:root{--bg:#fbfbf8;--fg:#1d1f22;--mut:#5d6470;--line:#dfe2e6;--card:#fff;--acc:#1f5fbf;--acc-bg:#e9f0fb}
@media (prefers-color-scheme:dark){:root{--bg:#131518;--fg:#e8eaed;--mut:#9aa1ab;--line:#2c3036;--card:#1b1e22;--acc:#7fb0ff;--acc-bg:#1d2a3d}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.6 system-ui,-apple-system,"Segoe UI","Hiragino Sans","PingFang SC","Noto Sans CJK SC",sans-serif}
header,main,footer{max-width:760px;margin:0 auto;padding:0 16px}header{display:flex;justify-content:space-between;align-items:center;padding-top:14px;gap:12px;flex-wrap:wrap}
header a{color:var(--fg);text-decoration:none;font-weight:700}nav.langs a{font-weight:400;margin-left:10px;color:var(--mut)}nav.langs a[aria-current]{color:var(--fg);font-weight:600}
h1{font-size:1.7rem;line-height:1.25;margin:20px 0 8px}h2{font-size:1.15rem;margin:28px 0 10px}.lead{color:var(--mut)}
.calc,.result{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:16px;margin:16px 0}
fieldset{border:0;padding:0;margin:0 0 12px}legend{font-weight:600;margin-bottom:6px}
.hms{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.hms label,.row,.col{display:flex;flex-direction:column;font-size:.9rem;color:var(--mut);gap:4px}
.row{margin:10px 0}.pp{display:grid;grid-template-columns:1fr 1fr;gap:8px}
input,textarea{font:inherit;color:var(--fg);background:var(--bg);border:1px solid var(--line);border-radius:6px;padding:8px 10px;width:100%}
.presets{display:flex;flex-wrap:wrap;gap:6px;margin:6px 0}.preset{font:inherit;font-size:.9rem;padding:6px 10px;border:1px solid var(--line);border-radius:6px;background:var(--bg);color:var(--fg);cursor:pointer}
.preset.on{background:var(--acc-bg);border-color:var(--acc);color:var(--acc)}
.result h2{margin-top:0}.out{display:flex;justify-content:space-between;gap:12px;padding:6px 0;border-bottom:1px solid var(--line)}.out strong{font-variant-numeric:tabular-nums;font-size:1.15rem}
table{border-collapse:collapse;width:100%;font-variant-numeric:tabular-nums}th,td{border-bottom:1px solid var(--line);padding:6px 8px;text-align:right}th:first-child{text-align:left}
.warn{color:#b3261e}details{border-bottom:1px solid var(--line);padding:8px 0}summary{cursor:pointer;font-weight:600}
ul.tools{padding-left:18px}a{color:var(--acc)}footer{color:var(--mut);font-size:.85rem;margin-top:40px;padding-bottom:30px}