:root {
  color-scheme: light;
  --paper: #f3f5f4;
  --slip: #ffffff;
  --ink: #1f2329;
  --muted: #646a73;
  --line: #dcdfe6;
  --well: #f5f7f6;
  --pine: #0e6b4f;
  --fail: #a33b2b;
  --warn: #8a5a12;
  --ok: #0e6b4f;
  --radius: 8px;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --shadow: 0 1px 2px rgba(31, 35, 41, 0.05);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body { min-height: 100%; }

body {
  margin: 0;
  min-height: 100dvh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
}

a { color: var(--pine); text-underline-offset: 2px; }
button, input, select, textarea { font: inherit; }
::selection { background: var(--pine); color: #ffffff; }

.site-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px 16px;
  min-height: 64px;
  padding: 10px 28px;
  background: var(--slip);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.mark {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: var(--pine);
  color: #ffffff;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.site-nav { display: flex; align-items: center; gap: 4px; }

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
}

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

.frame {
  width: min(1040px, calc(100% - 40px));
  margin: 0 auto;
  padding: 32px 0 24px;
}

.site-foot {
  width: min(1040px, calc(100% - 40px));
  margin: 0 auto;
  padding: 18px 0 32px;
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-size: 13px;
}

.contact {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
}

.contact img {
  width: 72px;
  height: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.contact-copy { display: grid; line-height: 1.35; }
.contact-copy strong { font-weight: 600; }
.contact-copy span { color: var(--muted); font-weight: 400; }

.sheet {
  background: var(--slip);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

:focus-visible { outline: 2px solid var(--pine); outline-offset: 2px; }

@media (max-width: 800px) {
  .site-top { padding: 10px 16px; }
  .frame, .site-foot { width: min(1040px, calc(100% - 28px)); }
  .site-nav a { padding: 8px 8px; }
}

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