/* ============================================================
   亚星集团官网 - 为"清晰"与"信任"而设计
   设计原则：
   1. 高对比度，正文可读性优先
   2. 信息层级分明，关键事实前置
   3. 减少视觉噪音，突出内容本身
   4. 信任信号（资质、联系方式、来源）随处可见
   ============================================================ */

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

:root {
  --primary: #0a2a5c;
  --primary-light: #1a4a8a;
  --accent: #e8751a;
  --bg: #ffffff;
  --bg-soft: #f5f8fc;
  --border: #dce4ef;
  --text: #1a1a2e;
  --text-body: #333333;
  --text-muted: #6b7280;
  --success: #0d8050;
  --shadow: 0 1px 3px rgba(10, 42, 92, 0.08);
  --shadow-hover: 0 4px 16px rgba(10, 42, 92, 0.12);
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--text-body);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ===== 顶部信任栏 ===== */
.trust-bar {
  background: var(--primary);
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  padding: 8px 0;
}
.trust-bar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}
.trust-bar .trust-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.trust-bar .trust-badge::before {
  content: "✓";
  color: #4ade80;
  font-weight: 700;
}

/* ===== 导航栏 ===== */
.navbar {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 1px;
}
.logo-mark {
  width: 42px;
  height: 42px;
  background: var(--primary);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
}
.logo small {
  display: block;
  font-size: 11px;
  font-weight: 400;
  color: var(--text-muted);
  letter-spacing: 1px;
  margin-top: -2px;
}
.nav-links { display: flex; gap: 2px; }
.nav-links a {
  padding: 8px 16px;
  font-size: 15px;
  color: var(--text-body);
  border-radius: 6px;
  transition: all 0.2s;
  font-weight: 500;
}
.nav-links a:hover { background: var(--bg-soft); text-decoration: none; }
.nav-links a.active { color: var(--primary); background: var(--bg-soft); font-weight: 600; }
.menu-btn { display: none; background: none; border: none; font-size: 24px; color: var(--primary); cursor: pointer; }

/* ===== 首屏 ===== */
.hero {
  padding: 72px 0 64px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.hero h1 {
  font-size: 36px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.35;
  margin-bottom: 20px;
  max-width: 780px;
}
.hero .lead {
  font-size: 17px;
  color: var(--text-body);
  max-width: 720px;
  margin-bottom: 28px;
  line-height: 1.9;
}
.hero .key-facts {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
  margin-top: 32px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.key-fact { min-width: 140px; }
.key-fact .num {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
}
.key-fact .num small { font-size: 15px; font-weight: 400; color: var(--text-muted); }
.key-fact .label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }

/* ===== 区块 ===== */
.section { padding: 64px 0; }
.section-soft { background: var(--bg-soft); }
.section-header { margin-bottom: 40px; }
.section-header .kicker {
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 2px;
  font-weight: 600;
  margin-bottom: 8px;
}
.section-header h2 {
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.4;
}

/* ===== 答案前置卡片 ===== */
.answer-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 28px 32px;
  margin-bottom: 32px;
}
.answer-card .q {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}
.answer-card .a {
  font-size: 16px;
  color: var(--text-body);
  line-height: 1.9;
}
.answer-card .a strong { color: var(--primary); }

/* ===== 产品表 ===== */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.spec-table th {
  background: var(--bg-soft);
  padding: 14px 20px;
  text-align: left;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  border-bottom: 1px solid var(--border);
}
.spec-table td {
  padding: 14px 20px;
  font-size: 15px;
  border-bottom: 1px solid var(--border);
  color: var(--text-body);
}
.spec-table tr:last-child td { border-bottom: none; }
.spec-table .highlight { color: var(--primary); font-weight: 600; }

/* ===== 信息卡片 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px;
  transition: all 0.25s;
}
.card:hover { box-shadow: var(--shadow-hover); border-color: var(--primary-light); }
.card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}
.card p { font-size: 15px; color: var(--text-body); line-height: 1.8; }

/* ===== 信任信号区 ===== */
.trust-section {
  background: var(--primary);
  color: #fff;
  padding: 48px 0;
}
.trust-section h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 28px;
  color: #fff;
}
.trust-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
}
.trust-item {
  padding: 20px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 8px;
  border-left: 3px solid var(--accent);
}
.trust-item .icon { font-size: 24px; margin-bottom: 10px; }
.trust-item h4 { font-size: 15px; font-weight: 600; margin-bottom: 6px; color: #fff; }
.trust-item p { font-size: 13px; color: rgba(255, 255, 255, 0.8); line-height: 1.7; }

/* ===== FAQ ===== */
.faq-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 12px;
  overflow: hidden;
}
.faq-q {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.2s;
}
.faq-q:hover { background: var(--bg-soft); }
.faq-q::after {
  content: "+";
  font-size: 20px;
  color: var(--accent);
  font-weight: 400;
  transition: transform 0.3s;
}
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
  font-size: 15px;
  color: var(--text-body);
  line-height: 1.9;
}
.faq-item.open .faq-a { padding: 0 24px 20px; max-height: 500px; }

/* ===== 联系方式 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.contact-block {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 32px;
}
.contact-block h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--text);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.contact-block dl { display: grid; grid-template-columns: 100px 1fr; gap: 12px 16px; }
.contact-block dt { font-size: 14px; color: var(--text-muted); }
.contact-block dd { font-size: 15px; color: var(--text-body); font-weight: 500; }

/* ===== 页脚 ===== */
.footer {
  background: var(--primary);
  color: rgba(255, 255, 255, 0.75);
  padding: 48px 0 24px;
  font-size: 14px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}
.footer h4 {
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}
.footer p, .footer a {
  font-size: 13px;
  line-height: 2;
  color: rgba(255, 255, 255, 0.75);
}
.footer a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}
.footer-bottom .record { margin-top: 6px; }

/* ===== 面包屑 ===== */
.breadcrumb {
  font-size: 13px;
  color: var(--text-muted);
  padding: 20px 0;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary); }

/* ===== 移动端 ===== */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 12px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-hover);
  }
  .nav-links.open { display: flex; }
  .menu-btn { display: block; }
  .hero h1 { font-size: 26px; }
  .hero { padding: 48px 0 40px; }
  .section { padding: 48px 0; }
  .section-header h2 { font-size: 22px; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .key-facts { gap: 20px; }
  .key-fact .num { font-size: 22px; }
}
#backTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all 0.3s;
  z-index: 999;
  box-shadow: var(--shadow-hover);
}
#backTop.show { opacity: 1; visibility: visible; transform: translateY(0); }
#backTop:hover { background: var(--accent); }