/* 困困兔 - 原创样式表 */
/* 配色：深碳黑 #0D0D12, 赛车红 #C41E3A, 钛灰 #2A2D35, 亮银 #E8ECF0, 霓虹蓝 #00B4D8 */

:root {
  --color-bg-dark: #0D0D12;
  --color-bg-section: #141419;
  --color-bg-card: #1C1F26;
  --color-red: #C41E3A;
  --color-red-hover: #E02A48;
  --color-titanium: #2A2D35;
  --color-silver: #E8ECF0;
  --color-neon: #00B4D8;
  --color-text: #CDD1D9;
  --color-text-muted: #8B919A;
  --color-border: #2E3340;
  --font-display: 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-body: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  --radius: 6px;
  --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
  --transition: 0.25s cubic-bezier(0.23,1,0.32,1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: var(--font-body);
  background: var(--color-bg-dark);
  color: var(--color-text);
  line-height: 1.7;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-neon); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-red-hover); }

.container { max-width: 1240px; margin: 0 auto; padding: 0 20px; }

/* ===== 导航 ===== */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(13,13,18,0.92); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.nav-logo { display: flex; align-items: center; gap: 10px; }
.nav-logo img { height: 42px; width: auto; }
.nav-logo span { font-size: 1.25rem; font-weight: 700; color: #fff; letter-spacing: 1px; }
.nav-menu { display: flex; gap: 28px; list-style: none; }
.nav-menu a { color: var(--color-text); font-size: 0.95rem; font-weight: 500; padding: 6px 0; position: relative; }
.nav-menu a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--color-red); transition: width var(--transition); }
.nav-menu a:hover { color: #fff; }
.nav-menu a:hover::after { width: 100%; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; }
.nav-toggle span { width: 24px; height: 2px; background: #fff; transition: var(--transition); }

/* 搜索框 */
.search-bar { background: var(--color-bg-section); padding: 14px 0; border-bottom: 1px solid var(--color-border); margin-top: 68px; }
.search-bar form { display: flex; max-width: 560px; margin: 0 auto; }
.search-bar input { flex: 1; padding: 10px 16px; border: 1px solid var(--color-border); border-radius: var(--radius) 0 0 var(--radius); background: var(--color-bg-card); color: #fff; font-size: 0.9rem; outline: none; }
.search-bar input:focus { border-color: var(--color-neon); }
.search-bar button { padding: 10px 22px; background: var(--color-red); color: #fff; border: none; border-radius: 0 var(--radius) var(--radius) 0; font-weight: 600; cursor: pointer; transition: background var(--transition); }
.search-bar button:hover { background: var(--color-red-hover); }

/* ===== Hero ===== */
.hero {
  position: relative; min-height: 520px; display: flex; align-items: center;
  background-size: cover; background-position: center; background-repeat: no-repeat;
}
.hero::before { content: ''; position: absolute; inset: 0; background: linear-gradient(135deg, rgba(13,13,18,0.85) 0%, rgba(13,13,18,0.4) 100%); }
.hero-content { position: relative; z-index: 2; max-width: 640px; padding: 80px 0; }
.hero h1 { font-size: 2.8rem; font-weight: 800; color: #fff; line-height: 1.2; margin-bottom: 16px; }
.hero h1 em { font-style: normal; color: var(--color-red); }
.hero p { font-size: 1.1rem; color: var(--color-text); margin-bottom: 28px; }
.btn-primary { display: inline-block; padding: 14px 32px; background: var(--color-red); color: #fff; font-weight: 600; border-radius: var(--radius); transition: all var(--transition); }
.btn-primary:hover { background: var(--color-red-hover); transform: translateY(-2px); color: #fff; }
.btn-outline { display: inline-block; padding: 14px 32px; border: 1px solid var(--color-neon); color: var(--color-neon); font-weight: 600; border-radius: var(--radius); margin-left: 12px; transition: all var(--transition); }
.btn-outline:hover { background: var(--color-neon); color: #0D0D12; }

/* ===== 通用段落 ===== */
.section { padding: 72px 0; }
.section-alt { background: var(--color-bg-section); }
.section-title { font-size: 1.8rem; font-weight: 700; color: #fff; text-align: center; margin-bottom: 12px; }
.section-subtitle { text-align: center; color: var(--color-text-muted); margin-bottom: 48px; font-size: 1rem; }

/* ===== 视频卡片网格 ===== */
.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.video-card { background: var(--color-bg-card); border-radius: var(--radius); overflow: hidden; border: 1px solid var(--color-border); transition: transform var(--transition), box-shadow var(--transition); }
.video-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-card); }
.video-thumb { position: relative; aspect-ratio: 16/9; overflow: hidden; background: #000; }
.video-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease; }
.video-card:hover .video-thumb img { transform: scale(1.05); }
.play-btn { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; opacity: 0; transition: opacity var(--transition); background: rgba(0,0,0,0.4); }
.video-card:hover .play-btn { opacity: 1; }
.play-btn svg { width: 56px; height: 56px; fill: #fff; filter: drop-shadow(0 2px 8px rgba(0,0,0,0.5)); }
.video-info { padding: 16px; }
.video-info h3 { font-size: 1rem; font-weight: 600; color: #fff; margin-bottom: 8px; line-height: 1.4; }
.video-meta { display: flex; gap: 14px; font-size: 0.82rem; color: var(--color-text-muted); }
.video-meta span { display: flex; align-items: center; gap: 4px; }

/* ===== 专家卡片 ===== */
.expert-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.expert-card { background: var(--color-bg-card); border-radius: var(--radius); padding: 28px; text-align: center; border: 1px solid var(--color-border); transition: transform var(--transition); }
.expert-card:hover { transform: translateY(-3px); }
.expert-avatar { width: 80px; height: 80px; border-radius: 50%; margin: 0 auto 16px; background: var(--color-titanium); display: flex; align-items: center; justify-content: center; font-size: 2rem; color: var(--color-red); }
.expert-card h4 { color: #fff; font-size: 1.05rem; margin-bottom: 4px; }
.expert-card .role { color: var(--color-neon); font-size: 0.85rem; margin-bottom: 12px; }
.expert-card p { font-size: 0.88rem; color: var(--color-text-muted); margin-bottom: 16px; }
.expert-links { display: flex; gap: 10px; justify-content: center; }
.expert-links a { padding: 6px 14px; font-size: 0.8rem; border: 1px solid var(--color-border); border-radius: var(--radius); color: var(--color-text); transition: all var(--transition); }
.expert-links a:hover { border-color: var(--color-red); color: var(--color-red); }

/* ===== FAQ ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--color-border); }
.faq-question { width: 100%; padding: 18px 0; display: flex; justify-content: space-between; align-items: center; background: none; border: none; color: #fff; font-size: 1rem; font-weight: 500; cursor: pointer; text-align: left; }
.faq-question::after { content: '+'; font-size: 1.4rem; color: var(--color-red); transition: transform var(--transition); }
.faq-item.active .faq-question::after { content: '−'; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; }
.faq-answer p { padding: 0 0 18px; color: var(--color-text-muted); font-size: 0.92rem; line-height: 1.7; }

/* ===== 用户评论 ===== */
.review-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 24px; }
.review-card { background: var(--color-bg-card); border-radius: var(--radius); padding: 24px; border: 1px solid var(--color-border); }
.review-card .stars { color: #F5A623; margin-bottom: 12px; font-size: 0.9rem; }
.review-card blockquote { font-size: 0.92rem; color: var(--color-text); margin-bottom: 14px; line-height: 1.6; font-style: italic; }
.review-card .reviewer { font-size: 0.82rem; color: var(--color-text-muted); }

/* ===== 合作品牌墙 ===== */
.brand-wall { display: flex; flex-wrap: wrap; gap: 24px; justify-content: center; align-items: center; }
.brand-wall-item { width: 120px; height: 60px; background: var(--color-bg-card); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; border: 1px solid var(--color-border); padding: 10px; }
.brand-wall-item span { font-size: 0.8rem; color: var(--color-text-muted); font-weight: 600; text-transform: uppercase; }

/* ===== 联系我们 ===== */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 28px; }
.contact-block { background: var(--color-bg-card); padding: 28px; border-radius: var(--radius); border: 1px solid var(--color-border); }
.contact-block h4 { color: #fff; margin-bottom: 14px; font-size: 1.05rem; }
.contact-block p { font-size: 0.9rem; color: var(--color-text-muted); margin-bottom: 8px; }

/* ===== 页脚 ===== */
.site-footer { background: #080810; padding: 48px 0 24px; border-top: 1px solid var(--color-border); }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 32px; margin-bottom: 32px; }
.footer-col h5 { color: #fff; font-size: 0.95rem; margin-bottom: 14px; }
.footer-col p, .footer-col a { display: block; font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 8px; }
.footer-col a:hover { color: var(--color-neon); }
.footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid var(--color-border); font-size: 0.82rem; color: var(--color-text-muted); }
.footer-qr { display: flex; gap: 24px; justify-content: center; margin-bottom: 20px; }
.footer-qr div { text-align: center; }
.footer-qr img { width: 100px; height: 100px; border-radius: var(--radius); margin-bottom: 6px; }
.footer-qr span { font-size: 0.78rem; color: var(--color-text-muted); }

/* ===== 社交分享 ===== */
.share-bar { display: flex; gap: 12px; justify-content: center; padding: 20px 0; }
.share-bar a { width: 40px; height: 40px; border-radius: 50%; background: var(--color-bg-card); border: 1px solid var(--color-border); display: flex; align-items: center; justify-content: center; font-size: 0.85rem; color: var(--color-text); transition: all var(--transition); }
.share-bar a:hover { background: var(--color-red); border-color: var(--color-red); color: #fff; }

/* ===== 面包屑 ===== */
.breadcrumb { padding: 14px 0; font-size: 0.85rem; color: var(--color-text-muted); margin-top: 68px; }
.breadcrumb a { color: var(--color-neon); }
.breadcrumb span { margin: 0 6px; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .nav-menu { display: none; position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; background: rgba(13,13,18,0.98); padding: 20px; gap: 16px; border-bottom: 1px solid var(--color-border); }
  .nav-menu.active { display: flex; }
  .nav-toggle { display: flex; }
  .hero h1 { font-size: 1.8rem; }
  .hero-content { padding: 50px 0; }
  .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .container { padding: 0 14px; }
  .hero h1 { font-size: 1.5rem; }
  .section { padding: 48px 0; }
  .section-title { font-size: 1.4rem; }
  .footer-grid { grid-template-columns: 1fr; }
}

/* 懒加载 */
img[loading="lazy"] { opacity: 0; transition: opacity 0.4s ease; }
img[loading="lazy"].loaded, img[loading="lazy"][src] { opacity: 1; }