/* =========================================================
   OMICA 网站建设 · 全站基础样式 base.css
   风格：极简卫浴风 —— 纯白 / 浅灰 / 哑光黑
   职责：重置、设计变量、统一顶部导航、统一页脚、动效基类、通用按钮、回到顶部
   页面独有布局样式一律写在 css/style-<页面>.css，禁止混入本文件
   ========================================================= */

/* ---------- 重置与基础 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; border: 0; background: none; cursor: pointer; color: inherit; }
input, textarea, select { font: inherit; }
address { font-style: normal; }

:root {
  --white: #FFFFFF;
  --gray-50: #FAFAF9;
  --gray-100: #F4F4F2;
  --gray-200: #E9E9E5;
  --gray-300: #D8D8D3;
  --gray-400: #B9B9B2;
  --gray-500: #9A9A94;
  --gray-600: #6E6E68;
  --ink: #1B1B1B;
  --ink-soft: #3A3A36;
  --ink-mute: #7C7C76;
  --line: #E4E4DF;
  --font: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --shadow-sm: 0 2px 10px rgba(27, 27, 27, .06);
  --shadow-md: 0 10px 30px rgba(27, 27, 27, .09);
  --shadow-lg: 0 22px 50px rgba(27, 27, 27, .12);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --header-h: 64px;
  --transition: .35s cubic-bezier(.22, .61, .36, 1);
}

body {
  font-family: var(--font);
  color: var(--ink-soft);
  background: var(--white);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
::selection { background: var(--ink); color: #fff; }

/* ---------- 顶部固定导航（全站逐字一致） ---------- */
.site-header { position: fixed; top: 0; left: 0; right: 0; z-index: 100; }

.header-top { background: var(--ink); color: #CFCFCA; font-size: 13px; }
.header-top-inner { display: flex; align-items: center; justify-content: space-between; height: 36px; }
.header-top-slogan { letter-spacing: .04em; }
.header-top-contact { display: flex; gap: 26px; }
.header-top-contact a:hover { color: #fff; }

.header-nav {
  background: rgba(255, 255, 255, .92);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow var(--transition), background var(--transition);
}
.site-header.scrolled .header-nav { background: #fff; box-shadow: var(--shadow-sm); }
.header-nav-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); }

.logo { display: flex; align-items: center; gap: 12px; }
.logo img { width: 48px; height: 48px; }
.logo-text { display: flex; flex-direction: column; line-height: 1.15; }
.logo-text b { font-size: 21px; letter-spacing: .14em; color: var(--ink); font-weight: 700; }
.logo-text em { font-style: normal; font-size: 11px; letter-spacing: .42em; color: var(--gray-600); }

.nav-list { display: flex; align-items: center; gap: 4px; }
.nav-link {
  display: inline-block;
  padding: 8px 13px;
  font-size: 15px;
  color: var(--ink-soft);
  position: relative;
  transition: color var(--transition);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 13px; right: 13px; bottom: 2px;
  height: 2px;
  background: var(--ink);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--ink); }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

.nav-toggle { display: none; width: 44px; height: 44px; flex-direction: column; align-items: center; justify-content: center; gap: 5px; }
.nav-toggle-bar { width: 22px; height: 2px; background: var(--ink); transition: transform var(--transition), opacity var(--transition); }
.nav-toggle.open .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle.open .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 统一页脚（全站逐字一致，备案号仅首页） ---------- */
.site-footer { background: var(--ink); color: var(--gray-400); }
.footer-top { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.25fr; gap: 48px; padding: 64px 24px 46px; }
.footer-col h4 { color: #fff; font-size: 15px; letter-spacing: .14em; font-weight: 600; margin-bottom: 18px; }
.footer-col li { margin-bottom: 10px; font-size: 14px; }
.footer-col a { transition: color var(--transition); }
.footer-col a:hover { color: #fff; }
.footer-col-about p { font-size: 14px; line-height: 1.9; color: var(--gray-400); }
.footer-logo { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.footer-logo img { width: 40px; height: 40px; }
.footer-logo-text b { font-size: 19px; letter-spacing: .14em; color: #fff; font-weight: 700; }
.footer-logo-text em { font-style: normal; font-size: 10px; letter-spacing: .42em; color: var(--gray-400); display: block; }
.footer-bottom { border-top: 1px solid #33332F; }
.footer-bottom-inner { display: flex; align-items: center; justify-content: space-between; min-height: 56px; font-size: 13px; color: var(--gray-500); }
.footer-icp { color: var(--gray-500); }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 15px;
  padding: 12px 28px;
  border-radius: 999px;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition), border-color var(--transition);
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 12px 24px rgba(27, 27, 27, .18); }
.btn-line { background: transparent; color: var(--ink); border: 1px solid var(--ink); }
.btn-line:hover { background: var(--ink); color: #fff; }
.btn-white { background: #fff; color: var(--ink); }
.btn-white:hover { box-shadow: 0 12px 26px rgba(255, 255, 255, .25); }

/* ---------- 滚动渐入动画基类 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s cubic-bezier(.22, .61, .36, 1); will-change: opacity, transform; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 章节骨架（各页可叠加独有样式） ---------- */
.sec { padding: 96px 0; position: relative; }
.sec-head { max-width: 740px; margin: 0 auto 56px; text-align: center; position: relative; z-index: 1; }
.sec-tag { display: inline-flex; align-items: center; gap: 10px; font-size: 13px; letter-spacing: .3em; color: var(--gray-600); margin-bottom: 18px; }
.sec-tag::before, .sec-tag::after { content: ""; width: 26px; height: 1px; background: var(--gray-400); }
.sec-head h2 { font-size: clamp(24px, 3vw, 36px); font-weight: 800; color: var(--ink); line-height: 1.35; }
.sec-head p { margin-top: 16px; font-size: 15px; color: var(--ink-mute); line-height: 1.9; }

/* ---------- CTA 骨架（各页自定义背景与装饰） ---------- */
.cta-inner { position: relative; z-index: 2; text-align: center; max-width: 780px; margin: 0 auto; }
.cta-inner h2 { font-size: clamp(26px, 3.4vw, 40px); font-weight: 800; line-height: 1.3; }
.cta-inner > p { margin: 20px 0 34px; font-size: 16px; line-height: 1.9; }
.cta-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 16px; margin-bottom: 40px; }
.cta-contact { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px 40px; font-size: 15px; }
.cta-contact a { font-weight: 700; font-size: 19px; }

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed;
  right: 26px; bottom: 30px;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--ink);
  color: #fff;
  font-size: 18px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top:hover { background: #3A3A36; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .nav-toggle { display: flex; }
  .nav-list {
    position: absolute;
    top: var(--header-h);
    left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 8px 0 12px;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    display: none;
  }
  .nav-list.open { display: flex; }
  .nav-link { padding: 13px 26px; font-size: 16px; }
  .nav-link::after { display: none; }
}

@media (max-width: 768px) {
  .header-top-inner { height: 34px; }
  .header-top-slogan { display: none; }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 32px 24px; padding: 48px 24px 36px; }
  .footer-col-about { grid-column: 1 / -1; }
  .footer-bottom-inner { flex-direction: column; gap: 6px; padding: 16px 0; text-align: center; }
  .back-top { right: 16px; bottom: 20px; width: 42px; height: 42px; }
}

@media (max-width: 560px) {
  .header-top-contact { gap: 12px; }
  .header-top-contact li:nth-child(2) { display: none; }
}