:root {
  --bg: #f7f8fb;
  --surface: #fff;
  --surface-soft: #f7f7f5;
  --line: #e9e9e7;
  --line-strong: #d9d9d6;
  --text: #37352f;
  --text-soft: #2f2f2b;
  --muted: #787774;
  --muted-light: #a6a5a1;
  --accent: #1d9bf0;
  --accent-strong: #0b83dc;
  --accent-soft: #e8f4ff;
  --green: #1f9d66;
  --green-soft: #e6f6ee;
  --amber: #b97511;
  --amber-soft: #fff4df;
  --shadow: 0 10px 28px rgba(15, 15, 15, .06);
  --shell: min(1120px, calc(100% - 64px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--surface); color: var(--text); font: 400 14px/1.8 "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif; -webkit-font-smoothing: antialiased; }
a { color: inherit; }
button, input { font: inherit; }
.shell { width: var(--shell); margin-inline: auto; }
.skip-link { position: fixed; z-index: 300; top: 8px; left: 8px; padding: 8px 12px; border-radius: 7px; background: var(--text); color: #fff; transform: translateY(-150%); }
.skip-link:focus { transform: translateY(0); }
.reading-progress { position: fixed; z-index: 210; inset: 0 0 auto; height: 2px; background: transparent; }
.reading-progress span { display: block; width: 0; height: 100%; background: var(--accent); }

.site-header { position: sticky; z-index: 100; top: 0; border-bottom: 1px solid var(--line); background: rgba(255,255,255,.92); backdrop-filter: blur(14px); }
.header-inner { min-height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.site-label { color: var(--muted); font-size: 10px; font-weight: 600; letter-spacing: .13em; }
.header-link { color: var(--accent-strong); font-size: 12px; font-weight: 600; text-decoration: none; }

.hero { min-height: 680px; display: grid; grid-template-columns: 1.05fr .95fr; gap: 72px; align-items: center; padding-block: 82px; }
.eyebrow, .kicker { margin: 0; color: var(--accent-strong); font-size: 10px; font-weight: 600; letter-spacing: .13em; }
.eyebrow { display: flex; align-items: center; gap: 8px; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }
.hero h1 { margin: 24px 0 20px; color: var(--text-soft); font-size: clamp(38px, 4.6vw, 62px); line-height: 1.3; letter-spacing: -.04em; font-weight: 600; }
.hero h1 span { color: var(--accent-strong); }
.hero-lead { max-width: 650px; margin: 0; color: var(--muted); font-size: 15px; line-height: 2; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }
.button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; gap: 18px; padding: 0 20px; border: 1px solid var(--line-strong); border-radius: 9px; background: var(--surface); font-size: 12px; font-weight: 600; text-decoration: none; transition: border-color .18s ease, background .18s ease, transform .18s ease; }
.button:hover { transform: translateY(-1px); }
.button-primary { border-color: var(--accent); background: var(--accent); color: #fff; }
.button-primary:hover { border-color: var(--accent-strong); background: var(--accent-strong); }
.button-secondary:hover { border-color: #b7c8d8; background: var(--accent-soft); }
.trust-note { margin: 18px 0 0; color: var(--muted); font-size: 11px; }
.trust-note span { margin-right: 5px; color: var(--green); font-weight: 600; }

.hero-visual { padding: 24px; border: 1px solid var(--line-strong); border-radius: 16px; background: var(--bg); box-shadow: var(--shadow); }
.visual-label { margin: 0 0 16px; color: var(--muted-light); font-size: 9px; font-weight: 600; letter-spacing: .11em; }
.visual-process { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 9px; align-items: center; }
.visual-process article { min-width: 0; min-height: 128px; display: flex; flex-direction: column; justify-content: center; padding: 15px; border: 1px solid var(--line); border-radius: 11px; background: var(--surface); }
.visual-process article > span { color: var(--muted-light); font-size: 9px; font-weight: 600; }
.visual-process strong { margin-top: 9px; font-size: 13px; font-weight: 600; }
.visual-process small { margin-top: 3px; color: var(--muted); font-size: 9px; }
.visual-process i { color: var(--muted-light); font-style: normal; }
.visual-process .visual-result { border-color: #b9dcf4; background: var(--accent-soft); }
.visual-process .visual-result strong { color: var(--accent-strong); }
.private-note { display: grid; grid-template-columns: auto 1fr; gap: 12px; align-items: center; margin-top: 14px; padding: 14px 16px; border: 1px solid #ead9b8; border-radius: 10px; background: var(--amber-soft); }
.private-note > span { font-size: 15px; }
.private-note div { display: grid; }
.private-note strong { color: #815512; font-size: 12px; font-weight: 600; }
.private-note small { color: #8c6d3d; font-size: 10px; }

.section-nav { position: sticky; z-index: 90; top: 66px; overflow-x: auto; border-block: 1px solid var(--line); background: rgba(247,248,251,.94); backdrop-filter: blur(14px); scrollbar-width: none; }
.section-nav::-webkit-scrollbar { display: none; }
.section-nav-inner { display: flex; align-items: center; justify-content: center; gap: 30px; white-space: nowrap; }
.section-nav a { position: relative; padding: 13px 0 11px; color: var(--muted); font-size: 11px; font-weight: 500; text-decoration: none; }
.section-nav a.is-active, .section-nav a:hover { color: var(--accent-strong); }
.section-nav a.is-active::after { content: ""; position: absolute; right: 0; bottom: -1px; left: 0; height: 2px; background: var(--accent); }

.section { padding-block: 88px; scroll-margin-top: 96px; }
.section-soft { border-block: 1px solid var(--line); background: var(--bg); }
.section-heading { display: grid; grid-template-columns: 28px 1fr; gap: 14px; align-items: start; }
.section-number { margin: 6px 0 0; color: var(--muted-light); font-size: 11px; font-weight: 600; font-variant-numeric: tabular-nums; }
.section-heading h2 { margin: 6px 0 0; color: var(--text-soft); font-size: clamp(28px, 3.2vw, 38px); line-height: 1.45; letter-spacing: -.03em; font-weight: 600; }
.section-intro { max-width: 760px; margin: 20px 0 36px 42px; color: var(--muted); font-size: 14px; }

.prerequisite-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.prerequisite-card { min-height: 184px; display: grid; grid-template-columns: 34px 1fr; gap: 14px; padding: 22px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.prerequisite-card > span { width: 34px; height: 34px; display: grid; place-items: center; border-radius: 9px; background: var(--accent-soft); color: var(--accent-strong); font-size: 10px; font-weight: 600; }
.prerequisite-card small { color: var(--muted-light); font-size: 9px; font-weight: 600; letter-spacing: .12em; }
.prerequisite-card h3 { margin: 12px 0 7px; font-size: 16px; font-weight: 600; }
.prerequisite-card p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.75; }
.warning-box { display: grid; grid-template-columns: 34px 1fr; gap: 14px; align-items: center; margin-top: 18px; padding: 17px 20px; border: 1px solid #ead9b8; border-radius: 11px; background: var(--amber-soft); }
.warning-icon { width: 32px; height: 32px; display: grid; place-items: center; border-radius: 8px; background: #f5dcae; color: #815512; font-weight: 700; }
.warning-box strong { color: #754e13; font-size: 13px; font-weight: 600; }
.warning-box p { margin: 2px 0 0; color: #8c6d3d; font-size: 11px; }

.platform-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.platform-card { min-height: 226px; display: block; padding: 25px; border: 1px solid var(--line-strong); border-radius: 14px; background: var(--surface); text-decoration: none; transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease; }
.platform-card:hover { border-color: #b7c8d8; box-shadow: var(--shadow); transform: translateY(-2px); }
.platform-card small { color: var(--muted-light); font-size: 9px; font-weight: 600; letter-spacing: .12em; }
.platform-card h3 { margin: 23px 0 8px; font-size: 20px; font-weight: 600; }
.platform-card p { margin: 0; color: var(--muted); font-size: 13px; }
.platform-card b { display: inline-block; margin-top: 27px; color: var(--accent-strong); font-size: 12px; font-weight: 600; }

.steps { max-width: 850px; margin: 38px auto 0; padding: 0; list-style: none; }
.step { position: relative; display: grid; grid-template-columns: 42px 1fr; gap: 18px; padding-bottom: 42px; }
.step:last-child { padding-bottom: 0; }
.step:not(:last-child)::before { content: ""; position: absolute; top: 42px; bottom: 0; left: 20px; width: 1px; background: var(--line-strong); }
.step-marker { position: relative; z-index: 1; width: 42px; height: 42px; display: grid; place-items: center; border: 1px solid var(--line-strong); border-radius: 11px; background: var(--surface); color: var(--muted); font-size: 12px; font-weight: 600; }
.section-soft .step-marker { background: var(--bg); }
.step-body { min-width: 0; padding-top: 4px; }
.step h3 { margin: 0; font-size: 17px; font-weight: 600; }
.step-body > p { margin: 7px 0 0; color: var(--muted); font-size: 13px; }
.command-box, .prompt-box { margin-top: 15px; overflow: hidden; border: 1px solid #262823; border-radius: 10px; background: #252622; color: #f7f7f5; }
.command-top { min-height: 40px; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 7px 9px 7px 14px; border-bottom: 1px solid rgba(255,255,255,.1); color: #a9aaa4; font: 600 9px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .1em; }
.command-box code { display: block; overflow-x: auto; padding: 19px 18px 21px; color: #bfe6ff; font: 500 12px/1.7 ui-monospace, SFMono-Regular, Menlo, monospace; white-space: nowrap; }
.copy-button { flex: 0 0 auto; min-height: 29px; border: 1px solid rgba(255,255,255,.16); border-radius: 6px; padding: 0 10px; background: rgba(255,255,255,.08); color: #f2f2ef; cursor: pointer; font-size: 10px; font-weight: 500; }
.copy-button:hover { background: rgba(255,255,255,.15); }
.mobile-break { display: none; }
.official-link { max-width: 850px; margin: 22px auto 0; color: var(--muted); font-size: 11px; }
.official-link a { color: var(--accent-strong); font-weight: 600; text-underline-offset: 3px; }

.prompt-box { max-width: 850px; margin: 34px auto 0; }
.prompt-box p { margin: 0; padding: 20px; color: #e8e8e3; font-size: 14px; line-height: 1.9; }
.completion-card { max-width: 850px; display: grid; grid-template-columns: 38px 1fr; gap: 14px; align-items: center; margin: 14px auto 0; padding: 18px 20px; border: 1px solid #b9e2cf; border-radius: 11px; background: var(--green-soft); }
.completion-card > span { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 9px; background: var(--green); color: #fff; font-weight: 600; }
.completion-card strong { color: #16784d; font-size: 13px; font-weight: 600; }
.completion-card p { margin: 2px 0 0; color: #467b64; font-size: 11px; }

.safety-card { display: grid; grid-template-columns: .8fr 1.2fr; gap: 44px; padding: 30px; border: 1px solid var(--line-strong); border-radius: 14px; background: var(--surface); }
.safety-card h2 { margin: 7px 0 0; font-size: 27px; line-height: 1.5; font-weight: 600; letter-spacing: -.03em; }
.safety-card ul { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; }
.safety-card li { min-height: 48px; display: grid; grid-template-columns: 28px 1fr; gap: 12px; align-items: center; padding: 8px 11px; border: 1px solid var(--line); border-radius: 9px; }
.safety-card li span { width: 25px; height: 25px; display: grid; place-items: center; border-radius: 7px; background: var(--accent-soft); color: var(--accent-strong); font-size: 10px; font-weight: 600; }
.safety-card li p { margin: 0; color: var(--muted); font-size: 12px; }

.section-faq { background: var(--surface); }
.faq-shell { max-width: 850px; }
.faq-list { margin-top: 34px; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { display: flex; justify-content: space-between; gap: 24px; padding: 20px 0; cursor: pointer; color: var(--text-soft); font-size: 14px; font-weight: 600; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary span { color: var(--accent-strong); font-size: 18px; font-weight: 400; transition: transform .18s ease; }
.faq-list details[open] summary span { transform: rotate(45deg); }
.faq-list details p { margin: -3px 0 22px; padding-right: 44px; color: var(--muted); font-size: 13px; }

.final-cta { padding-block: 62px; border-top: 1px solid var(--line); background: var(--bg); }
.final-cta-inner { display: flex; align-items: flex-end; justify-content: space-between; gap: 36px; }
.final-cta h2 { margin: 6px 0 8px; font-size: 29px; line-height: 1.45; font-weight: 600; letter-spacing: -.03em; }
.final-cta p { margin: 0; color: var(--muted); font-size: 12px; }
.site-footer { padding-block: 32px; border-top: 1px solid var(--line); background: var(--surface); }
.footer-inner { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; }
.footer-inner > div { display: grid; }
.footer-inner strong { font-size: 12px; font-weight: 600; }
.footer-inner span, .footer-inner p { color: var(--muted); font-size: 10px; }
.footer-inner p { margin: 0; }
.toast { position: fixed; z-index: 200; left: 50%; bottom: 22px; padding: 9px 14px; border-radius: 8px; background: var(--text); color: #fff; font-size: 11px; font-weight: 500; opacity: 0; pointer-events: none; transform: translate(-50%, 14px); transition: opacity .18s ease, transform .18s ease; }
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }
.reveal { opacity: 1; transform: none; }

@media (max-width: 900px) {
  .hero { min-height: auto; grid-template-columns: 1fr; gap: 40px; padding-block: 64px 70px; }
  .hero-copy { max-width: 760px; }
  .prerequisite-grid { grid-template-columns: 1fr; }
  .prerequisite-card { min-height: auto; }
  .safety-card { grid-template-columns: 1fr; gap: 24px; }
}

@media (max-width: 767px) {
  :root { --shell: calc(100% - 32px); }
  body { font-size: 14px; }
  .header-inner { min-height: 62px; }
  .site-label { font-size: 9px; }
  .header-link { font-size: 11px; }
  .hero { gap: 30px; padding-block: 48px 54px; }
  .hero h1 { margin: 18px 0 17px; font-size: 35px; line-height: 1.35; }
  .hero-lead { font-size: 14px; line-height: 1.9; }
  .hero-actions { display: grid; margin-top: 24px; }
  .button { width: 100%; }
  .hero-visual { padding: 15px; border-radius: 13px; box-shadow: none; }
  .visual-process { grid-template-columns: 1fr; }
  .visual-process article { min-height: auto; padding: 13px 14px; }
  .visual-process strong { margin-top: 4px; }
  .visual-process i { justify-self: center; transform: rotate(90deg); line-height: 1; }
  .private-note { align-items: start; padding: 13px; }
  .section-nav { top: 62px; }
  .section-nav-inner { justify-content: flex-start; gap: 22px; }
  .section-nav a { font-size: 11px; }
  .section { padding-block: 62px; scroll-margin-top: 88px; }
  .section-heading { grid-template-columns: 22px 1fr; gap: 9px; }
  .section-heading h2 { font-size: 24px; line-height: 1.5; }
  .section-intro { margin: 16px 0 28px 31px; font-size: 13px; }
  .prerequisite-grid { gap: 8px; }
  .prerequisite-card { grid-template-columns: 32px 1fr; gap: 12px; padding: 18px; }
  .prerequisite-card > span { width: 32px; height: 32px; }
  .prerequisite-card h3 { margin-top: 8px; font-size: 15px; }
  .warning-box { align-items: start; padding: 15px; }
  .platform-grid { grid-template-columns: 1fr; gap: 8px; }
  .platform-card { min-height: 200px; padding: 20px; }
  .steps { margin-top: 28px; }
  .step { grid-template-columns: 36px 1fr; gap: 12px; padding-bottom: 34px; }
  .step-marker { width: 36px; height: 36px; border-radius: 9px; }
  .step:not(:last-child)::before { top: 36px; left: 17px; }
  .step h3 { font-size: 15px; }
  .step-body > p { font-size: 12px; }
  .command-box code { padding: 16px 14px 18px; font-size: 10px; white-space: normal; overflow-wrap: anywhere; }
  .mobile-break { display: inline; }
  .prompt-box p { padding: 17px 15px 19px; font-size: 12px; }
  .completion-card { grid-template-columns: 34px 1fr; padding: 16px; }
  .completion-card > span { width: 32px; height: 32px; }
  .safety-card { padding: 22px 18px; }
  .safety-card h2 { font-size: 22px; }
  .faq-list summary { padding-block: 18px; font-size: 13px; }
  .faq-list details p { padding-right: 14px; font-size: 12px; }
  .final-cta { padding-block: 52px; }
  .final-cta-inner { align-items: flex-start; flex-direction: column; gap: 24px; }
  .final-cta h2 { font-size: 24px; }
  .footer-inner { align-items: flex-start; flex-direction: column; gap: 12px; }
}

@media (max-width: 410px) {
  .hero h1 { font-size: 32px; }
  .command-top { align-items: center; gap: 8px; padding-left: 10px; letter-spacing: .06em; }
  .copy-button { padding-inline: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}