:root {
  --bg: #080b11;
  --bg-2: #0d121b;
  --panel: #111824;
  --line: #1e2a3b;
  --text: #e8eef6;
  --muted: #93a1b3;
  --faint: #66748a;
  --accent: #19b6ff;
  --accent-2: #0b84e0;
  --observed: #2aa3ff;
  --inferred: #e5a13a;
  --unknown: #8a94a2;
  --paper: #f5f7fa;
  --ink: #111722;
  --ink-muted: #4c5869;
  --radius: 12px;
  --wrap: 1120px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Noto Sans JP', 'Hiragino Sans', 'Yu Gothic UI', 'Meiryo', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.mono { font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace; }
.colon { color: var(--accent); }

/* ヘッダー */
.band { position: sticky; top: 0; z-index: 10; background: rgba(8, 11, 17, 0.86); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.band .wrap { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 900; font-size: 20px; letter-spacing: 0.04em; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand small { font-weight: 400; font-size: 12px; color: var(--muted); letter-spacing: 0; margin-left: 4px; }
.band nav { margin-left: auto; display: flex; align-items: center; gap: 22px; font-size: 14px; }
.band nav a { color: var(--muted); text-decoration: none; }
.band nav a:hover { color: var(--text); }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 22px; border-radius: 10px; font-weight: 700; text-decoration: none; border: 1px solid transparent; transition: transform 0.12s ease, background 0.12s ease; }
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: linear-gradient(180deg, #22bbff, #0b84e0); color: #fff; box-shadow: 0 8px 30px rgba(25, 182, 255, 0.25); }
.btn.ghost { border-color: #2c3b52; color: var(--text); background: rgba(255, 255, 255, 0.03); }
.band nav .btn { padding: 8px 16px; color: #fff; }

/* ヒーロー */
.hero { position: relative; overflow: hidden; padding: 88px 0 40px; background: radial-gradient(1200px 500px at 70% -10%, rgba(25, 182, 255, 0.18), transparent 60%), radial-gradient(800px 400px at 0% 10%, rgba(11, 132, 224, 0.12), transparent 60%); }
.hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; }
.eyebrow { display: inline-block; font-size: 13px; color: var(--accent); border: 1px solid rgba(25, 182, 255, 0.35); background: rgba(25, 182, 255, 0.08); padding: 4px 12px; border-radius: 999px; margin-bottom: 18px; }
.nb { white-space: nowrap; }
.hero h1 { font-size: clamp(28px, 3.9vw, 48px); line-height: 1.3; margin: 0 0 20px; font-weight: 900; letter-spacing: 0.01em; }
.hero h1 em { font-style: normal; background: linear-gradient(90deg, #5fd0ff, #19b6ff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { font-size: 18px; color: #c6d1de; margin: 0 0 28px; }
.hero .actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero .note { margin-top: 14px; font-size: 13px; color: var(--faint); }
.hero-art { position: relative; }
.hero-art .shot { border-radius: var(--radius); border: 1px solid #22324a; box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(25, 182, 255, 0.08); }
.hero-art .logo { position: absolute; left: -26px; bottom: -26px; width: 104px; border-radius: 22px; box-shadow: 0 10px 40px rgba(25, 182, 255, 0.35); }
.proof { display: flex; flex-wrap: wrap; gap: 10px 28px; margin-top: 56px; color: var(--muted); font-size: 14px; }
.proof span::before { content: '✓'; color: var(--accent); margin-right: 6px; }

/* セクション */
section { padding: 96px 0; }
section.alt { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
section.paper { background: var(--paper); color: var(--ink); }
section.paper .sub { color: var(--ink-muted); }
.sec-head { max-width: 760px; margin-bottom: 48px; }
.sec-head .kicker { font-size: 13px; font-weight: 700; color: var(--accent); letter-spacing: 0.12em; }
.sec-head h2 { font-size: clamp(26px, 3.2vw, 36px); line-height: 1.4; margin: 6px 0 12px; }
.sub { color: var(--muted); }

/* 区分の説明 */
.claims { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.claim-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.claim-card .tag { display: inline-block; font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 999px; border: 1px solid; margin-bottom: 10px; }
.tag.observed { color: #8dd0ff; border-color: rgba(42, 163, 255, 0.55); background: rgba(42, 163, 255, 0.1); }
.tag.inferred { color: #ffd08f; border-color: rgba(229, 161, 58, 0.55); background: rgba(229, 161, 58, 0.1); border-style: dashed; }
.tag.unknown { color: #c3cad3; border-color: rgba(138, 148, 162, 0.6); background: rgba(138, 148, 162, 0.12); border-style: dotted; }
.claim-card h3 { margin: 0 0 6px; font-size: 18px; }
.claim-card p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* 機能 */
.feature { display: grid; grid-template-columns: 1fr 1.25fr; gap: 48px; align-items: center; margin-bottom: 88px; }
.feature:last-child { margin-bottom: 0; }
.feature.flip { grid-template-columns: 1.25fr 1fr; }
.feature.flip .text { order: 2; }
.feature .num { font-family: ui-monospace, Menlo, monospace; color: var(--accent); font-size: 13px; }
.feature h3 { font-size: 24px; line-height: 1.5; margin: 6px 0 12px; }
.feature p { color: #c0cbd8; margin: 0 0 12px; }
.feature ul { margin: 0; padding-left: 1.2em; color: var(--muted); font-size: 15px; }
.feature img { border-radius: var(--radius); border: 1px solid #22324a; box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5); }

/* 用途 */
.uses { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.use { background: #fff; border: 1px solid #dfe5ec; border-radius: var(--radius); padding: 22px; }
.use h3 { margin: 0 0 6px; font-size: 17px; }
.use p { margin: 0 0 10px; color: var(--ink-muted); font-size: 14.5px; }
.use .fn { font-size: 12.5px; color: var(--accent-2); font-weight: 700; }

/* 流れ */
.flow { counter-reset: s; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.flow li { list-style: none; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; position: relative; }
.flow li::before { counter-increment: s; content: counter(s); display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: rgba(25, 182, 255, 0.14); color: var(--accent); font-weight: 900; margin-bottom: 12px; }
.flow h3 { margin: 0 0 6px; font-size: 16.5px; }
.flow p { margin: 0; color: var(--muted); font-size: 14px; }
.outputs { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.outputs span { font-size: 13px; padding: 6px 12px; border-radius: 8px; background: var(--panel); border: 1px solid var(--line); color: #c6d1de; }

/* 安全 */
.safe { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 16px; }
.safe div { border-left: 3px solid var(--accent); padding: 4px 0 4px 18px; }
.safe h3 { margin: 0 0 4px; font-size: 16.5px; }
.safe p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* 動作環境 */
table.spec { width: 100%; border-collapse: collapse; font-size: 15px; }
table.spec th, table.spec td { text-align: left; padding: 14px 16px; border-bottom: 1px solid #dfe5ec; vertical-align: top; }
table.spec th { width: 220px; color: var(--ink-muted); font-weight: 700; }

/* FAQ */
.faq details { border-bottom: 1px solid var(--line); padding: 18px 0; }
.faq summary { cursor: pointer; font-weight: 700; font-size: 16.5px; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::after { content: '+'; color: var(--accent); font-size: 22px; line-height: 1; }
.faq details[open] summary::after { content: '−'; }
.faq p { color: var(--muted); margin: 10px 0 0; }

/* CTA */
.cta-band { text-align: center; background: radial-gradient(700px 300px at 50% 0%, rgba(25, 182, 255, 0.2), transparent 70%), var(--bg-2); }
.cta-band h2 { font-size: clamp(26px, 3.2vw, 36px); margin: 0 0 12px; }
.cta-band .actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px; margin-top: 26px; }

footer { padding: 36px 0 48px; color: var(--faint); font-size: 13px; border-top: 1px solid var(--line); }
footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
footer a { color: var(--muted); text-decoration: none; }

/* ダウンロード */
.dl-hero { padding: 64px 0 32px; }
.dl-hero h1 { font-size: clamp(28px, 4vw, 40px); margin: 0 0 8px; }
.dl-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 18px; margin-top: 28px; }
.dl-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; display: flex; flex-direction: column; gap: 12px; }
.dl-card h2 { margin: 0; font-size: 21px; display: flex; align-items: center; gap: 10px; }
.dl-card .meta { color: var(--muted); font-size: 14px; }
.dl-card .btn { align-self: flex-start; }
.dl-card .alt-link { font-size: 14px; }
.hash { font-size: 11.5px; color: var(--faint); word-break: break-all; }
.steps { counter-reset: st; padding: 0; margin: 0; }
.steps li { list-style: none; position: relative; padding: 0 0 18px 44px; color: #c6d1de; }
.steps li::before { counter-increment: st; content: counter(st); position: absolute; left: 0; top: 2px; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; background: rgba(25, 182, 255, 0.14); color: var(--accent); font-weight: 900; font-size: 14px; }
.steps b { color: var(--text); }
.box { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.box + .box { margin-top: 18px; }
.box h2 { margin: 0 0 16px; font-size: 20px; }
.notice { background: rgba(229, 161, 58, 0.08); border: 1px solid rgba(229, 161, 58, 0.35); color: #f2cf96; padding: 12px 16px; border-radius: 10px; font-size: 14.5px; }
code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 0.9em; background: #0a0f17; border: 1px solid var(--line); padding: 1px 6px; border-radius: 5px; }

@media (max-width: 900px) {
  .band nav a:not(.btn) { display: none; }
  .hero { padding-top: 56px; }
  .hero-grid, .feature, .feature.flip { grid-template-columns: 1fr; gap: 28px; }
  .feature.flip .text { order: 0; }
  .hero-art .logo { width: 72px; left: -8px; bottom: -18px; }
  .claims, .flow { grid-template-columns: 1fr; }
  section { padding: 64px 0; }
  table.spec th { width: 120px; }
  .brand small { display: none; }
}
@media (max-width: 480px) {
  .wrap { padding: 0 16px; }
  .btn { width: 100%; }
}