:root{
  --ink:#18343b;--muted:#60757a;--brand:#187d79;--brand2:#3fa59d;
  --soft:#edf8f6;--line:#d9e8e6;--warm:#fff8e8;--white:#fff;
  --shadow:0 12px 32px rgba(18,63,67,.08);--radius:18px;--max:1080px
}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;color:var(--ink);line-height:1.85;background:#fff}
a{color:var(--brand);text-decoration-thickness:1px;text-underline-offset:3px}a:hover{opacity:.78}
img{max-width:100%;height:auto}
.container{width:min(calc(100% - 36px),var(--max));margin:auto}
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);border-bottom:1px solid var(--line);backdrop-filter:blur(10px)}
.header-inner{height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.logo{font-weight:800;color:var(--ink);text-decoration:none;line-height:1.25}.logo small{display:block;font-size:11px;color:var(--brand);letter-spacing:.08em}
.nav{display:flex;gap:18px;align-items:center}.nav a{font-size:14px;color:var(--ink);text-decoration:none;font-weight:650}
.menu-btn{display:none;border:0;background:var(--soft);border-radius:10px;padding:9px 12px;font-size:20px}
.hero{background:linear-gradient(135deg,#effaf8 0%,#fff 55%,#f5fbff 100%);padding:72px 0 58px;border-bottom:1px solid var(--line)}
.hero-grid{display:grid;grid-template-columns:1.25fr .75fr;gap:48px;align-items:center}
.eyebrow{display:inline-block;color:var(--brand);background:#dff4f1;border-radius:999px;padding:5px 12px;font-size:13px;font-weight:750}
h1{font-size:clamp(32px,5vw,54px);line-height:1.3;margin:16px 0 20px;letter-spacing:-.02em}
.lead{font-size:18px;color:#49676d;max-width:760px}
.hero-card{background:#fff;border:1px solid var(--line);border-radius:26px;padding:28px;box-shadow:var(--shadow)}
.hero-card strong{display:block;font-size:20px;margin-bottom:12px}.hero-card ul{margin:0;padding-left:1.2em}
.breadcrumb{font-size:13px;color:var(--muted);padding:18px 0}.breadcrumb a{color:var(--muted)}
main{padding-bottom:72px}.section{padding:52px 0}.section + .section{border-top:1px solid #edf2f1}
h2{font-size:30px;line-height:1.45;margin:0 0 20px;padding-left:16px;border-left:5px solid var(--brand2)}
h3{font-size:21px;margin:30px 0 10px}.muted{color:var(--muted)}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:26px}
.card{border:1px solid var(--line);border-radius:var(--radius);padding:24px;background:#fff;box-shadow:0 5px 18px rgba(18,63,67,.04)}
.card .num{font-size:12px;font-weight:800;color:var(--brand);letter-spacing:.1em}.card h3{margin:6px 0 8px}
.card a.stretch{font-weight:700;text-decoration:none}
.note{background:var(--soft);border-radius:var(--radius);padding:24px 26px;margin:26px 0;border:1px solid #d5efeb}
.warn{background:var(--warm);border-color:#f0dfb3}.note strong{display:block;margin-bottom:5px}
.steps{counter-reset:step;display:grid;gap:14px}.step{position:relative;padding:20px 22px 20px 72px;border:1px solid var(--line);border-radius:16px}
.step:before{counter-increment:step;content:counter(step);position:absolute;left:20px;top:20px;width:36px;height:36px;display:grid;place-items:center;background:var(--brand);color:#fff;border-radius:50%;font-weight:800}
.table-wrap{overflow-x:auto}.simple-table{width:100%;border-collapse:collapse;margin:22px 0}.simple-table th,.simple-table td{padding:14px;border:1px solid var(--line);vertical-align:top}.simple-table th{background:var(--soft);text-align:left}
.related{background:#f7faf9;border-radius:22px;padding:28px;margin-top:44px}.related h2{font-size:24px}.related ul{margin-bottom:0}
.source-box{font-size:13px;color:var(--muted);background:#fafcfc;border:1px solid var(--line);padding:18px 20px;border-radius:14px;margin-top:32px}
.source-box a{word-break:break-all}
.site-footer{background:#17373b;color:#d9e7e6;padding:42px 0}.site-footer a{color:#fff}.footer-grid{display:grid;grid-template-columns:1fr 1fr;gap:30px}.footer-links{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:13px}
.copy{font-size:12px;color:#a9c0c0;margin-top:28px}
.article-hero{padding:38px 0 30px;background:linear-gradient(180deg,#f1faf8,#fff)}.article-hero h1{font-size:clamp(30px,4vw,44px)}
.kicker{font-weight:700;color:var(--brand)}.checklist{list-style:none;padding:0}.checklist li{padding:8px 0 8px 30px;position:relative}.checklist li:before{content:"✓";position:absolute;left:0;color:var(--brand);font-weight:900}
@media(max-width:820px){
 .header-inner{height:64px}.menu-btn{display:block}.nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:16px 20px;flex-direction:column;align-items:flex-start}.nav.open{display:flex}
 .hero{padding:48px 0 38px}.hero-grid{grid-template-columns:1fr;gap:24px}.cards{grid-template-columns:1fr 1fr}.footer-grid{grid-template-columns:1fr}
 h2{font-size:25px}.section{padding:38px 0}
}
@media(max-width:560px){.container{width:min(calc(100% - 28px),var(--max))}.cards{grid-template-columns:1fr}.lead{font-size:16px}.hero-card{padding:22px}h1{font-size:34px}}

/* Illustration and accessibility polish */
.hero-visual{min-width:0}.hero-visual>img{display:block;border-radius:22px;width:100%;margin-bottom:18px;box-shadow:var(--shadow)}
.hero-visual .hero-card{padding:22px;font-size:14px}.hero-visual .hero-card strong{font-size:17px}
.article-illustration{margin:24px 0 0;max-width:460px}.article-illustration img{display:block;border-radius:18px}
h2[id]{scroll-margin-top:100px}.section h2:not(:first-child){margin-top:42px}
a:focus-visible,button:focus-visible{outline:3px solid #187d79;outline-offset:5px}
.header-inner{height:auto;min-height:92px;flex-wrap:wrap;padding-top:14px;padding-bottom:14px;gap:12px}.nav{flex-wrap:wrap;gap:10px 18px}.nav a[aria-current]{color:var(--brand);text-decoration:underline}
@media(max-width:820px){.header-inner{min-height:64px;padding-top:8px;padding-bottom:8px;flex-wrap:nowrap}.hero-visual{max-width:540px;width:100%;margin:auto}.article-illustration{max-width:400px}.nav{gap:4px}.logo{max-width:calc(100% - 62px)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.card{transition:none}}
.link-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.link-url{display:block;font-size:14px;overflow-wrap:anywhere}.link-url span{display:block;font-size:12px}
@media(max-width:560px){.link-cards{grid-template-columns:1fr}}
/* Final polish */
body{font-feature-settings:"palt";letter-spacing:.01em}
.site-header{box-shadow:0 2px 14px rgba(18,63,67,.035)}
.logo{font-size:16px}.logo small{margin-bottom:2px}
.hero{position:relative;overflow:hidden}.hero:after{content:"";position:absolute;width:420px;height:420px;border-radius:50%;right:-160px;top:-220px;background:rgba(63,165,157,.09);pointer-events:none}
.hero h1 em{font-style:normal;color:var(--brand)}
.hero-card{position:relative}.hero-card:before{content:"GUIDE";position:absolute;right:22px;top:12px;font-size:11px;letter-spacing:.2em;color:#9ab9b5;font-weight:800}
.card{transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}.card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#bcded9}
.card h3{line-height:1.45}.card p{color:#536e73;font-size:15px}
.article-hero{border-bottom:1px solid var(--line)}
.article-hero .lead{max-width:800px}
main p{max-width:880px}
.toc{border:1px solid var(--line);border-radius:18px;padding:22px 26px;background:#fbfdfd;margin:30px 0}.toc strong{display:block;margin-bottom:8px}.toc a{display:inline-block;margin:4px 14px 4px 0;font-size:14px}
.trust-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:18px;overflow:hidden;margin-top:28px}.trust-strip div{background:#fff;padding:18px}.trust-strip strong{display:block;color:var(--brand);font-size:13px;margin-bottom:3px}.trust-strip span{font-size:14px;color:#536e73}
.cta-panel{background:linear-gradient(135deg,#17373b,#24565a);color:#fff;border-radius:24px;padding:30px;margin-top:36px}.cta-panel h2{color:#fff;border-left-color:#72c8c0}.cta-panel a{color:#fff}
@media(max-width:820px){.trust-strip{grid-template-columns:1fr}.logo{font-size:14px}.nav{max-height:calc(100vh - 64px);overflow:auto}.nav a{width:100%;padding:8px 0}.article-hero{padding-top:28px}}