/* ============================================
   色虎 - 鬼灭之刃风格原创CSS
   域名: ppvivg.cn
   配色: 深夜蓝 #0a0e1a | 绯红 #c0392b | 青碧 #1abc9c | 金色 #d4a017 | 紫藤 #8e44ad
   ============================================ */

/* === 基础重置 === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", sans-serif; background: #0a0e1a; color: #e8e6e3; line-height: 1.7; overflow-x: hidden; }
a { color: #1abc9c; text-decoration: none; transition: color 0.3s; }
a:hover { color: #d4a017; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* === 顶部导航栏 === */
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; background: rgba(10,14,26,0.92); backdrop-filter: blur(12px); border-bottom: 1px solid rgba(26,188,156,0.15); transition: all 0.3s; }
.site-header.scrolled { background: rgba(10,14,26,0.98); box-shadow: 0 2px 20px rgba(0,0,0,0.5); }
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 68px; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-brand img { height: 40px; width: auto; }
.nav-brand span { font-size: 1.3rem; font-weight: 700; background: linear-gradient(135deg, #1abc9c, #d4a017); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.nav-menu { display: flex; gap: 6px; }
.nav-menu a { padding: 8px 16px; border-radius: 6px; font-size: 0.95rem; color: #b8b5b0; transition: all 0.3s; position: relative; }
.nav-menu a:hover, .nav-menu a.active { color: #1abc9c; background: rgba(26,188,156,0.1); }
.nav-menu a.active::after { content: ''; position: absolute; bottom: 2px; left: 50%; transform: translateX(-50%); width: 20px; height: 2px; background: #1abc9c; border-radius: 1px; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.nav-toggle span { width: 24px; height: 2px; background: #e8e6e3; border-radius: 2px; transition: all 0.3s; }

/* === Hero区域 === */
.hero-section { position: relative; min-height: 88vh; display: flex; align-items: center; justify-content: center; overflow: hidden; margin-top: 68px; }
.hero-bg { position: absolute; inset: 0; background-size: cover; background-position: center; background-repeat: no-repeat; }
.hero-bg::after { content: ''; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(10,14,26,0.3) 0%, rgba(10,14,26,0.6) 50%, rgba(10,14,26,0.95) 100%); }
.hero-content { position: relative; z-index: 2; text-align: center; padding: 40px 20px; max-width: 800px; }
.hero-content h1 { font-size: 3.2rem; font-weight: 800; margin-bottom: 16px; line-height: 1.3; }
.hero-content h1 .brand-highlight { background: linear-gradient(135deg, #c0392b, #d4a017, #1abc9c); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-content p { font-size: 1.15rem; color: #b8b5b0; margin-bottom: 28px; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary { display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px; background: linear-gradient(135deg, #c0392b, #d4a017); color: #fff; font-size: 1rem; font-weight: 600; border-radius: 50px; border: none; cursor: pointer; transition: all 0.3s; box-shadow: 0 4px 20px rgba(192,57,43,0.3); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 30px rgba(192,57,43,0.5); color: #fff; }
.btn-outline { display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px; background: transparent; color: #1abc9c; font-size: 1rem; font-weight: 600; border-radius: 50px; border: 2px solid #1abc9c; cursor: pointer; transition: all 0.3s; }
.btn-outline:hover { background: rgba(26,188,156,0.1); transform: translateY(-2px); color: #1abc9c; }

/* === 通用区块标题 === */
.section-block { padding: 70px 0; }
.section-block:nth-child(even) { background: rgba(15,20,35,0.5); }
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 2rem; font-weight: 700; margin-bottom: 12px; }
.section-title h2 .accent { color: #1abc9c; }
.section-title h2 .accent-red { color: #c0392b; }
.section-title h2 .accent-gold { color: #d4a017; }
.section-title p { color: #8a8784; font-size: 1rem; max-width: 600px; margin: 0 auto; }
.section-title .divider { width: 60px; height: 3px; background: linear-gradient(90deg, #c0392b, #1abc9c); margin: 16px auto 0; border-radius: 2px; }

/* === 视频卡片网格 === */
.video-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.video-card { background: #111827; border-radius: 12px; overflow: hidden; transition: all 0.35s; border: 1px solid rgba(26,188,156,0.08); }
.video-card:hover { transform: translateY(-6px); box-shadow: 0 12px 40px rgba(26,188,156,0.15); border-color: rgba(26,188,156,0.25); }
.video-card .thumb { position: relative; aspect-ratio: 16/9; overflow: hidden; }
.video-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.video-card:hover .thumb img { transform: scale(1.08); }
.video-card .play-btn { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0.8); width: 56px; height: 56px; background: rgba(192,57,43,0.85); border-radius: 50%; display: flex; align-items: center; justify-content: center; opacity: 0; transition: all 0.35s; }
.video-card:hover .play-btn { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.video-card .play-btn::after { content: ''; width: 0; height: 0; border-left: 18px solid #fff; border-top: 11px solid transparent; border-bottom: 11px solid transparent; margin-left: 4px; }
.video-card .thumb .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; }
.video-card .card-body { padding: 16px; }
.video-card .card-body h3 { font-size: 0.95rem; font-weight: 600; margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-card .card-body .meta { display: flex; gap: 12px; font-size: 0.8rem; color: #6b6966; }
.video-card .card-body .tag { display: inline-block; padding: 2px 10px; background: rgba(26,188,156,0.1); color: #1abc9c; border-radius: 20px; font-size: 0.75rem; margin-top: 8px; }

/* === Tab切换 === */
.tab-nav { display: flex; gap: 8px; justify-content: center; margin-bottom: 36px; flex-wrap: wrap; }
.tab-btn { padding: 10px 24px; background: rgba(26,188,156,0.08); color: #8a8784; border: 1px solid rgba(26,188,156,0.12); border-radius: 30px; cursor: pointer; font-size: 0.9rem; transition: all 0.3s; }
.tab-btn:hover { color: #1abc9c; border-color: rgba(26,188,156,0.3); }
.tab-btn.active { background: linear-gradient(135deg, #c0392b, #d4a017); color: #fff; border-color: transparent; box-shadow: 0 4px 15px rgba(192,57,43,0.3); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* === 专家展示 === */
.expert-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.expert-card { background: #111827; border-radius: 12px; padding: 28px 20px; text-align: center; border: 1px solid rgba(26,188,156,0.08); transition: all 0.35s; }
.expert-card:hover { transform: translateY(-4px); border-color: rgba(212,160,23,0.3); box-shadow: 0 8px 30px rgba(212,160,23,0.1); }
.expert-card .avatar { width: 90px; height: 90px; border-radius: 50%; overflow: hidden; margin: 0 auto 16px; border: 3px solid rgba(26,188,156,0.3); }
.expert-card .avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-card h4 { font-size: 1.05rem; margin-bottom: 4px; color: #e8e6e3; }
.expert-card .role { color: #d4a017; font-size: 0.85rem; margin-bottom: 10px; }
.expert-card p { font-size: 0.85rem; color: #8a8784; line-height: 1.5; }

/* === 社区功能 === */
.community-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.community-item { background: #111827; border-radius: 12px; padding: 32px 24px; text-align: center; border: 1px solid rgba(142,68,173,0.1); transition: all 0.35s; }
.community-item:hover { transform: translateY(-4px); border-color: rgba(142,68,173,0.3); box-shadow: 0 8px 30px rgba(142,68,173,0.1); }
.community-item .icon-circle { width: 64px; height: 64px; border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; font-size: 1.8rem; }
.community-item .icon-circle.ic-red { background: rgba(192,57,43,0.15); color: #c0392b; }
.community-item .icon-circle.ic-teal { background: rgba(26,188,156,0.15); color: #1abc9c; }
.community-item .icon-circle.ic-gold { background: rgba(212,160,23,0.15); color: #d4a017; }
.community-item .icon-circle.ic-purple { background: rgba(142,68,173,0.15); color: #8e44ad; }
.community-item h4 { font-size: 1.05rem; margin-bottom: 8px; }
.community-item p { font-size: 0.85rem; color: #8a8784; line-height: 1.5; }

/* === AI赋能区 === */
.ai-showcase { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.ai-showcase .ai-img { border-radius: 12px; overflow: hidden; border: 1px solid rgba(26,188,156,0.15); }
.ai-showcase .ai-img img { width: 100%; }
.ai-showcase .ai-text h3 { font-size: 1.5rem; margin-bottom: 16px; }
.ai-showcase .ai-text p { color: #8a8784; margin-bottom: 16px; line-height: 1.7; }
.ai-feature-list { display: flex; flex-direction: column; gap: 12px; }
.ai-feature-list .feat { display: flex; align-items: flex-start; gap: 12px; }
.ai-feature-list .feat .dot { width: 8px; height: 8px; border-radius: 50%; background: #1abc9c; margin-top: 8px; flex-shrink: 0; }
.ai-feature-list .feat span { font-size: 0.95rem; color: #b8b5b0; }

/* === FAQ手风琴 === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: #111827; border-radius: 10px; margin-bottom: 12px; border: 1px solid rgba(26,188,156,0.08); overflow: hidden; }
.faq-item .faq-q { padding: 18px 24px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 0.95rem; transition: background 0.3s; }
.faq-item .faq-q:hover { background: rgba(26,188,156,0.05); }
.faq-item .faq-q .arrow { transition: transform 0.3s; color: #1abc9c; font-size: 1.2rem; }
.faq-item.open .faq-q .arrow { transform: rotate(180deg); }
.faq-item .faq-a { padding: 0 24px; max-height: 0; overflow: hidden; transition: all 0.35s ease; }
.faq-item.open .faq-a { padding: 0 24px 18px; max-height: 500px; }
.faq-item .faq-a p { color: #8a8784; font-size: 0.9rem; line-height: 1.7; }

/* === 用户评价 === */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card { background: #111827; border-radius: 12px; padding: 24px; border: 1px solid rgba(212,160,23,0.08); }
.review-card .stars { color: #d4a017; font-size: 1rem; margin-bottom: 12px; letter-spacing: 2px; }
.review-card p { font-size: 0.9rem; color: #b8b5b0; line-height: 1.6; margin-bottom: 12px; font-style: italic; }
.review-card .reviewer { font-size: 0.85rem; color: #6b6966; }

/* === 面包屑 === */
.breadcrumb { padding: 16px 0; font-size: 0.85rem; color: #6b6966; }
.breadcrumb a { color: #1abc9c; }
.breadcrumb span { margin: 0 8px; }

/* === 页脚 === */
.site-footer { background: #060810; border-top: 1px solid rgba(26,188,156,0.1); padding: 50px 0 0; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand img { height: 36px; margin-bottom: 12px; }
.footer-brand p { color: #6b6966; font-size: 0.85rem; line-height: 1.6; }
.footer-col h4 { font-size: 1rem; margin-bottom: 16px; color: #e8e6e3; position: relative; padding-bottom: 10px; }
.footer-col h4::after { content: ''; position: absolute; bottom: 0; left: 0; width: 30px; height: 2px; background: #c0392b; border-radius: 1px; }
.footer-col a { display: block; color: #6b6966; font-size: 0.85rem; padding: 4px 0; transition: color 0.3s; }
.footer-col a:hover { color: #1abc9c; }
.footer-qr { display: flex; gap: 16px; }
.footer-qr img { width: 90px; height: 90px; border-radius: 8px; border: 1px solid rgba(26,188,156,0.15); }
.footer-bottom { border-top: 1px solid rgba(26,188,156,0.08); padding: 20px 0; text-align: center; font-size: 0.8rem; color: #4a4744; }

/* === 内页通用 === */
.page-hero { padding: 120px 0 50px; text-align: center; background: linear-gradient(180deg, rgba(10,14,26,0.5), #0a0e1a); }
.page-hero h1 { font-size: 2.4rem; font-weight: 700; margin-bottom: 12px; }
.page-hero p { color: #8a8784; max-width: 600px; margin: 0 auto; }
.page-content { padding: 50px 0; }

/* === 联系表单 === */
.contact-form { max-width: 600px; margin: 0 auto; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 0.9rem; color: #b8b5b0; }
.form-group input, .form-group textarea { width: 100%; padding: 12px 16px; background: #111827; border: 1px solid rgba(26,188,156,0.15); border-radius: 8px; color: #e8e6e3; font-size: 0.95rem; transition: border-color 0.3s; }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: #1abc9c; }
.form-group textarea { min-height: 120px; resize: vertical; }

/* === 响应式 === */
@media (max-width: 1024px) {
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .ai-showcase { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-menu { display: none; position: fixed; top: 68px; left: 0; width: 100%; background: rgba(10,14,26,0.98); flex-direction: column; padding: 20px; gap: 4px; border-bottom: 1px solid rgba(26,188,156,0.15); }
  .nav-menu.open { display: flex; }
  .nav-toggle { display: flex; }
  .hero-content h1 { font-size: 2rem; }
  .video-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .section-block { padding: 40px 0; }
  .tab-nav { gap: 4px; }
  .tab-btn { padding: 8px 16px; font-size: 0.8rem; }
}
@media (max-width: 480px) {
  .hero-content h1 { font-size: 1.6rem; }
  .hero-btns { flex-direction: column; align-items: center; }
  .btn-primary, .btn-outline { width: 100%; justify-content: center; }
}