:root {
  color-scheme: light;
  --paper: #f4f1e8;
  --ink: #171713;
  --muted: #65645e;
  --line: #22221e;
  --card: #faf8f1;
  font-family: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
}

a { color: inherit; }

.site-header {
  width: min(1180px, calc(100% - 48px));
  height: 88px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 21px;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: .08em;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  color: var(--paper);
  background: var(--ink);
  font-family: serif;
  font-size: 21px;
}

.header-download {
  padding: 8px 18px;
  border: 1px solid var(--line);
  text-decoration: none;
  font-size: 14px;
}

main, footer {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.hero {
  min-height: 690px;
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 72px;
  align-items: center;
  padding: 72px 0 88px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .18em;
}

h1 {
  margin: 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", SimSun, serif;
  font-size: clamp(48px, 6.3vw, 86px);
  font-weight: 600;
  line-height: 1.18;
  letter-spacing: -.04em;
}

.lead {
  max-width: 590px;
  margin: 32px 0 0;
  color: #3e3e39;
  font-size: 18px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: 38px;
}

.primary-button {
  display: inline-block;
  min-width: 180px;
  padding: 14px 24px;
  color: var(--paper);
  background: var(--ink);
  border: 1px solid var(--ink);
  text-align: center;
  text-decoration: none;
  font-weight: 700;
}

.primary-button.is-disabled { cursor: default; opacity: .55; }
.version { color: var(--muted); font-size: 14px; }

.device {
  max-width: 430px;
  margin-left: auto;
  padding: 14px;
  border: 2px solid var(--line);
  border-radius: 8px;
  background: #dedbd1;
}

.device-screen {
  aspect-ratio: 1264 / 1680;
  padding: 18px;
  border: 1px solid var(--line);
  background: #fff;
}

.app-grid {
  width: 100%;
  height: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 10px;
}

.app-grid div {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 1px solid #111;
}

.app-grid strong { font-size: clamp(21px, 2.4vw, 32px); }
.app-grid small { margin-top: 8px; color: #555; font-size: 13px; }

.principles {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-bottom: 1px solid var(--line);
}

.principles article {
  min-height: 280px;
  padding: 42px 34px;
  border-right: 1px solid var(--line);
}

.principles article:first-child { padding-left: 0; }
.principles article:last-child { border-right: 0; }
.principles span { color: var(--muted); font: 14px ui-monospace, monospace; }
.principles h2 { margin: 58px 0 10px; font-size: 24px; }
.principles p { margin: 0; color: var(--muted); }

.content-section {
  display: grid;
  grid-template-columns: .85fr 1.15fr;
  gap: 90px;
  padding: 96px 0;
  border-bottom: 1px solid var(--line);
}

.content-section h2 {
  max-width: 420px;
  margin: 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", SimSun, serif;
  font-size: clamp(34px, 4vw, 54px);
  font-weight: 600;
  line-height: 1.3;
}

.content-list div {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 20px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
}

.content-list div:last-child { border-bottom: 1px solid var(--line); }
.content-list span { font-weight: 700; }
.content-list p { margin: 0; color: var(--muted); }

footer {
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

.not-found {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 28px;
}

.not-found h1 { font-size: clamp(40px, 7vw, 72px); }

@media (max-width: 760px) {
  .site-header, main, footer { width: min(100% - 28px, 1180px); }
  .site-header { height: 70px; }
  .hero { grid-template-columns: 1fr; gap: 52px; padding: 54px 0 64px; }
  h1 { font-size: clamp(42px, 13vw, 64px); }
  .lead { font-size: 16px; }
  .hero-actions { align-items: flex-start; flex-direction: column; }
  .device { width: min(92%, 430px); margin: 0 auto; }
  .principles { grid-template-columns: 1fr; }
  .principles article, .principles article:first-child { min-height: 0; padding: 30px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .principles article:last-child { border-bottom: 0; }
  .principles h2 { margin-top: 28px; }
  .content-section { grid-template-columns: 1fr; gap: 48px; padding: 68px 0; }
  .content-list div { grid-template-columns: 1fr; gap: 6px; }
  footer { align-items: flex-start; flex-direction: column; justify-content: center; gap: 5px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}