/* ============================================================
   知数记账官网 · 移动端优先设计系统
   ============================================================ */
:root {
  --blue: #2b52ff;
  --blue-deep: #1c3bdf;
  --blue-soft: #eef2ff;
  --ink: #0e1430;
  --ink-2: #2a3352;
  --muted: #69708a;
  --bg: #f5f6fa;
  --card: #ffffff;
  --line: #e7e9f2;
  --green: #12b76a;
  --radius: 22px;
  --shadow: 0 14px 34px -14px rgba(20, 30, 80, .18);
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
img { display: block; max-width: 100%; }

/* 页面容器：移动端全宽，桌面端居中窄栏，保持手机观感 */
.page {
  max-width: 520px;
  margin: 0 auto;
  background: var(--bg);
  min-height: 100vh;
  position: relative;
}
@media (min-width: 720px) {
  body { background: #e9ebf3; }
  .page { box-shadow: 0 0 60px rgba(15, 22, 60, .10); }
}

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: rgba(245, 246, 250, .82);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  border-bottom: 1px solid rgba(231, 233, 242, .7);
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: -.01em;
}
.nav-brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  box-shadow: 0 3px 8px rgba(43, 82, 255, .22);
}
.nav-links { display: flex; gap: 6px; }
.nav-links a {
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  padding: 7px 13px;
  border-radius: 99px;
  transition: background .18s, color .18s;
}
.nav-links a:hover { background: var(--blue-soft); color: var(--blue); }
.nav-links a.active { background: var(--blue); color: #fff; }

/* ---------- 首页 Hero ---------- */
.hero {
  margin: 14px 14px 0;
  padding: 34px 26px 0;
  border-radius: 28px;
  background:
    radial-gradient(120% 90% at 85% -10%, rgba(120, 160, 255, .55), transparent 55%),
    linear-gradient(160deg, #2244ee 0%, #2b52ff 45%, #4a6bff 100%);
  color: #fff;
  overflow: hidden;
  position: relative;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .07) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(180deg, black, transparent 75%);
  pointer-events: none;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .12em;
  padding: 6px 12px;
  border-radius: 99px;
  border: 1px solid rgba(255, 255, 255, .35);
  background: rgba(255, 255, 255, .12);
}
.hero h1 {
  margin: 18px 0 10px;
  font-size: 38px;
  line-height: 1.22;
  letter-spacing: -.02em;
  font-weight: 800;
  position: relative;
}
.hero p {
  margin: 0;
  font-size: 15px;
  color: rgba(255, 255, 255, .85);
  max-width: 300px;
  position: relative;
}
.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
  position: relative;
}
.hero-tags span {
  font-size: 12.5px;
  font-weight: 600;
  padding: 7px 13px;
  border-radius: 99px;
  background: rgba(255, 255, 255, .16);
  border: 1px solid rgba(255, 255, 255, .22);
}
.hero-phone {
  margin: 30px auto 26px;
  width: min(72%, 250px);
  position: relative;
}
.hero-phone img {
  border-radius: 10.5% / 4.6%;
  filter: drop-shadow(0 24px 30px rgba(8, 15, 60, .45));
}

/* ---------- 通用区块 ---------- */
.section { padding: 46px 20px 0; }
.section-label {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--blue);
  margin-bottom: 12px;
}
.section h2 {
  margin: 0 0 8px;
  font-size: 27px;
  line-height: 1.3;
  letter-spacing: -.02em;
  font-weight: 800;
}
.section > p {
  margin: 0 0 22px;
  font-size: 14.5px;
  color: var(--muted);
}

/* 功能卡片 */
.feature-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.feature-card .shot {
  padding: 28px 26px 24px;
  background: linear-gradient(180deg, var(--blue-soft), #f7f9ff);
}
.feature-card.tint-mint .shot { background: linear-gradient(180deg, #e8faf2, #f5fdf9); }
.feature-card.tint-amber .shot { background: linear-gradient(180deg, #fff4e2, #fffcf5); }
.feature-card.tint-violet .shot { background: linear-gradient(180deg, #f1ecff, #faf8ff); }
.feature-card .shot img {
  width: min(62%, 210px);
  margin: 0 auto;
  border-radius: 10.5% / 4.6%;
  filter: drop-shadow(0 16px 22px rgba(15, 25, 70, .20));
}
.feature-card .body { padding: 20px 22px 22px; }
.feature-card .chip {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: 8px;
  padding: 4px 10px;
  margin-bottom: 10px;
}
.feature-card.tint-mint .chip { color: #0a9155; background: #e2f8ee; }
.feature-card.tint-amber .chip { color: #b25f06; background: #ffedd6; }
.feature-card.tint-violet .chip { color: #6a4fe0; background: #efe9ff; }
.feature-card h3 {
  margin: 0 0 6px;
  font-size: 20px;
  letter-spacing: -.01em;
  font-weight: 800;
}
.feature-card p { margin: 0; font-size: 14px; color: var(--muted); }

/* 隐私亮点横幅 */
.privacy-banner {
  margin: 46px 14px 0;
  padding: 30px 26px;
  border-radius: 28px;
  background: linear-gradient(150deg, #10173a, #1d2a66);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.privacy-banner::after {
  content: "✦";
  position: absolute;
  right: 18px;
  top: 6px;
  font-size: 90px;
  color: rgba(255, 255, 255, .07);
}
.privacy-banner .section-label { color: #8fa4ff; }
.privacy-banner h2 { font-size: 25px; margin: 0 0 10px; font-weight: 800; letter-spacing: -.02em; }
.privacy-banner p { margin: 0 0 22px; font-size: 14px; color: rgba(255, 255, 255, .78); }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  font-size: 14.5px;
  font-weight: 700;
  padding: 13px 22px;
  border-radius: 99px;
  background: var(--blue);
  color: #fff;
  box-shadow: 0 10px 22px -8px rgba(43, 82, 255, .55);
  transition: transform .15s, box-shadow .15s;
}
.btn:active { transform: scale(.97); }
.btn.light { background: #fff; color: var(--ink); box-shadow: none; }
.btn.ghost {
  background: transparent;
  color: var(--blue);
  border: 1.5px solid #c9d4ff;
  box-shadow: none;
}

/* 结尾 CTA */
.cta { text-align: center; padding: 52px 24px 8px; }
.cta h2 { font-size: 26px; margin: 0 0 10px; font-weight: 800; letter-spacing: -.02em; }
.cta p { font-size: 14px; color: var(--muted); margin: 0 0 24px; }
.cta .btn-row { display: flex; flex-direction: column; gap: 12px; align-items: center; }

/* ---------- 页脚 ---------- */
.footer {
  margin-top: 54px;
  padding: 28px 22px 40px;
  border-top: 1px solid var(--line);
  text-align: center;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  margin-bottom: 14px;
}
.footer-brand img { width: 26px; height: 26px; border-radius: 7px; }
.footer-links {
  display: flex;
  justify-content: center;
  gap: 22px;
  margin-bottom: 14px;
}
.footer-links a {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
}
.footer-links a:hover { color: var(--blue); }
.footer small { font-size: 12px; color: #a2a8bd; }

/* ---------- 文档页（隐私政策 / 技术支持） ---------- */
.doc-hero { padding: 44px 24px 6px; }
.doc-hero .crumb {
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--blue);
  margin-bottom: 14px;
  display: block;
}
.doc-hero h1 {
  margin: 0 0 12px;
  font-size: 34px;
  letter-spacing: -.02em;
  line-height: 1.25;
  font-weight: 800;
}
.doc-hero .lead { margin: 0; font-size: 15px; color: var(--muted); }
.doc-meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-2);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 99px;
  padding: 7px 14px;
}
.doc-meta i { color: var(--green); font-style: normal; }

.doc-body { padding: 10px 20px 0; }
.doc-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 22px;
  margin: 18px 0;
  box-shadow: var(--shadow);
}
.doc-card.highlight {
  background: linear-gradient(150deg, #10173a, #1d2a66);
  border: none;
  color: #fff;
}
.doc-card.highlight strong { display: block; font-size: 16px; margin-bottom: 6px; }
.doc-card.highlight span { font-size: 14px; color: rgba(255, 255, 255, .82); }

.doc-body h2 {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 34px 0 4px;
  font-size: 20px;
  letter-spacing: -.01em;
  font-weight: 800;
}
.doc-body h2 .no {
  font-size: 12px;
  font-weight: 800;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: 8px;
  padding: 4px 9px;
  letter-spacing: .05em;
  flex-shrink: 0;
  transform: translateY(-2px);
}
.doc-body p { margin: 10px 0; font-size: 14.5px; color: var(--ink-2); }
.doc-body ul { margin: 10px 0; padding-left: 4px; list-style: none; }
.doc-body li {
  position: relative;
  padding-left: 20px;
  margin: 8px 0;
  font-size: 14.5px;
  color: var(--ink-2);
}
.doc-body li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .68em;
  width: 7px;
  height: 7px;
  border-radius: 3px;
  background: var(--blue);
}
.doc-body a { color: var(--blue); font-weight: 600; }

/* ---------- 技术支持页 ---------- */
.support-hero {
  margin: 14px 14px 0;
  padding: 36px 26px 32px;
  border-radius: 28px;
  background: linear-gradient(160deg, #2244ee, #4a6bff);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.support-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .07) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(180deg, black, transparent 80%);
}
.support-hero .crumb { color: #aebcff; font-size: 11.5px; font-weight: 700; letter-spacing: .16em; position: relative; }
.support-hero h1 { margin: 14px 0 10px; font-size: 32px; letter-spacing: -.02em; line-height: 1.25; font-weight: 800; position: relative; }
.support-hero p { margin: 0 0 24px; font-size: 14.5px; color: rgba(255, 255, 255, .85); position: relative; }
.support-hero .btn { position: relative; }
.support-email {
  margin-top: 16px;
  font-size: 13.5px;
  font-weight: 600;
  color: rgba(255, 255, 255, .8);
  position: relative;
}

.faq { padding: 42px 20px 0; }
.faq details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  margin-bottom: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.faq summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 18px 20px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary .plus {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 9px;
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 16px;
  font-weight: 700;
  display: grid;
  place-items: center;
  transition: transform .2s;
}
.faq details[open] summary .plus { transform: rotate(45deg); }
.faq details p {
  margin: 0;
  padding: 0 20px 20px;
  font-size: 14px;
  color: var(--muted);
}

.tips-card {
  margin: 26px 14px 0;
  padding: 22px;
  border-radius: var(--radius);
  background: #fff8ec;
  border: 1px solid #ffe9c4;
}
.tips-card strong { display: block; font-size: 15px; margin-bottom: 6px; color: #8a5300; }
.tips-card p { margin: 0; font-size: 13.5px; color: #7a6435; }