/* ============================================================
   CloudHold 官网 · 设计系统
   令牌来源：storage-app app_tokens.dart（见 docs/官网设计方案.md §6.2）
   ============================================================ */

:root {
  --bg-primary: #FBFAF8;
  --bg-card: #FFFFFF;
  --text-primary: #292824;
  --text-secondary: #74726B;
  --brand: #37352F;
  --brand-fg: #FBFAF8;
  --success: #16A34A;
  --warning: #C58B24;
  --danger: #DC2626;
  --remote: #0284C7;
  --divider: #E5E3DE;
  /* --bg-subtle：主文字色 4.5% 透明度叠于页面底（对齐 App 逻辑） */
  --bg-subtle: rgba(41, 40, 36, 0.045);
  --shadow-soft: 0 1px 2px rgba(41, 40, 36, 0.05), 0 8px 24px rgba(41, 40, 36, 0.06);
  --radius-card: 14px;
  --radius-stage: 22px;
  --wrap: 1160px;
  --prose: 720px;
  --focus: #0284C7;
}

html[data-theme="dark"] {
  --bg-primary: #191918;
  --bg-card: #222220;
  --text-primary: #F0EFEB;
  --text-secondary: #ADABA5;
  --brand: #F0EFEB;
  --brand-fg: #191918;
  --success: #22C55E;
  --warning: #F59E0B;
  --danger: #EF4444;
  --remote: #38BDF8;
  --divider: #383733;
  --bg-subtle: rgba(240, 239, 235, 0.05);
  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.25);
  --focus: #38BDF8;
}

/* ---------- 基础 ---------- */

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  margin: 0;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.25s ease, color 0.25s ease;
}

img { max-width: 100%; height: auto; }

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

h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 0.5em; font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: clamp(34px, 5.4vw, 60px); line-height: 1.14; }
h2 { font-size: clamp(26px, 3.4vw, 38px); }
h3 { font-size: clamp(19px, 2.2vw, 23px); }
p { margin: 0 0 1em; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.prose { max-width: var(--prose); }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--brand); color: var(--brand-fg);
  padding: 10px 18px; z-index: 200; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; border-radius: 4px; }

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; min-width: 44px;
  padding: 10px 22px;
  border-radius: 12px;
  font-size: 16px; font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--brand); color: var(--brand-fg); }
.btn-primary:hover { box-shadow: var(--shadow-soft); }
.btn-outline { border-color: var(--divider); color: var(--text-primary); background: var(--bg-card); }
.btn-outline:hover { border-color: var(--text-secondary); }
.btn-text { color: var(--remote); padding: 10px 8px; }
.btn[disabled], .btn.is-disabled {
  opacity: 0.55; cursor: not-allowed; pointer-events: none;
}

/* ---------- 站点头部 ---------- */

.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--bg-primary) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--divider);
}
.header-inner { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text-primary); font-weight: 700; font-size: 18px; }
.brand:hover { text-decoration: none; }

.site-nav { display: flex; gap: 4px; margin-left: 12px; }
/* 菜单内的下载按钮仅在移动导航展开时显示；桌面端使用右侧入口。 */
.site-nav .btn { display: none; color: var(--brand-fg); }
.site-nav a {
  color: var(--text-secondary); font-size: 15px; padding: 8px 12px; border-radius: 8px;
}
.site-nav a:hover { color: var(--text-primary); background: var(--bg-subtle); text-decoration: none; }
.site-nav a[aria-current="page"] { color: var(--text-primary); font-weight: 600; }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }

.theme-toggle, .nav-toggle {
  width: 44px; height: 44px; border-radius: 10px;
  border: 1px solid var(--divider); background: var(--bg-card);
  color: var(--text-primary); cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
}
.theme-toggle svg, .nav-toggle svg { width: 20px; height: 20px; }
.theme-toggle .icon-sun { display: none; }
html[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
html[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
.nav-toggle { display: none; }

/* ---------- 区块节奏 ---------- */

.section { padding: 96px 0; }
.section + .section { padding-top: 0; }
.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head .eyebrow { margin-bottom: 10px; }
.section-head p { color: var(--text-secondary); font-size: 18px; }

.eyebrow {
  font-size: 14px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--text-secondary);
}

/* ---------- 首屏 ---------- */

.hero { padding: 88px 0 72px; position: relative; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 45fr 55fr; gap: 56px; align-items: center; }
.hero h1 { margin-bottom: 20px; }
.hero .lede { font-size: 19px; color: var(--text-secondary); max-width: 34em; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 30px 0 18px; }
.hero-note { font-size: 14px; color: var(--text-secondary); }
.hero-note strong { color: var(--text-primary); font-weight: 600; }
.hero-platforms { margin-top: 26px; font-size: 13px; color: var(--text-secondary); }
.hero-platforms span { display: inline-block; margin-right: 14px; }

.hero-stage { position: relative; }
.hero-illo {
  position: absolute; right: -24px; bottom: -32px; width: 148px; z-index: 0;
}

/* 摘要条 */
.hero-facts {
  margin-top: 64px;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px;
  background: var(--divider); border: 1px solid var(--divider); border-radius: var(--radius-card);
  overflow: hidden;
}
.hero-facts > div { background: var(--bg-card); padding: 20px 24px; }
.hero-facts strong { display: block; font-size: 18px; margin-bottom: 2px; }
.hero-facts span { font-size: 14px; color: var(--text-secondary); }

/* ---------- 品牌、真实截图与主题插画 ---------- */
.brand-logo { display: block; width: 32px; height: 32px; border-radius: 8px; flex: none; }
.vendor-icon { display: block; width: 24px; height: 24px; object-fit: contain; flex: none; }
.image-frame { margin: 0; min-width: 0; }
.shot-images { display: flex; justify-content: center; align-items: flex-start; gap: 16px; }
.app-shot { display: block; width: 100%; height: auto; min-width: 0; border-radius: 16px; border: 1px solid var(--divider); box-shadow: var(--shadow-soft); background: #FBFAF8; }
.shot-main { flex: 1.2; max-width: 260px; }
.shot-sub { flex: 1; max-width: 220px; }
.shot-guide { margin: 28px auto; max-width: 660px; }
.shot-guide .app-shot { width: min(100%, 300px); }
.image-frame figcaption { margin-top: 12px; font-size: 12px; line-height: 1.6; color: var(--text-secondary); text-align: center; }
.image-frame figcaption .tag { margin: 0 4px 4px 0; }
.illustration { display: block; margin: 24px auto; max-width: 440px; }
.illustration img { display: block; width: 100%; height: auto; }
.illustration .illustration-dark { display: none; }
html[data-theme="dark"] .illustration .illustration-light { display: none; }
html[data-theme="dark"] .illustration .illustration-dark { display: block; }
.illustration.hero-illo { margin: 0; }
.migration-illo { flex: 1; min-width: 0; max-width: 220px; align-self: center; }
.download-illo { max-width: 500px; margin-bottom: 48px; }
.download-illo img { max-height: 320px; object-fit: contain; }
.footer-illo { max-width: 220px; margin: 0 auto 32px; }
.image-guidance { padding: 16px 20px; border-left: 3px solid var(--divider); color: var(--text-secondary); font-size: 15px; }

/* 截图展示台 */
.stage {
  background: var(--bg-card);
  border: 1px solid var(--divider);
  border-radius: var(--radius-stage);
  box-shadow: var(--shadow-soft);
  padding: 28px;
  display: flex; gap: 24px; align-items: flex-end; justify-content: center;
  position: relative; z-index: 1;
}
.stage-note { font-size: 13px; color: var(--text-secondary); text-align: center; margin-top: 12px; }

/* ---------- 存储分组 ---------- */

.storage-groups { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.storage-group {
  background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card);
  padding: 26px; display: flex; flex-direction: column;
}
.storage-group h3 { display: flex; align-items: baseline; gap: 10px; }
.storage-group h3 .proto { font-size: 13px; font-weight: 600; color: var(--text-secondary); }
.vendor-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; margin: 14px 0 18px; }
.vendor {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border: 1px solid var(--divider); border-radius: 10px;
  font-size: 14px; color: var(--text-primary);
}

.storage-group .more { margin-top: auto; font-size: 14px; }

/* ---------- 上手三步 ---------- */

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; counter-reset: step; }
.step {
  background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card);
  padding: 28px;
}
.step::before {
  counter-increment: step; content: counter(step, decimal-leading-zero);
  display: block; font-size: 14px; font-weight: 700; color: var(--text-secondary);
  letter-spacing: 0.1em; margin-bottom: 14px;
}
.step p { color: var(--text-secondary); font-size: 15px; }

/* ---------- 功能场景 ---------- */

.feature-row { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; padding: 56px 0; }
.feature-row:nth-child(even) .feature-copy { order: 2; }
.feature-copy p { color: var(--text-secondary); font-size: 17px; }
.tag {
  display: inline-block; font-size: 12px; font-weight: 700;
  padding: 3px 10px; border-radius: 999px; vertical-align: middle; margin-left: 8px;
  background: var(--bg-subtle); border: 1px solid var(--divider); color: var(--text-secondary);
}
.tag-pro { color: var(--warning); border-color: color-mix(in srgb, var(--warning) 40%, transparent); background: color-mix(in srgb, var(--warning) 8%, transparent); }

/* ---------- 数据去向示意图 ---------- */

.flow-diagram {
  background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card);
  padding: 32px; font-size: 15px;
}
.flow-line {
  display: grid; grid-template-columns: 150px 1fr; gap: 6px 20px; align-items: baseline;
  padding: 12px 0; border-bottom: 1px dashed var(--divider);
}
.flow-line:last-child { border-bottom: 0; }
.flow-line .k { font-weight: 700; }
.flow-line .v { color: var(--text-secondary); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13.5px; }
.flow-notes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 28px; }
.flow-notes > div { font-size: 14px; color: var(--text-secondary); background: var(--bg-subtle); border-radius: 12px; padding: 16px 18px; }
.flow-notes strong { color: var(--text-primary); display: block; margin-bottom: 4px; font-size: 15px; }

/* ---------- 对照表 ---------- */

.table-wrap { overflow-x: auto; border: 1px solid var(--divider); border-radius: var(--radius-card); background: var(--bg-card); }
table.compare { border-collapse: collapse; width: 100%; min-width: 560px; font-size: 15px; }
table.compare th, table.compare td { padding: 14px 20px; text-align: left; border-bottom: 1px solid var(--divider); }
table.compare thead th { background: var(--bg-subtle); font-size: 14px; letter-spacing: 0.04em; }
table.compare tbody tr:last-child td { border-bottom: 0; }
table.compare td:first-child { font-weight: 600; }
table.compare .yes { color: var(--success); font-weight: 600; }
table.compare .no { color: var(--text-secondary); }
table.compare .limit { color: var(--text-secondary); font-size: 13.5px; display: block; }

/* ---------- FAQ ---------- */

.faq-list { max-width: var(--prose); }
details.faq {
  border: 1px solid var(--divider); border-radius: var(--radius-card);
  background: var(--bg-card); margin-bottom: 12px; overflow: hidden;
}
details.faq summary {
  cursor: pointer; padding: 18px 22px; font-weight: 600; font-size: 16px;
  list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after {
  content: "+"; font-size: 20px; font-weight: 400; color: var(--text-secondary); flex: none;
  transition: transform 0.2s ease;
}
details.faq[open] summary::after { transform: rotate(45deg); }
details.faq .faq-body { padding: 0 22px 20px; color: var(--text-secondary); font-size: 15px; }

/* ---------- 底部 CTA ---------- */

.final-cta { text-align: center; padding: 112px 0; }
.final-cta h2 { max-width: 16em; margin-left: auto; margin-right: auto; }
.final-cta .hero-cta { justify-content: center; }

/* ---------- 页脚 ---------- */

.site-footer { border-top: 1px solid var(--divider); padding: 56px 0 40px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 32px; }
.footer-grid h4 { font-size: 14px; margin-bottom: 12px; }
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: var(--text-secondary); font-size: 14px; }
.footer-grid a:hover { color: var(--text-primary); }
.footer-brand p { color: var(--text-secondary); font-size: 14px; max-width: 26em; }
.footer-legal { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--divider); font-size: 13px; color: var(--text-secondary); display: flex; flex-wrap: wrap; gap: 8px 24px; }

/* ---------- 下载页 ---------- */

.platform-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.platform-card {
  background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card);
  padding: 28px; display: flex; flex-direction: column; gap: 14px;
}
.platform-card.is-current { border-color: var(--remote); box-shadow: 0 0 0 1px var(--remote) inset; }
.platform-head { display: flex; align-items: center; gap: 14px; }
.platform-head h3 { margin: 0; }
.status {
  font-size: 12px; font-weight: 700; padding: 3px 10px; border-radius: 999px;
  border: 1px solid var(--divider); background: var(--bg-subtle); color: var(--text-secondary);
}
.status-available { color: var(--success); border-color: color-mix(in srgb, var(--success) 40%, transparent); background: color-mix(in srgb, var(--success) 8%, transparent); }
.status-testing { color: var(--warning); border-color: color-mix(in srgb, var(--warning) 40%, transparent); background: color-mix(in srgb, var(--warning) 8%, transparent); }
.channel {
  border: 1px solid var(--divider); border-radius: 12px; padding: 16px 18px; font-size: 14px;
}
.channel h4 { margin: 0 0 6px; font-size: 15px; }
.channel p { margin: 0 0 8px; color: var(--text-secondary); font-size: 13.5px; }
.meta-list { font-size: 13px; color: var(--text-secondary); margin: 0; padding: 0; list-style: none; }
.meta-list li { display: flex; justify-content: space-between; gap: 16px; padding: 4px 0; border-bottom: 1px dashed var(--divider); }
.meta-list li:last-child { border-bottom: 0; }
.meta-list .k { flex: none; }

/* ---------- 定价页 ---------- */

.plan-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.plan-card {
  background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card);
  padding: 32px; display: flex; flex-direction: column;
}
.plan-card .price-pending {
  font-size: 15px; color: var(--text-secondary);
  border: 1px dashed var(--divider); border-radius: 10px; padding: 14px 16px; margin: 14px 0;
  background: var(--bg-subtle);
}
.plan-card ul { padding-left: 1.2em; color: var(--text-secondary); font-size: 15px; }
.plan-card .btn { margin-top: auto; }
.channel-steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

/* ---------- 帮助中心 ---------- */

.help-groups { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.help-group { background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card); padding: 26px; }
.help-group ul { list-style: none; margin: 0; padding: 0; }
.help-group li { border-bottom: 1px dashed var(--divider); }
.help-group li:last-child { border-bottom: 0; }
.help-group li a { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 4px; color: var(--text-primary); font-size: 15px; }
.help-group li a:hover { color: var(--remote); text-decoration: none; }
.help-group li a .arrow { color: var(--text-secondary); }

.help-layout { display: grid; grid-template-columns: 220px 1fr; gap: 48px; align-items: start; }
.help-toc { position: sticky; top: 96px; font-size: 14px; border-left: 2px solid var(--divider); }
.help-toc a { display: block; padding: 6px 0 6px 16px; color: var(--text-secondary); border-left: 2px solid transparent; margin-left: -2px; }
.help-toc a:hover { color: var(--text-primary); }
.help-body { max-width: var(--prose); }
.help-body h2 { font-size: 24px; margin-top: 48px; }
.help-body h3 { font-size: 18px; margin-top: 32px; }
.help-body ol, .help-body ul { padding-left: 1.4em; }
.help-body li { margin-bottom: 6px; }
.help-meta { font-size: 13px; color: var(--text-secondary); margin-bottom: 32px; }
.callout {
  border: 1px solid var(--divider); border-left: 3px solid var(--warning);
  border-radius: 10px; background: var(--bg-card); padding: 16px 20px; font-size: 14.5px;
  color: var(--text-secondary); margin: 20px 0;
}
.callout strong { color: var(--text-primary); }
.callout.info { border-left-color: var(--remote); }

/* ---------- 隐私页 ---------- */

.policy-summary { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin: 40px 0 56px; }
.policy-summary > div { background: var(--bg-card); border: 1px solid var(--divider); border-radius: var(--radius-card); padding: 22px; font-size: 14.5px; color: var(--text-secondary); }
.policy-summary strong { display: block; color: var(--text-primary); margin-bottom: 6px; font-size: 15px; }
.policy-body h2 { font-size: 24px; margin-top: 48px; }

/* ---------- 入场动效（可减弱） ---------- */

.reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.5s ease, transform 0.5s ease; }
.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, details.faq summary::after { transition: none; }
}

/* ---------- 响应式 ---------- */

@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero { padding: 56px 0 48px; }
  .storage-groups, .steps, .flow-notes, .channel-steps, .policy-summary { grid-template-columns: 1fr; }
  .feature-row { grid-template-columns: 1fr; gap: 32px; padding: 40px 0; }
  .feature-row:nth-child(even) .feature-copy { order: 0; }
  .platform-grid, .plan-grid, .help-groups { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .help-layout { grid-template-columns: 1fr; }
  .help-toc { position: static; border-left: 0; border-bottom: 2px solid var(--divider); padding-bottom: 12px; margin-bottom: 8px; }
  .help-toc a { display: inline-block; padding: 6px 12px 6px 0; border: 0; margin: 0; }
  .section { padding: 64px 0; }

  .site-nav {
    display: none;
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: var(--bg-primary); border-bottom: 1px solid var(--divider);
    padding: 8px 24px 16px; margin-left: 0;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 12px 8px; font-size: 16px; }
  .nav-toggle { display: inline-flex; }
  .header-actions .btn { display: none; }
  .site-nav .btn { display: inline-flex; margin-top: 8px; }
  .stage { align-items: flex-start; }
  .shot-main, .shot-sub { max-width: 240px; }
}

@media (max-width: 560px) {
  body { font-size: 16px; }
  .hero-facts { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .flow-line { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .stage { padding: 14px; gap: 12px; }
  .image-frame figcaption { font-size: 11px; }
  .shot-guide .shot-images { flex-wrap: wrap; }
  .shot-guide .app-shot { max-width: 280px; }
  .hero-illo { right: -12px; width: 110px; }
}