:root {
  --ink: #1c1917;
  --ink-soft: #3f3a35;
  --muted: #6f675e;
  --paper: #f6f1e8;
  --paper-2: #efe8dc;
  --card: #fffdf8;
  --line: #e4d9c8;
  --cinnabar: #8b3a2f;
  --cinnabar-deep: #6e2c24;
  --seal: #a34438;
  --max: 1080px;
  --header: 4.25rem;
}

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

html {
  scroll-behavior: smooth;
}

html[data-lang="zh"] .i18n-en,
html[data-lang="en"] .i18n-zh {
  display: none !important;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC",
    "Microsoft YaHei", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--cinnabar);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--cinnabar-deep);
}

.skip {
  position: absolute;
  left: 0.75rem;
  top: -4rem;
  z-index: 20;
  padding: 0.5rem 0.8rem;
  background: var(--ink);
  color: var(--paper);
}

.skip:focus {
  top: 0.75rem;
}

.wrap {
  width: min(calc(100% - 2.5rem), var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--header);
  background: var(--paper);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: inherit;
  text-decoration: none;
  min-width: 9rem;
}

.brand img {
  width: 36px;
  height: 36px;
  object-fit: contain;
}

.brand strong {
  display: block;
  font-size: 1.05rem;
  letter-spacing: 0.12em;
  line-height: 1.1;
}

.brand small {
  display: block;
  margin-top: 0.12rem;
  color: var(--muted);
  font-size: 0.62rem;
  letter-spacing: 0.22em;
}

.nav {
  display: flex;
  flex: 1;
  justify-content: flex-end;
  gap: 1.35rem;
}

.nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.92rem;
}

.nav a[aria-current="page"],
.nav a:hover {
  color: var(--ink);
}

.lang {
  display: flex;
  border: 1px solid var(--line);
  background: var(--card);
}

.lang button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 0.28rem 0.55rem;
  font: inherit;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  cursor: pointer;
}

.lang button[aria-pressed="true"] {
  background: var(--ink);
  color: var(--paper);
}

.hero {
  padding: 4.5rem 0 3.5rem;
}

.kicker {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--cinnabar);
  font-size: 0.78rem;
  letter-spacing: 0.22em;
}

.kicker::before {
  content: "";
  width: 1.6rem;
  height: 2px;
  background: var(--cinnabar);
}

.hero h1 {
  margin: 0.9rem 0 0.8rem;
  max-width: 14em;
  font-family: "Songti SC", "Noto Serif SC", "Iowan Old Style", Palatino, serif;
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: 0.04em;
}

.lede {
  max-width: 38rem;
  color: var(--ink-soft);
  font-size: 1.08rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.8rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.7rem;
  padding: 0.45rem 1.1rem;
  border: 1px solid var(--ink);
  color: var(--paper);
  background: var(--ink);
  text-decoration: none;
  font-size: 0.92rem;
}

.btn:hover {
  background: var(--cinnabar-deep);
  border-color: var(--cinnabar-deep);
  color: var(--paper);
}

.btn-ghost {
  color: var(--ink);
  background: transparent;
}

.btn-ghost:hover {
  background: var(--paper-2);
  color: var(--ink);
  border-color: var(--ink);
}

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

.facts article {
  padding: 1.35rem 1.2rem 1.35rem 0;
}

.facts article + article {
  border-left: 1px solid var(--line);
  padding-left: 1.4rem;
}

.facts h2,
.panel h2,
.section-title {
  margin: 0 0 0.35rem;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--muted);
  text-transform: uppercase;
}

.facts p,
.panel p {
  margin: 0;
  font-size: 1.05rem;
}

.section {
  padding: 3.6rem 0;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: end;
  margin-bottom: 1.5rem;
}

.section h2 {
  margin: 0.35rem 0 0;
  font-family: "Songti SC", "Noto Serif SC", Palatino, serif;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 600;
}

.split {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.25rem;
}

.card,
.dossier {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1.4rem 1.45rem 1.5rem;
}

.dossier {
  border-left: 3px solid var(--seal);
}

.card h3,
.product-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.2rem;
}

.muted {
  color: var(--muted);
}

.record {
  width: 100%;
  border-collapse: collapse;
}

.record th,
.record td {
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.record th {
  width: 10.5rem;
  color: var(--muted);
  font-weight: 500;
  padding-right: 1rem;
}

.product-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem 1.2rem;
  align-items: start;
}

.app-icon {
  width: 72px;
  height: 72px;
  border-radius: 18px;
  object-fit: cover;
  background: #e8f0dc;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.contact-grid a[href^="mailto"] {
  font-size: 1.15rem;
}

.prose {
  max-width: 44rem;
}

.prose h1 {
  margin: 0 0 0.6rem;
  font-family: "Songti SC", "Noto Serif SC", Palatino, serif;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
}

.prose h2 {
  margin: 1.8rem 0 0.5rem;
  font-size: 1.15rem;
}

.prose p,
.prose li {
  color: var(--ink-soft);
}

.page-hero {
  padding: 3rem 0 1.5rem;
}

.page-hero h1 {
  margin: 0.55rem 0 0;
  font-family: "Songti SC", "Noto Serif SC", Palatino, serif;
  font-size: clamp(2rem, 5vw, 3.1rem);
}

.site-footer {
  margin-top: 2rem;
  border-top: 1px solid var(--line);
  padding: 2rem 0 2.4rem;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.55;
}

.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem 2rem;
  flex-wrap: wrap;
}

.site-footer p {
  margin: 0;
}

.site-footer .wrap > div p + p {
  margin-top: 0.35rem;
  max-width: 38rem;
}

.site-footer a {
  color: inherit;
}

.placeholder-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 2rem;
}

.placeholder-box {
  width: min(36rem, 100%);
  border: 1px solid var(--line);
  background: var(--card);
  padding: 2rem 1.6rem;
}

@media (max-width: 820px) {
  .site-header {
    height: auto;
  }

  .site-header .wrap {
    flex-wrap: wrap;
    padding: 0.7rem 0 0.85rem;
    gap: 0.7rem 1rem;
  }

  .nav {
    order: 3;
    flex: 1 1 100%;
    justify-content: flex-start;
    gap: 0.9rem;
    overflow-x: auto;
  }

  .facts,
  .split,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .facts article + article {
    border-left: 0;
    border-top: 1px solid var(--line);
    padding-left: 0;
  }

  .record th {
    width: 7.2rem;
  }
}

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

@media print {
  .site-header,
  .hero-actions,
  .lang {
    display: none;
  }

  body {
    background: #fff;
  }
}