:root{--ink:#172033;--muted:#5c667a;--paper:#fff;--wash:#f3f7fb;--blue:#155eef;--navy:#0d2344;--line:#dbe4ee;--mint:#dff8ef;--orange:#ffb547;--shadow:0 18px 50px rgba(13,35,68,.1)}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:var(--paper);font-family:"Yu Gothic","Hiragino Kaku Gothic ProN",Meiryo,sans-serif;font-size:16px;line-height:1.8}a{color:inherit}.wrap{width:min(1120px,calc(100% - 40px));margin:auto}.site-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.94);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.header-inner{min-height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px}.brand{text-decoration:none;font-weight:800;letter-spacing:.02em}.brand small{display:block;color:var(--muted);font-size:.72rem;font-weight:600;line-height:1.2}.nav{display:flex;gap:22px}.nav a{text-decoration:none;font-size:.92rem;font-weight:700}.hero{background:linear-gradient(135deg,#eef5ff 0%,#fff 52%,#e8fbf4 100%);border-bottom:1px solid var(--line)}.hero-inner{display:grid;grid-template-columns:1.25fr .75fr;gap:60px;padding:80px 0}.eyebrow{color:var(--blue);font-weight:800;letter-spacing:.08em;font-size:.84rem}.hero h1{font-size:clamp(2.35rem,5.6vw,4.9rem);line-height:1.12;letter-spacing:-.045em;margin:.25em 0}.lead{font-size:1.12rem;color:var(--muted);max-width:650px}.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:28px}.button{display:inline-block;padding:12px 20px;border-radius:8px;background:var(--blue);color:#fff;text-decoration:none;font-weight:800}.button.secondary{background:#fff;color:var(--navy);border:1px solid var(--line)}.hero-card{align-self:center;background:var(--navy);color:#fff;padding:30px;border-radius:18px;box-shadow:var(--shadow);transform:rotate(1.5deg)}.hero-card h2{margin-top:0;font-size:1.35rem}.hero-card ol{padding-left:1.4em}.section{padding:72px 0}.section.alt{background:var(--wash)}.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:30px}.section h2{font-size:clamp(1.7rem,3vw,2.45rem);line-height:1.3;margin:0}.section-head p{color:var(--muted);margin:0}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:24px;box-shadow:0 8px 30px rgba(13,35,68,.04)}.card .tag{display:inline-block;padding:3px 9px;border-radius:999px;background:var(--mint);color:#116149;font-size:.75rem;font-weight:800}.card h3{font-size:1.18rem;line-height:1.5;margin:13px 0 8px}.card p{color:var(--muted);font-size:.94rem}.card a.more{color:var(--blue);font-weight:800;text-decoration:none}.topics{display:grid;grid-template-columns:repeat(5,1fr);gap:12px}.topic{padding:18px 14px;border:1px solid var(--line);border-radius:12px;background:#fff;font-weight:800;text-align:center}.freebie{display:grid;grid-template-columns:.8fr 1.2fr;gap:38px;align-items:center;background:var(--navy);color:#fff;border-radius:20px;padding:42px}.sheet{background:#fff;color:var(--ink);border-radius:10px;padding:22px;box-shadow:var(--shadow)}.sheet-row{height:12px;background:#dce6f2;margin:10px 0;border-radius:3px}.sheet-row:nth-child(2){width:82%;background:#99baff}.sheet-row:nth-child(3){width:65%}.notice{border-left:5px solid var(--orange);background:#fff8e9;padding:16px 18px;margin:26px 0}.profile{display:grid;grid-template-columns:160px 1fr;gap:28px;align-items:center}.avatar{width:140px;height:140px;border-radius:50%;background:var(--navy);color:#fff;display:grid;place-items:center;font-size:2.4rem;font-weight:900}.site-footer{padding:38px 0;background:#09182e;color:#dce6f2}.footer-inner{display:flex;justify-content:space-between;gap:25px;flex-wrap:wrap}.footer-links{display:flex;gap:18px;flex-wrap:wrap}.footer-links a{color:#dce6f2}.article{width:min(800px,calc(100% - 40px));margin:auto;padding:64px 0 90px}.article h1{font-size:clamp(2rem,5vw,3.25rem);line-height:1.35;letter-spacing:-.025em}.article h2{margin-top:2.2em;line-height:1.45}.article h3{margin-top:1.7em}.article table{width:100%;border-collapse:collapse;margin:24px 0;font-size:.95rem}.article th,.article td{border:1px solid var(--line);padding:12px 14px;text-align:left;vertical-align:top}.article th{background:var(--wash);font-weight:800}.meta{color:var(--muted);font-size:.9rem}.breadcrumb{font-size:.88rem;color:var(--muted)}.article-cta{background:var(--navy);color:#fff;border-radius:16px;padding:28px;margin-top:48px}.article-cta h2{margin-top:0}.skip{position:absolute;left:-9999px}.skip:focus{left:12px;top:12px;z-index:99;background:#fff;padding:8px}@media(max-width:820px){.nav{display:none}.hero-inner,.freebie{grid-template-columns:1fr}.hero-inner{padding:54px 0}.hero-card{transform:none}.grid{grid-template-columns:1fr 1fr}.topics{grid-template-columns:1fr 1fr}.profile{grid-template-columns:1fr}.avatar{width:100px;height:100px}.section{padding:54px 0}}@media(max-width:560px){.wrap{width:min(100% - 28px,1120px)}.grid{grid-template-columns:1fr}.freebie{padding:28px}.hero h1{font-size:2.55rem}.section-head{display:block}.topics{grid-template-columns:1fr}.article{width:min(100% - 28px,800px);padding-top:42px}}