faq-item.open .ph-faq-q::after { content: '−'; }
.ph-faq-a {
    max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
    padding: 0 24px; color: var(--ph-text-muted); font-size: 0.9rem; line-height: 1.7;
}
.ph-faq-item.open .ph-faq-a { max-height: 300px; padding: 0 24px 18px; }

/* === 用户评论 === */
.ph-review-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.ph-review-card {
    background: var(--ph-card); border-radius: var(--ph-radius);
    padding: 24px; border: 1px solid var(--ph-border);
    transition: var(--ph-transition);
}
.ph-review-card:hover { border-color: var(--ph-accent); }
.ph-review-header { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.ph-review-avatar {
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--ph-secondary); display: flex;
    align-items: center; justify-content: center;
    font-weight: 700; color: var(--ph-accent); font-size: 1.1rem;
}
.ph-review-name { font-weight: 600; font-size: 0.95rem; }
.ph-review-stars { color: var(--ph-accent); font-size: 0.85rem; letter-spacing: 2px; }
.ph-review-text { font-size: 0.9rem; color: var(--ph-text-muted); line-height: 1.7; }
.ph-review-date { font-size: 0.8rem; color: var(--ph-text-muted); margin-top: 10px; opacity: 0.7; }

/* === 合作品牌 === */
.ph-brand-wall {
    display: flex; flex-wrap: wrap; gap: 20px; justify-content: center; align-items: center;
}
.ph-brand-item {
    background: var(--ph-card); border-radius: var(--ph-radius);
    padding: 20px 32px; border: 1px solid var(--ph-border);
    font-size: 1.1rem; font-weight: 600; color: var(--ph-text-muted);
    transition: var(--ph-transition);
}
.ph-brand-item:hover { border-color: var(--ph-accent); color: var(--ph-accent); }

/* === 联系我们 === */
.ph-contact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.ph-contact-card {
    background: var(--ph-card); border-radius: var(--ph-radius);
    padding: 28px; text-align: center;
    border: 1px solid var(--ph-border);
}
.ph-contact-icon {
    width: 56px; height: 56px; border-radius: 50%;
    background: rgba(200,169,110,0.1); margin: 0 auto 14px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.5rem; color: var(--ph-accent);
}
.ph-contact-card h4 { margin-bottom: 8px; font-size: 1rem; }
.ph-contact-card p { font-size: 0.9rem; color: var(--ph-text-muted); }

/* === How-To 指南 === */
.ph-howto-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.ph-howto-step {
    background: var(--ph-card); border-radius: var(--ph-radius);
    padding: 28px 20px; text-align: center;
    border: 1px solid var(--ph-border);
    position: relative;
}
.ph-howto-num {
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--ph-gold-gradient); color: var(--ph-primary);
    font-weight: 800; font-size: 1.2rem;
    display: flex; align-items: center; justify-content: center;
    margin: 0 auto 14px;
}
.ph-howto-step h4 { font-size: 0.95rem; margin-bottom: 8px; }
.ph-howto-step p { font-size: 0.85rem; color: var(--ph-text-muted); }

/* === 社交分享 === */
.ph-share-bar { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.ph-share-btn {
    padding: 10px 22px; border-radius: 24px;
    background: var(--ph-card); border: 1px solid var(--ph-border);
    color: var(--ph-text); font-size: 0.9rem; cursor: pointer;
    transition: var(--ph-transition);
}
.ph-share-btn:hover { border-color: var(--ph-accent); color: var(--ph-accent); }

/* === Footer === */
.ph-footer {
    background: var(--ph-primary);
    border-top: 1px solid var(--ph-border);
    padding: 50px 0 24px;
}
.ph-footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 36px; }
.ph-footer-brand p { color: var(--ph-text-muted); font-size: 0.9rem; margin-top: 12px; line-height: 1.7; }
.ph-footer-col h4 {
    font-size: 1rem; margin-bottom: 16px; color: var(--ph-accent);
    padding-bottom: 8px; border-bottom: 2px solid var(--ph-accent);
    display: inline-block;
}
.ph-footer-col a { display: block; color: var(--ph-text-muted); font-size: 0.9rem; margin-bottom: 8px; }
.ph-footer-col a:hover { color: var(--ph-accent); }
.ph-footer-qr { display: flex; gap: 20px; margin-top: 12px; }
.ph-footer-qr img { width: 100px; height: 100px; border-radius: 8px; }
.ph-footer-bottom {
    border-top: 1px solid var(--ph-border);
    padding-top: 20px; text-align: center;
    font-size: 0.85rem; color: var(--ph-text-muted);
}
.ph-footer-bottom a { color: var(--ph-accent); }

/* === 面包屑 === */
.ph-breadcrumb {
    padding: 14px 0; font-size: 0.85rem; color: var(--ph-text-muted);
    margin-top: 68px;
}
.ph-breadcrumb a { color: var(--ph-accent); }
.ph-breadcrumb span { margin: 0 8px; }

/* === 内页通用 === */
.ph-page-hero {
    padding: 100px 0 50px;
    background: var(--ph-gradient);
    text-align: center;
}
.ph-page-hero h1 { font-size: 2.2rem; margin-bottom: 12px; color: #fff; }
.ph-page-hero p { color: var(--ph-text-muted); font-size: 1rem; }

/* === 懒加载 === */
.ph-lazy { opacity: 0; transition: opacity 0.5s ease; }
.ph-lazy.loaded { opacity: 1; }

/* === 干扰标签隐藏 === */
.ph-jammer { position: absolute; width: 0; height: 0; overflow: hidden; opacity: 0; pointer-events: none; z-index: -9999; }

/* === 响应式 === */
@media (max-width: 1024px) {
    .ph-video-grid { grid-template-columns: repeat(3, 1fr); }
    .ph-expert-grid { grid-template-columns: repeat(2, 1fr); }
    .ph-footer-grid { grid-template-columns: repeat(2, 1fr); }
    .ph-howto-steps { grid-template-columns: repeat(2, 1fr); }
    .ph-contact-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .ph-nav { display: none; }
    .ph-mobile-toggle { display: block; }
    .ph-nav.open {
        display: flex; flex-direction: column;
        position: absolute; top: 68px; left: 0; width: 100%;
        background: var(--ph-primary); padding: 16px;
        border-bottom: 1px solid var(--ph-border);
    }
    .ph-hero { height: 400px; }
    .ph-hero-overlay { padding: 0 24px; }
    .ph-hero-content h1 { font-size: 1.8rem; }
    .ph-video-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
    .ph-expert-grid { grid-template-columns: 1fr; }
    .ph-review-grid { grid-template-columns: 1fr; }
    .ph-footer-grid { grid-template-columns: 1fr; }
    .ph-contact-grid { grid-template-columns: 1fr; }
    .ph-howto-steps { grid-template-columns: 1fr; }
    .ph-section { padding: 40px 0; }
    .ph-section-header h2 { font-size: 1.5rem; }
}
@media (max-width: 480px) {
    .ph-video-grid { grid-template-columns: 1fr; }
    .ph-hero { height: 320px; }
    .ph-hero-content h1 { font-size: 1.4rem; }
    .ph-hero-btns { flex-direction: column; }
}