/* =========================================================
   AIReader · 读伴 — mobiustech.cc 官网样式
   品牌色：纸 #FAF9F5 / 墨 #211f1a / 朱砂 #AF3830
   ========================================================= */

:root {
  --paper: #FAF9F5;
  --paper-deep: #F3F1E9;
  --ink: #211F1A;
  --ink-soft: #57534A;
  --ink-faint: #8B877C;
  --cinnabar: #AF3830;
  --cinnabar-deep: #8E2C25;
  --line: #E5E1D6;
  --dark: #17181C;
  --radius: 14px;
  --serif: "Songti SC", "STSong", "Noto Serif SC", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--cinnabar); text-decoration: none; }
a:hover { color: var(--cinnabar-deep); }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- 导航 ---------- */
.site-nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 249, 245, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-nav .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.brand .brand-name {
  font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--ink);
  letter-spacing: 1px;
}
.brand .brand-sub { font-size: 12px; color: var(--ink-faint); margin-left: 2px; }
.nav-links { display: flex; gap: 32px; align-items: center; }
.nav-links a { color: var(--ink-soft); font-size: 15px; }
.nav-links a:hover, .nav-links a.active { color: var(--cinnabar); }
.nav-cta {
  background: var(--cinnabar); color: #fff !important;
  padding: 8px 20px; border-radius: 999px; font-size: 14px !important;
}
.nav-cta:hover { background: var(--cinnabar-deep); }
.nav-toggle { display: none; background: none; border: none; font-size: 24px; color: var(--ink); cursor: pointer; }

/* ---------- Hero ---------- */
.hero { padding: 96px 0 80px; text-align: center; position: relative; overflow: hidden; }
.hero .hero-icon { width: 108px; height: 108px; border-radius: 26px; margin: 0 auto 28px;
  box-shadow: 0 12px 32px rgba(33, 31, 26, 0.14); }
.hero h1 {
  font-family: var(--serif); font-size: 52px; font-weight: 700;
  letter-spacing: 2px; line-height: 1.3;
}
.hero h1 .accent { color: var(--cinnabar); }
.hero .tagline {
  margin: 20px auto 0; max-width: 640px;
  font-size: 19px; color: var(--ink-soft);
}
.hero .hero-actions { margin-top: 40px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 14px 34px; border-radius: 999px;
  font-size: 16px; font-weight: 600; transition: all .2s ease;
}
.btn-primary { background: var(--cinnabar); color: #fff; }
.btn-primary:hover { background: var(--cinnabar-deep); color: #fff; transform: translateY(-2px); }
.btn-ghost { border: 1px solid var(--ink); color: var(--ink); }
.btn-ghost:hover { border-color: var(--cinnabar); color: var(--cinnabar); transform: translateY(-2px); }
.hero .note { margin-top: 18px; font-size: 13px; color: var(--ink-faint); }

/* ---------- 通用区块 ---------- */
.section { padding: 88px 0; }
.section.alt { background: var(--paper-deep); }
.section.dark { background: var(--dark); color: #EDEDE6; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head .kicker {
  display: inline-block; font-size: 13px; letter-spacing: 4px;
  color: var(--cinnabar); margin-bottom: 12px; font-weight: 600;
}
.section-head h2 { font-family: var(--serif); font-size: 36px; letter-spacing: 1px; }
.section-head p { margin-top: 14px; color: var(--ink-soft); font-size: 17px; }
.section.dark .section-head p { color: #A8A8A0; }

/* ---------- 支柱卡片 ---------- */
.pillars { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.pillar {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px 26px; transition: all .25s ease;
}
.pillar:hover { transform: translateY(-4px); box-shadow: 0 14px 34px rgba(33,31,26,.09); border-color: var(--cinnabar); }
.pillar .glyph {
  width: 46px; height: 46px; border-radius: 12px;
  background: var(--paper-deep); color: var(--cinnabar);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--serif); font-size: 24px; font-weight: 700; margin-bottom: 18px;
}
.pillar h3 { font-family: var(--serif); font-size: 20px; margin-bottom: 10px; }
.pillar p { font-size: 14.5px; color: var(--ink-soft); }
.pillar .not { margin-top: 12px; font-size: 12.5px; color: var(--ink-faint); }
.pillar .not::before { content: "— "; }

/* ---------- 截图展示 ---------- */
.shots { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.shot { text-align: center; }
.shot img {
  border-radius: 22px; border: 1px solid var(--line);
  box-shadow: 0 16px 40px rgba(33,31,26,.12);
}
.shot figcaption { margin-top: 16px; font-size: 14px; color: var(--ink-soft); }
.shot figcaption b { display: block; font-family: var(--serif); font-size: 16px; color: var(--ink); font-weight: 700; }
.section.dark .shot img { border-color: #2A2C33; box-shadow: 0 16px 40px rgba(0,0,0,.45); }
.section.dark .shot figcaption { color: #A8A8A0; }
.section.dark .shot figcaption b { color: #EDEDE6; }

/* ---------- 功能列表（产品页） ---------- */
.feature { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; padding: 56px 0; }
.feature + .feature { border-top: 1px solid var(--line); }
.feature.flip .feature-text { order: 2; }
.feature-text h3 { font-family: var(--serif); font-size: 28px; margin-bottom: 16px; }
.feature-text h3 .idx { color: var(--cinnabar); margin-right: 10px; }
.feature-text p { color: var(--ink-soft); font-size: 16px; }
.feature-text ul { margin-top: 16px; list-style: none; }
.feature-text li { padding: 6px 0 6px 22px; position: relative; color: var(--ink-soft); font-size: 15px; }
.feature-text li::before { content: ""; position: absolute; left: 0; top: 16px; width: 8px; height: 8px; border-radius: 50%; background: var(--cinnabar); }
.feature-img img { border-radius: 22px; border: 1px solid var(--line); box-shadow: 0 16px 40px rgba(33,31,26,.12); max-width: 340px; margin: 0 auto; }

/* ---------- 场景 ---------- */
.scenes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.scene { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px; }
.scene h4 { font-family: var(--serif); font-size: 18px; margin-bottom: 8px; }
.scene h4 span { color: var(--cinnabar); margin-right: 8px; }
.scene p { font-size: 14px; color: var(--ink-soft); }

/* ---------- 公司区块 ---------- */
.company-band { background: var(--dark); color: #EDEDE6; padding: 88px 0; }
.company-band .wrap { display: grid; grid-template-columns: 1.2fr 1fr; gap: 64px; align-items: center; }
.company-band h2 { font-family: var(--serif); font-size: 32px; margin-bottom: 18px; letter-spacing: 1px; }
.company-band p { color: #A8A8A0; font-size: 16px; }
.company-band .company-facts { list-style: none; }
.company-band .company-facts li {
  padding: 14px 0; border-bottom: 1px solid #2A2C33;
  display: flex; justify-content: space-between; font-size: 15px;
}
.company-band .company-facts li b { color: #EDEDE6; font-weight: 600; }
.company-band .company-facts li span { color: #A8A8A0; }

/* ---------- 公司页 ---------- */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.about-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 32px 28px; }
.about-card h3 { font-family: var(--serif); font-size: 20px; margin-bottom: 12px; color: var(--cinnabar); }
.about-card p { font-size: 15px; color: var(--ink-soft); }
.fact-table { width: 100%; border-collapse: collapse; }
.fact-table td { padding: 14px 4px; border-bottom: 1px solid var(--line); font-size: 15px; }
.fact-table td:first-child { color: var(--ink-faint); width: 130px; }

/* ---------- 隐私政策页 ---------- */
.doc { max-width: 760px; margin: 0 auto; }
.doc h1 { font-family: var(--serif); font-size: 34px; margin-bottom: 8px; }
.doc .doc-date { color: var(--ink-faint); font-size: 14px; margin-bottom: 40px; }
.doc h2 { font-family: var(--serif); font-size: 22px; margin: 36px 0 12px; color: var(--ink); }
.doc p { color: var(--ink-soft); font-size: 15.5px; margin-bottom: 12px; }
.doc ul { margin: 0 0 12px 20px; color: var(--ink-soft); font-size: 15.5px; }
.doc li { margin-bottom: 6px; }

/* ---------- CTA 横幅 ---------- */
.cta-band { text-align: center; padding: 88px 0; }
.cta-band h2 { font-family: var(--serif); font-size: 34px; margin-bottom: 16px; }
.cta-band p { color: var(--ink-soft); margin-bottom: 32px; font-size: 17px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--dark); color: #8A8A84; padding: 56px 0 32px; font-size: 14px; }
.site-footer .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.site-footer h5 { color: #EDEDE6; font-size: 15px; margin-bottom: 14px; font-weight: 600; }
.site-footer a { color: #8A8A84; display: block; padding: 4px 0; }
.site-footer a:hover { color: #EDEDE6; }
.site-footer .footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.site-footer .footer-brand img { width: 32px; height: 32px; border-radius: 8px; }
.site-footer .footer-brand b { color: #EDEDE6; font-family: var(--serif); font-size: 18px; }
.footer-bottom { border-top: 1px solid #2A2C33; padding-top: 24px; text-align: center; line-height: 2; }
.footer-bottom a { display: inline; }

/* ---------- 动效 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .pillars, .shots { grid-template-columns: repeat(2, 1fr); }
  .scenes { grid-template-columns: 1fr; }
  .feature { grid-template-columns: 1fr; gap: 32px; }
  .feature.flip .feature-text { order: 0; }
  .company-band .wrap { grid-template-columns: 1fr; gap: 40px; }
  .about-grid { grid-template-columns: 1fr; }
  .site-footer .footer-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 38px; }
  .section-head h2 { font-size: 28px; }
}
@media (max-width: 640px) {
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: var(--paper); flex-direction: column; gap: 0;
    border-bottom: 1px solid var(--line); padding: 8px 0;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 24px; width: 100%; }
  .nav-cta { margin: 8px 24px; text-align: center; }
  .nav-toggle { display: block; }
  .shots { grid-template-columns: 1fr; }
  .pillars { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 56px; }
  .section { padding: 64px 0; }
}