/* Balloons — one stylesheet, no external font, no external anything. */
:root {
  color-scheme: light dark;
  --bg: #f2f4f9; --panel: #ffffff; --ink: #182034; --dim: #5c6884;
  --line: #dfe4ee; --accent: #e0405c; --accent2: #2f7fbf; --ok: #1f9d55;
  --shadow: 0 1px 2px rgba(20,28,48,.08), 0 8px 24px rgba(20,28,48,.06);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101420; --panel: #1a2030; --ink: #e9edf5; --dim: #9aa6bd;
    --line: #2a3242; --accent: #e2536b; --accent2: #4aa3df; --ok: #4ade80;
    --shadow: 0 1px 2px rgba(0,0,0,.5), 0 10px 28px rgba(0,0,0,.35);
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg); color: var(--ink);
  font: 15px/1.55 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}
.top { max-width: 960px; margin: 0 auto; padding: 18px 16px 0; }
h1 { margin: 0 0 10px; font-size: 27px; letter-spacing: -.01em; }
h2 { font-size: 19px; margin: 26px 0 8px; }
h3 { font-size: 16px; margin: 20px 0 6px; }
.tabs { display: flex; flex-wrap: wrap; gap: 6px; border-bottom: 1px solid var(--line); padding-bottom: 8px; }
.tab {
  font: inherit; font-size: 14px; cursor: pointer; border: 1px solid var(--line);
  background: var(--panel); color: var(--dim); padding: 6px 12px; border-radius: 999px;
}
.tab:hover { color: var(--ink); }
.tab.on { background: var(--ink); color: var(--bg); border-color: var(--ink); }
main { max-width: 960px; margin: 0 auto; padding: 14px 16px 40px; }
.panel[hidden] { display: none !important; }
p { margin: 9px 0; }
.eq { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 15px;
      background: var(--panel); border: 1px solid var(--line); border-radius: 8px;
      padding: 10px 12px; overflow-x: auto; }
blockquote { margin: 10px 0; padding: 10px 14px; border-left: 3px solid var(--accent);
             background: var(--panel); border-radius: 0 8px 8px 0; font-style: italic; }
.stagewrap { background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
             box-shadow: var(--shadow); overflow: hidden; }
.stagewrap canvas { display: block; width: 100%; height: 440px; }
.stagewrap.tall canvas { height: 330px; }
.stagewrap.narrow { max-width: 620px; margin: 0 auto; }
.stagewrap.chart { margin: 10px 0 4px; }
.stagewrap.chart canvas { height: 300px; }
.two-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.hud { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0 6px; }
.stat { background: var(--panel); border: 1px solid var(--line); border-radius: 10px;
        padding: 6px 12px; min-width: 96px; }
.stat .k { display: block; font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--dim); }
.stat .v { display: block; font-size: 17px; font-variant-numeric: tabular-nums; }
.status { min-height: 1.6em; color: var(--dim); }
.controls { display: flex; gap: 8px; margin: 10px 0; align-items: center; }
.controls.wrap { flex-wrap: wrap; }
button {
  font: inherit; cursor: pointer; border: 1px solid var(--line); background: var(--panel);
  color: var(--ink); padding: 8px 14px; border-radius: 9px;
}
button:hover { border-color: var(--dim); }
button.big { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600;
             padding: 12px 26px; font-size: 16px; touch-action: manipulation; user-select: none; }
button.big:active, button.big.held { filter: brightness(.85); }
button.demo { font-size: 14px; }
button.on { background: var(--ok); border-color: var(--ok); color: #fff; }
.slider { display: flex; align-items: center; gap: 6px; font-size: 14px; color: var(--dim); }
.slider input { width: 130px; }
.slider output { font-variant-numeric: tabular-nums; color: var(--ink); min-width: 3.4em; }
.hint { font-size: 13px; color: var(--dim); }
kbd { font: inherit; font-size: 12px; border: 1px solid var(--line); border-bottom-width: 2px;
      border-radius: 5px; padding: 1px 5px; background: var(--panel); }
.tbl { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 14px; }
.tbl th, .tbl td { text-align: left; padding: 7px 9px; border-bottom: 1px solid var(--line); }
.tbl th { color: var(--dim); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .05em; }
.tbl td { font-variant-numeric: tabular-nums; }
.tbl .wrong { color: var(--accent); font-weight: 600; }
.tbl .right { color: var(--ok); }
ul, ol { margin: 9px 0; padding-left: 22px; }
li { margin: 5px 0; }
a { color: var(--accent2); }
footer { max-width: 960px; margin: 0 auto; padding: 0 16px 36px; color: var(--dim); font-size: 13px;
         border-top: 1px solid var(--line); padding-top: 14px; }
@media (max-width: 700px) {
  .two-grid { grid-template-columns: 1fr; }
  .stagewrap canvas { height: 330px; }
  h1 { font-size: 23px; }
  .tbl { display: block; overflow-x: auto; font-size: 13px; }
  .tbl th, .tbl td { padding: 6px 5px; }
  .tbl th { letter-spacing: 0; }
}