:root{color-scheme:light;--ink:#18233b;--muted:#56627a;--accent:#414ac7;--line:#dfe4ed}*{box-sizing:border-box}body{margin:0;background:#f5f7fb;color:var(--ink);font:16px/1.85 -apple-system,BlinkMacSystemFont,"Helvetica Neue","Noto Sans JP",sans-serif}a{color:var(--accent);text-underline-offset:4px}a:hover{text-decoration-thickness:2px}a:focus-visible{outline:3px solid #db8a22;outline-offset:5px}header,main,footer{max-width:880px;margin:auto;padding:24px}header{display:flex;justify-content:space-between;gap:20px;border-bottom:1px solid var(--line)}header a{font-weight:700;text-decoration:none}h1{font-size:clamp(1.8rem,5vw,2.8rem);line-height:1.4;letter-spacing:-.035em;margin:16px 0}h2{font-size:1.3rem;margin-top:32px}p{margin:12px 0}.eyebrow{color:var(--muted);font-size:.875rem;letter-spacing:.1em}.intro{padding:24px 0}.card,article{background:white;border:1px solid var(--line);border-radius:18px;padding:28px;margin:20px 0}.card h2{margin-top:0}.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.button{display:inline-block;padding:10px 20px;border-radius:10px;background:var(--accent);color:#fff;text-decoration:none;font-weight:600}.secondary{background:#edf0fc;color:var(--accent)}.note,footer{color:var(--muted);font-size:.875rem}details{padding:16px 0;border-bottom:1px solid var(--line)}summary{cursor:pointer;font-weight:600}footer{border-top:1px solid var(--line);margin-top:28px}ul{padding-left:24px}li{margin:8px 0}@media(max-width:480px){header,main,footer{padding:20px}.card,article{padding:20px}.actions{flex-direction:column}.button{text-align:center}}