:root{--bg:#f6f8fb;--card:#fff;--ink:#1a2230;--mut:#5b6b82;--line:#e4e9f0;--brand:#1e6bd6;--brand2:#12437f;--accent:#0fb98b;--accentbg:#e8f8f2;--warn:#b76b00;--shadow:0 1px 3px rgba(20,40,80,.06),0 8px 24px rgba(20,40,80,.05);}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;line-height:1.6;font-size:16px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1080px;margin:0 auto;padding:0 20px}
header.site{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
header.site .container{display:flex;align-items:center;justify-content:space-between;height:62px}
.logo{font-weight:800;font-size:20px;letter-spacing:-.02em;color:var(--ink);display:flex;align-items:center;gap:8px}
.logo .mark{width:26px;height:26px;border-radius:7px;background:linear-gradient(135deg,var(--brand),var(--accent));display:inline-block}
nav.top a{color:var(--mut);font-weight:600;font-size:14.5px;margin-left:20px}
nav.top a:hover{color:var(--brand);text-decoration:none}
.hero{background:linear-gradient(160deg,#0e356d 0%,#1e6bd6 100%);color:#fff;padding:52px 0 46px}
.hero h1{margin:0 0 10px;font-size:34px;letter-spacing:-.02em}
.hero p{margin:0;font-size:18px;opacity:.92;max-width:620px}
.search{margin-top:22px;max-width:520px}
.search input{width:100%;padding:14px 16px;border-radius:12px;border:0;font-size:16px;box-shadow:var(--shadow)}
main{padding:34px 0 60px}
h2.section{font-size:14px;text-transform:uppercase;letter-spacing:.06em;color:var(--mut);margin:34px 0 12px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px 18px 16px;box-shadow:var(--shadow);transition:transform .12s ease,box-shadow .12s ease;display:block}
.card:hover{transform:translateY(-2px);box-shadow:0 6px 14px rgba(20,40,80,.10),0 16px 40px rgba(20,40,80,.08);text-decoration:none}
.card h3{margin:0 0 6px;font-size:17.5px;color:var(--ink)}
.card p{margin:0;color:var(--mut);font-size:14px}
.card .cat{display:inline-block;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.04em;color:var(--brand);background:#eaf1fc;padding:3px 8px;border-radius:20px;margin-bottom:10px}
.breadcrumb{font-size:13.5px;color:var(--mut);margin:0 0 14px}
.breadcrumb a{color:var(--mut)}
.layout{display:grid;grid-template-columns:1fr 300px;gap:28px;align-items:start}
@media(max-width:860px){.layout{grid-template-columns:1fr}.hero h1{font-size:27px}}
.page h1{font-size:28px;letter-spacing:-.02em;margin:0 0 6px}
.lead{color:var(--mut);font-size:17px;margin:0 0 22px}
.calc{background:var(--card);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);padding:22px;margin-bottom:26px}
.fields{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:520px){.fields{grid-template-columns:1fr}}
.field{display:flex;flex-direction:column;gap:6px}
.field.full{grid-column:1/-1}
.field label{font-size:13.5px;font-weight:600;color:var(--ink)}
.inputrow{display:flex;gap:8px}
.field input,.field select{padding:11px 12px;border:1px solid var(--line);border-radius:10px;font-size:15px;background:#fff;color:var(--ink);width:100%}
.field .unit{max-width:96px}
.field input:focus,.field select:focus{outline:2px solid rgba(30,107,214,.35);border-color:var(--brand)}
.results{margin-top:20px;background:linear-gradient(160deg,#f2fbf8,#eef6ff);border:1px solid #d9ece6;border-radius:14px;padding:18px 20px}
.primary{display:flex;align-items:baseline;gap:10px;flex-wrap:wrap}
.primary .plabel{font-size:14px;color:var(--mut);font-weight:600}
.primary .pval{font-size:34px;font-weight:800;letter-spacing:-.02em;color:var(--brand2)}
.primary .punit{font-size:16px;color:var(--mut);font-weight:600}
.rows{margin-top:12px;display:grid;gap:8px}
.rowline{display:flex;justify-content:space-between;font-size:15px;border-top:1px dashed #cfe3dc;padding-top:8px}
.rowline .rl{color:var(--mut)}
.rowline .rv{font-weight:700;font-variant-numeric:tabular-nums}
.note{margin-top:12px;font-size:13.5px;color:var(--warn);background:#fff8ee;border:1px solid #f2e2c4;border-radius:10px;padding:9px 12px}
.prose h2{font-size:20px;margin:30px 0 8px;letter-spacing:-.01em}
.prose p{color:#33405a}
.formula{background:#0e1b30;color:#dbe7ff;border-radius:10px;padding:12px 14px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:14px;overflow-x:auto}
.faq{border:1px solid var(--line);border-radius:12px;background:#fff;padding:4px 16px;margin-top:10px}
.faq details{border-bottom:1px solid var(--line)}
.faq details:last-child{border-bottom:0}
.faq summary{cursor:pointer;font-weight:600;padding:13px 0;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"+";color:var(--brand);font-weight:800;margin-right:10px}
.faq details[open] summary::before{content:"–"}
.faq p{margin:0 0 13px;color:#33405a;font-size:15px}
aside .box{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px 18px;box-shadow:var(--shadow);margin-bottom:18px}
aside .box h4{margin:0 0 10px;font-size:13px;text-transform:uppercase;letter-spacing:.05em;color:var(--mut)}
aside .box ul{margin:0;padding:0;list-style:none}
aside .box li{margin:0 0 9px}
aside .box a{font-weight:600;font-size:14.5px}
.adslot{border:1px dashed #c7d2e2;border-radius:12px;background:#fbfdff;color:#9fb0c8;font-size:12px;text-align:center;padding:22px 10px;margin:18px 0}
footer.site{background:#0e1b30;color:#aab8cf;padding:34px 0 40px;font-size:14px}
footer.site a{color:#cdd9ee}
footer.site .cols{display:flex;flex-wrap:wrap;gap:30px;justify-content:space-between}
footer.site h5{color:#fff;font-size:13px;text-transform:uppercase;letter-spacing:.05em;margin:0 0 10px}
footer.site ul{list-style:none;padding:0;margin:0;line-height:2}
.fnote{margin-top:26px;border-top:1px solid #23334f;padding-top:16px;color:#8296b4;font-size:12.5px}
.tabbar{display:flex;gap:6px;overflow-x:auto;padding:10px 0;position:sticky;top:0;background:var(--bg);z-index:10;border-bottom:1px solid var(--line)}
.tabbar button{white-space:nowrap;border:1px solid var(--line);background:#fff;color:var(--mut);font-weight:600;font-size:13.5px;padding:8px 13px;border-radius:20px;cursor:pointer}
.tabbar button.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.tabpane{display:none}.tabpane.active{display:block}