/* 小鹦学语 LinguaPop · 公司官网静态样式
   零外部依赖（无 CDN / 无字体 / 无 JS），可直接部署到国内任意静态服务器或对象存储。 */

:root {
  --brand: #12a37f;
  --brand-dark: #0b7a5f;
  --brand-light: #e8f7f2;
  --accent: #ff8a3d;
  --ink: #1f2933;
  --ink-soft: #52606d;
  --line: #e4e9ee;
  --bg: #ffffff;
  --bg-soft: #f6f9f8;
  --footer: #102a23;
  --radius: 14px;
  --maxw: 980px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
}

a { color: var(--brand-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.brand small { color: var(--ink-soft); font-weight: 500; font-size: 12px; letter-spacing: .5px; }

.nav { display: flex; gap: 22px; font-size: 14.5px; }
.nav a { color: var(--ink-soft); }
.nav a:hover { color: var(--brand-dark); text-decoration: none; }
.nav a.active { color: var(--brand-dark); font-weight: 600; }

/* ---------- 首页 Hero ---------- */
.hero {
  background: linear-gradient(150deg, #0e8f6f 0%, #12a37f 45%, #35b88f 100%);
  color: #fff;
  padding: 72px 0 84px;
}
.hero .container { display: flex; align-items: center; gap: 48px; flex-wrap: wrap; }
.hero-copy { flex: 1 1 420px; min-width: 280px; }
.hero h1 { font-size: 40px; line-height: 1.25; margin: 0 0 14px; letter-spacing: 1px; }
.hero p.lead { font-size: 18px; margin: 0 0 28px; opacity: .94; }
.hero-meta { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 30px; }
.hero-meta span {
  background: rgba(255, 255, 255, .16);
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 13px;
}
.btn-store {
  display: inline-block;
  background: #fff;
  color: var(--brand-dark);
  font-weight: 700;
  font-size: 16px;
  padding: 13px 28px;
  border-radius: 12px;
}
.btn-store:hover { text-decoration: none; transform: translateY(-1px); box-shadow: 0 8px 22px rgba(0,0,0,.18); }
.btn-store .sub { display: block; font-size: 12px; font-weight: 500; color: var(--ink-soft); }

.hero-card {
  flex: 0 1 320px;
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .25);
  border-radius: 20px;
  padding: 22px;
  font-size: 14.5px;
  line-height: 1.9;
}
.hero-card .book-title { font-weight: 700; font-size: 16px; margin-bottom: 6px; }
.hero-card mark { background: rgba(255, 224, 130, .9); color: #5a3d00; border-radius: 4px; padding: 0 3px; }
.hero-card .tip { margin-top: 12px; font-size: 12.5px; opacity: .9; }

/* ---------- 通用区块 ---------- */
.section { padding: 64px 0; }
.section.alt { background: var(--bg-soft); }
.section h2 { font-size: 28px; text-align: center; margin: 0 0 8px; }
.section .sub-head { text-align: center; color: var(--ink-soft); margin: 0 auto 40px; max-width: 640px; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.feature {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
}
.section.alt .feature { background: #fff; }
.feature .ico {
  width: 44px; height: 44px; border-radius: 12px;
  background: var(--brand-light); color: var(--brand-dark);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 700; margin-bottom: 14px;
}
.feature h3 { margin: 0 0 8px; font-size: 17.5px; }
.feature p { margin: 0; color: var(--ink-soft); font-size: 14.5px; }

/* 方法论编号列表 */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }
.step { text-align: left; padding: 22px; border-radius: var(--radius); background: #fff; border: 1px solid var(--line); }
.step .n {
  display: inline-flex; width: 30px; height: 30px; border-radius: 50%;
  background: var(--brand); color: #fff; align-items: center; justify-content: center;
  font-weight: 700; margin-bottom: 10px;
}
.step h3 { margin: 0 0 6px; font-size: 16.5px; }
.step p { margin: 0; font-size: 14px; color: var(--ink-soft); }

/* 公司信息条 */
.company-strip {
  background: var(--brand-light);
  border: 1px solid #cfe9e0;
  border-radius: var(--radius);
  padding: 26px 28px;
}
.company-strip dl { display: grid; grid-template-columns: max-content 1fr; gap: 8px 22px; margin: 0; }
.company-strip dt { font-weight: 600; color: var(--brand-dark); white-space: nowrap; }
.company-strip dd { margin: 0; color: var(--ink-soft); }

/* ---------- 法律文档 / 支持页排版 ---------- */
.legal { padding: 44px 0 70px; }
.legal .doc-head { border-bottom: 1px solid var(--line); padding-bottom: 20px; margin-bottom: 28px; }
.legal h1 { font-size: 28px; margin: 0 0 10px; }
.legal .meta-line { color: var(--ink-soft); font-size: 14px; margin: 2px 0; }
.notice {
  background: #fff8ec; border: 1px solid #f3ddb0; color: #7a5410;
  border-radius: 10px; padding: 14px 18px; font-size: 14px; margin: 18px 0;
}
.legal h2 { font-size: 21px; margin: 38px 0 12px; padding-top: 10px; text-align: left; }
.legal h3 { font-size: 17px; margin: 24px 0 8px; }
.legal p, .legal li { color: #33414d; }
.legal table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14.5px; display: block; overflow-x: auto; }
.legal th, .legal td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; vertical-align: top; }
.legal th { background: var(--bg-soft); white-space: nowrap; }
.legal strong { color: var(--ink); }
.legal ul, .legal ol { padding-left: 24px; }
.toc { background: var(--bg-soft); border-radius: 12px; padding: 18px 24px; font-size: 14.5px; columns: 2; column-gap: 40px; }
.toc a { color: var(--brand-dark); }
.toc ol { margin: 0; padding-left: 20px; }

/* 支持页 */
.faq { border-bottom: 1px solid var(--line); padding: 20px 0; }
.faq:last-child { border-bottom: none; }
.faq h3 { margin: 0 0 8px; font-size: 17px; }
.faq p { margin: 0; color: var(--ink-soft); }
.contact-card {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px; margin: 26px 0;
}
.contact-card .c {
  border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; background: #fff;
}
.contact-card .c h3 { margin: 0 0 6px; font-size: 16px; }
.contact-card .c p { margin: 0; font-size: 14.5px; color: var(--ink-soft); word-break: break-all; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--footer); color: #b9ccc5; padding: 46px 0 30px; font-size: 14px; }
.site-footer .cols { display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.site-footer h4 { color: #fff; font-size: 15px; margin: 0 0 12px; }
.site-footer a { color: #b9ccc5; }
.site-footer a:hover { color: #fff; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 8px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.12);
  margin-top: 34px; padding-top: 20px;
  font-size: 13px; color: #8fa89f; line-height: 2;
}
.footer-bottom a.beian { margin-left: 14px; }

/* ---------- 响应式 ---------- */
@media (max-width: 720px) {
  .nav { gap: 14px; font-size: 13.5px; }
  .nav .hide-sm { display: none; }
  .hero { padding: 52px 0 60px; }
  .hero h1 { font-size: 30px; }
  .hero p.lead { font-size: 16px; }
  .section { padding: 48px 0; }
  .section h2 { font-size: 23px; }
  .company-strip dl { grid-template-columns: 1fr; gap: 2px; }
  .company-strip dt { margin-top: 10px; }
  .toc { columns: 1; }
}