*{box-sizing:border-box}
:root{--blue:#1769c8;--blue-bright:#2e83da;--blue-deep:#155eb4;--teal:#0f8b8d;--teal-ink:#087a7c;--ink:#0f2f4a;--body:rgba(18,50,74,.8);--faint:rgba(18,50,74,.55);--line:rgba(31,112,183,.12);--green:#07694a}
html{scroll-behavior:smooth}
body{margin:0;overflow-x:hidden;font:15px/1.55 Inter,ui-sans-serif,system-ui,sans-serif;color:var(--ink);-webkit-font-smoothing:antialiased;background:radial-gradient(circle at 82% 3%,rgba(80,166,240,.13),transparent 28%),linear-gradient(180deg,#f7fcff 0%,#f3f9ff 40%,#f9fbfd 100%)}
a{color:var(--blue-deep)}
a:focus-visible,button:focus-visible{outline:2px solid var(--blue);outline-offset:3px;border-radius:6px}
.wrap{max-width:1120px;margin:0 auto;padding:0 28px}
.prog{position:fixed;top:0;left:0;height:3px;width:0;background:linear-gradient(90deg,var(--blue),var(--teal));z-index:60;transition:width .1s linear}
.nav{position:sticky;top:0;z-index:50;background:rgba(247,251,255,.86);backdrop-filter:blur(16px) saturate(1.5);-webkit-backdrop-filter:blur(16px) saturate(1.5);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px 28px;max-width:1120px;margin:0 auto}
.brand{display:flex;align-items:center;gap:10px}
.nav nav{display:flex;align-items:center;gap:14px;font-weight:600;font-size:14px}
.nav nav a{color:var(--ink);text-decoration:none}
.nav nav a:hover{color:var(--blue)}
.back{display:inline-flex;align-items:center;gap:7px;font-size:13.5px;font-weight:650}
.back svg{width:14px;height:14px}
.cta{display:inline-flex;align-items:center;gap:8px;padding:9px 18px;border-radius:999px;background:linear-gradient(180deg,var(--blue-bright),var(--blue));color:#fff!important;font-weight:650;font-size:13.5px;border:1px solid rgba(21,94,180,.18);box-shadow:0 12px 28px rgba(25,118,210,.2);transition:transform .2s,box-shadow .2s;text-decoration:none}
.cta:hover{transform:translateY(-2px);box-shadow:0 16px 36px rgba(25,118,210,.28)}
.cta:focus-visible{outline:2px solid var(--blue-deep);outline-offset:3px}
.art-head{max-width:760px;margin:0 auto;padding:52px 0 30px;text-align:center}
.k-cat{display:inline-block;font-size:11.5px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--teal-ink);background:rgba(15,139,141,.1);border-radius:999px;padding:6px 13px;margin:0 0 20px}
.art-head h1{font-size:42px;line-height:1.12;font-weight:750;letter-spacing:-.02em;margin:0 0 20px}
.dek{font-size:19px;line-height:1.6;color:var(--body);margin:0 0 26px}
.byline{display:flex;align-items:center;gap:13px;justify-content:center;font-size:13.5px;color:var(--faint);font-weight:600}
.byline .dot{width:3px;height:3px;border-radius:50%;background:var(--faint)}
.art{display:grid;grid-template-columns:220px minmax(0,720px);gap:56px;justify-content:center;padding:26px 0 40px}
.toc{position:sticky;top:96px;align-self:start;font-size:13.5px}
.toc p{font-size:11.5px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;color:var(--faint);margin:0 0 14px}
.toc a{display:block;color:var(--body);padding:7px 0 7px 14px;border-left:2px solid var(--line);text-decoration:none;transition:color .2s,border-color .2s;line-height:1.4}
.toc a:hover{color:var(--blue-deep)}
.toc a.active{color:var(--blue-deep);border-color:var(--blue);font-weight:650}
.prose{font-size:17px;line-height:1.75;color:var(--body);min-width:0}
.prose h2{font-size:26px;line-height:1.2;font-weight:750;letter-spacing:-.015em;color:var(--ink);margin:44px 0 14px;scroll-margin-top:96px}
.prose h3{font-size:19px;line-height:1.3;font-weight:700;color:var(--ink);margin:30px 0 10px}
.prose p{margin:0 0 20px}
.prose strong{color:var(--ink);font-weight:700}
.prose em{font-style:italic}
.prose ul,.prose ol{margin:0 0 20px;padding-left:22px}
.prose li{margin:0 0 9px}
.prose li::marker{color:var(--teal)}
.prose a{color:var(--blue-deep);text-decoration:underline;text-underline-offset:2px;text-decoration-color:rgba(21,94,180,.35)}
.prose a:hover{text-decoration-color:var(--blue-deep)}
.prose>p:last-child{font-size:14px;color:var(--faint);border-top:1px solid var(--line);margin-top:34px;padding-top:20px}
.prose>p:last-child a{color:var(--blue-deep)}
.letter-paper{background:#fff;border:1px solid var(--line);border-radius:12px;padding:30px 32px;margin:0 0 26px;box-shadow:0 20px 48px rgba(38,109,170,.12);font-size:14.5px;line-height:1.7;color:var(--ink)}
.letter-paper p{margin:0 0 14px}
.letter-meta{color:var(--faint);font-size:13.5px}
.letter-sig{margin-top:22px}
.ph{background:rgba(23,105,200,.1);color:var(--blue-deep);border-radius:5px;padding:1px 6px;font-weight:600;font-style:normal;white-space:nowrap}
.end-cta{max-width:760px;margin:20px auto 0;background:linear-gradient(135deg,#fff,#eef8ff 55%,#eafaf6);border:1px solid var(--line);border-radius:20px;padding:40px;text-align:center;box-shadow:0 24px 60px rgba(38,109,170,.1)}
.end-cta h2{font-size:25px;font-weight:750;letter-spacing:-.015em;margin:0 0 10px}
.end-cta p{font-size:15.5px;color:var(--body);max-width:480px;margin:0 auto 24px}
footer{border-top:1px solid var(--line);padding:30px 0 44px;margin-top:80px}
.foot{display:flex;justify-content:space-between;align-items:center;font-size:13px;color:var(--body);gap:20px;flex-wrap:wrap}
.foot nav{display:flex;gap:22px}
.foot a{color:var(--blue-deep);text-decoration:none}
.prose blockquote{margin:0 0 14px;padding:16px 20px;background:rgba(23,105,200,.05);border-left:3px solid var(--blue);border-radius:0 10px 10px 0;font-size:16px;color:var(--ink)}
.prose .src{font-size:13px;color:var(--faint);margin:-4px 0 24px}
.prose .lead{font-size:19px;line-height:1.6;color:var(--ink);font-weight:500;margin:0 0 26px}
.related{list-style:none;padding:18px 0 0;margin:36px 0 0;border-top:1px solid var(--line);display:grid;gap:10px}
.related li{margin:0}
.related a{display:inline-flex;align-items:baseline;gap:9px;color:var(--blue-deep);text-decoration:none;font-weight:600;font-size:15px}
.related a::before{content:"→";color:var(--teal)}
.related a:hover{text-decoration:underline}
/* reference index */
.ref-hero{max-width:720px;margin:0 auto;text-align:center;padding:56px 0 10px}
.ref-hero h1{font-size:44px;line-height:1.08;font-weight:750;letter-spacing:-.02em;margin:0 0 16px}
.ref-hero p{font-size:18px;line-height:1.6;color:var(--body);margin:0 auto;max-width:560px}
.ref-sec{margin:56px 0 0}
.ref-sec h2{font-size:14px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--teal-ink);margin:0 0 18px}
.ref-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.ref-card{display:block;background:rgba(255,255,255,.9);border:1px solid var(--line);border-radius:14px;padding:20px 22px;box-shadow:0 14px 34px rgba(38,109,170,.08);transition:transform .2s,box-shadow .2s;color:var(--ink);text-decoration:none}
.ref-card:hover{transform:translateY(-3px);box-shadow:0 22px 50px rgba(38,109,170,.15);text-decoration:none}
.ref-card b{display:block;font-size:16px;font-weight:700;line-height:1.3;margin:0 0 6px;letter-spacing:-.01em}
.ref-card span{font-size:13.5px;color:var(--body);line-height:1.5}
.carc-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px}
.carc-chip{display:flex;flex-direction:column;gap:2px;background:rgba(255,255,255,.9);border:1px solid var(--line);border-radius:11px;padding:13px 15px;color:var(--ink);transition:border-color .2s,transform .2s;text-decoration:none}
.carc-chip:hover{border-color:rgba(23,105,200,.45);transform:translateY(-2px);text-decoration:none}
.carc-chip b{font-size:15px;font-weight:750;color:var(--blue-deep)}
.carc-chip span{font-size:12px;color:var(--faint);line-height:1.35}
@media(max-width:760px){.ref-grid{grid-template-columns:1fr}}
@media(max-width:900px){.art{grid-template-columns:minmax(0,720px)}.toc{display:none}.art-head h1{font-size:32px}.ref-hero h1{font-size:32px}.nav nav .hideable{display:none}}
.dl-list{display:grid;gap:14px;margin:0 0 8px}
.dl{border:1px solid var(--line);border-radius:14px;padding:20px 22px;background:rgba(255,255,255,.85)}
.dl-top{display:flex;justify-content:space-between;gap:16px;align-items:baseline;flex-wrap:wrap}
.dl-rule{font-size:16px;font-weight:700;color:var(--ink);margin:0}
.dl-win{font-size:15px;font-weight:800;color:var(--blue-deep);white-space:nowrap;font-variant-numeric:tabular-nums}
.dl-meta{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0 0}
.dl-badge{font-size:11px;font-weight:700;letter-spacing:.03em;text-transform:uppercase;padding:4px 10px;border-radius:999px}
.dl-ours{background:rgba(15,139,141,.1);color:var(--teal-ink)}
.dl-theirs{background:rgba(23,105,200,.09);color:var(--blue-deep)}
.dl-ver{background:rgba(11,140,99,.1);color:var(--green)}
.dl-clock{font-size:13px;color:var(--body);margin:10px 0 0}
.dl-quote{margin:13px 0 0;padding:12px 16px;background:rgba(23,105,200,.05);border-left:3px solid var(--blue);border-radius:0 8px 8px 0;font-size:13.5px;line-height:1.55;color:var(--ink)}
.dl-src{font-size:12.5px;margin:11px 0 0;color:var(--faint)}
.dl-src a{color:var(--blue-deep)}
.dl-note{font-size:13.5px;color:var(--body);background:rgba(183,121,31,.08);border:1px solid rgba(183,121,31,.22);border-radius:10px;padding:12px 16px;margin:0 0 26px;line-height:1.55}
.dl-disc{font-size:13px;color:var(--faint);border-top:1px solid var(--line);margin-top:30px;padding-top:18px;line-height:1.55}
.prose .warning{background:rgba(23,105,200,.06);border-left:3px solid var(--blue);border-radius:0 10px 10px 0;padding:15px 20px;margin:0 0 22px;color:var(--ink);font-size:16px;line-height:1.6}
.prose .warning strong{color:var(--ink)}
.legal-updated{font-size:13.5px;color:var(--teal-ink);font-weight:650;margin:0 0 6px}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}