:root{
  --bg:#f3f6f4;--surface:#ffffff;--ink:#14231c;--muted:#5b6b63;--line:#d5dfd9;
  --accent:#0b6b4b;--accent-ink:#ffffff;--soft:#e2efe8;
  box-sizing:border-box;
  padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){--bg:#101a15;--surface:#17231d;--ink:#e8f1ec;--muted:#9bb0a5;--line:#2a3a32;--accent:#4fc596;--accent-ink:#06261a;--soft:#1d3028}
}
:root[data-theme="dark"]{--bg:#101a15;--surface:#17231d;--ink:#e8f1ec;--muted:#9bb0a5;--line:#2a3a32;--accent:#4fc596;--accent-ink:#06261a;--soft:#1d3028}
*{box-sizing:border-box}
html{scroll-padding-top:env(safe-area-inset-top,0px)}
body{margin:0;background:var(--bg);color:var(--ink);font-family:Georgia,"Times New Roman",serif;line-height:1.5}
main{max-width:760px;margin:0 auto;padding:28px 18px 48px}
h1{font-size:clamp(1.9rem,6vw,2.7rem);line-height:1.1;margin:0 0 8px;letter-spacing:-.02em}
.lede{color:var(--muted);margin:0 0 26px;max-width:52ch}
.grid{display:grid;gap:22px;grid-template-columns:1fr}
@media(min-width:720px){.grid{grid-template-columns:1fr 1fr;align-items:start}}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:20px}
label{display:block;font-family:system-ui,-apple-system,Segoe UI,sans-serif;font-size:.9rem;font-weight:600;margin-bottom:4px}
.hint{display:block;font-weight:400;color:var(--muted);font-size:.8rem}
.field{margin-bottom:16px}
.inp{display:flex;align-items:center;border:1px solid var(--line);border-radius:6px;background:var(--bg);overflow:hidden}
.inp:focus-within{outline:2px solid var(--accent);outline-offset:1px}
.inp span{padding:0 10px;color:var(--muted);font-family:system-ui,sans-serif}
.inp input{flex:1;min-width:0;border:0;background:transparent;color:var(--ink);font:inherit;font-family:system-ui,sans-serif;font-size:1rem;padding:10px 10px 10px 0;outline:none}
.result{background:var(--accent);color:var(--accent-ink);border-radius:10px;padding:22px}
.result .big{font-size:clamp(2.6rem,10vw,3.8rem);line-height:1;font-weight:700;letter-spacing:-.03em}
.result .cap{font-family:system-ui,sans-serif;font-size:.9rem;opacity:.85;margin-top:4px}
.sub{display:flex;gap:22px;margin-top:18px;flex-wrap:wrap}
.sub b{display:block;font-size:1.5rem}
.break{margin-top:16px;font-family:system-ui,sans-serif;font-size:.9rem}
.break div{display:flex;justify-content:space-between;padding:7px 0;border-bottom:1px solid var(--line)}
.break div:last-child{border:0;font-weight:700}
.note{font-family:system-ui,sans-serif;font-size:.8rem;color:var(--muted);margin-top:14px}
.warn{background:var(--soft);border-radius:6px;padding:10px 12px;font-family:system-ui,sans-serif;font-size:.85rem;margin-top:12px}
button{font:inherit;font-family:system-ui,sans-serif;font-weight:600;background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:6px;padding:9px 14px;cursor:pointer;margin-top:14px}
button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
h2{font-size:1.35rem;margin:0 0 6px;letter-spacing:-.01em}
h3{font-size:1.05rem;margin:22px 0 4px}
.tw{overflow-x:auto;margin-top:12px}
table{border-collapse:collapse;width:100%;font-family:system-ui,sans-serif;font-size:.9rem;min-width:420px}
th,td{text-align:right;padding:8px 10px;border-bottom:1px solid var(--line)}
th:first-child,td:first-child{text-align:left}
th{color:var(--muted);font-weight:600}
td.cur,th.cur{background:var(--soft);font-weight:700}
.gap{margin-top:22px}
.inp select{flex:1;min-width:0;border:0;background:transparent;color:var(--ink);font-family:system-ui,sans-serif;font-size:1rem;padding:10px 12px;outline:none}
.opt{margin-top:18px;border-top:1px solid var(--line);padding-top:14px}
.opt summary{font-family:system-ui,sans-serif;font-weight:600;cursor:pointer;margin-bottom:14px}
.opt input[type=checkbox]{margin-right:8px}
#ty{font-family:system-ui,sans-serif;font-size:.8rem;color:var(--muted);margin:-14px 0 20px}
#ty.warn{color:var(--ink);padding:8px 12px}
.seo p,.seo li{max-width:68ch;color:var(--ink)}
.seo code{font-family:ui-monospace,Menlo,monospace;background:var(--soft);padding:2px 6px;border-radius:4px;font-size:.9em}
.row{display:flex;gap:10px;flex-wrap:wrap}
@media print{
  :root{--bg:#fff;--surface:#fff;--ink:#000;--muted:#444;--line:#bbb;--accent:#0b6b4b;--accent-ink:#fff;--soft:#e8f2ec}
  button,.seo,.inp span,#whatif .lede{display:none}
  .grid{grid-template-columns:1fr 1fr}
  .result,.warn,td.cur{-webkit-print-color-adjust:exact;print-color-adjust:exact}
}

nav{display:flex;gap:18px;flex-wrap:wrap;font-family:system-ui,-apple-system,Segoe UI,sans-serif;font-size:.9rem;margin-bottom:22px}
nav a,footer a,.seo a{color:var(--accent);font-weight:600}
nav a[aria-current]{text-decoration:none;color:var(--ink)}
footer{margin-top:40px;padding-top:16px;border-top:1px solid var(--line);font-family:system-ui,sans-serif;font-size:.8rem;color:var(--muted)}
@media print{nav,footer{display:none}}