:root {
  --bg: #101418;
  --bg-2: #171c22;
  --panel: #1c232c;
  --line: #2a333e;
  --text: #e7ebe4;
  --muted: #9aa4ae;
  --cyan: #2fd3c8;
  --red: #e24b4b;
  --gold: #e6c15a;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "IBM Plex Sans", "Noto Sans JP", "Segoe UI", system-ui, sans-serif;
  line-height: 1.55;
}
html[lang="ja"] body { line-height: 1.75; }

img { max-width: 100%; display: block; }
a { color: inherit; }
button { font: inherit; }

.wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }

header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 64px;
}
.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
}
.brand strong {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  letter-spacing: 0.08em;
  font-size: 15px;
}
.brand span { color: var(--muted); font-size: 12px; }
.nav-links {
  display: flex;
  gap: 22px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: var(--muted);
}
.nav-links a { text-decoration: none; }
.nav-links a:hover { color: var(--text); }
.langs { display: flex; gap: 4px; }
.lang {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  padding: 6px 9px;
  cursor: pointer;
  min-width: 2.4em;
}
.lang[aria-pressed="true"] { color: var(--cyan); border-color: var(--cyan); }
.mail {
  color: var(--cyan);
  text-decoration: none;
}
.mail:hover { text-decoration: underline; }
.contact-box {
  margin-top: 8px;
  padding: 28px 0 0;
  border-top: 1px solid var(--line);
}
.contact-box a {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 18px;
  color: var(--cyan);
  text-decoration: none;
}
.contact-box a:hover { text-decoration: underline; }

.hero {
  position: relative;
  min-height: 78vh;
  display: grid;
  align-items: end;
}
.hero img {
  width: 100%;
  height: 78vh;
  object-fit: cover;
  filter: saturate(0.85) contrast(1.05);
}
.hero-scrim {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(16,20,24,0.15) 20%, rgba(16,20,24,0.92) 100%);
}
.hero-copy {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 0 0 48px;
}
.kicker {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin: 0 0 12px;
}
h1 {
  font-family: Newsreader, "Noto Serif JP", Georgia, serif;
  font-weight: 500;
  font-size: clamp(36px, 6vw, 68px);
  line-height: 1.05;
  margin: 0 0 16px;
  max-width: 14em;
}
.lede {
  max-width: 46ch;
  color: var(--muted);
  font-size: 18px;
  margin: 0 0 28px;
}
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  padding: 11px 16px;
  border: 1px solid var(--line);
  font-size: 14px;
}
.btn.primary { background: var(--cyan); color: #102226; border-color: var(--cyan); }
.btn:hover { filter: brightness(1.08); }

.facts {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.facts div {
  padding: 22px 18px;
  border-right: 1px solid var(--line);
}
.facts div:last-child { border-right: 0; }
.facts b {
  display: block;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 13px;
  color: var(--cyan);
  margin-bottom: 6px;
}
.facts span { color: var(--muted); font-size: 14px; }

section { padding: 72px 0; }
h2 {
  font-family: Newsreader, "Noto Serif JP", Georgia, serif;
  font-weight: 500;
  font-size: clamp(28px, 4vw, 42px);
  margin: 0 0 12px;
}
.section-lead { color: var(--muted); max-width: 62ch; margin: 0 0 36px; }

.split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}
.split.reverse { grid-template-columns: 0.9fr 1.1fr; }
.split.reverse .copy { order: 2; }
.frame {
  background: var(--bg-2);
  border: 1px solid var(--line);
}
.frame img { width: 100%; height: auto; }
.caption {
  padding: 10px 12px;
  font-size: 12px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-family: "IBM Plex Mono", ui-monospace, monospace;
}

.legend {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin: 18px 0 0;
  font-size: 13px;
  color: var(--muted);
}
.swatch {
  display: inline-block;
  width: 12px; height: 12px;
  margin-right: 6px;
  vertical-align: -1px;
}
.swatch.cyan { background: var(--cyan); }
.swatch.red { background: var(--red); }
.swatch.gold { background: var(--gold); }

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.tag {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 10px;
}
.app {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 20px 18px 22px;
  min-height: 180px;
}
.app h3 { margin: 0 0 8px; font-size: 18px; }
.app p { margin: 0; color: var(--muted); font-size: 14px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 0;
  overflow: hidden;
}
.card img { height: 180px; width: 100%; object-fit: cover; }
.card .body { padding: 18px 18px 22px; }
.card h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
}
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.gallery {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 12px;
}
.gallery .stack { display: grid; gap: 12px; }
.gallery img { width: 100%; height: 100%; object-fit: cover; background: #0b0e12; }

.arch {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 8px;
}
.arch article {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 16px;
  min-height: 150px;
}
.arch .mono {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  color: var(--cyan);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.arch h3 { margin: 10px 0 8px; font-size: 16px; }
.arch p { margin: 0; color: var(--muted); font-size: 13px; }
.flow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cyan);
  font-size: 22px;
}

.class-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.class-table th, .class-table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
}
.class-table th { color: var(--muted); font-weight: 500; }
.dot { width: 10px; height: 10px; display: inline-block; }

footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 48px;
  color: var(--muted);
  font-size: 13px;
}
.foot {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.note {
  font-size: 12px;
  color: var(--muted);
  margin-top: 10px;
}

@media (max-width: 900px) {
  .facts, .split, .split.reverse, .grid-2, .grid-3, .grid-4, .gallery, .arch {
    grid-template-columns: 1fr;
  }
  .split.reverse .copy { order: 0; }
  .nav-links { display: none; }
  .hero img, .hero { min-height: 64vh; height: auto; }
  .hero img { height: 64vh; }
  .arch .flow { display: none; }
}