:root{--bg: #faf8f5;--fg: #1a1a24;--muted: #5b5e7a;--accent: #4f7cff;--line: #e2e3ec;--max-width: 760px;--font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Sans", "Noto Sans JP", sans-serif}*{box-sizing:border-box}html,body{margin:0;padding:0;background:var(--bg);color:var(--fg);font-family:var(--font-sans);font-size:16px;line-height:1.7}a{color:var(--accent);text-decoration:underline;text-underline-offset:2px}a:hover{text-decoration:none}.site-header{border-bottom:1px solid var(--line);padding:12px 20px;background:#fff}.site-header__inner{max-width:var(--max-width);margin:0 auto;display:flex;align-items:center;justify-content:space-between;gap:16px}.site-header__brand{display:flex;flex-direction:column;text-decoration:none;color:inherit;line-height:1.2}.site-header__brand-name{font-weight:800;font-size:18px;color:var(--fg);letter-spacing:-.01em}.site-header__brand-tagline{color:var(--muted);font-size:12px}.site-header__nav{display:flex;align-items:center;gap:6px;flex-wrap:wrap}.site-header__nav-link{display:inline-block;padding:6px 10px;border-radius:6px;color:var(--fg);text-decoration:none;font-size:13px;font-weight:600}.site-header__nav-link:hover{background:#efeff5;text-decoration:none}.site-main{max-width:var(--max-width);margin:0 auto;padding:32px 20px 80px}.site-footer{border-top:1px solid var(--line);padding:24px 20px 32px;background:#fff;font-size:12px;color:var(--muted)}.site-footer__inner{max-width:var(--max-width);margin:0 auto;display:grid;gap:6px;text-align:center}.site-footer__copy,.site-footer__links,.site-footer__credits{margin:0}.site-footer__sep{margin:0 6px;color:var(--line)}.site-footer a{color:var(--muted);text-decoration:underline;text-underline-offset:2px}.site-footer a:hover{color:var(--accent)}@media(max-width:600px){.site-header__inner{flex-direction:column;align-items:flex-start;gap:8px}.site-header__nav{width:100%}}h1,h2,h3{line-height:1.3;letter-spacing:-.01em}h1{font-size:28px;margin:0 0 8px}h2{font-size:22px;margin:32px 0 12px}h3{font-size:18px;margin:24px 0 8px}p{margin:0 0 16px}ul,ol{margin:0 0 16px 1.2em;padding:0}code{font-family:ui-monospace,SFMono-Regular,SF Mono,Menlo,Consolas,monospace;background:#efeff5;padding:1px 5px;border-radius:4px;font-size:.92em}.lesson-meta{color:var(--muted);font-size:13px;margin-bottom:16px}.lesson-card{display:block;padding:14px 16px;border:1px solid var(--line);border-radius:8px;background:#fff;text-decoration:none;color:inherit;transition:border-color .12s ease}.lesson-card:hover{border-color:var(--accent)}.lesson-card__chapter{font-size:12px;color:var(--muted)}.lesson-card__title{font-size:17px;font-weight:700;margin:4px 0 6px}.lesson-card__desc{font-size:14px;color:var(--muted);margin:0}.lesson-list{display:grid;gap:10px}.hero{margin:8px 0 40px}.hero__title{font-size:40px;margin:0 0 8px;letter-spacing:-.02em}.hero__subtitle{font-size:18px;color:var(--fg);margin:0 0 12px}.hero__lead{color:var(--muted);font-size:15px;margin:0 0 20px}.hero__points{list-style:none;margin:0 0 24px;padding:0;display:grid;gap:8px}.hero__points li{display:flex;align-items:baseline;gap:10px;font-size:14px}.hero__points-num{font-family:ui-monospace,SFMono-Regular,SF Mono,Menlo,Consolas,monospace;font-size:11px;font-weight:700;color:var(--accent);background:#eaf0ff;padding:2px 6px;border-radius:4px;letter-spacing:.05em}.hero__points-text{color:var(--fg)}.features{margin:16px 0 40px}.features__title{margin:0 0 16px}.features__list{list-style:none;margin:0;padding:0;display:grid;gap:12px;grid-template-columns:minmax(0,1fr)}@media(min-width:720px){.features__list{grid-template-columns:repeat(3,minmax(0,1fr))}}.features__card{background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px 18px}.features__icon{font-size:24px;margin-bottom:6px}.features__card-title{margin:0 0 6px;font-size:15px}.features__card-body{margin:0;font-size:13px;color:var(--muted);line-height:1.6}.home-chapters-section{margin:16px 0 0}.home-chapters-section h2{margin:0 0 16px}.home-chapters__head{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.home-chapters__desc{margin:6px 0 0;font-size:13px;color:var(--muted)}.home-chapters__badge{display:inline-block;padding:2px 8px;font-size:11px;font-weight:700;letter-spacing:.04em;border-radius:999px}.home-chapters__badge--ready{background:#def4e0;color:#1f6634}.home-chapters__badge--soon{background:#ffe9b5;color:#7a4a00}.home-chapters__item[data-status=comingSoon]{background:#f7f7fb;opacity:.85}.home-chapters__more{margin:14px 0 0;font-size:14px}.home-cta{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin:24px 0 32px}.home-cta__primary{display:inline-block;padding:12px 20px;border-radius:8px;background:var(--accent);color:#fff;font-weight:700;text-decoration:none;border:1px solid var(--accent)}.home-cta__primary:hover{background:#3565ee;text-decoration:none}.home-cta__secondary{display:inline-block;padding:12px 16px;border-radius:8px;background:transparent;color:var(--fg);font-weight:600;text-decoration:none;border:1px solid var(--line)}.home-cta__secondary:hover{border-color:var(--accent);text-decoration:none}.home-chapters{list-style:none;margin:0 0 16px;padding:0;display:grid;gap:6px}.home-chapters__item{display:block;padding:12px 16px;background:#fff;border:1px solid var(--line);border-radius:8px}.home-chapters__name{font-weight:700;font-size:15px}.chapter-list{display:grid;gap:18px;margin:24px 0 0}.chapter-card{padding:16px 18px;border:1px solid var(--line);border-radius:10px;background:#fff}.chapter-card[data-status=comingSoon]{background:#f7f7fb;opacity:.85}.chapter-card__header{display:flex;flex-direction:column;gap:4px}.chapter-card__title-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.chapter-card__title{margin:0;font-size:18px}.chapter-card__badge{display:inline-block;padding:2px 8px;font-size:11px;font-weight:700;letter-spacing:.04em;background:#ffe9b5;color:#7a4a00;border-radius:999px}.chapter-card__desc{margin:0;color:var(--muted);font-size:14px}.chapter-card__lessons{list-style:none;margin:14px 0 0;padding:0;display:grid;gap:10px}.chapter-card__lesson{margin:0}.lesson-nav{display:grid;grid-template-columns:1fr auto 1fr;gap:12px;align-items:stretch;margin:32px 0 0;padding-top:20px;border-top:1px solid var(--line)}.lesson-nav__side{display:flex}.lesson-nav__side--prev{justify-content:flex-start}.lesson-nav__side--next{justify-content:flex-end}.lesson-nav__link{display:flex;flex-direction:column;gap:2px;padding:10px 14px;border:1px solid var(--line);border-radius:8px;background:#fff;color:inherit;text-decoration:none;min-width:160px;max-width:280px}.lesson-nav__side--next .lesson-nav__link{text-align:right}.lesson-nav__link:hover{border-color:var(--accent);text-decoration:none}.lesson-nav__link.is-disabled{opacity:.5;cursor:not-allowed;background:#f7f7fb}.lesson-nav__direction{font-size:12px;color:var(--muted)}.lesson-nav__title{font-weight:600;font-size:14px}.lesson-nav__index{align-self:center;padding:8px 12px;border:1px solid var(--line);border-radius:8px;background:#fff;text-decoration:none;font-size:13px;color:inherit;white-space:nowrap}.lesson-nav__index:hover{border-color:var(--accent);text-decoration:none}@media(max-width:600px){.lesson-nav{grid-template-columns:1fr}.lesson-nav__side--next .lesson-nav__link{text-align:left}}