:root {
  --bg: #f7f6f2;
  --card: #ffffff;
  --ink: #16161d;
  --muted: #5d5d6b;
  --line: #e4e2db;
  --grid: #e7e5de;
  --chart-bg: #fdfcf9;
  --accent: #0b8a5a;
  --accent-ink: #ffffff;
  --radius: 16px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111115;
    --card: #1a1a20;
    --ink: #f2f1ec;
    --muted: #a3a2ad;
    --line: #2c2c35;
    --grid: #2a2a32;
    --chart-bg: #15151a;
  }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { overflow-x: hidden; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 1100px; margin: 0 auto; padding: 0 16px; }
header.top { border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.brand { font-weight: 800; letter-spacing: -0.02em; color: var(--ink); text-decoration: none; display: flex; align-items: center; gap: 8px; }
.brand svg { width: 26px; height: 26px; }
nav.top a { color: var(--muted); text-decoration: none; font-size: 14px; margin-left: 16px; }
nav.top a:hover { color: var(--ink); }
.hero { padding: 32px 0 12px; }
h1 { font-size: clamp(30px, 5vw, 48px); line-height: 1.08; letter-spacing: -0.03em; margin: 0 0 10px; }
.lead { color: var(--muted); font-size: 18px; margin: 0; max-width: 680px; }
.tool { display: grid; grid-template-columns: 330px 1fr; gap: 16px; margin: 24px 0 8px; }
.tool > * { min-width: 0; }
@media (max-width: 860px) { .tool { grid-template-columns: 1fr; } .chart-card { order: -1; } }
@media (max-width: 560px) { nav.top a:not(:first-child) { display: none; } nav.top a { margin-left: 0; } .brand span { font-size: 15px; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.card h2 { font-size: 15px; margin: 0 0 12px; letter-spacing: -0.01em; }
label.f { display: block; font-size: 13px; color: var(--muted); margin: 10px 0 4px; }
input[type=text], input[type=number], .hc-rname, .hc-rcm {
  width: 100%; font: inherit; color: var(--ink); background: var(--bg);
  border: 1px solid var(--line); border-radius: 10px; padding: 9px 11px;
}
input:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.seg button, .seg label { font: inherit; font-size: 14px; background: transparent; color: var(--muted); border: 0; padding: 7px 12px; cursor: pointer; }
.seg button[aria-pressed=true] { background: var(--ink); color: var(--bg); }
.seg input { position: absolute; opacity: 0; }
.seg label:has(input:checked) { background: var(--ink); color: var(--bg); }
.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.btn { font: inherit; font-weight: 600; border-radius: 10px; padding: 10px 14px; cursor: pointer; border: 1px solid var(--line); background: var(--card); color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); width: 100%; margin-top: 14px; }
.btn:hover { filter: brightness(0.97); }
.presets { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { font: inherit; font-size: 13px; padding: 6px 10px; border-radius: 999px; border: 1px solid var(--line); background: var(--bg); color: var(--ink); cursor: pointer; }
.chip:hover { border-color: var(--ink); }
.chart-card { padding: 10px; }
#hc-svg { width: 100%; height: auto; display: block; border-radius: 10px; }
.hc-axis { font: 12px system-ui, sans-serif; fill: var(--muted); }
.hc-unit { font-weight: 700; }
.hc-name { font: 600 15px system-ui, sans-serif; fill: var(--ink); }
.hc-h { font: 12px system-ui, sans-serif; fill: var(--muted); }
.hc-empty { font: 16px system-ui, sans-serif; fill: var(--muted); }
.hc-mark { font: 600 13px system-ui, sans-serif; fill: var(--muted); opacity: 0.7; }
.toolbar { display: flex; gap: 8px; flex-wrap: wrap; padding: 10px 4px 2px; align-items: center; }
.toolbar .spacer { flex: 1; }
#hc-result { margin: 8px 4px 0; font-weight: 600; }
#hc-list { list-style: none; padding: 0; margin: 10px 0 0; display: grid; gap: 8px; }
.hc-row { display: grid; grid-template-columns: 12px 1fr 84px 24px auto 32px; gap: 8px; align-items: center; }
@media (max-width: 560px) {
  .hc-row { grid-template-columns: 12px minmax(0, 1fr) 70px 24px 32px; }
  .hc-del { grid-row: 1; grid-column: 5; }
  .hc-lift { grid-row: 2; grid-column: 2 / -1; }
  .hc-lift input { flex: 1; width: auto; }
}
.hc-dot { width: 12px; height: 12px; border-radius: 50%; }
.hc-u { font-size: 13px; color: var(--muted); }
.hc-lift { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.hc-lift input { accent-color: var(--accent); width: 90px; }
.hc-lift output { min-width: 24px; font-weight: 600; color: var(--ink); }
.hc-del { width: 32px; height: 32px; border-radius: 8px; border: 1px solid var(--line); background: transparent; color: var(--muted); font-size: 18px; cursor: pointer; }
main section { margin: 44px 0; }
main h2 { font-size: clamp(22px, 3vw, 28px); letter-spacing: -0.02em; line-height: 1.2; margin: 0 0 12px; }
main h3 { font-size: 18px; margin: 20px 0 6px; }
.prose { max-width: 760px; }
.prose p, .prose li { color: var(--ink); }
.answer { background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--accent); border-radius: 12px; padding: 14px 16px; }
table { border-collapse: collapse; width: 100%; max-width: 760px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); font-size: 15px; }
th { background: var(--bg); font-size: 13px; color: var(--muted); font-weight: 600; }
.note { font-size: 13px; color: var(--muted); }
details { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 16px; margin: 8px 0; max-width: 760px; }
summary { font-weight: 600; cursor: pointer; }
footer { border-top: 1px solid var(--line); padding: 24px 0 40px; color: var(--muted); font-size: 14px; }
footer a { color: var(--muted); margin-right: 14px; }
.cta { display: flex; gap: 16px; align-items: center; justify-content: space-between; flex-wrap: wrap; }