:root {
  --ink: #10151F;
  --surface: #171E2B;
  --rule: #2A3445;
  --text: #E6EAF0;
  --muted: #93A0B4;
  --shu: #D2452F;
  --link: #8DB4FF;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: "BIZ UDPGothic", "Hiragino Sans", "Yu Gothic", Meiryo, system-ui, sans-serif;
}

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

html { color-scheme: dark; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-weight: 400;
  font-size: 1rem;
  line-height: 1.8;
  overflow-wrap: anywhere;
}

p, dl, dd, ol, h1, h2 { margin: 0; }
ol { padding: 0; list-style: none; }

a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 0.25em;
  text-decoration-thickness: 1px;
}
a:hover { text-decoration-thickness: 2px; }
a:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ドメイン名の表示（トップと /about/ の見出し） */
.domain {
  font-family: var(--mono);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.1;
}
.domain-tld { color: var(--muted); }

/* トップ */
.top { min-height: 100vh; min-height: 100svh; }
.top-main {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: 1.5rem;
}
.top .domain {
  font-size: clamp(2.5rem, 9vw, 6rem);
  text-align: center;
  overflow-wrap: normal;
}

/* /about/ */
.about {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100svh;
}
.page {
  width: 100%;
  max-width: 44rem;
  margin: 0 auto;
  padding: clamp(2.5rem, 8vw, 5rem) 1.25rem 2rem;
  flex: 1 0 auto;
}

.eyebrow {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.eyebrow [lang="en"] { font-family: var(--mono); letter-spacing: 0.02em; }

.domain--heading {
  margin-top: 0.75rem;
  font-size: clamp(2.25rem, 8vw, 3.5rem);
  overflow-wrap: anywhere;
}

.lead { margin-top: 1.25rem; font-size: 1.125rem; font-weight: 700; line-height: 1.7; }
.lead--en { margin-top: 0.25rem; font-size: 0.9375rem; font-weight: 400; color: var(--muted); }

/* 記録票 */
.record {
  position: relative;
  margin-top: 3.25rem;
  padding: 2.75rem 1.5rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 4px;
}

.record-list { display: block; }
.row {
  display: grid;
  grid-template-columns: 12.5rem 1fr;
  column-gap: 1.25rem;
  padding: 0.9rem 0;
  border-top: 1px solid var(--rule);
}
.row:first-child { border-top: 0; }
.row dt {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 0.8125rem;
  line-height: 1.9;
  letter-spacing: 0.01em;
  color: var(--muted);
}
.row dd { min-width: 0; }
.row .en {
  display: block;
  margin-top: 0.15rem;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--muted);
}

/* 朱の印鑑 */
.seal {
  position: absolute;
  top: -1.75rem;
  right: 1.25rem;
  width: 7em;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 0.2em solid var(--shu);
  border-radius: 50%;
  color: var(--shu);
  background: transparent;
  font-size: 1rem;
  transform: rotate(-8deg);
  transform-origin: 50% 50%;
  animation: stamp 260ms cubic-bezier(0.2, 0.9, 0.3, 1) 1 both;
}
.seal::before {
  content: "";
  position: absolute;
  inset: 0.28em;
  border: 1px solid var(--shu);
  border-radius: 50%;
}
.seal-text {
  writing-mode: vertical-rl;
  font-family: var(--sans);
  font-weight: 700;
  font-size: 1.05em;
  line-height: 1;
  letter-spacing: 0.04em;
}

@keyframes stamp {
  from { opacity: 0; transform: rotate(-8deg) scale(1.35); }
  to { opacity: 1; transform: rotate(-8deg) scale(1); }
}

/* 所有の経緯 */
.history { margin-top: 3.5rem; }
.section-title {
  font-size: 0.8125rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.section-title [lang="en"] { font-family: var(--mono); letter-spacing: 0.02em; }

.timeline {
  position: relative;
  margin-top: 1.25rem;
  padding-left: 1.75rem;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 0.3125rem;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 1px;
  background: var(--rule);
}
.stage {
  position: relative;
  display: grid;
  grid-template-columns: 13.5rem 1fr;
  column-gap: 1.25rem;
  padding: 0.75rem 0;
}
.stage::before {
  content: "";
  position: absolute;
  left: -1.75rem;
  top: 1.2rem;
  width: 0.625rem;
  height: 0.625rem;
  border: 1px solid var(--muted);
  border-radius: 50%;
  background: var(--ink);
}
.stage--current::before { background: var(--text); border-color: var(--text); }
.stage-date { font-size: 0.9375rem; color: var(--muted); }
.stage-owner { font-weight: 700; }
.stage .en {
  display: block;
  margin-top: 0.1rem;
  font-size: 0.875rem;
  font-weight: 400;
  line-height: 1.6;
  color: var(--muted);
}

/* 注記 */
.notice {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
}
.note { font-size: 0.875rem; line-height: 1.8; color: var(--muted); }
.note--en { margin-top: 0.5rem; }

.foot {
  width: 100%;
  max-width: 44rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 2.5rem;
  font-family: var(--mono);
  font-weight: 500;
  font-size: 0.75rem;
  color: var(--muted);
}

/* スマホ幅 */
@media (max-width: 40rem) {
  .record { padding: 2.5rem 1.125rem 0.5rem; margin-top: 3rem; }
  .row { grid-template-columns: 1fr; row-gap: 0.1rem; padding: 0.8rem 0; }
  .row dt { line-height: 1.6; }
  .seal { font-size: 0.8rem; top: -1.4rem; right: 0.875rem; }
  .stage { grid-template-columns: 1fr; row-gap: 0.15rem; }
  .stage-date { font-size: 0.875rem; }
}

@media (prefers-reduced-motion: reduce) {
  .seal { animation: none; opacity: 1; transform: rotate(-8deg); }
}