:root{
  --ink:#122339; --ink-2:#3d4d61; --muted:#657387; --line:#dce3eb;
  --bg:#f6f8fb; --card:#fff; --accent:#b25f00; --accent-soft:#fff0db;
  --radius:16px; --shadow:0 10px 30px #1423380b;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font:16px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
a{color:var(--ink); text-decoration:none; border-bottom:1px solid #c6d1de}
a:hover{border-bottom-color:var(--ink)}
code{font:0.92em/1.4 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace; background:#eef2f7; padding:1px 5px; border-radius:5px}
.sr{position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; border:0}

.topbar{
  display:flex; align-items:center; justify-content:space-between; gap:16px;
  padding:12px 20px; background:#fff; border-bottom:1px solid var(--line);
}
.brand{display:flex; align-items:center; gap:8px; font-weight:800; border:0; letter-spacing:-.01em}
.brand .dot{width:12px; height:12px; border-radius:4px; background:var(--ink); display:inline-block}
.topbar nav{display:flex; gap:14px; font-size:.86rem}
.topbar nav a{color:var(--muted); border:0}
.topbar nav a:hover{color:var(--ink)}

main{max-width:920px; margin:0 auto; padding:20px 20px 64px}

/* ---------- tool ---------- */
.tool{background:var(--card); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow); padding:20px}
h1{font-size:1.62rem; line-height:1.2; margin:0 0 6px; letter-spacing:-.02em}
.lede{margin:0 0 14px; color:var(--ink-2); font-size:.94rem}

.units{display:flex; align-items:center; gap:6px; margin:0 0 12px}
.units-lab{font-size:.74rem; letter-spacing:.04em; text-transform:uppercase; color:var(--muted); font-weight:700; margin-right:2px}
.seg{
  font:inherit; font-size:.82rem; font-weight:700; min-height:32px; padding:5px 12px;
  border:1px solid #c9d4e1; background:#fff; color:var(--muted); border-radius:8px; cursor:pointer;
}
.seg.on{background:var(--ink); border-color:var(--ink); color:#fff}

.panels{display:grid; grid-template-columns:1fr 1fr; gap:12px; align-items:start}
.panel{border:1px solid var(--line); border-radius:12px; padding:12px 12px 14px; background:#fbfcfe}
.ptitle{margin:0 0 10px; display:flex; align-items:center; gap:8px; font-weight:800; font-size:.92rem}
.pill{display:inline-flex; align-items:center; justify-content:center; width:22px; height:22px; border-radius:7px; font-size:.78rem; font-weight:800; color:#fff}
.pill-a{background:#122339}
.pill-b{background:#b25f00}

.pfields{display:grid; grid-template-columns:1fr 1fr; gap:8px}
.field{display:block; min-width:0}
.field.span2{grid-column:span 2}
.lab{display:block; font-size:.72rem; font-weight:700; letter-spacing:.04em; text-transform:uppercase; color:var(--muted); margin-bottom:4px}
.inline{display:flex; gap:6px; align-items:stretch}
input[type=number],select{
  width:100%; min-width:0; padding:9px 10px; font-size:.98rem; color:var(--ink);
  background:#fff; border:1px solid #c9d4e1; border-radius:9px; -webkit-appearance:none; appearance:none;
}
select{background-image:linear-gradient(45deg,transparent 50%,#7b8798 50%),linear-gradient(135deg,#7b8798 50%,transparent 50%);
  background-position:calc(100% - 15px) 52%,calc(100% - 10px) 52%; background-size:5px 5px,5px 5px; background-repeat:no-repeat; padding-right:28px}
input[type=number]:focus,select:focus{outline:2px solid #9dc0e8; outline-offset:1px; border-color:#9dc0e8}
.colon{align-self:center; color:var(--muted); font-weight:700; font-size:.9rem}
.hidden{display:none !important}

/* ---------- result ---------- */
.result{margin-top:14px; padding:14px 16px 12px; border-radius:12px; background:var(--ink); color:#fff}
.cmp{width:100%; border-collapse:collapse; font-size:.94rem; font-variant-numeric:tabular-nums}
.cmp th,.cmp td{text-align:right; padding:7px 8px; border-bottom:1px solid #24384f}
.cmp thead th{font-size:.68rem; letter-spacing:.06em; text-transform:uppercase; color:#8ea0b5; font-weight:700; padding-bottom:5px}
.cmp tbody th{text-align:left; font-weight:600; color:#c3cfdd; font-size:.86rem}
.cmp tbody td{font-weight:700; color:#fff}
.cmp tbody td.d{color:#ffd08a}
.cmp tbody td .p{margin-left:6px; color:#93a6bc; font-weight:600; font-size:.86em}
.cmp tr:last-child th,.cmp tr:last-child td{border-bottom:0}
.verdict{margin:10px 0 0; font-size:.9rem; line-height:1.45; color:#dbe5ef}
.actions{display:flex; align-items:center; gap:12px; margin-top:10px}
button#copy{
  font:inherit; font-weight:700; padding:10px 16px; min-height:42px; border-radius:9px;
  border:1px solid #ffd08a; background:#ffd08a; color:#12233a; cursor:pointer;
}
button#copy:active{transform:translateY(1px)}
.copied{font-size:.82rem; color:#8fe0b0; font-weight:600}

/* ---------- prose ---------- */
.prose{background:var(--card); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow); padding:20px; margin-top:18px}
h2{font-size:1.12rem; margin:22px 0 8px; letter-spacing:-.01em}
h2:first-child{margin-top:0}
.prose p{color:var(--ink-2); font-size:.94rem}
.eq{margin:10px 0; padding:12px 14px; background:#f2f6fa; border-radius:10px; font-size:.9rem; color:var(--ink)}
.eq p{margin:4px 0; color:var(--ink)}
.faq details{border-top:1px solid #eef2f6; padding:10px 0}
.faq details:first-of-type{border-top:0}
.faq summary{cursor:pointer; font-weight:700; font-size:.96rem}
.faq details p{margin:8px 0 0; font-size:.92rem}

footer{max-width:920px; margin:0 auto; padding:0 20px 40px; display:flex; justify-content:space-between; gap:16px; font-size:.84rem; color:var(--muted)}
footer a{color:var(--muted); border:0}
footer nav{display:flex; gap:14px}

@media(max-width:760px){
  main{padding:10px 10px 40px}
  .tool,.prose{padding:12px; border-radius:14px}
  .topbar{padding:8px 12px}
  .topbar nav a:first-child{display:none}
  h1{font-size:1.24rem; line-height:1.16; margin-bottom:4px}
  .lede{font-size:.82rem; line-height:1.35; margin-bottom:9px}
  .units{margin-bottom:9px}
  .seg{min-height:30px; padding:4px 10px; font-size:.78rem}
  .panels{grid-template-columns:1fr 1fr; gap:7px}
  .panel{padding:9px 8px 10px}
  .ptitle{margin-bottom:6px; font-size:.8rem; gap:6px}
  .pill{width:18px; height:18px; border-radius:6px; font-size:.7rem}
  .pfields{grid-template-columns:1fr; gap:6px}
  .field.span2{grid-column:auto}
  .lab{font-size:.64rem; margin-bottom:2px}
  input[type=number],select{padding:7px 8px; font-size:.9rem; border-radius:8px}
  select{padding-right:24px; background-position:calc(100% - 13px) 52%,calc(100% - 9px) 52%}
  .result{margin-top:9px; padding:10px 9px 9px}
  .cmp{font-size:.78rem}
  .cmp th,.cmp td{padding:4px 3px}
  .cmp tbody th{font-size:.74rem}
  .cmp thead th{font-size:.58rem; padding-bottom:3px}
  .cmp tbody td .p{margin-left:3px; font-size:.9em}
  .verdict{margin-top:7px; font-size:.8rem; line-height:1.34}
  .actions{margin-top:7px}
  button#copy{min-height:38px; padding:8px 13px; font-size:.9rem}
  footer{padding:0 12px 30px; flex-direction:column; gap:8px}
}