/* NKS-327 — 官网 Use cases 页共享样式（en/zh 两页共用）。
   Token 与 landing（../Alayo Landing Page.html）、help（../help/help.css）同源：
   Noether Indigo #4257B5 / Ink #1E2230 / Newsreader 衬线；改 token 请三处保持一致。
   --ink-3 取 help 的 AA 修正值（landing 的 #9AA0AE 在 --canvas 上仅 2.3:1，见 NKS-312）。 */
:root {
  --canvas: #EEF0F4;
  --surface: #FBFCFE;
  --card: #FFFFFF;
  --border: #DCE0E8;
  --ink: #1E2230;
  --ink-2: #5A6072;
  --ink-3: #676B76;
  --accent: #4257B5;
  --accent-ink: #35468F;
  --accent-soft: #E9ECF7;
  --serif: "Newsreader", "Iowan Old Style", Georgia, "Songti SC", "STSong", serif;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Segoe UI", sans-serif;
  --radius: 10px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--sans);
  background: var(--canvas);
  color: var(--ink);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--accent-soft); }

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

/* ---------- nav（landing 同形＋help 的 lang-switch） ---------- */
.nav { display: flex; align-items: center; justify-content: space-between; padding: 22px 0; gap: 16px; }
.logo {
  font-family: var(--serif); font-weight: 600; font-size: 22px;
  letter-spacing: -0.01em; color: var(--ink); text-decoration: none;
  display: inline-flex; align-items: center; gap: 9px; flex: none;
}
.logo .dot { color: var(--accent); }
.logo svg { display: block; }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-cta {
  font-size: 13.5px; font-weight: 590; color: var(--accent-ink);
  text-decoration: none; padding: 7px 14px; border: 1px solid var(--border);
  border-radius: 99px; background: var(--card); flex: none;
  transition: border-color .15s ease, box-shadow .15s ease;
}
.nav-cta:hover { border-color: var(--accent); box-shadow: 0 1px 6px rgba(66,87,181,.12); }
/* NKS-355 — 语言切换弱化为文字链接：nav 只保留 CTA 一颗药丸；Help 入口同批新增 */
.nav-link { font-size: 14px; font-weight: 550; color: var(--ink-2); text-decoration: none; flex: none; }
.nav-link:hover { color: var(--accent-ink); }
.lang-switch {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13.5px; font-weight: 550; color: var(--ink-2);
  text-decoration: none; flex: none; transition: color .15s ease;
}
.lang-switch:hover { color: var(--accent-ink); }
.lang-switch svg { display: block; opacity: .8; }
/* NKS-355 — 小屏收起文字链（footer 仍有 Help 入口） */
@media (max-width: 700px) { .nav-link { display: none; } .nav-right { gap: 12px; } }

/* ---------- hero ---------- */
.uc-hero { padding: 56px 0 8px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent-ink); background: var(--accent-soft);
  padding: 6px 14px; border-radius: 99px; margin-bottom: 26px;
}
h1 {
  font-family: var(--serif); font-weight: 500; font-size: clamp(36px, 5.5vw, 54px);
  line-height: 1.12; letter-spacing: -0.015em; max-width: 820px; text-wrap: balance;
}
h1 em { font-style: italic; color: var(--accent-ink); }
.subhead {
  margin-top: 22px; font-size: clamp(17.5px, 2.1vw, 20px); color: var(--ink-2);
  max-width: 700px; text-wrap: pretty;
}

/* ---------- sections ---------- */
section { padding: 72px 0; }
.section-label {
  font-size: 13px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink-3); margin-bottom: 18px;
}
h2 {
  font-family: var(--serif); font-weight: 500; font-size: clamp(28px, 4vw, 38px);
  line-height: 1.2; letter-spacing: -0.01em; margin-bottom: 18px; text-wrap: balance;
}
.lede { font-size: 18.5px; color: var(--ink-2); max-width: 720px; text-wrap: pretty; }
.lede strong { color: var(--ink); font-weight: 600; }

/* ---------- case feature rows（U1/U5/U7/U2 富媒体） ---------- */
.case-list { display: grid; gap: 72px; margin-top: 52px; }
.case-row { display: grid; grid-template-columns: 5fr 6fr; gap: 48px; align-items: center; }
.case-row.flip .case-text { order: 2; }
.case-row.flip .case-media { order: 1; }
.case-kicker {
  font-size: 13px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent-ink); margin-bottom: 10px;
}
.case-text h3 {
  font-family: var(--serif); font-weight: 550; font-size: clamp(24px, 3vw, 30px);
  line-height: 1.22; letter-spacing: -0.008em; margin-bottom: 14px; text-wrap: balance;
}
.case-text p { font-size: 16px; color: var(--ink-2); margin-bottom: 12px; text-wrap: pretty; }
.case-text p strong { color: var(--ink); font-weight: 650; }
.case-link { margin-top: 4px; }
.case-link a { color: var(--accent-ink); font-weight: 590; text-decoration: none; font-size: 15px; }
.case-link a:hover { text-decoration: underline; }
.case-media video {
  width: 100%; display: block; background: var(--card);
  border: 1px solid var(--border); border-radius: 12px;
  box-shadow: 0 18px 44px -20px rgba(30,34,48,.28);
}

/* ---------- more cards（U3/U4/U6/U8 文字卡） ---------- */
.more-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; margin-top: 40px; }
.more-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  padding: 26px 26px 24px;
}
.more-card h3 { font-size: 17px; font-weight: 650; margin-bottom: 8px; letter-spacing: -0.005em; }
.more-card p { font-size: 15.5px; color: var(--ink-2); text-wrap: pretty; }
.more-card p + p { margin-top: 10px; }
.more-card .soon { font-size: 14px; color: var(--ink-3); }
.soon-tag {
  display: inline-block; font-size: 11.5px; font-weight: 650; letter-spacing: .05em;
  text-transform: uppercase; color: var(--accent-ink); background: var(--accent-soft);
  border-radius: 99px; padding: 2px 9px; margin-right: 7px; vertical-align: 1px;
}

/* ---------- DT switch block（温和对标：全页唯一提 DEVONthink 的区块） ---------- */
.dt { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.dt-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; margin-top: 40px; }
.dt-card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 24px 26px; }
.dt-card h3 { font-size: 16.5px; font-weight: 650; margin-bottom: 8px; letter-spacing: -0.005em; }
.dt-card p { font-size: 15px; color: var(--ink-2); text-wrap: pretty; }
.dt-note { margin-top: 28px; font-size: 15.5px; color: var(--ink-2); max-width: 760px; text-wrap: pretty; }
.dt-note em { font-style: italic; }

/* ---------- final CTA ---------- */
.cta-final { text-align: center; padding: 88px 0 96px; }
.cta-final .lede { margin: 0 auto; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 16px; font-weight: 600; text-decoration: none;
  padding: 14px 26px; border-radius: var(--radius);
  transition: transform .12s ease, box-shadow .15s ease, background .15s ease;
}
.btn-primary {
  background: var(--accent); color: #fff; margin-top: 26px;
  box-shadow: 0 2px 10px rgba(66,87,181,.28);
}
.btn-primary:hover { background: var(--accent-ink); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(66,87,181,.32); }
.cta-note { font-size: 13.5px; color: var(--ink-3); margin-top: 14px; }

/* ---------- footer ---------- */
footer { padding: 40px 0 64px; }
.foot-row {
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  border-top: 1px solid var(--border); padding-top: 28px;
}
footer p { font-size: 13.5px; color: var(--ink-3); }
footer a { color: var(--ink-2); text-decoration: none; }
footer a:hover { color: var(--accent-ink); }

@media (max-width: 860px) {
  section { padding: 56px 0; }
  .uc-hero { padding: 36px 0 4px; }
  .case-list { gap: 52px; }
  .case-row { grid-template-columns: 1fr; gap: 20px; }
  .case-row.flip .case-text { order: 1; }
  .case-row.flip .case-media { order: 2; }
  .more-grid, .dt-grid { grid-template-columns: 1fr; }
  .cta-final { padding: 64px 0 72px; }
}