/* DuoSay 官网 · 与 App 同源的视觉语言 */
:root {
  --bg: #F4F3EF;
  --card: #FFFFFF;
  --ink: #2B2B2E;
  --ink-soft: #6B6B70;
  --ink-faint: #A0A0A6;
  --purple: #5B5FC7;
  --teal: #0E9384;
  --radius: 24px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
}
a { color: var(--purple); text-decoration: none; }
.wrap { max-width: 1020px; margin: 0 auto; padding: 0 24px; }

/* 顶栏 */
header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(244, 243, 239, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.05);
}
.nav { display: flex; align-items: center; gap: 12px; padding: 14px 0; }
.nav img { width: 34px; height: 34px; border-radius: 9px; }
.nav .brand { font-weight: 700; font-size: 17px; }
.nav .links { margin-left: auto; display: flex; gap: 22px; font-size: 14px; }
.nav .links a { color: var(--ink-soft); }
.nav .links a:hover { color: var(--purple); }

/* Hero */
.hero { text-align: center; padding: 84px 0 64px; }
.hero img.logo { width: 96px; height: 96px; border-radius: 24px;
  box-shadow: 0 12px 40px rgba(91,95,199,0.18); }
.hero h1 { font-size: 42px; font-weight: 800; margin: 26px 0 6px; letter-spacing: 1px; }
.hero .slogan { font-size: 21px; color: var(--purple); font-weight: 600; letter-spacing: 4px; }
.hero .sub { font-size: 16px; color: var(--ink-soft); margin-top: 16px; }
.cta { margin-top: 36px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 14px 30px; border-radius: 999px;
  font-size: 15px; font-weight: 600; transition: transform .15s, box-shadow .15s;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--purple); color: #fff;
  box-shadow: 0 8px 24px rgba(91,95,199,0.35); }
.btn-ghost { background: var(--card); color: var(--ink-soft);
  border: 1px solid rgba(0,0,0,0.08); }
.hero .note { margin-top: 14px; font-size: 12.5px; color: var(--ink-faint); }

/* 双面板演示 */
.demo { margin: 30px auto 0; max-width: 420px; }
.demo .panel {
  background: var(--card); border-radius: var(--radius); padding: 26px 28px;
  box-shadow: 0 6px 28px rgba(0,0,0,0.06); text-align: left; font-size: 17px;
}
.demo .panel.flip { transform: rotate(180deg); color: var(--purple); }
.demo .bar {
  display: flex; align-items: center; justify-content: center; gap: 10px;
  margin: 12px 0; font-size: 13px; color: var(--ink-faint);
}
.demo .bar span { background: var(--card); border-radius: 999px; padding: 6px 16px;
  box-shadow: 0 3px 12px rgba(0,0,0,0.05); }
.demo .panel.me { color: var(--teal); }

/* 章节 */
section { padding: 64px 0; }
section h2 { font-size: 28px; font-weight: 800; text-align: center; margin-bottom: 8px; }
section .lead { text-align: center; color: var(--ink-soft); margin-bottom: 44px; }

/* 功能网格 */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.card {
  background: var(--card); border-radius: var(--radius); padding: 28px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}
.card .icon { font-size: 30px; }
.card h3 { font-size: 17px; margin: 12px 0 6px; }
.card p { font-size: 14px; color: var(--ink-soft); }

/* 定价 */
.plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 20px; max-width: 720px; margin: 0 auto; }
.plan { background: var(--card); border-radius: var(--radius); padding: 32px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.04); }
.plan.featured { border: 2px solid var(--purple);
  box-shadow: 0 12px 36px rgba(91,95,199,0.15); }
.plan .name { font-weight: 700; font-size: 16px; }
.plan .price { font-size: 36px; font-weight: 800; color: var(--purple); margin: 10px 0; }
.plan .price small { font-size: 14px; color: var(--ink-faint); font-weight: 400; }
.plan ul { list-style: none; margin-top: 14px; }
.plan li { font-size: 14px; color: var(--ink-soft); padding: 5px 0 5px 26px; position: relative; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--teal); font-weight: 700; }

/* 隐私承诺 */
.trust { background: var(--card); border-radius: var(--radius); padding: 40px;
  max-width: 760px; margin: 0 auto; box-shadow: 0 4px 20px rgba(0,0,0,0.04); }
.trust ul { list-style: none; }
.trust li { padding: 8px 0 8px 30px; position: relative; font-size: 15px; color: var(--ink-soft); }
.trust li::before { content: "🔒"; position: absolute; left: 0; font-size: 15px; }

/* 页脚 */
footer { border-top: 1px solid rgba(0,0,0,0.06); padding: 36px 0 48px;
  text-align: center; font-size: 13px; color: var(--ink-faint); }
footer .links { display: flex; gap: 20px; justify-content: center; margin-bottom: 14px; }
footer a { color: var(--ink-soft); }

/* 法务长文页 */
.legal { max-width: 760px; margin: 0 auto; padding: 56px 24px 80px; }
.legal h1 { font-size: 26px; margin-bottom: 6px; }
.legal .meta { color: var(--ink-faint); font-size: 13px; margin-bottom: 30px; }
.legal h2 { font-size: 18px; margin: 28px 0 10px; }
.legal p, .legal li { font-size: 14.5px; color: var(--ink-soft); margin-bottom: 8px; }
.legal ul { padding-left: 22px; }

/* 支付结果页 */
.result { min-height: 72vh; display: flex; align-items: center; justify-content: center; }
.result .box { background: var(--card); border-radius: 28px; padding: 56px 48px;
  text-align: center; box-shadow: 0 10px 40px rgba(0,0,0,0.08); max-width: 360px; }
.result .emoji { font-size: 60px; }
.result h1 { font-size: 22px; margin: 18px 0 10px; }
.result p { font-size: 14px; color: var(--ink-soft); }

@media (max-width: 640px) {
  .hero h1 { font-size: 32px; }
  .hero { padding: 56px 0 40px; }
  .nav .links { display: none; }
}