*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text-body); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', Meiryo, sans-serif; font-size: 16px; line-height: 1.7; transition: background 0.25s, color 0.25s; -webkit-font-smoothing: antialiased; }

:root, [data-theme="dark"] {
  --gold: #C9A84C; --gold-l: #ddb95a;
  --bg: #08090d; --bg2: #0d0f15; --bg3: #12141c;
  --nav-bg: rgba(8,9,13,0.96);
  --line: rgba(255,255,255,0.07); --line2: rgba(255,255,255,0.12);
  --heading: #ffffff; --heading2: #e4eaf4;
  --text-body: rgba(210,220,234,0.78); --text-dim: rgba(200,208,222,0.72); --text-faint: rgba(200,208,222,0.60);
  --tag-border: rgba(255,255,255,0.1);
  --green: #4ade80; --red: #f87171;
  --mono: ui-monospace, 'Cascadia Mono', Consolas, monospace;
  --col: 860px; --pad: 60px; --site-max: 1040px;
  --side: max(var(--pad), calc((100vw - var(--site-max)) / 2));
}
[data-theme="light"] {
  --bg: #f4f2ee; --bg2: #eceae5; --bg3: #e4e2de;
  --nav-bg: rgba(244,242,238,0.96);
  --line: rgba(0,0,0,0.08); --line2: rgba(0,0,0,0.14);
  --heading: #0a0909; --heading2: #1c1a17;
  --text-body: rgba(18,16,12,0.72); --text-dim: rgba(18,16,12,0.62); --text-faint: rgba(18,16,12,0.60);
  --tag-border: rgba(0,0,0,0.12);
  --green: #16a34a; --red: #dc2626;
}

.top-stripe { height: 3px; background: var(--gold); }
.site-nav { padding: 0 var(--side); height: 60px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); position: sticky; top: 0; background: var(--nav-bg); backdrop-filter: none; z-index: 200; }
.nav-left { display: flex; align-items: center; gap: 32px; }
.nav-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.nav-logo-box { width: 26px; height: 26px; border: 1px solid var(--gold); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.nav-logo-box span { font-size: 10px; font-weight: 700; color: var(--gold); font-family: var(--mono); }
.nav-wordmark { font-size: 14px; font-weight: 700; letter-spacing: 0.12em; color: var(--heading); }
.nav-back { font-size: 12px; color: var(--text-faint); text-decoration: none; letter-spacing: 0.08em; transition: color 0.2s; }
.nav-back::before { content: '← '; }
.nav-back:hover { color: var(--heading); }
.theme-toggle { display: flex; align-items: center; gap: 8px; background: none; border: 1px solid var(--line); cursor: pointer; padding: 7px 14px; font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; color: var(--text-faint); transition: color 0.2s, border-color 0.2s; }
.theme-toggle:hover { color: var(--heading); border-color: var(--text-faint); }
.theme-toggle-icon { width: 14px; height: 14px; position: relative; flex-shrink: 0; }
.icon-sun, .icon-moon { position: absolute; inset: 0; transition: opacity 0.2s; }
[data-theme="dark"] .icon-sun { opacity: 1; } [data-theme="dark"] .icon-moon { opacity: 0; }
[data-theme="light"] .icon-sun { opacity: 0; } [data-theme="light"] .icon-moon { opacity: 1; }

.toc-bar { position: sticky; top: 60px; z-index: 100; background: var(--nav-bg); backdrop-filter: none; border-bottom: 1px solid var(--line); }
.toc-bar::before, .toc-bar::after { content: ''; position: absolute; top: 0; bottom: 0; width: 56px; z-index: 2; pointer-events: none; opacity: 0; transition: opacity 0.25s; }
.toc-bar::before { left: 0; background: var(--nav-bg); }
.toc-bar::after { right: 0; background: var(--nav-bg); }
.toc-bar.show-left::before { opacity: 1; }
.toc-bar.show-right::after { opacity: 1; }
.toc-bar-inner { display: flex; padding: 0 var(--side); white-space: nowrap; overflow-x: auto; scrollbar-width: none; }
.toc-bar-inner::-webkit-scrollbar { display: none; }
.toc-arrow { position: absolute; top: 50%; transform: translateY(-50%); z-index: 3; width: 24px; height: 24px; display: flex; align-items: center; justify-content: center; background: var(--bg2); border: 1px solid var(--line2); color: var(--text-faint); cursor: pointer; opacity: 0; pointer-events: none; transition: opacity 0.25s, color 0.15s, border-color 0.15s; }
.toc-arrow:hover { color: var(--heading); border-color: var(--gold); }
.toc-arrow.visible { opacity: 1; pointer-events: auto; }
.toc-arrow-left { left: 10px; }
.toc-arrow-right { right: 10px; }
.toc-btn { display: flex; align-items: center; gap: 8px; padding: 14px 20px; font-size: 12px; color: var(--text-faint); letter-spacing: 0.08em; text-decoration: none; border-bottom: 2px solid transparent; transition: color 0.2s, border-color 0.2s; }
.toc-btn:hover { color: var(--text-dim); }
.toc-btn.active { color: var(--heading); border-bottom-color: var(--gold); }
.toc-btn-num { font-size: 10px; font-family: var(--mono); color: var(--gold); opacity: 0.6; }
.toc-btn.active .toc-btn-num { opacity: 1; }

.hero { padding: 72px var(--side) 68px; border-bottom: 1px solid var(--line); }
.hero-platform { display: inline-block; font-size: 10px; letter-spacing: 0.2em; color: var(--gold); border: 1px solid rgba(201,168,76,0.3); padding: 4px 10px; margin-bottom: 20px; font-family: var(--mono); }
.hero-title { font-size: 56px; font-weight: 900; line-height: 1.1; color: var(--heading); letter-spacing: -0.02em; margin-bottom: 22px; }
.hero-title .hero-sub-name { font-size: 24px; font-weight: 400; color: var(--text-faint); }
.hero-subtitle { font-size: 17px; color: var(--text-body); line-height: 1.85; letter-spacing: 0.04em; max-width: 560px; margin-bottom: 28px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 40px; }
.hero-tag { font-size: 11px; padding: 5px 12px; border: 1px solid var(--tag-border); color: var(--text-dim); letter-spacing: 0.04em; }
.hero-cta { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.btn-dl { display: inline-flex; align-items: center; gap: 10px; background: var(--gold); color: var(--bg); text-decoration: none; padding: 15px 36px; font-size: 14px; font-weight: 700; letter-spacing: 0.08em; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', Meiryo, sans-serif; transition: filter 0.2s; }
.btn-dl:hover { filter: brightness(1.08); }
.hero-version { font-size: 14px; color: var(--text-faint); font-family: var(--mono); letter-spacing: 0.06em; }

.sections-wrap { padding: 0 var(--side); }
.section { max-width: var(--col); padding: 72px 0; border-bottom: 1px solid var(--line); }
.section:last-child { border-bottom: none; }
.section-eyebrow { display: flex; align-items: center; gap: 16px; margin-bottom: 28px; }
.section-num { width: 28px; height: 28px; background: var(--gold); display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; color: #fff; font-family: var(--mono); flex-shrink: 0; }
.section-label { font-size: 11px; letter-spacing: 0.25em; color: var(--text-faint); font-family: var(--mono); }
.section-title { font-size: 28px; font-weight: 700; color: var(--heading); letter-spacing: -0.01em; margin-bottom: 28px; }
.section-h3 { font-size: 14px; font-weight: 600; color: var(--heading2); margin: 32px 0 14px; display: flex; align-items: center; gap: 10px; }
.section-h3::before { content: ''; display: inline-block; width: 3px; height: 13px; background: var(--gold); flex-shrink: 0; }
p { color: var(--text-body); margin-bottom: 14px; line-height: 1.9; letter-spacing: 0.025em; }
code { font-family: var(--mono); font-size: 12px; background: var(--bg2); padding: 2px 6px; color: var(--gold); border: 1px solid var(--line2); }

/* Feature grid */
.feat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line); margin-top: 8px; }
.feat-card { background: var(--bg); padding: 24px 28px; }
.feat-card:hover { background: var(--bg2); }
.feat-icon { font-size: 18px; margin-bottom: 10px; }
.feat-title { font-size: 14px; font-weight: 600; color: var(--heading2); margin-bottom: 8px; }
.feat-desc { font-size: 14px; color: var(--text-body); line-height: 1.75; letter-spacing: 0.02em; }

/* Spec table */
.dtable { width: 100%; border-collapse: collapse; margin-top: 8px; }
.dtable th { font-family: var(--mono); font-size: 10px; color: var(--text-faint); letter-spacing: 0.1em; padding: 8px 0; border-bottom: 1px solid var(--line); text-align: left; text-transform: uppercase; }
.dtable td { padding: 12px 0; font-size: 14px; border-bottom: 1px solid var(--line); vertical-align: top; letter-spacing: 0.02em; color: var(--text-body); }
.dtable td:first-child { font-size: 13px; color: var(--text-dim); width: 170px; padding-right: 20px; }
.dtable tr:last-child td { border-bottom: none; }

/* Preset tags */
.preset-list { display: flex; gap: 7px; flex-wrap: wrap; margin-top: 8px; }
.preset-tag { background: var(--bg2); border: 1px solid var(--line2); padding: 5px 14px; font-family: var(--mono); font-size: 12px; color: var(--text-dim); transition: all 0.2s; }
.preset-tag:hover { color: var(--heading); border-color: var(--gold); }

/* Steps */
.steps { list-style: none; margin-top: 8px; }
.steps li { display: grid; grid-template-columns: 36px 1fr; gap: 20px; padding: 20px 0; border-bottom: 1px solid var(--line); align-items: start; }
.steps li:last-child { border-bottom: none; }
.snum { width: 32px; height: 32px; background: var(--gold); display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 700; color: var(--bg); font-family: var(--mono); flex-shrink: 0; }
.sbody { padding-top: 4px; }
.stitle { font-size: 14px; font-weight: 600; color: var(--heading2); margin-bottom: 6px; }
.sdesc { font-size: 14px; color: var(--text-body); line-height: 1.85; letter-spacing: 0.025em; }

/* Alerts */
.alert { display: flex; gap: 12px; padding: 14px 18px; margin-bottom: 10px; font-size: 14px; line-height: 1.85; }
.a-warn { background: rgba(234,179,8,0.05); border: 1px solid rgba(234,179,8,0.18); color: var(--text-body); }
.a-info { background: rgba(255,255,255,0.02); border: 1px solid var(--line2); color: var(--text-body); }
.a-privacy { background: rgba(74,222,128,0.05); border: 1px solid rgba(74,222,128,0.2); color: var(--text-body); }

/* Terms list */
.terms-list { list-style: none; margin-top: 8px; }
.terms-list li { display: flex; gap: 8px; font-size: 14px; color: var(--text-body); padding: 8px 0; border-bottom: 1px solid var(--line); line-height: 1.85; }
.terms-list li:last-child { border-bottom: none; }
.terms-list li::before { content: '▸'; color: var(--gold); flex-shrink: 0; font-size: 11px; margin-top: 3px; }
.section a { color: var(--gold); text-underline-offset: 3px; }

footer { padding: 24px var(--side); border-top: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-copy { font-size: 11px; color: var(--text-faint); font-family: var(--mono); }
.footer-link { font-size: 11px; color: var(--text-faint); font-family: var(--mono); text-decoration: none; transition: color 0.2s; }
.footer-link:hover { color: var(--gold); }

@media (max-width: 720px) { :root { --pad: 20px; } .hero-title { font-size: 38px; } .feat-grid { grid-template-columns: 1fr; } .dtable td:first-child { width: 120px; } }
[data-theme="light"] { --gold: #88671c; --gold-l: #765913; }
.btn-dl { color: #fff; background: #88671c; }
.btn-dl:hover { background: #765913; color: #fff; }
[data-theme="dark"] .btn-dl { background: #C9A84C; color: #08090d; }
[data-theme="dark"] .btn-dl:hover { background: #ddb95a; }
button, a { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible { outline: 3px solid var(--gold); outline-offset: 4px; }
.theme-toggle { min-height: 44px; min-width: 66px; }
.nav-back { font-size: 13px; }
.skip-link { position: fixed; top: -100px; left: 16px; padding: 12px 20px; background: var(--bg); color: var(--heading); z-index: 999; }
.skip-link:focus { top: 8px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.mode-intro { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line2); margin-top: 40px; max-width: 860px; }
.mode-intro > div { padding: 24px 28px; }
.mode-intro > div + div { border-left: 1px solid var(--line2); }
.mode-label { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; color: var(--gold); }
.mode-intro h2 { font-size: 20px; color: var(--heading); font-weight: 600; margin: 8px 0; }
.mode-intro p { font-size: 14px; }
.hero-note { font-size: 13px; color: var(--text-dim); line-height: 1.85; max-width: 860px; margin-top: 16px; }
.feat-icon { font-family: var(--mono); font-size: 15px; color: var(--gold); }
.dtable { width: 100%; border-collapse: collapse; }
.dtable tbody th { width: 170px; padding: 12px 20px 12px 0; font-family: inherit; font-size: 14px; font-weight: 500; color: var(--text-dim); text-align: left; vertical-align: top; letter-spacing: 0; border-bottom: 1px solid var(--line); }
.dtable tr:last-child th { border-bottom: 0; }
.closing-cta { border-top: 1px solid var(--line); padding: 40px 0 48px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.closing-cta p { font-size: 18px; color: var(--heading); }
.footer-links { display: flex; flex-wrap: wrap; gap: 20px; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { transition: none !important; } }
@media (max-width: 720px) { .nav-left { gap: 16px; } .nav-wordmark { font-size: 12px; letter-spacing: .08em; } .nav-logo { gap: 8px; } .theme-toggle { padding: 7px 10px; } .toc-btn { padding: 14px 16px; } .mode-intro { grid-template-columns: 1fr; margin-top: 28px; } .mode-intro > div { padding: 20px; } .mode-intro > div + div { border-left: 0; border-top: 1px solid var(--line2); } .mode-intro h2 { font-size: 19px; } .dtable tbody th { width: 104px; padding-right: 12px; font-size: 13px; } .dtable td { font-size: 14px; overflow-wrap: anywhere; } .closing-cta { align-items: flex-start; flex-direction: column; } }
@media (max-width: 370px) { .nav-back { display: none; } .hero-title { font-size: 34px; } }[data-theme="dark"] .section-num{color:#08090d}
@media(max-width:720px){.hero-sub-name{display:block;margin:10px 0 0;font-size:20px}}