/* ========================================
   91 修车改装视频社区 - 全站样式表
   品牌色: 深红 #B71C1C / 深灰 #1A1A2E / 金属银 #C0C0C0
   ======================================== */

/* CSS Reset & Base */
*, *::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: #0D0D1A;
  color: #E0E0E0;
  line-height: 1.8;
  overflow-x: hidden;
}
a { color: #E53935; text-decoration: none; transition: color .3s; }
a:hover { color: #FF6F61; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; color: #FFFFFF; }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section-padding { padding: 60px 0; }

/* ========== Header / Navigation ========== */
.site-header {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(13, 13, 26, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(229, 57, 53, 0.3);
  transition: all .3s;
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 70px;
}
.logo-link { display: flex; align-items: center; gap: 10px; }
.logo-link img { height: 45px; width: auto; }
.logo-text { font-size: 1.5rem; font-weight: 800; color: #E53935; letter-spacing: 2px; }
.main-nav { display: flex; align-items: center; gap: 0; }
.main-nav a {
  padding: 8px 16px; font-size: 0.95rem; color: #CCC;
  transition: all .3s; border-radius: 4px; white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active { color: #FFF; background: rgba(229, 57, 53, 0.2); }
.mobile-toggle { display: none; cursor: pointer; font-size: 1.5rem; color: #FFF; }

/* Search Bar */
.search-bar-wrap {
  background: #111128; border-bottom: 1px solid rgba(255,255,255,0.05);
  padding: 12px 0;
}
.search-bar {
  max-width: 600px; margin: 0 auto; display: flex; gap: 0;
}
.search-bar input {
  flex: 1; padding: 10px 18px; border: 1px solid #333;
  background: #1A1A2E; color: #FFF; border-radius: 25px 0 0 25px;
  font-size: 0.95rem; outline: none; transition: border-color .3s;
}
.search-bar input:focus { border-color: #E53935; }
.search-bar input::placeholder { color: #666; }
.search-bar button {
  padding: 10px 24px; background: #E53935; color: #FFF; border: none;
  border-radius: 0 25px 25px 0; cursor: pointer; font-size: 0.95rem;
  transition: background .3s;
}
.search-bar button:hover { background: #C62828; }

/* ========== Banner / Hero ========== */
.hero-banner {
  position: relative; width: 100%; min-height: 520px;
  margin-top: 70px; overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
.hero-banner .hero-bg {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  object-fit: cover; filter: brightness(0.4);
}
.hero-content {
  position: relative; z-index: 2; text-align: center;
  max-width: 800px; padding: 40px 20px;
}
.hero-content h1 { font-size: 2.8rem; margin-bottom: 16px; text-shadow: 2px 2px 8px rgba(0,0,0,0.7); }
.hero-content h1 span { color: #E53935; }
.hero-content p { font-size: 1.15rem; color: #CCC; margin-bottom: 24px; }
.hero-btn {
  display: inline-block; padding: 14px 36px; background: #E53935;
  color: #FFF; border-radius: 30px; font-size: 1.05rem; font-weight: 600;
  transition: all .3s; box-shadow: 0 4px 15px rgba(229, 57, 53, 0.4);
}
.hero-btn:hover { background: #C62828; transform: translateY(-2px); color: #FFF; }

/* ========== Breadcrumb ========== */
.breadcrumb {
  padding: 15px 0; font-size: 0.85rem; color: #888;
}
.breadcrumb a { color: #E53935; }
.breadcrumb span { margin: 0 6px; }

/* ========== Section Titles ========== */
.section-title {
  text-align: center; margin-bottom: 40px;
}
.section-title h2 {
  font-size: 2rem; margin-bottom: 10px; position: relative; display: inline-block;
}
.section-title h2::after {
  content: ''; display: block; width: 60px; height: 3px;
  background: #E53935; margin: 12px auto 0;
}
.section-title p { color: #999; font-size: 1rem; margin-top: 8px; }

/* ========== Video Cards ========== */
.video-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}
.video-card {
  background: #1A1A2E; border-radius: 12px; overflow: hidden;
  transition: transform .3s, box-shadow .3s; cursor: pointer;
  border: 1px solid rgba(255,255,255,0.05);
}
.video-card:hover { transform: translateY(-5px); box-shadow: 0 10px 30px rgba(229, 57, 53, 0.15); }
.video-thumb {
  position: relative; overflow: hidden; aspect-ratio: 16/9;
}
.video-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.video-card:hover .video-thumb img { transform: scale(1.05); }
.play-btn {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 60px; height: 60px; background: rgba(229, 57, 53, 0.85);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  opacity: 0; transition: opacity .3s;
}
.play-btn::after {
  content: ''; width: 0; height: 0;
  border-left: 20px solid #FFF; border-top: 12px solid transparent;
  border-bottom: 12px solid transparent; margin-left: 4px;
}
.video-card:hover .play-btn { opacity: 1; }
.video-duration {
  position: absolute; bottom: 8px; right: 8px;
  background: rgba(0,0,0,0.8); color: #FFF; padding: 2px 8px;
  border-radius: 4px; font-size: 0.8rem;
}
.video-info { padding: 16px; }
.video-info h3 { font-size: 1.05rem; margin-bottom: 8px; color: #FFF; }
.video-meta { display: flex; gap: 16px; font-size: 0.85rem; color: #888; flex-wrap: wrap; }
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-tags { display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap; }
.video-tags span {
  background: rgba(229, 57, 53, 0.15); color: #E53935;
  padding: 2px 10px; border-radius: 12px; font-size: 0.78rem;
}

/* ========== Short Video / TikTok Style ========== */
.short-video-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}
.short-video-card {
  position: relative; border-radius: 12px; overflow: hidden;
  aspect-ratio: 9/16; background: #1A1A2E; cursor: pointer;
}
.short-video-card img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.short-video-card:hover img { transform: scale(1.05); }
.short-video-overlay {
  position: absolute; bottom: 0; left: 0; right: 0;
  background: linear-gradient(transparent, rgba(0,0,0,0.85));
  padding: 20px 12px 12px; color: #FFF;
}
.short-video-overlay h4 { font-size: 0.9rem; margin-bottom: 4px; }
.short-video-overlay .views { font-size: 0.8rem; color: #CCC; }
.short-play-btn {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 50px; height: 50px; background: rgba(229, 57, 53, 0.8);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  opacity: 0; transition: opacity .3s;
}
.short-play-btn::after {
  content: ''; width: 0; height: 0;
  border-left: 16px solid #FFF; border-top: 10px solid transparent;
  border-bottom: 10px solid transparent; margin-left: 3px;
}
.short-video-card:hover .short-play-btn { opacity: 1; }

/* ========== AI Section ========== */
.ai-section { background: linear-gradient(135deg, #0D0D1A 0%, #1A1A3E 100%); }
.ai-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.ai-card {
  background: rgba(255,255,255,0.03); border: 1px solid rgba(229, 57, 53, 0.2);
  border-radius: 12px; padding: 30px; text-align: center;
  transition: all .3s;
}
.ai-card:hover { border-color: #E53935; background: rgba(229, 57, 53, 0.05); }
.ai-icon { font-size: 2.5rem; margin-bottom: 16px; }
.ai-card h3 { font-size: 1.15rem; margin-bottom: 10px; }
.ai-card p { color: #999; font-size: 0.92rem; }

/* ========== Expert Cards ========== */
.expert-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}
.expert-card {
  background: #1A1A2E; border-radius: 12px; overflow: hidden;
  text-align: center; border: 1px solid rgba(255,255,255,0.05);
  transition: transform .3s;
}
.expert-card:hover { transform: translateY(-5px); }
.expert-card img { width: 100%; height: 280px; object-fit: cover; }
.expert-card-body { padding: 20px; }
.expert-card h3 { font-size: 1.1rem; margin-bottom: 4px; }
.expert-card .role { color: #E53935; font-size: 0.9rem; margin-bottom: 10px; }
.expert-card p { color: #999; font-size: 0.88rem; margin-bottom: 12px; }
.expert-links { display: flex; gap: 10px; justify-content: center; }
.expert-links a {
  padding: 6px 16px; border: 1px solid #E53935; border-radius: 20px;
  color: #E53935; font-size: 0.85rem; transition: all .3s;
}
.expert-links a:hover { background: #E53935; color: #FFF; }

/* ========== Partner Logos ========== */
.partner-wall {
  display: flex; flex-wrap: wrap; gap: 30px;
  justify-content: center; align-items: center;
}
.partner-logo {
  background: rgba(255,255,255,0.05); padding: 20px 30px;
  border-radius: 8px; font-size: 1.2rem; font-weight: 700;
  color: #888; letter-spacing: 2px; transition: all .3s;
  border: 1px solid rgba(255,255,255,0.08);
}
.partner-logo:hover { color: #E53935; border-color: #E53935; }

/* ========== FAQ ========== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: #1A1A2E; border-radius: 8px; margin-bottom: 12px;
  border: 1px solid rgba(255,255,255,0.05); overflow: hidden;
}
.faq-question {
  padding: 18px 24px; cursor: pointer; display: flex;
  justify-content: space-between; align-items: center;
  font-weight: 600; color: #FFF; transition: background .3s;
}
.faq-question:hover { background: rgba(229, 57, 53, 0.1); }
.faq-arrow { transition: transform .3s; color: #E53935; font-size: 1.2rem; }
.faq-item.active .faq-arrow { transform: rotate(180deg); }
.faq-answer { padding: 0 24px; max-height: 0; overflow: hidden; transition: all .4s; color: #BBB; }
.faq-item.active .faq-answer { padding: 0 24px 18px; max-height: 500px; }

/* ========== Reviews ========== */
.review-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.review-card {
  background: #1A1A2E; border-radius: 12px; padding: 24px;
  border: 1px solid rgba(255,255,255,0.05);
}
.review-stars { color: #FFD700; font-size: 1rem; margin-bottom: 10px; letter-spacing: 2px; }
.review-card p { color: #CCC; font-size: 0.95rem; margin-bottom: 12px; font-style: italic; }
.review-author { color: #888; font-size: 0.85rem; }

/* ========== How-To Guide ========== */
.howto-steps {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 24px; counter-reset: step;
}
.howto-step {
  background: #1A1A2E; border-radius: 12px; padding: 30px;
  text-align: center; position: relative; border: 1px solid rgba(255,255,255,0.05);
}
.howto-step::before {
  counter-increment: step; content: counter(step);
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; background: #E53935; border-radius: 50%;
  color: #FFF; font-weight: 700; font-size: 1.1rem; margin: 0 auto 16px;
}
.howto-step h4 { margin-bottom: 8px; }
.howto-step p { color: #999; font-size: 0.9rem; }

/* ========== Contact Section ========== */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
}
.contact-card {
  background: #1A1A2E; border-radius: 12px; padding: 30px;
  border: 1px solid rgba(255,255,255,0.05);
}
.contact-card h3 { margin-bottom: 16px; color: #E53935; font-size: 1.15rem; }
.contact-card p { color: #BBB; margin-bottom: 8px; font-size: 0.95rem; }

/* ========== Share Buttons ========== */
.share-bar {
  display: flex; gap: 12px; justify-content: center; flex-wrap: wrap;
  padding: 20px 0;
}
.share-btn {
  padding: 8px 20px; border-radius: 20px; font-size: 0.9rem;
  color: #FFF; transition: all .3s; cursor: pointer; border: none;
}
.share-wechat { background: #07C160; }
.share-weibo { background: #E6162D; }
.share-douyin { background: #161823; border: 1px solid #FE2C55; }
.share-bilibili { background: #00A1D6; }
.share-btn:hover { opacity: 0.85; transform: translateY(-2px); }

/* ========== Footer ========== */
.site-footer {
  background: #0A0A18; border-top: 1px solid rgba(229, 57, 53, 0.2);
  padding: 50px 0 20px;
}
.footer-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 30px; margin-bottom: 30px;
}
.footer-col h4 { color: #E53935; margin-bottom: 16px; font-size: 1.05rem; }
.footer-col p, .footer-col a { color: #888; font-size: 0.9rem; display: block; margin-bottom: 6px; }
.footer-col a:hover { color: #E53935; }
.footer-qr { display: flex; gap: 20px; margin-top: 10px; }
.footer-qr img { width: 100px; height: 100px; border-radius: 8px; }
.footer-qr-label { font-size: 0.8rem; color: #888; text-align: center; margin-top: 4px; }
.footer-bottom {
  text-align: center; padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.05);
  color: #666; font-size: 0.85rem;
}
.footer-logo { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }
.footer-logo img { height: 35px; }

/* ========== MCP Frontend Placeholder ========== */
.mcp-widget {
  background: rgba(229, 57, 53, 0.05); border: 1px dashed rgba(229, 57, 53, 0.3);
  border-radius: 8px; padding: 20px; text-align: center; margin: 20px 0;
  color: #888; font-size: 0.9rem;
}

/* ========== Inner Page Layout ========== */
.page-hero {
  margin-top: 70px; padding: 60px 0; text-align: center;
  background: linear-gradient(135deg, #1A1A2E 0%, #0D0D1A 100%);
  border-bottom: 1px solid rgba(229, 57, 53, 0.2);
}
.page-hero h1 { font-size: 2.2rem; margin-bottom: 10px; }
.page-hero p { color: #999; }
.page-content { padding: 40px 0; }

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .header-inner { height: 60px; }
  .main-nav { 
    display: none; position: fixed; top: 60px; left: 0; right: 0;
    background: rgba(13, 13, 26, 0.98); flex-direction: column;
    padding: 20px; gap: 5px;
  }
  .main-nav.open { display: flex; }
  .mobile-toggle { display: block; }
  .hero-banner { min-height: 400px; margin-top: 60px; }
  .hero-content h1 { font-size: 1.8rem; }
  .video-grid { grid-template-columns: 1fr; }
  .short-video-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .section-title h2 { font-size: 1.5rem; }
  .page-hero { margin-top: 60px; padding: 40px 0; }
  .page-hero h1 { font-size: 1.6rem; }
  .search-bar { margin: 0 15px; }
}
@media (max-width: 480px) {
  .short-video-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .hero-content h1 { font-size: 1.5rem; }
  .container { padding: 0 15px; }
}

/* ========== Lazy Load ========== */
img[loading="lazy"] { opacity: 0; transition: opacity .5s; }
img[loading="lazy"].loaded, img[loading="lazy"][src] { opacity: 1; }

/* ========== Animations ========== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-in { animation: fadeInUp 0.6s ease forwards; }

/* ========== Community Tags ========== */
.community-tags {
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: center;
  margin: 20px 0;
}
.community-tag {
  padding: 8px 20px; background: rgba(229, 57, 53, 0.1);
  border: 1px solid rgba(229, 57, 53, 0.3); border-radius: 20px;
  color: #E53935; font-size: 0.9rem; transition: all .3s; cursor: pointer;
}
.community-tag:hover { background: #E53935; color: #FFF; }

/* ========== Stats Bar ========== */
.stats-bar {
  display: flex; justify-content: center; gap: 40px; flex-wrap: wrap;
  padding: 30px 0; background: rgba(229, 57, 53, 0.05);
  border-radius: 12px; margin: 30px 0;
}
.stat-item { text-align: center; }
.stat-num { font-size: 2rem; font-weight: 800; color: #E53935; }
.stat-label { font-size: 0.85rem; color: #999; margin-top: 4px; }

/* ========== Parts Grid ========== */
.parts-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}
.part-card {
  background: #1A1A2E; border-radius: 12px; overflow: hidden;
  border: 1px solid rgba(255,255,255,0.05); transition: transform .3s;
}
.part-card:hover { transform: translateY(-3px); }
.part-card img { width: 100%; height: 200px; object-fit: cover; }
.part-card-body { padding: 16px; }
.part-card h4 { margin-bottom: 6px; font-size: 1rem; }
.part-card .price { color: #E53935; font-weight: 700; font-size: 1.1rem; }
.part-card p { color: #999; font-size: 0.85rem; margin-top: 6px; }

/* ========== Video Modal ========== */
.video-modal-overlay {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.85); z-index: 9999;
  display: flex; align-items: center; justify-content: center;
}
.video-modal {
  background: #1A1A2E; border-radius: 16px; padding: 24px;
  max-width: 700px; width: 90%; position: relative;
  border: 1px solid rgba(229,57,53,0.3);
}
.video-modal-close {
  position: absolute; top: 12px; right: 16px;
  font-size: 2rem; color: #FFF; cursor: pointer; z-index: 10;
  transition: color .3s;
}
.video-modal-close:hover { color: #E53935; }
.video-modal-player {
  position: relative; border-radius: 8px; overflow: hidden;
  margin-bottom: 16px;
}
.video-modal-play-icon {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%);
  font-size: 4rem; color: rgba(255,255,255,0.8);
  text-shadow: 0 2px 10px rgba(0,0,0,0.5);
}
.video-modal-title {
  font-size: 1.1rem; color: #FFF; text-align: center;
  margin-bottom: 8px; font-weight: 600;
}

/* ========== Scrollbar ========== */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: #0D0D1A; }
::-webkit-scrollbar-thumb { background: #333; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #E53935; }

/* ========== Selection ========== */
::selection { background: rgba(229,57,53,0.3); color: #FFF; }