/* Google Chrome 下载引导 — Material 居中三列骨架（第 1 套） */
:root {
  --ink: #202124;
  --muted: #5f6368;
  --line: #dadce0;
  --paper: #ffffff;
  --wash: #f8f9fa;
  --blue: #1A73E8;
  --blue-deep: #1558b0;
  --blue-soft: #e8f0fe;
  --ok: #188038;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(60, 64, 67, 0.12), 0 2px 8px rgba(60, 64, 67, 0.08);
  --max: 1100px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
  font-size: 16px;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { max-width: 100%; vertical-align: middle; }

.wrap {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

/* 顶栏 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.topbar-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 700;
  font-size: 17px;
  text-decoration: none;
}
.brand:hover { text-decoration: none; color: var(--blue); }
.brand-mark { width: 28px; height: 28px; flex: 0 0 28px; }

.menu-btn {
  display: none;
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--ink);
  cursor: pointer;
}
.menu-btn:hover { background: var(--wash); }

.nav { display: flex; gap: 6px; }
.nav a {
  padding: 8px 14px;
  border-radius: 20px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
}
.nav a:hover { background: var(--blue-soft); color: var(--blue); text-decoration: none; }
.nav a.is-on {
  background: var(--blue);
  color: #fff;
}
.nav a.is-on:hover { color: #fff; }

/* Hero */
.hero {
  padding: 56px 0 36px;
  background: linear-gradient(180deg, var(--blue-soft) 0%, var(--paper) 100%);
  border-bottom: 1px solid var(--line);
}
.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin: 0 0 12px;
}
.hero h1 {
  margin: 0 0 16px;
  font-size: 36px;
  line-height: 1.28;
  letter-spacing: -0.02em;
  max-width: 18em;
}
.hero-lead {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 17px;
  max-width: 46em;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 18px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 650;
  font-size: 15px;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn-main {
  background: var(--blue);
  color: #fff;
}
.btn-main:hover { background: var(--blue-deep); color: #fff; }
.btn-ghost {
  background: var(--paper);
  color: var(--blue);
  border-color: var(--line);
}
.btn-ghost:hover { background: var(--blue-soft); }
.hero-note {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
}

/* 区块 */
.block { padding: 56px 0; }
.block + .block { border-top: 1px solid var(--line); }
.block-alt { background: var(--wash); }
.block h2 {
  margin: 0 0 12px;
  font-size: 26px;
  line-height: 1.35;
}
.block-intro {
  margin: 0 0 28px;
  color: var(--muted);
  max-width: 50em;
}
.block p { margin: 0 0 14px; }
.block h3 {
  margin: 28px 0 10px;
  font-size: 18px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
  box-shadow: var(--shadow);
}
.card h3 {
  margin: 10px 0 8px;
  font-size: 17px;
}
.card p { margin: 0 0 10px; color: var(--ink); font-size: 15px; }
.card p:last-child { margin-bottom: 0; }
.card-ico {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--blue-soft);
  border-radius: 10px;
}
.card-ico svg { width: 22px; height: 22px; }

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.dl-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
}
.dl-card .btn { margin-top: auto; justify-content: center; }
.dl-meta {
  font-size: 13px;
  color: var(--muted);
  margin: 0 0 14px;
}

.quote-box {
  background: var(--paper);
  border-left: 4px solid var(--blue);
  padding: 16px 18px;
  margin: 0 0 16px;
  border-radius: 0 10px 10px 0;
}
.quote-box p { margin: 0 0 8px; }
.quote-who { font-size: 13px; color: var(--muted); }

.stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 22px;
}
.stat {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  text-align: center;
}
.stat b {
  display: block;
  font-size: 28px;
  color: var(--blue);
  line-height: 1.2;
}
.stat span { font-size: 13px; color: var(--muted); }

.compare {
  width: 100%;
  border-collapse: collapse;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.compare th, .compare td {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  vertical-align: top;
}
.compare th { background: var(--blue-soft); color: var(--ink); }
.compare tr:last-child td { border-bottom: 0; }

.steps { margin: 0; padding: 0; list-style: none; }
.steps li {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
  margin-bottom: 18px;
}
.step-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
}
.check-list { margin: 0; padding-left: 1.2em; }
.check-list li { margin-bottom: 8px; }

.faq { display: grid; gap: 14px; }
.faq-item {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
}
.faq-item h3 { margin: 0 0 8px; font-size: 16px; }
.faq-item p { margin: 0 0 8px; }
.faq-item p:last-child { margin-bottom: 0; }

.cta-strip {
  background: var(--blue-soft);
  border: 1px solid #c5d7f7;
  border-radius: var(--radius);
  padding: 22px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}
.cta-strip p { margin: 0; }

.site-foot {
  background: #202124;
  color: #e8eaed;
  padding: 36px 0 28px;
  font-size: 13px;
  line-height: 1.7;
}
.site-foot a { color: #8ab4f8; }
.foot-safe {
  background: #303134;
  border-radius: 8px;
  padding: 12px 14px;
  margin-bottom: 16px;
}
.foot-nav { display: flex; gap: 16px; margin-bottom: 12px; flex-wrap: wrap; }
.foot-copy { color: #9aa0a6; margin: 0; }

@media (max-width: 900px) {
  .grid-3, .stat-row, .grid-2 { grid-template-columns: 1fr; }
  .hero h1 { font-size: 28px; }
  .menu-btn { display: inline-flex; }
  .nav {
    display: none;
    position: absolute;
    left: 0; right: 0;
    top: 64px;
    flex-direction: column;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    padding: 10px 20px 16px;
  }
  .nav.is-open { display: flex; }
  .topbar { position: sticky; }
  .topbar-row { position: relative; }
}