:root{
  --navy:#0b1026; --navy2:#131a3d; --violet:#6d5cff; --blue:#2f7bff;
  --grad:linear-gradient(90deg,#2f7bff,#6d5cff);
  --bg:#f6f7fb; --card:#ffffff; --ink:#1c2130; --muted:#5b6274;
  --line:#e3e6f0; --good:#0a7d4f; --warn:#b8860b; --bad:#c0392b;
  --radius:14px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1080px;margin:0 auto;padding:0 18px}
header.site{background:var(--navy);color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 2px 10px rgba(0,0,0,.25)}
header.site .wrap{display:flex;align-items:center;gap:18px;padding-top:12px;padding-bottom:12px}
.logo{display:flex;align-items:center;gap:10px;color:#fff;font-weight:800;font-size:20px;letter-spacing:.2px}
.logo:hover{text-decoration:none}
.logo .mark{width:38px;height:38px;border-radius:9px;background:#fff;display:inline-flex;align-items:center;justify-content:center;overflow:hidden;flex:none}
.logo .mark img{width:100%;height:100%;object-fit:cover;display:block}
.foot-logo{background:#fff;border-radius:12px;padding:10px 14px;max-width:230px;margin-bottom:14px}
.foot-logo img{width:100%;height:auto;display:block}
.logo small{display:block;font-weight:500;font-size:11px;color:#aeb6d9;letter-spacing:1.2px}
nav.main{margin-left:auto;display:flex;gap:16px;flex-wrap:wrap}
nav.main a{color:#dfe4ff;font-size:14.5px;font-weight:600}
.hero{background:linear-gradient(135deg,var(--navy) 0%,var(--navy2) 55%,#241a5e 100%);color:#fff;padding:52px 0 44px}
.hero h1{font-size:38px;line-height:1.15;margin:0 0 12px}
.hero p{color:#c9d0f2;font-size:17px;max-width:720px;margin:0 0 22px}
.searchbox{display:flex;gap:10px;max-width:620px}
.searchbox input{flex:1;padding:14px 16px;border-radius:11px;border:none;font-size:16px}
.badges{margin-top:16px;color:#aeb6d9;font-size:13.5px}
.badges span{margin-right:16px}
main{padding:28px 0 10px}
h2.sec{font-size:23px;margin:30px 0 6px}
p.secsub{color:var(--muted);margin:0 0 14px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(235px,1fr));gap:14px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;display:block;color:var(--ink);transition:transform .12s,box-shadow .12s}
.card:hover{text-decoration:none;transform:translateY(-2px);box-shadow:0 8px 22px rgba(20,25,60,.10)}
.card .ic{font-size:24px}
.card h3{margin:8px 0 4px;font-size:16.5px}
.card p{margin:0;color:var(--muted);font-size:13.5px}
.cat-tag{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.6px;text-transform:uppercase;color:var(--violet);margin-top:8px}
article.toolpage,article.plain{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;margin-bottom:22px}
article h1{font-size:30px;margin:2px 0 8px;line-height:1.2}
.lede{color:var(--muted);font-size:16.5px;margin:0 0 18px}
.crumbs{font-size:13px;color:var(--muted);margin-bottom:10px}
.toolbox{background:#fbfcff;border:1.5px solid var(--line);border-radius:12px;padding:20px;margin:18px 0 24px}
label.f{display:block;font-weight:600;font-size:13.5px;margin:12px 0 5px}
input[type=text],input[type=number],input[type=date],input[type=file],select,textarea{width:100%;padding:10px 12px;border:1.5px solid #ccd2e4;border-radius:9px;font-size:15px;font-family:inherit;background:#fff;color:var(--ink)}
textarea{min-height:130px;resize:vertical}
input:focus,select:focus,textarea:focus{outline:2px solid #b9ccff;border-color:var(--blue)}
.row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.row3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px}
@media(max-width:640px){.row,.row3{grid-template-columns:1fr}.hero h1{font-size:29px}article h1{font-size:25px}}
.btn{display:inline-block;background:var(--grad);color:#fff;border:none;padding:11px 20px;border-radius:9px;font-size:15px;font-weight:700;cursor:pointer;margin-top:14px}
.btn:hover{opacity:.92;text-decoration:none}
.btn.secondary{background:#eef1fb;color:var(--navy);border:1.5px solid var(--line)}
.btn.small{padding:7px 13px;font-size:13.5px;margin-top:0}
.btnrow{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.checks{display:flex;gap:16px;flex-wrap:wrap;margin-top:10px}
.checks label{font-size:14px;font-weight:500;display:flex;gap:6px;align-items:center}
.checks input{width:auto}
.result{background:#eef7f1;border:1.5px solid #bfe3cd;border-radius:10px;padding:16px 18px;margin-top:18px;display:none}
.result.show{display:block}
.result .big{font-size:27px;font-weight:800;color:var(--navy)}
table.break{width:100%;border-collapse:collapse;margin-top:10px;font-size:14.5px}
table.break td,table.break th{padding:7px 8px;border-bottom:1px solid var(--line);text-align:left}
table.break td:last-child,table.break th:last-child{text-align:right;font-variant-numeric:tabular-nums}
.error{background:#fdeeee;border:1.5px solid #f0c1c1;color:var(--bad);border-radius:9px;padding:10px 14px;margin-top:12px;display:none;font-size:14.5px}
.error.show{display:block}
.note{font-size:13px;color:var(--muted);margin-top:10px}
article h2{font-size:21px;margin:26px 0 8px}
article h3{font-size:17px;margin:18px 0 6px}
article p,article li{font-size:15.5px}
article code{background:#eef1fb;padding:1px 6px;border-radius:5px;font-size:14px}
.formula{background:#f2f4fd;border-left:4px solid var(--violet);padding:12px 16px;border-radius:0 9px 9px 0;font-size:15px}
.faq{border-top:1px solid var(--line);padding:12px 0}
.faq h3{margin:0 0 4px;font-size:16px}
.faq p{margin:0;color:#333a4d}
.stats{display:flex;gap:22px;flex-wrap:wrap;margin-top:8px}
.stats div b{font-size:22px;display:block;color:var(--navy)}
.stats div span{font-size:12.5px;color:var(--muted)}
output.val, .mono{font-variant-numeric:tabular-nums}
.bigclock{font-size:44px;font-weight:800;text-align:center;font-variant-numeric:tabular-nums;color:var(--navy);padding:8px 0}
.swatch{height:70px;border-radius:10px;border:1.5px solid var(--line);margin-top:12px}
footer.site{background:var(--navy);color:#c9d0f2;margin-top:44px;padding:34px 0 26px;font-size:14px}
footer.site .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:22px}
footer.site h4{color:#fff;margin:0 0 10px;font-size:15px}
footer.site a{color:#c9d0f2;display:block;margin:5px 0}
footer.site .brand{font-weight:800;color:#fff;font-size:17px}
footer.site .fine{border-top:1px solid #26305e;margin-top:22px;padding-top:14px;color:#8f98bd;font-size:12.5px}
.hidden{display:none!important}