/* Google Chrome 下载引导 — Set 1 corporate light theme */
:root {
  --blue: #1a73e8;
  --blue-hover: #1558c0;
  --blue-soft: #e8f0fe;
  --ink: #202124;
  --muted: #5f6368;
  --line: #dadce0;
  --paper: #ffffff;
  --wash: #f6f8fc;
  --wash-deep: #eef2f8;
  --ok: #188038;
  --shadow: 0 8px 24px rgba(26, 115, 232, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: auto;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: system-ui, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.8;
}

img,
svg {
  max-width: 100%;
  vertical-align: middle;
}

a {
  color: var(--blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.wrap {
  width: min(1080px, calc(100% - 40px));
  margin: 0 auto;
}

.wrap-wide {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

/* Four-color official stripe */
.chroma-bar {
  display: flex;
  height: 4px;
}

.chroma-bar span {
  flex: 1;
}

.chroma-bar span:nth-child(1) { background: #4285f4; }
.chroma-bar span:nth-child(2) { background: #ea4335; }
.chroma-bar span:nth-child(3) { background: #fbbc04; }
.chroma-bar span:nth-child(4) { background: #34a853; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  text-decoration: none;
  flex-shrink: 0;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: block;
  width: 36px;
  height: 36px;
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.nav-toggle {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

.nav-btn {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  background: var(--paper);
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.nav-btn svg {
  width: 22px;
  height: 22px;
  stroke: var(--ink);
  fill: none;
  stroke-width: 2;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a {
  position: relative;
  display: inline-block;
  padding: 10px 16px;
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--blue);
  text-decoration: none;
}

.site-nav a.active {
  color: var(--blue);
}

.site-nav a.active::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 4px;
  height: 3px;
  background: var(--blue);
}

/* Hero */
.hero {
  background:
    linear-gradient(180deg, var(--wash) 0%, var(--paper) 100%);
  border-bottom: 1px solid var(--line);
  padding: 72px 0 64px;
}

.hero-inner {
  width: min(860px, calc(100% - 40px));
  margin: 0 auto;
  text-align: center;
}

.hero-kicker {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 12px;
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.hero h1 {
  margin: 0 0 20px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.35;
  font-weight: 700;
}

.hero p {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 17px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 28px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 12px 28px;
  background: var(--blue);
  color: #fff;
  font-weight: 700;
  border-radius: 2px;
  text-decoration: none;
  border: 2px solid var(--blue);
}

.btn:hover {
  background: var(--blue-hover);
  border-color: var(--blue-hover);
  color: #fff;
  text-decoration: none;
}

.btn-ghost {
  background: #fff;
  color: var(--blue);
}

.btn-ghost:hover {
  background: var(--blue-soft);
  color: var(--blue);
  border-color: var(--blue);
}

.btn svg {
  width: 18px;
  height: 18px;
}

/* Sections */
.section {
  padding: 72px 0;
  background: var(--paper);
}

.section-alt {
  background: var(--wash);
}

.section h2 {
  margin: 0 0 16px;
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1.4;
}

.lead {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 17px;
}

.prose p {
  margin: 0 0 16px;
}

.prose h3 {
  margin: 28px 0 12px;
  font-size: 20px;
  line-height: 1.45;
}

.prose .btn {
  margin: 8px 0 0;
}

/* Numbered feature rows */
.feat-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--line);
  background: var(--paper);
}

.feat-row {
  display: grid;
  grid-template-columns: 88px 56px 1fr;
  gap: 20px;
  padding: 28px 28px;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.feat-row:last-child {
  border-bottom: 0;
}

.feat-num {
  font-size: 28px;
  font-weight: 800;
  color: var(--blue);
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.feat-icon {
  width: 48px;
  height: 48px;
  background: var(--blue-soft);
  display: flex;
  align-items: center;
  justify-content: center;
}

.feat-icon svg {
  width: 26px;
  height: 26px;
}

.feat-body h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.feat-body p {
  margin: 0 0 10px;
  color: var(--ink);
}

.feat-body p:last-child {
  margin-bottom: 0;
}

/* Download cards 4-up */
.dl-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin: 28px 0 8px;
}

.dl-card {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 24px 20px 22px;
  display: flex;
  flex-direction: column;
  min-height: 280px;
}

.dl-card.primary {
  border-color: var(--blue);
  box-shadow: var(--shadow);
}

.dl-card h3 {
  margin: 14px 0 8px;
  font-size: 18px;
}

.dl-card p {
  margin: 0 0 16px;
  color: var(--muted);
  flex: 1;
  font-size: 15px;
}

.dl-ico {
  width: 44px;
  height: 44px;
  background: var(--wash);
  display: flex;
  align-items: center;
  justify-content: center;
}

.dl-ico svg {
  width: 26px;
  height: 26px;
}

.dl-card .btn {
  width: 100%;
  min-height: 42px;
  padding: 10px 16px;
}

/* Quotes */
.quote-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.quote {
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 4px solid var(--blue);
  padding: 22px 22px 18px;
}

.quote p {
  margin: 0 0 12px;
}

.quote-name {
  margin: 0;
  font-weight: 700;
}

.quote-role {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* Data proof */
.data-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 8px 0 28px;
}

.data-item {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 22px 20px;
}

.data-item strong {
  display: block;
  font-size: 28px;
  color: var(--blue);
  line-height: 1.2;
  margin-bottom: 8px;
}

.data-item p {
  margin: 0;
  color: var(--muted);
}

/* Table */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  background: var(--paper);
  margin: 20px 0;
}

.compare-table,
.req-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
}

.compare-table th,
.req-table th,
.compare-table td,
.req-table td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.compare-table thead th,
.req-table thead th {
  background: var(--blue);
  color: #fff;
  font-weight: 700;
}

.compare-table tbody tr:nth-child(even),
.req-table tbody tr:nth-child(even) {
  background: var(--wash);
}

.compare-table td:first-child,
.req-table td:first-child {
  font-weight: 600;
}

/* Steps */
.steps {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 12px;
}

.step-col {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 24px;
}

.step-col h3 {
  margin: 0 0 14px;
  font-size: 18px;
}

.step-item {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
  margin-bottom: 16px;
}

.step-item:last-child {
  margin-bottom: 0;
}

.step-n {
  width: 36px;
  height: 36px;
  background: var(--blue);
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-item p {
  margin: 0;
}

/* Changelog */
.change-list {
  border: 1px solid var(--line);
  background: var(--paper);
}

.change-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 16px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
}

.change-item:last-child {
  border-bottom: 0;
}

.change-item time {
  font-weight: 700;
  color: var(--blue);
}

.change-item p {
  margin: 0;
}

/* Primary download zone */
.primary-zone {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 24px;
  align-items: stretch;
}

.primary-copy,
.primary-panel {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 28px;
}

.primary-panel {
  background: var(--blue-soft);
  border-color: #c5d7f7;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.primary-panel .btn {
  margin-top: 12px;
}

.verify-note {
  margin: 14px 0 0;
  color: var(--ok);
  font-weight: 600;
}

/* FAQ — always visible */
.faq-list {
  margin: 8px 0 0;
}

.faq-list dt {
  margin: 0;
  padding: 16px 18px 6px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-bottom: 0;
  font-weight: 700;
}

.faq-list dd {
  margin: 0 0 12px;
  padding: 0 18px 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 0;
  color: var(--ink);
}

/* CTA band */
.cta-band {
  background: var(--blue);
  color: #fff;
  padding: 48px 0;
  text-align: center;
}

.cta-band .cta-title {
  margin: 0 0 12px;
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1.4;
  font-weight: 700;
  color: #fff;
}

.cta-band p {
  color: #e8f0fe;
  max-width: 720px;
  margin: 0 auto 22px;
}

.cta-band .btn {
  background: #fff;
  color: var(--blue);
  border-color: #fff;
}

.cta-band .btn:hover {
  background: var(--wash);
  color: var(--blue-hover);
}

/* Article extras */
.lang-note {
  background: var(--blue-soft);
  border-left: 4px solid var(--blue);
  padding: 16px 18px;
  margin: 0 0 24px;
}

/* Footer */
.site-footer {
  background: var(--wash-deep);
  border-top: 1px solid var(--line);
  padding: 36px 0 28px;
}

.verify-bar {
  background: #fff;
  border: 1px solid #c8e6c9;
  color: var(--ok);
  padding: 12px 16px;
  font-weight: 700;
  margin-bottom: 20px;
}

.site-footer p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 14px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 12px 0 16px;
}

.footer-links a {
  font-weight: 600;
}

/* Responsive */
@media (max-width: 960px) {
  .dl-grid,
  .data-grid {
    grid-template-columns: 1fr 1fr;
  }

  .primary-zone,
  .steps,
  .quote-grid {
    grid-template-columns: 1fr;
  }

  .change-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (max-width: 760px) {
  .nav-btn {
    display: flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 76px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: 8px 16px 16px;
  }

  .nav-toggle:checked ~ .site-nav {
    display: flex;
  }

  .site-nav a.active::after {
    display: none;
  }

  .site-nav a.active {
    background: var(--blue-soft);
  }

  .feat-row {
    grid-template-columns: 56px 1fr;
  }

  .feat-icon {
    display: none;
  }

  .dl-grid,
  .data-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 48px 0 40px;
  }

  .section {
    padding: 48px 0;
  }
}