/* ===== CELA 万籁官网 — 全局样式 ===== */
/* 2026-08-04 v1.0 | 纯HTML+CSS+JS | 响应式 | GEO优化 */

:root {
  /* 品牌色 */
  --primary: #00A870;
  --primary-dark: #008A5C;
  --primary-light: #E6F7F2;
  --accent: #FF6B35;
  --bg: #FFFFFF;
  --bg-light: #F8FAFB;
  --text: #1A1A2E;
  --text-muted: #6B7280;
  --border: #E5E7EB;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --max-w: 1200px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--primary); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; }
h1 { font-size: 2.25rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.25rem; }

.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }

/* ===== 导航 ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1.35rem;
  color: var(--text);
}
.nav-logo span { color: var(--primary); }
.nav-links { display: flex; gap: 0.25rem; list-style: none; }
.nav-links a {
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: all 0.2s;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: var(--primary-light);
}
.nav-cta {
  background: var(--primary);
  color: #fff !important;
  border-radius: 8px;
  padding: 0.5rem 1.25rem;
  font-weight: 600;
  font-size: 0.9rem;
}
.nav-cta:hover { background: var(--primary-dark) !important; color: #fff !important; }

/* 移动端菜单 */
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 0.5rem; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--text); margin: 5px 0; transition: 0.3s; }

@media (max-width: 768px) {
  .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 1rem; box-shadow: var(--shadow-md); border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.4rem; }
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(160deg, #F0FAF4 0%, #E8F5FF 50%, #FFF 100%);
  padding: 5rem 0 4rem;
  text-align: center;
}
.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  max-width: 720px;
  margin: 0 auto 1rem;
  line-height: 1.25;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(135deg, var(--primary), #0095E0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 1rem auto 2rem;
}
.hero-cta {
  display: inline-flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
}
.btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
  text-align: center;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-outline {
  background: #fff;
  color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-outline:hover { background: var(--primary-light); }

@media (max-width: 768px) {
  .hero { padding: 3rem 0 2.5rem; }
  .hero h1 { font-size: 2rem; }
}

/* ===== 三效合一卡片 ===== */
.triple-section { padding: 4rem 0; }
.triple-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}
.triple-card {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  transition: transform 0.2s, box-shadow 0.2s;
  border: 1px solid transparent;
}
.triple-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: var(--primary-light); }
.triple-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.triple-card h3 { margin-bottom: 0.5rem; }
.triple-card p { color: var(--text-muted); font-size: 0.95rem; }

@media (max-width: 768px) {
  .triple-grid { grid-template-columns: 1fr; }
}

/* ===== 特性展示 ===== */
.features { padding: 3rem 0 4rem; }
.features h2 { text-align: center; margin-bottom: 2.5rem; }
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}
.feature-item {
  display: flex;
  gap: 1rem;
  padding: 1.25rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  align-items: flex-start;
}
.feature-item .icon { font-size: 1.5rem; flex-shrink: 0; margin-top: 0.15rem; }
.feature-item h4 { font-size: 1rem; margin-bottom: 0.25rem; }
.feature-item p { font-size: 0.9rem; color: var(--text-muted); }

/* ===== 四大卖点展示区 ===== */
.selling-points { padding: 4rem 0; background: var(--bg); }
.selling-points h2 { text-align: center; margin-bottom: 0.75rem; }
.selling-points .sp-sub { text-align: center; color: var(--text-muted); margin-bottom: 2.5rem; font-size: 0.95rem; }
.sp-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.sp-card {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 2rem;
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
  position: relative;
  overflow: hidden;
}
.sp-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--primary-light); }
.sp-card .sp-icon { font-size: 2rem; margin-bottom: 0.75rem; }
.sp-card h3 { font-size: 1.2rem; margin-bottom: 0.4rem; }
.sp-card .sp-value { font-weight: 700; color: var(--primary-dark); font-size: 1.05rem; margin-bottom: 0.5rem; line-height: 1.45; }
.sp-card .sp-advantage { color: var(--text); font-size: 0.93rem; margin-bottom: 0.75rem; line-height: 1.55; }
.sp-card .sp-tech {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.55;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--border);
}
.sp-card .sp-tech b { color: var(--primary-dark); font-weight: 600; }
@media (max-width: 768px) {
  .sp-grid { grid-template-columns: 1fr; }
}

/* ===== 场景区 ===== */
.scenes { padding: 4rem 0; background: var(--bg-light); }
.scenes h2 { text-align: center; margin-bottom: 2.5rem; }
.scene-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 1.5rem;
}
.scene-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--primary);
}
.scene-card h3 { margin-bottom: 0.5rem; }
.scene-card .pain { color: var(--accent); font-weight: 600; margin-bottom: 0.75rem; font-size: 0.95rem; }
.scene-card .solution { font-size: 0.95rem; color: var(--text-muted); line-height: 1.6; }

/* ===== 信任条 ===== */
.trust { padding: 3rem 0; text-align: center; }
.trust h2 { margin-bottom: 2rem; }
.trust-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2rem 3rem;
}
.trust-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}
.trust-item .num { font-size: 2rem; font-weight: 800; color: var(--primary); }
.trust-item .label { font-size: 0.9rem; color: var(--text-muted); }

/* ===== 页面内通用区块 ===== */
.section { padding: 3rem 0; }
.section-title { text-align: center; margin-bottom: 3rem; }
.section-title h2 { color: var(--text); }
.section-title p { color: var(--text-muted); margin-top: 0.5rem; font-size: 1.05rem; }

/* ===== 产品页 ===== */
.product-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}
.product-card h3 { color: var(--primary); margin-bottom: 0.75rem; }
.product-card .specs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
  margin: 1.5rem 0;
  padding: 1rem;
  background: var(--bg-light);
  border-radius: 8px;
}
.spec-item { font-size: 0.9rem; }
.spec-item strong { display: block; font-size: 0.8rem; color: var(--text-muted); text-transform: uppercase; margin-bottom: 0.15rem; }
.product-card .usage { margin-top: 1rem; padding: 1rem; border-left: 3px solid var(--primary); background: var(--primary-light); border-radius: 0 8px 8px 0; font-size: 0.95rem; }

/* ===== FAQ ===== */
.faq-item { border-bottom: 1px solid var(--border); padding: 1.25rem 0; }
.faq-question { font-weight: 700; font-size: 1.05rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.faq-question::after { content: '+'; font-size: 1.3rem; color: var(--primary); }
.faq-answer { margin-top: 0.75rem; color: var(--text-muted); font-size: 0.95rem; line-height: 1.7; }

/* ===== 技术对比表 ===== */
.compare-table { width: 100%; border-collapse: collapse; margin: 2rem 0; font-size: 0.9rem; }
.compare-table th, .compare-table td { padding: 0.75rem 1rem; border: 1px solid var(--border); text-align: left; }
.compare-table th { background: var(--primary); color: #fff; font-weight: 600; }
.compare-table tr:nth-child(even) { background: var(--bg-light); }
.compare-table td:first-child { font-weight: 600; }
.compare-table .win { color: var(--primary); font-weight: 700; }

/* ===== Footer ===== */
.footer {
  background: #1A1A2E;
  color: #9CA3AF;
  padding: 3rem 0 2rem;
  margin-top: auto;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-col h4 { color: #fff; margin-bottom: 1rem; font-size: 0.95rem; }
.footer-col p, .footer-col a { font-size: 0.9rem; line-height: 2; color: #9CA3AF; }
.footer-col a:hover { color: var(--primary); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.85rem;
}

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 1rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { color: var(--text); }

/* ===== 工艺流程图 ===== */
.process-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}
.process-step {
  padding: 2rem 1.5rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  position: relative;
}
.process-step .step-num {
  width: 40px; height: 40px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-weight: 700;
}

/* ===== 对比区块 ===== */
.vs-block {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1rem;
  align-items: start;
  margin: 2rem 0;
}
.vs-left, .vs-right { padding: 2rem; border-radius: var(--radius); }
.vs-left { background: var(--primary-light); border: 1px solid var(--primary); }
.vs-right { background: #FEF2F2; border: 1px solid #FCA5A5; }
.vs-center { font-size: 1.5rem; font-weight: 800; color: var(--accent); align-self: center; }
.vs-left h3 { color: var(--primary); }
.vs-right h3 { color: #DC2626; }

@media (max-width: 768px) {
  .vs-block { grid-template-columns: 1fr; }
  .vs-center { justify-self: center; transform: rotate(90deg); }
}

/* ===== 文章内容样式 ===== */
.article-content { max-width: 800px; margin: 0 auto; line-height: 1.9; }
.article-content h2 { margin: 2.5rem 0 1rem; }
.article-content h3 { margin: 1.5rem 0 0.75rem; }
.article-content p { margin-bottom: 1rem; color: #374151; }
.article-content ul, .article-content ol { margin: 0.75rem 0 1.5rem 1.5rem; }
.article-content li { margin-bottom: 0.5rem; }
.article-content blockquote {
  padding: 1rem 1.5rem;
  border-left: 4px solid var(--primary);
  background: var(--bg-light);
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
  color: var(--text-muted);
}