/* hiyu.sh — night-sky landing page. Mobile-first; desktop diagrams switch on at 880px. */
:root {
  --bg: #050b1c;
  --bg2: #0a1735;
  --panel: rgba(14, 30, 66, .55);
  --panel-strong: rgba(16, 36, 80, .78);
  --line: rgba(120, 180, 255, .26);
  --line-strong: rgba(120, 200, 255, .55);
  --text: #eef3ff;
  --muted: #a9bbdd;
  --faint: #7f93bb;
  --cyan: #6fdcff;
  --blue: #3d8bff;
  --glow: 0 0 18px rgba(80, 180, 255, .45);
  --serif: "Noto Serif JP", "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif CJK JP", serif;
  --sans: system-ui, -apple-system, "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Noto Sans CJK JP", sans-serif;
  --gutter: clamp(16px, 4vw, 40px);
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: var(--sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { max-width: 100%; }
a { color: inherit; }
p, h1, h2, h3 { overflow-wrap: anywhere; }
body { word-break: auto-phrase; }
h1, h2, h3, .phrase { text-wrap: balance; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.icon { width: 1em; height: 1em; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; flex: none; }

/* ---------- scene (sky + stars + landscape) ---------- */
.scene {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(28px, 5vw, 56px) var(--gutter) clamp(56px, 9vw, 110px);
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(60, 110, 220, .28), transparent 65%),
    linear-gradient(180deg, #030712 0%, #06102a 12%, var(--bg2) 55%, #07112a 100%);
}
.scene::before { /* stars */
  content: "";
  position: absolute; inset: 0; z-index: -2;
  background-image:
    radial-gradient(1px 1px at 12% 18%, #fff 60%, transparent),
    radial-gradient(1px 1px at 28% 8%, #cfe2ff 60%, transparent),
    radial-gradient(1.5px 1.5px at 44% 22%, #fff 60%, transparent),
    radial-gradient(1px 1px at 63% 12%, #dbe8ff 60%, transparent),
    radial-gradient(1px 1px at 78% 26%, #fff 60%, transparent),
    radial-gradient(1.5px 1.5px at 88% 6%, #cfe2ff 60%, transparent),
    radial-gradient(1px 1px at 6% 40%, #fff 60%, transparent),
    radial-gradient(1px 1px at 94% 44%, #fff 60%, transparent);
  background-size: 520px 360px;
  opacity: .55;
}
.scene::after { /* landscape */
  content: "";
  position: absolute; left: 0; right: 0; bottom: 0; z-index: -1;
  height: min(78%, 620px);
  background: url("scene.svg") center bottom / cover no-repeat;
  opacity: .9;
  pointer-events: none;
}
.scene > * { position: relative; }
.inner { max-width: 1180px; margin: 0 auto; }
.arc { /* planetary horizon, top right */
  position: absolute; z-index: -1; pointer-events: none;
  width: 1400px; height: 1400px; right: -760px; top: -560px;
  border-radius: 50%;
  border: 1.5px solid rgba(150, 200, 255, .55);
  box-shadow: 0 0 40px rgba(90, 160, 255, .35), inset 0 0 80px rgba(60, 120, 255, .18);
}

/* ---------- header ---------- */
.site-header {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 20px;
  max-width: 1180px; margin: 0 auto clamp(24px, 4vw, 44px);
}
.brand { display: flex; align-items: center; gap: 14px; text-decoration: none; }
.brand .word { font-family: var(--serif); font-size: 28px; letter-spacing: .16em; line-height: 1; }
.brand .rule { width: 1px; height: 22px; background: var(--line-strong); }
.brand .claim { font-size: 11px; letter-spacing: .32em; color: var(--muted); }
.motto { display: flex; align-items: center; gap: 12px; margin: 0; font-size: 13px; letter-spacing: .14em; color: var(--muted); }
.motto::after { content: ""; width: 42px; height: 1px; background: var(--line-strong); }

/* ---------- headings ---------- */
.headline { text-align: center; margin: 0 auto clamp(26px, 4vw, 44px); max-width: 1100px; }
.headline h1, .headline h2 {
  margin: 0 0 12px;
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(28px, 5.4vw, 60px); line-height: 1.3; letter-spacing: .02em;
  text-shadow: 0 2px 24px rgba(40, 90, 200, .45);
}
.headline p { margin: 0; font-family: var(--serif); font-size: clamp(15px, 2vw, 22px); color: #d9e4fa; letter-spacing: .06em; }
.kicker { text-align: center; margin: 0 0 clamp(20px, 3vw, 32px); font-family: var(--serif); font-size: clamp(15px, 1.8vw, 18px); letter-spacing: .18em; color: #d9e4fa; }
.tagline {
  display: flex; align-items: center; justify-content: center; gap: 20px;
  margin: clamp(32px, 5vw, 56px) auto 0; max-width: 1000px;
  font-family: var(--serif); font-size: clamp(16px, 2.3vw, 26px); letter-spacing: .06em; text-align: center;
}
.tagline::before, .tagline::after { content: ""; flex: 1 1 40px; max-width: 110px; height: 1px; background: var(--line-strong); }
.tagline b { font-weight: 500; letter-spacing: .14em; }

/* side notes on wide screens only */
.side-note { display: none; margin: 0; font-size: 11px; letter-spacing: .3em; line-height: 2; color: var(--muted); }
.side-note::after { content: ""; display: block; width: 36px; height: 1px; margin-top: 10px; background: var(--line-strong); }

/* ---------- glass node ---------- */
.node {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 14px; min-height: 60px;
  border: 1px solid var(--line); border-radius: 14px;
  background: var(--panel);
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .06), 0 10px 30px rgba(0, 8, 30, .35);
}
.node .badge {
  display: grid; place-items: center; flex: none;
  width: 44px; height: 44px; border-radius: 50%;
  border: 1px solid var(--line-strong); color: var(--cyan);
  background: radial-gradient(circle at 35% 30%, rgba(90, 200, 255, .28), rgba(20, 50, 110, .5));
  font-size: 22px;
}
.node .badge.warm { color: #ffd9c2; background: radial-gradient(circle at 35% 30%, rgba(240, 150, 110, .55), rgba(120, 60, 50, .55)); border-color: rgba(255, 190, 160, .5); }
.node strong { display: block; font-size: 16px; font-weight: 600; line-height: 1.3; }
.node > span:last-child { min-width: 0; overflow-wrap: anywhere; word-break: normal; }
.node small { display: block; font-size: 12px; color: var(--muted); letter-spacing: .06em; line-height: 1.4; }

/* ---------- hiyu disc ---------- */
.disc {
  position: relative; z-index: 0; display: grid; place-items: center; align-content: center; gap: 2px;
  width: min(360px, 86%); aspect-ratio: 2.3; margin: 0 auto;
  text-align: center;
}
.disc::before { /* face + rim */
  content: ""; position: absolute; inset: 0; z-index: -1; border-radius: 50%;
  background: radial-gradient(ellipse at 50% 35%, #1d3f86 0%, #0c1f4a 60%, #081636 100%);
  border: 1.5px solid rgba(140, 210, 255, .8);
  box-shadow: 0 14px 0 -2px #0a1b40, 0 14px 0 0 rgba(120, 200, 255, .55), 0 0 60px rgba(60, 150, 255, .5);
}
.disc::after { /* halo ring below the rim */
  content: ""; position: absolute; left: -8%; right: -8%; top: 30%; bottom: -34%; z-index: -2;
  border-radius: 50%;
  border: 2px solid rgba(100, 200, 255, .6);
  background: radial-gradient(ellipse at 50% 50%, rgba(60, 150, 255, .35), transparent 70%);
  box-shadow: 0 0 34px rgba(80, 180, 255, .55);
}
.disc .mark { width: 64px; height: 26px; }
.disc .name { font-family: var(--serif); font-size: clamp(26px, 3.4vw, 40px); letter-spacing: .16em; line-height: 1.1; }
.disc .motif { font-size: 9.5px; letter-spacing: .3em; color: var(--cyan); white-space: nowrap; }

/* ---------- hub map: stacked on mobile, positioned diagram on desktop ---------- */
.hub-map { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; max-width: 1080px; margin: 0 auto; }
.hub-map .disc { grid-column: 1 / -1; order: -1; margin-bottom: 34px; }
.hub-map .wires { display: none; }
.hub-map .node { min-width: 0; }

/* ---------- benefits row ---------- */
.benefits { display: grid; grid-template-columns: 1fr; gap: 22px; max-width: 1180px; margin: clamp(40px, 6vw, 70px) auto 0; padding: 0; list-style: none; }
.benefits li { display: grid; grid-template-columns: auto 1fr; gap: 4px 16px; align-items: center; }
.benefits .icon { font-size: 40px; color: var(--cyan); filter: drop-shadow(var(--glow)); grid-row: span 2; }
.benefits h3 { margin: 0; font-size: 18px; font-weight: 600; line-height: 1.45; }
.benefits p { margin: 0; grid-column: 2; font-size: 14px; color: var(--muted); }

/* ---------- compare (short vs long) ---------- */
.compare { display: grid; grid-template-columns: 1fr; gap: 48px; max-width: 1180px; margin: 0 auto; }
.compare h3 { margin: 0 0 22px; font-family: var(--serif); font-weight: 700; font-size: clamp(22px, 3vw, 34px); line-height: 1.4; }
.compare h3 span { display: block; color: var(--cyan); text-shadow: var(--glow); }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 28px; padding: 0; list-style: none; align-items: center; }
.chips li { padding: 10px 18px; border: 1px solid var(--line); border-radius: 10px; background: var(--panel); font-size: 15px; }
.chips li.lead { border-color: rgba(255, 190, 160, .6); box-shadow: 0 0 18px rgba(255, 170, 130, .25); }
.chips li.more { border: 0; background: none; color: var(--muted); font-size: 13px; padding: 0 6px; }
.points { display: grid; gap: 18px; margin: 0; padding: 0; list-style: none; }
.points li { display: grid; grid-template-columns: 48px 1fr; gap: 2px 16px; align-items: center; }
.points .ring { grid-row: span 2; display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; border: 1px solid var(--line-strong); color: var(--cyan); font-size: 22px; box-shadow: var(--glow); }
.points strong { font-size: 16px; font-weight: 600; line-height: 1.45; }
.points span:not(.ring) { grid-column: 2; font-size: 13.5px; color: var(--muted); }
.compare .hub-map { margin-bottom: 28px; }
.compare .hub-map .disc { width: min(280px, 80%); }

/* ---------- execution layer stack ---------- */
.stack-wrap { display: grid; grid-template-columns: 1fr; gap: 40px; max-width: 1180px; margin: 0 auto; }
.stack { display: grid; gap: 0; }
.tier {
  padding: 18px 16px 20px; text-align: center;
  border: 1px solid var(--line-strong); border-radius: 22px;
  background: linear-gradient(180deg, rgba(24, 56, 120, .6), rgba(10, 26, 62, .7));
  box-shadow: 0 0 30px rgba(50, 140, 255, .2), inset 0 1px 0 rgba(255, 255, 255, .08);
}
.tier h3 { margin: 0; font-size: 19px; font-weight: 700; letter-spacing: .08em; }
.tier .note { margin: 0 0 14px; font-size: 12px; color: var(--muted); letter-spacing: .12em; }
.tier ul { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; margin: 0; padding: 0; list-style: none; }
.tier li {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px;
  min-height: 72px; padding: 10px 6px;
  border: 1px solid var(--line); border-radius: 12px; background: rgba(8, 22, 54, .7);
  font-size: 13.5px; font-weight: 600; line-height: 1.3;
}
.tier li .icon { font-size: 26px; color: #cfe6ff; }
.tier.core { border-radius: 40px; border-width: 1.5px; padding: 26px 16px 22px; background: radial-gradient(ellipse at 50% 0%, rgba(40, 100, 210, .55), rgba(8, 22, 58, .85) 70%); box-shadow: 0 0 50px rgba(60, 160, 255, .45), inset 0 1px 0 rgba(255, 255, 255, .1); }
.tier.core .mark { width: 60px; height: 24px; }
.tier.core h3 { font-family: var(--serif); font-size: 30px; letter-spacing: .16em; font-weight: 500; line-height: 1.2; }
.tier.core .sub { display: block; font-family: var(--serif); font-size: 17px; letter-spacing: .08em; }
.tier.core .motif { margin: 4px 0 16px; font-size: 9.5px; letter-spacing: .3em; color: var(--cyan); }
.tier.core li { flex-direction: row; justify-content: flex-start; gap: 10px; min-height: 52px; padding: 8px 12px; text-align: left; font-weight: 500; }
.tier.core li .icon { font-size: 22px; }
.links { display: flex; justify-content: space-around; height: 34px; padding: 0 12%; }
.links i { position: relative; width: 1.5px; background: linear-gradient(180deg, rgba(110, 200, 255, .2), rgba(110, 210, 255, .9)); box-shadow: var(--glow); }
.links i::after { content: ""; position: absolute; left: 50%; bottom: -3px; width: 6px; height: 6px; margin-left: -3px; border-radius: 50%; background: #bfeaff; box-shadow: 0 0 10px #6fdcff; }
.aside-points { display: grid; gap: 24px; margin: 0; padding: 0; list-style: none; align-content: center; }
.aside-points li { display: grid; grid-template-columns: 52px 1fr; gap: 4px 16px; }
.aside-points .ring { grid-row: span 2; display: grid; place-items: center; width: 52px; height: 52px; border-radius: 50%; border: 1px solid var(--line-strong); color: var(--cyan); font-size: 24px; box-shadow: var(--glow); }
.aside-points strong { font-size: 17px; line-height: 1.45; }
.aside-points span:not(.ring) { grid-column: 2; font-size: 13.5px; color: var(--muted); }

/* ---------- pillars ---------- */
.pillars { display: grid; grid-template-columns: 1fr; gap: 34px; max-width: 1180px; margin: 0 auto; padding: 0; list-style: none; text-align: center; }
.pillars .orb {
  display: grid; place-items: center; width: 120px; height: 120px; margin: 0 auto 16px;
  border-radius: 50%; font-size: 52px; color: #bff0ff;
  border: 1.5px solid rgba(120, 220, 255, .7);
  background: radial-gradient(circle at 50% 40%, rgba(60, 170, 230, .45), rgba(10, 40, 90, .75) 70%);
  box-shadow: 0 0 36px rgba(70, 190, 255, .45), inset 0 0 30px rgba(120, 220, 255, .25);
}
.pillars li:nth-child(2) .orb { color: #cfe0ff; border-color: rgba(120, 170, 255, .7); background: radial-gradient(circle at 50% 40%, rgba(70, 120, 240, .45), rgba(10, 30, 90, .75) 70%); }
.pillars li:nth-child(3) .orb { color: #e1d8ff; border-color: rgba(170, 150, 255, .7); background: radial-gradient(circle at 50% 40%, rgba(120, 100, 240, .45), rgba(30, 24, 90, .75) 70%); box-shadow: 0 0 36px rgba(140, 120, 255, .45); }
.pillars h3 { margin: 0 0 10px; font-family: var(--serif); font-size: 22px; font-weight: 700; letter-spacing: .06em; }
.pillars p { margin: 0 auto; max-width: 17em; font-size: 14.5px; color: #cdd9f1; letter-spacing: .06em; }

/* ---------- roadmap ---------- */
.road { max-width: 1180px; margin: clamp(46px, 7vw, 80px) auto 0; }
.road ol { position: relative; display: grid; gap: 26px; margin: 0; padding: 0 0 0 64px; list-style: none; }
.road ol::before { content: ""; position: absolute; left: 27px; top: 28px; bottom: 28px; width: 2px; background: linear-gradient(180deg, #6fdcff, #3d8bff); box-shadow: var(--glow); }
.road li { position: relative; min-height: 56px; display: grid; align-content: center; }
.road .dot {
  position: absolute; left: -64px; top: 50%; translate: 0 -50%;
  display: grid; place-items: center; width: 56px; height: 56px; border-radius: 50%;
  background: #0a1c44; border: 1.5px solid rgba(130, 215, 255, .85); box-shadow: 0 0 20px rgba(80, 190, 255, .6);
  color: #d6f2ff; font-size: 24px; font-family: var(--serif); font-weight: 700;
}
.road .dot.end { font-size: 17px; }
.road li.step .dot { width: 44px; height: 44px; left: -58px; font-size: 20px; }
.road strong { font-size: 16.5px; font-weight: 600; line-height: 1.45; }
.road span.d { font-size: 13px; color: var(--muted); }
.road .wire { display: none; }

/* ---------- closing ---------- */
.closing {
  padding: clamp(56px, 9vw, 110px) var(--gutter) clamp(52px, 8vw, 96px);
  text-align: center;
  background: radial-gradient(900px 360px at 50% 0%, rgba(60, 130, 255, .22), transparent 70%), #030712;
}
.closing .mark { width: 72px; height: 30px; margin-bottom: 18px; filter: drop-shadow(var(--glow)); }
.closing h2 { margin: 0 0 14px; font-family: var(--serif); font-weight: 700; font-size: clamp(26px, 4.4vw, 46px); line-height: 1.35; letter-spacing: .04em; text-wrap: balance; }
.closing .en { margin: 0 0 20px; color: var(--cyan); font-size: clamp(13px, 1.6vw, 16px); font-weight: 600; letter-spacing: .28em; text-transform: uppercase; text-shadow: var(--glow); }
.closing .en span { display: inline-block; }
.closing .lead { margin: 0; color: var(--muted); font-size: clamp(14px, 1.7vw, 17px); letter-spacing: .06em; }
.closing .lead b { color: var(--text); font-family: var(--serif); font-weight: 500; letter-spacing: .14em; }

/* ---------- footer ---------- */
.site-footer { padding: 28px var(--gutter) max(32px, env(safe-area-inset-bottom)); background: #030712; color: var(--faint); font-size: 13px; }
.site-footer .inner { display: flex; flex-wrap: wrap; gap: 10px 24px; justify-content: space-between; align-items: baseline; }
.site-footer a { color: var(--text); font-weight: 700; text-decoration: none; border-bottom: 1px solid rgba(111, 220, 255, .5); }
.site-footer a:hover, .site-footer a:focus-visible { color: var(--cyan); }
.site-footer .status { flex-basis: 100%; margin: 0; color: var(--faint); }
a:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 4px; }

@media (max-width: 479px) {
  .hub-map .node { gap: 9px; padding: 10px; }
  .hub-map .node .badge { width: 34px; height: 34px; font-size: 17px; }
  .hub-map .node strong { font-size: 14.5px; }
  .hub-map .node small { font-size: 11px; letter-spacing: 0; }
}

/* ---------- tablet ---------- */
@media (min-width: 640px) {
  .benefits { grid-template-columns: 1fr 1fr; gap: 32px 28px; }
  .pillars { grid-template-columns: 1fr 1fr; }
  .tier ul { grid-template-columns: repeat(4, 1fr); }
  .tier.infra ul { grid-template-columns: repeat(5, 1fr); }
}

/* ---------- desktop ---------- */
@media (min-width: 880px) {
  .side-note { display: block; position: absolute; }
  .hub-map {
    position: relative; display: block;
    aspect-ratio: 1000 / 540; width: 100%;
  }
  .hub-map .wires { display: block; position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
  .hub-map .wires path { fill: none; stroke: rgba(130, 205, 255, .8); stroke-width: 1.6; filter: drop-shadow(0 0 4px rgba(90, 190, 255, .9)); }
  .hub-map .wires circle { fill: #c9efff; filter: drop-shadow(0 0 5px #6fdcff); }
  .hub-map .node { position: absolute; left: calc(var(--x) * 1%); top: calc(var(--y) * 1%); translate: -50% -50%; width: var(--w, 25%); }
  .hub-map .disc { position: absolute; left: 50%; top: calc(var(--dy, 64) * 1%); translate: -50% -50%; width: var(--dw, 36%); margin: 0; }
  .compare .hub-map .disc { width: var(--dw, 30%); }
  .compare .hub-map .disc .name { font-size: clamp(20px, 2.2vw, 28px); }
  .compare .hub-map .disc .motif { font-size: 7.5px; letter-spacing: .2em; }
  .compare .hub-map .disc .mark { width: 44px; height: 18px; }
  .compare .hub-map .node { padding: 8px 12px; min-height: 0; }
  .compare .hub-map .node .badge { width: 36px; height: 36px; font-size: 18px; }
  .compare .hub-map .node strong { font-size: 14px; }

  .benefits { grid-template-columns: repeat(4, 1fr); gap: 0; }
  .benefits li { padding: 0 26px; border-left: 1px solid var(--line); align-items: start; }
  .benefits li:first-child { border-left: 0; padding-left: 0; }
  .benefits .icon { font-size: 44px; }

  .compare { grid-template-columns: 1fr 1fr; gap: 0; }
  .compare > div { padding: 0 clamp(20px, 3vw, 46px); }
  .compare > div + div { border-left: 1px solid transparent; border-image: linear-gradient(180deg, transparent, rgba(255, 230, 190, .8) 60%, transparent) 1; }
  .compare .chips { min-height: 220px; align-content: center; justify-content: center; }

  .stack-wrap { grid-template-columns: 1fr 300px; gap: 48px; }
  .tier.core ul { grid-template-columns: repeat(4, 1fr); }
  .aside-points li { padding-bottom: 22px; border-bottom: 1px solid var(--line); }
  .aside-points li:last-child { border-bottom: 0; }

  .pillars { grid-template-columns: repeat(4, 1fr); gap: 0; }
  .pillars li { padding: 0 20px; border-left: 1px solid var(--line); }
  .pillars li:first-child { border-left: 0; }

  .road { position: relative; }
  .road ol { grid-template-columns: 90px 1fr 1fr 1fr 90px; gap: 0 12px; padding: 0; text-align: center; }
  .road ol::before { display: none; }
  .road .wire { display: block; position: absolute; left: 0; right: 0; top: 0; width: 100%; height: 90px; overflow: visible; pointer-events: none; }
  .road .wire path { fill: none; stroke: #7fdcff; stroke-width: 2; filter: drop-shadow(0 0 6px rgba(90, 200, 255, .9)); }
  .road li { min-height: 0; align-content: start; justify-items: center; }
  .road .dot { position: relative; left: auto; top: auto; translate: none; margin: 0 0 12px; }
  .road li.edge .dot { width: 76px; height: 76px; }
  .road li.step .dot { left: auto; margin-top: 0; }
  .road li.step:nth-child(2) .dot, .road li.step:nth-child(4) .dot { margin-top: -6px; }
  .road li.step:nth-child(3) .dot { margin-top: 10px; }
  .road li.edge { padding-top: 0; }
}
@media (min-width: 1200px) {
  .side-note.l { left: -8px; }
  .side-note.r { right: -8px; }
}
@media (max-width: 1199px) { .side-note { display: none !important; } }

@media (prefers-reduced-motion: no-preference) {
  .disc::after { animation: breathe 6s ease-in-out infinite; }
  @keyframes breathe { 50% { box-shadow: 0 0 60px rgba(90, 190, 255, .8); } }
}