*,*::before,*::after{box-sizing:border-box}
:root{
  --ink:#0f1a2e;--mut:#5b6b85;--line:#e3e8f2;--bg:#f4f7fc;--card:#fff;
  --acc:#1b4fd8;--acc-soft:#ecf1ff;--ok:#0b7a4d;--ok-soft:#e7f6ef;
  --warn:#a8550a;--warn-soft:#fdf2e3;
}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);
  font:16px/1.68 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei",sans-serif}
a{color:var(--acc);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1080px;margin:0 auto;padding:0 20px}

header.site{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.94);
  backdrop-filter:saturate(1.4) blur(8px);border-bottom:1px solid var(--line)}
header.site .wrap{display:flex;align-items:center;gap:18px;height:62px}
.logo{font-weight:750;font-size:16px;letter-spacing:-.2px;color:var(--ink);white-space:nowrap}
.logo span{color:var(--acc)}
nav.main{margin-left:auto;display:flex;gap:4px;flex-wrap:wrap}
nav.main a{font-size:14px;color:#3c4b64;padding:7px 10px;border-radius:8px}
nav.main a:hover{background:var(--acc-soft);color:var(--acc);text-decoration:none}
nav.main a.on{background:var(--acc-soft);color:var(--acc);font-weight:600}

main{padding:34px 0 10px}
h1{font-size:31px;line-height:1.25;letter-spacing:-.6px;margin:0 0 12px}
h2{font-size:22px;line-height:1.35;letter-spacing:-.3px;margin:36px 0 12px}
h3{font-size:17px;margin:22px 0 8px}
p{margin:0 0 14px}
.lede{font-size:17px;color:var(--mut);max-width:70ch;margin:0 0 22px}
.breadcrumb{font-size:13px;color:var(--mut);margin:0 0 14px}
.breadcrumb a{color:var(--mut)}

.card{background:var(--card);border:1px solid var(--line);border-radius:16px;
  padding:22px;box-shadow:0 1px 2px rgba(16,26,46,.04)}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.grid-tools{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:8px}
.tool-link{display:block;background:#fff;border:1px solid var(--line);border-radius:13px;padding:15px 16px}
.tool-link:hover{border-color:#c3d2f0;text-decoration:none;box-shadow:0 4px 14px rgba(27,79,216,.07)}
.tool-link b{display:block;font-size:15px;margin-bottom:4px;color:var(--ink)}
.tool-link span{font-size:13.5px;color:var(--mut);line-height:1.5}

/* calculator */
.calc{display:grid;grid-template-columns:1.05fr .95fr;gap:0;border:1px solid var(--line);
  border-radius:18px;overflow:hidden;background:#fff;box-shadow:0 2px 10px rgba(16,26,46,.05)}
.calc-in{padding:24px}
.calc-out{padding:24px;background:linear-gradient(180deg,#f7f9ff,#eef3ff);border-left:1px solid var(--line)}
.modes{display:flex;gap:6px;background:#eef2f9;padding:4px;border-radius:10px;margin-bottom:18px}
.modes button{flex:1;border:0;background:transparent;padding:8px 6px;border-radius:8px;
  font:inherit;font-size:13.5px;color:#46556e;cursor:pointer}
.modes button.on{background:#fff;color:var(--acc);font-weight:650;box-shadow:0 1px 3px rgba(16,26,46,.12)}
.field{margin-bottom:16px}
.field label{display:flex;justify-content:space-between;align-items:baseline;
  font-size:14px;font-weight:600;margin-bottom:7px}
.field label em{font-style:normal;font-weight:500;font-size:12.5px;color:var(--mut)}
.field .row{display:flex;gap:10px;align-items:center}
input[type=number]{width:96px;padding:10px 12px;border:1px solid #ccd6e6;border-radius:9px;
  font:inherit;font-weight:650;font-size:16px;color:var(--ink)}
input[type=number]:focus,select:focus{outline:2px solid #b9cdfb;outline-offset:1px}
input[type=range]{flex:1;accent-color:var(--acc)}
select{padding:9px 10px;border:1px solid #ccd6e6;border-radius:9px;font:inherit;font-size:14px;background:#fff;max-width:100%}
.hint{font-size:12.5px;color:var(--mut);margin-top:6px}

.big{font-size:52px;font-weight:800;letter-spacing:-2px;line-height:1;color:var(--acc)}
.big small{font-size:19px;font-weight:600;color:var(--mut);letter-spacing:0}
.out-label{font-size:12px;text-transform:uppercase;letter-spacing:.8px;color:var(--mut);font-weight:700;margin:0 0 6px}
.split{display:flex;gap:24px;margin-top:16px;padding-top:16px;border-top:1px dashed #c9d6ee}
.split div{flex:1}
.split .v{font-size:22px;font-weight:750;letter-spacing:-.5px}
.split .k{font-size:12.5px;color:var(--mut)}
.verdict{margin-top:16px;padding:13px 14px;border-radius:11px;font-size:14px;line-height:1.55}
.verdict.ok{background:var(--ok-soft);color:#0a5c3d;border:1px solid #bfe6d3}
.verdict.warn{background:var(--warn-soft);color:#7c3f06;border:1px solid #f0d6ae}
.verdict b{font-weight:750}

table{width:100%;border-collapse:collapse;font-size:14.5px;background:#fff}
.tablewrap{border:1px solid var(--line);border-radius:13px;overflow:hidden;overflow-x:auto}
th,td{padding:9px 12px;text-align:left;border-bottom:1px solid var(--line)}
th{background:#f2f6fd;font-size:12.5px;text-transform:uppercase;letter-spacing:.5px;color:#46556e;font-weight:700;white-space:nowrap}
tbody tr:last-child td{border-bottom:0}
tbody tr:hover{background:#fafcff}
td.num,th.num{text-align:right;font-variant-numeric:tabular-nums}
.up{color:#3d4b63;font-weight:650}
.down{color:#3d4b63;font-weight:650}

.note{background:var(--acc-soft);border-left:3px solid var(--acc);border-radius:0 11px 11px 0;
  padding:14px 16px;font-size:14.5px;color:#233a6b;margin:18px 0}
.note b{color:#12285c}
.warnbox{background:var(--warn-soft);border-left:3px solid #e0a05a;border-radius:0 11px 11px 0;
  padding:14px 16px;font-size:14.5px;color:#6f3c05;margin:18px 0}

details.faq{background:#fff;border:1px solid var(--line);border-radius:12px;padding:0;margin-bottom:10px}
details.faq summary{cursor:pointer;padding:15px 18px;font-weight:650;font-size:15.5px;list-style:none;position:relative}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary::after{content:"+";position:absolute;right:18px;top:13px;color:var(--mut);font-weight:400;font-size:19px}
details.faq[open] summary::after{content:"–"}
details.faq .body{padding:0 18px 16px;color:#33415a;font-size:15px}

footer.site{margin-top:52px;border-top:1px solid var(--line);background:#fff;padding:30px 0 40px}
footer.site .wrap{display:flex;flex-wrap:wrap;gap:26px;justify-content:space-between;align-items:flex-start}
footer.site .col{font-size:13.5px;color:var(--mut);max-width:44ch}
footer.site .col b{display:block;color:var(--ink);font-size:13.5px;margin-bottom:8px}
footer.site .col a{display:block;color:var(--mut);padding:2px 0}
footer.site .legal{width:100%;border-top:1px solid var(--line);padding-top:16px;font-size:12.5px;color:#7c8aa1}

.related{margin-top:30px}
.related h2{margin-top:0}

@media (max-width:880px){
  .calc{grid-template-columns:1fr}
  .calc-out{border-left:0;border-top:1px solid var(--line)}
  .grid2,.grid3,.grid-tools{grid-template-columns:1fr}
  h1{font-size:26px}
  header.site .wrap{height:auto;padding:10px 20px;flex-wrap:wrap}
  nav.main{margin-left:0;width:100%;gap:2px}
  nav.main a{padding:6px 8px;font-size:13px}
  main{padding:22px 0 0}
  .big{font-size:44px}
}