:root{--accent:#0891b2;--accent-d:#0e7490;--accent-l:#ecfeff;--accent-m:#cffafe;--ink:#0f172a;--ink2:#334155;--muted:#64748b;--line:#e2e8f0;--bg:#fff;--soft:#f8fafc;--warn:#fffbeb;--warn-b:#f59e0b;--r:14px}
[hidden]{display:none!important}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.65;font-size:17px}
a{color:var(--accent-d);text-underline-offset:2px}
a:hover{color:var(--accent)}
img,svg{max-width:100%}
.wrap{max-width:1120px;margin:0 auto;padding:0 20px}
.narrow{max-width:760px}
.small{font-size:.88rem}.muted{color:var(--muted)}
.skip{position:absolute;left:-999px}.skip:focus{left:10px;top:10px;background:#fff;padding:8px;z-index:9}
/* header */
.site-header{border-bottom:1px solid var(--line);background:rgba(255,255,255,.92);backdrop-filter:saturate(1.5) blur(8px);position:sticky;top:0;z-index:5}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:64px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-size:1.15rem;letter-spacing:-.01em}
.brand b,.brand-foot b{color:var(--accent)}
.nav{display:flex;gap:4px;flex-wrap:wrap}
.nav a{text-decoration:none;color:var(--ink2);padding:8px 12px;border-radius:999px;font-size:.95rem;font-weight:500}
.nav a:hover{background:var(--accent-l);color:var(--accent-d)}
/* hero */
.hero{background:linear-gradient(180deg,var(--accent-l),#fff);padding:64px 0 48px}
.hero-inner{display:grid;grid-template-columns:1.2fr .8fr;gap:48px;align-items:center}
.eyebrow{text-transform:uppercase;letter-spacing:.08em;font-size:.8rem;font-weight:700;color:var(--accent-d);margin:0 0 10px}
h1{font-size:clamp(1.9rem,4.2vw,2.9rem);line-height:1.15;letter-spacing:-.02em;margin:0 0 16px}
h2{font-size:1.55rem;line-height:1.25;letter-spacing:-.01em;margin:2.2em 0 .6em}
h3{font-size:1.18rem;line-height:1.3;margin:1.6em 0 .4em}
.lede{font-size:1.15rem;color:var(--ink2);margin:0 0 24px}
.hero-card{background:#fff;border:1px solid var(--line);border-radius:24px;padding:20px;box-shadow:0 20px 50px -24px rgba(8,145,178,.35)}
.cta-row{display:flex;gap:12px;flex-wrap:wrap}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;font-weight:600;padding:12px 22px;border-radius:999px;border:2px solid var(--accent);transition:.15s}
.btn:hover{background:var(--accent-d);border-color:var(--accent-d);color:#fff}
.btn-ghost{background:#fff;color:var(--accent-d)}
.btn-ghost:hover{background:var(--accent-l);color:var(--accent-d)}
.btn-sm{padding:7px 14px;font-size:.88rem}
.trust{display:flex;gap:28px;flex-wrap:wrap;justify-content:center;padding:22px 20px;color:var(--ink2);font-size:.95rem}
.trust-item{display:flex;align-items:center;gap:8px}
.section{padding:28px 20px}
/* cards */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));gap:20px}
.card{display:flex;flex-direction:column;border:1px solid var(--line);border-radius:var(--r);padding:22px;text-decoration:none;color:var(--ink);background:#fff;transition:.15s}
.card:hover{border-color:var(--accent);box-shadow:0 10px 30px -18px rgba(8,145,178,.5);transform:translateY(-2px);color:var(--ink)}
.card h3{margin:.5em 0 .4em}
.card p{color:var(--ink2);font-size:.95rem;margin:0 0 14px;flex:1}
.tag{align-self:flex-start;background:var(--accent-l);color:var(--accent-d);font-size:.75rem;font-weight:700;padding:3px 10px;border-radius:999px;text-transform:uppercase;letter-spacing:.04em}
.more{color:var(--accent-d);font-weight:600;font-size:.92rem}
.callout{display:flex;gap:24px;align-items:center;justify-content:space-between;background:var(--soft);border:1px solid var(--line);border-radius:20px;margin:28px auto 56px;padding:28px 32px}
.callout h2{margin-top:0}
/* article */
.article-head{background:linear-gradient(180deg,var(--accent-l),#fff);padding:40px 0 16px}
.crumbs{color:var(--muted);margin-bottom:10px}.crumbs a{color:var(--muted)}
.meta{color:var(--muted);margin:0 0 12px}
.disclosure{display:flex;gap:8px;align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 14px;color:var(--ink2)}
.disclosure svg{flex:none;margin-top:3px;color:var(--accent)}
.prose{padding-bottom:40px}
.prose p,.prose li{color:var(--ink2)}
.prose li{margin:.3em 0}
.prose strong{color:var(--ink)}
.toc{background:var(--soft);border:1px solid var(--line);border-radius:var(--r);padding:16px 22px;margin:20px 0}
.toc-h{font-weight:700;margin:0 0 6px;color:var(--ink)}
.toc ol{margin:0;padding-left:20px}.toc a{text-decoration:none}
.table-wrap{overflow-x:auto;margin:20px 0;border:1px solid var(--line);border-radius:var(--r)}
table{border-collapse:collapse;width:100%;font-size:.93rem;min-width:560px}
th,td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
thead th{background:var(--accent-l);color:var(--ink);font-weight:700;white-space:nowrap}
tbody tr:last-child td{border-bottom:0}
tbody tr:nth-child(even){background:#fcfeff}
.note,.warn,.tip{border-radius:12px;padding:14px 18px;margin:20px 0;border:1px solid}
.note{background:var(--accent-l);border-color:var(--accent-m)}
.warn{background:var(--warn);border-color:#fde68a}
.tip{background:#f0fdf4;border-color:#bbf7d0}
.note p,.warn p,.tip p{margin:.3em 0}
.pick{border:1px solid var(--line);border-left:5px solid var(--accent);border-radius:var(--r);padding:18px 22px;margin:22px 0;background:#fff}
.pick h3{margin-top:0}
.pick .btn{margin-top:6px}
.checklist{list-style:none;padding-left:0}
.checklist li{padding-left:30px;position:relative}
.checklist li:before{content:"";position:absolute;left:0;top:.35em;width:18px;height:18px;border:2px solid var(--accent);border-radius:5px}
.faq details{border:1px solid var(--line);border-radius:12px;padding:12px 18px;margin:10px 0;background:#fff}
.faq summary{font-weight:600;cursor:pointer;color:var(--ink)}
.faq details[open] summary{margin-bottom:6px}
.related{padding-bottom:56px}
.related h2{margin-top:0}
.sources{font-size:.88rem}
/* calculator */
.calc{border:1px solid var(--accent-m);background:#fff;border-radius:20px;padding:22px;margin:24px 0;box-shadow:0 18px 40px -28px rgba(8,145,178,.6)}
.calc h3{margin:.2em 0 .6em}
.calc fieldset{border:0;padding:0;margin:0 0 14px}
.calc legend{font-weight:700;margin-bottom:8px;color:var(--ink)}
.grid2{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px;align-items:end}
.calc label{display:block;font-size:.88rem;font-weight:600;color:var(--ink2)}
.calc input,.calc select{width:100%;margin-top:4px;padding:10px 12px;font-size:1rem;border:1px solid #cbd5e1;border-radius:10px;font-family:inherit;background:#fff}
.calc input:focus,.calc select:focus{outline:3px solid var(--accent-m);border-color:var(--accent)}
.result{background:var(--accent-l);border-radius:14px;padding:14px 18px;margin-top:12px}
.result .big{font-size:1.6rem;font-weight:800;color:var(--accent-d);display:block;line-height:1.2}
.result p{margin:.25em 0}
.seg{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:12px}
.seg button{border:1px solid #cbd5e1;background:#fff;border-radius:999px;padding:7px 14px;font:inherit;font-size:.9rem;cursor:pointer}
.seg button[aria-pressed=true]{background:var(--accent);border-color:var(--accent);color:#fff}
/* footer */
.site-footer{background:var(--soft);border-top:1px solid var(--line);padding:40px 0 20px;margin-top:20px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:32px}
.brand-foot{font-size:1.1rem;margin:0 0 8px}
.foot-h{font-weight:700;margin:0 0 8px}
.foot-links{list-style:none;padding:0;margin:0;font-size:.92rem}.foot-links li{margin:5px 0}
.foot-links a{color:var(--ink2);text-decoration:none}.foot-links a:hover{color:var(--accent)}
.foot-bottom{border-top:1px solid var(--line);margin-top:24px;padding-top:16px}
@media (max-width:820px){.site-header{position:static}.header-inner{min-height:56px;padding-top:8px;padding-bottom:4px}.nav{flex-wrap:nowrap;overflow-x:auto;width:100%;margin:0 -8px}.nav a{white-space:nowrap;font-size:.9rem;padding:6px 10px}.hero-inner{grid-template-columns:1fr}.hero-card{display:none}.footer-grid{grid-template-columns:1fr}.callout{flex-direction:column;align-items:flex-start}.hero{padding:40px 0 32px}body{font-size:16px}}
@media (min-width:1100px){.prose .table-wrap{margin-left:-110px;margin-right:-110px}}
.pin-save{display:flex;gap:22px;align-items:center;background:var(--soft);border:1px solid var(--line);border-radius:var(--r);padding:18px;margin:32px 0}
.pin-save img{width:150px;height:auto;border-radius:10px;flex:none;box-shadow:0 8px 24px -14px rgba(15,23,42,.45)}
.pin-save figcaption{display:flex;flex-direction:column;align-items:flex-start;gap:6px}
.pin-save .pin-h{font-weight:700;color:var(--ink);margin:0;font-size:1.05rem}
.pin-save p{margin:0}
@media (max-width:520px){.pin-save{flex-direction:column;align-items:flex-start}.pin-save img{width:140px}}
.hub-list{display:grid;gap:16px;margin:24px 0 48px}
.topics{display:flex;flex-wrap:wrap;gap:10px;margin:12px 0 0}
.topics a{border:1px solid var(--line);border-radius:999px;padding:8px 16px;text-decoration:none;font-weight:600;background:#fff}
.topics a:hover{border-color:var(--accent)}
.card .h3{font-size:1.17em;margin:.5em 0 .4em}