:root {
  --color-paper: #F6F5F1;
  --color-paper-soft: #FAF9F6;
  --color-ink: #2B2F33;
  --color-ink-soft: #1B1E22;
  --color-body-gray: #4E545B;
  --color-line-gray: #D9DDE0;
  --color-soft-gray: #A7ADB4;
  --color-observation-turquoise: #0F858A;
  --color-muted-turquoise: #78AEAD;
  --font-philosophy: "Noto Serif JP", "Yu Mincho", "Hiragino Mincho ProN", serif;
  --font-archive: "IBM Plex Mono", "JetBrains Mono", "SFMono-Regular", ui-monospace, monospace;
  --font-interface: "Noto Sans JP", "Hiragino Sans", "Yu Gothic", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-weight: 400;
  color: var(--color-ink-soft);
  background:
    linear-gradient(rgba(27, 30, 34, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27, 30, 34, 0.055) 1px, transparent 1px),
    radial-gradient(circle at 78% 14%, rgba(120, 174, 173, 0.10), transparent 32%),
    linear-gradient(180deg, #FAF9F6 0%, #F6F5F1 52%, #F3F2EE 100%);
  background-size: 96px 96px, 96px 96px, auto, auto;
  font-family: var(--font-interface);
  font-size: 16px;
  line-height: 1.9;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
.site-shell { width: min(100%, 1480px); margin: 0 auto; padding: 48px 56px 32px; }
.site-header {
  display: grid;
  grid-template-columns: minmax(240px, 0.7fr) 1fr auto;
  gap: 32px;
  align-items: start;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-line-gray);
}
.site-brand { display: grid; gap: 2px; }
.site-brand__main { font-family: var(--font-archive); font-size: 14px; letter-spacing: 0.16em; text-transform: uppercase; }
.site-brand__slash { color: var(--color-muted-turquoise); }
.site-brand__sub { font-family: var(--font-philosophy); font-size: 26px; letter-spacing: 0.08em; display: flex; align-items: center; gap: 0.4em; }
.site-brand__mark { width: auto; height: 1.15em; flex: none; }
.site-nav {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 18px 28px;
  font-family: var(--font-archive);
  font-size: 12px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}
.site-nav a { display: inline-grid; gap: 2px; }
.site-nav a span { color: var(--color-body-gray); font-family: var(--font-interface); font-size: 12px; letter-spacing: 0.08em; }
.site-nav a.is-disabled { color: var(--color-soft-gray); cursor: default; }
.logbook-button {
  min-height: 42px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--color-soft-gray);
  background: rgba(250, 249, 246, 0.68);
  color: var(--color-body-gray);
  font-family: var(--font-archive);
  font-size: 11px;
  letter-spacing: 0.14em;
}
.logbook-button::after { content: "◎"; margin-left: 8px; color: var(--color-observation-turquoise); }
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(330px, 0.58fr);
  gap: 64px;
  align-items: center;
  min-height: 720px;
  padding: 88px 0 72px;
}
.hero-copy { position: relative; z-index: 0; }
.cassette { position: absolute; z-index: -1; top: 50%; right: -6%; width: min(640px, 80%); height: auto; transform: translateY(-46%); fill: none; stroke: var(--color-ink); stroke-width: 1; opacity: 0.26; pointer-events: none; }
.cassette * { vector-effect: non-scaling-stroke; }
.inclusion-panel { overflow: hidden; }
.inclusion-photo { position: relative; z-index: 1; margin: 0 -36px -36px; height: 180px; overflow: hidden; border-top: 1px solid rgba(120, 174, 173, 0.48); }
.inclusion-photo img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: center 22%; filter: saturate(0.6); }
.inclusion-photo::after { content: ""; position: absolute; inset: 0; background: linear-gradient(to bottom, rgba(246, 245, 241, 0.55), rgba(246, 245, 241, 0) 45%); pointer-events: none; }
.cassette text { fill: var(--color-ink); stroke: none; font-family: var(--font-archive); font-size: 22px; letter-spacing: 0.18em; }
.cassette .cassette__side { font-size: 40px; letter-spacing: 0; }
.cassette__window { stroke-dasharray: 3 4; }
.cassette__pack { fill: var(--color-observation-turquoise); fill-opacity: 0.1; stroke: var(--color-observation-turquoise); }
.cassette__hub { stroke: var(--color-observation-turquoise); }
.cassette__tape { stroke: var(--color-observation-turquoise); }
.cassette__tape { stroke-width: 1.4; }
.cassette__tape--flow { stroke-width: 2.6; stroke-dasharray: 2 12; }
.eyebrow {
  margin: 0 0 24px;
  color: var(--color-observation-turquoise);
  font-family: var(--font-archive);
  font-size: 12px;
  letter-spacing: 0.22em;
  line-height: 1.65;
  text-transform: uppercase;
}
.hero-title {
  margin: 0;
  color: var(--color-ink);
  font-family: var(--font-philosophy);
  font-size: clamp(54px, 7vw, 108px);
  font-weight: 300;
  line-height: 1.22;
  letter-spacing: 0.06em;
}
.hero-title span { display: block; }
.hero-title .hero-title__rule { width: 1.6em; height: 0; margin: 0.42em 0 0.5em 0.06em; border-top: 1px solid var(--color-observation-turquoise); }
@media (max-width: 1100px) { .cassette { right: 0; width: min(560px, 92%); } }
.hero-lead {
  margin: 32px 0 0;
  max-width: 760px;
  color: var(--color-body-gray);
  font-family: var(--font-philosophy);
  font-size: clamp(20px, 2.2vw, 32px);
  line-height: 2.05;
  letter-spacing: 0.05em;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 40px; }
.button {
  min-height: 50px;
  padding: 0 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-line-gray);
  border-radius: 2px;
  background: rgba(250, 249, 246, 0.70);
  font-size: 14px;
  letter-spacing: 0.08em;
}
.button--primary { border-color: var(--color-ink); background: var(--color-ink); color: var(--color-paper); }
.button--disabled { color: var(--color-soft-gray); cursor: default; }
.inclusion-panel {
  position: relative;
  display: grid;
  gap: 24px;
  align-content: center;
  min-height: 520px;
  padding: 36px;
  border: 1px solid rgba(120, 174, 173, 0.48);
  background:
    linear-gradient(rgba(217, 221, 224, 0.20) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 221, 224, 0.20) 1px, transparent 1px),
    rgba(250, 249, 246, 0.70);
  background-size: 48px 48px, 48px 48px, auto;
}
.inclusion-panel::before {
  content: "";
  position: absolute;
  inset: 18px;
  border: 1px solid rgba(217, 221, 224, 0.88);
  pointer-events: none;
}
.inclusion-note { position: relative; z-index: 1; margin: 0; color: var(--color-body-gray); font-family: var(--font-philosophy); font-size: 15px; line-height: 1.9; letter-spacing: 0.06em; text-align: center; }
.inclusion-mark { position: relative; z-index: 1; width: min(260px, 70%); margin: 0 auto; opacity: 0.98; }
.inclusion-mark svg { width: 100%; height: auto; }
.inclusion-label { position: relative; z-index: 1; margin: 0; padding-top: 22px; border-top: 1px dotted var(--color-soft-gray); font-family: var(--font-archive); }
.inclusion-label dt { margin: 0 0 8px; color: var(--color-body-gray); font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase; }
.inclusion-label dd { margin: 0 0 20px; color: var(--color-ink); font-size: 24px; line-height: 1.35; letter-spacing: 0.05em; }
.inclusion-label dd.is-observed { color: var(--color-observation-turquoise); }
.section { padding: 72px 0; border-top: 1px solid var(--color-line-gray); }
.section-grid { display: grid; grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr); gap: 64px; }
.section-grid > div { container-type: inline-size; min-width: 0; }
.section-title { white-space: nowrap; margin: 0; color: var(--color-ink); font-family: var(--font-philosophy); font-size: min(72px, calc(100cqi / 11)); font-weight: 300; line-height: 1.24; letter-spacing: 0.05em; }
.concept-text { margin: 0; color: var(--color-body-gray); font-family: var(--font-philosophy); font-size: clamp(18px, 1.8vw, 26px); line-height: 2.05; letter-spacing: 0.04em; }
.record-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.record-card { position: relative; min-height: 360px; padding: 28px; border: 1px solid var(--color-line-gray); background: rgba(250, 249, 246, 0.68); }
.record-card::after {
  content: "";
  position: absolute;
  right: 24px;
  bottom: 20px;
  width: 112px;
  height: 24px;
  opacity: 0.36;
  background: repeating-linear-gradient(90deg, rgba(17, 19, 21, 0.82) 0 2px, transparent 2px 5px, rgba(17, 19, 21, 0.82) 5px 7px, transparent 7px 12px);
}
.record-card__index { color: var(--color-observation-turquoise); font-family: var(--font-archive); font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase; }
.record-card h3 { margin: 36px 0 14px; color: var(--color-ink); font-family: var(--font-archive); font-size: clamp(24px, 2.2vw, 34px); line-height: 1.35; letter-spacing: 0.04em; }
.record-card p { margin: 0; color: var(--color-body-gray); font-size: 14px; line-height: 1.95; }
.notice-panel { display: grid; grid-template-columns: 1fr auto; gap: 32px; align-items: center; padding: 36px; border: 1px solid rgba(120, 174, 173, 0.48); background: rgba(250, 249, 246, 0.70); }
.notice-panel p { margin: 0; color: var(--color-body-gray); font-size: 14px; line-height: 1.95; }
.notice-panel strong { display: block; margin-bottom: 6px; color: var(--color-ink); font-family: var(--font-archive); font-size: 18px; letter-spacing: 0.08em; }
.site-footer { display: flex; justify-content: space-between; gap: 32px; padding-top: 28px; border-top: 1px solid var(--color-line-gray); color: var(--color-body-gray); font-family: var(--font-archive); font-size: 13px; letter-spacing: 0.08em; }
.site-footer span { color: var(--color-observation-turquoise); }
@media (max-width: 1100px) {
  .site-header, .hero, .section-grid { grid-template-columns: 1fr; }
  .site-nav { justify-content: flex-start; }
  .record-grid { grid-template-columns: 1fr; }
  .inclusion-panel { min-height: auto; }
}
@media (max-width: 767px) {
  .hero { display: flex; flex-direction: column; gap: 0; }
  .hero-copy { display: contents; }
  .hero-copy .eyebrow { order: 1; }
  .hero-title { order: 2; font-size: min(92px, calc((100vw - 40px) / 7.6)); white-space: nowrap; }
  .hero-lead { font-size: min(26px, calc((100vw - 40px) / 17.6)); white-space: nowrap; }
  .inclusion-panel { order: 5; margin-top: 48px; }
  .cassette { order: 3; position: static; z-index: auto; width: 100%; margin: 36px 0 4px; transform: none; opacity: 0.5; }
  .hero-lead { order: 4; }
  .hero-actions { order: 6; }
  .inclusion-photo { margin: 0 -28px -28px; height: 160px; }
  body { background-size: 84px 84px, 84px 84px, auto, auto; }
  .site-shell { padding: 28px 20px 28px; }
  .site-header { gap: 22px; padding-bottom: 28px; }
  .site-brand__main { font-size: 20px; }
  .site-brand__sub { font-size: 34px; }
  .site-nav { gap: 12px 22px; font-size: 22px; line-height: 1.4; }
  .site-nav a span { display: inline; margin-left: 2px; font-size: 20px; }
  .logbook-button { width: fit-content; min-height: 58px; padding: 0 28px; font-size: 22px; }
  .hero { gap: 0; align-items: stretch; min-height: auto; padding: 72px 0 64px; }
  .hero-title { line-height: 1.18; }
  .button { min-height: 58px; padding: 0 26px; font-size: 16px; }
  .inclusion-panel { padding: 28px; }
  .inclusion-mark { width: min(220px, 72%); }
  .section { padding: 64px 0; }
  .section-grid { gap: 32px; }
  .concept-text { font-size: 22px; }
  .record-card { min-height: 300px; }
  .notice-panel { grid-template-columns: 1fr; padding: 28px; }
  .site-footer { display: grid; gap: 10px; }
}
@media (max-width: 430px) {
  .site-nav { font-size: 20px; gap: 10px 18px; }
  .site-nav a span { font-size: 18px; }
}