:root {
  --bg: #f4f5f2;
  --card: #ffffff;
  --ink: #1d2320;
  --muted: #5d6763;
  --line: #d9ddd8;
  --accent: #b3261e; /* the AIOC's red */
  --accent-ink: #ffffff;
  --ok: #1f6b3a;
  --ok-bg: #e5f3ea;
  --warn: #7a5200;
  --warn-bg: #fdf3dc;
  --err: #9b1c1c;
  --err-bg: #fbe7e6;
  --code: #eef0ec;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #151816;
    --card: #1e2220;
    --ink: #e7ebe8;
    --muted: #9aa49f;
    --line: #333a36;
    --accent: #e0544b;
    --ok: #8fd6a6;
    --ok-bg: #173323;
    --warn: #f0c46b;
    --warn-bg: #3a2e12;
    --err: #f29b95;
    --err-bg: #3d1b1a;
    --code: #262b28;
  }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.top, main { max-width: 52rem; margin: 0 auto; padding: 0 1rem; }
.top { padding-top: 2.2rem; }
h1 { font-size: 1.9rem; margin: 0 0 .4rem; letter-spacing: -0.01em; }
.lede { font-size: 1.1rem; color: var(--muted); margin: 0 0 1.4rem; }
h2 { font-size: 1.35rem; margin: 0 0 .6rem; display: flex; align-items: center; gap: .6rem; }
h3 { font-size: 1.05rem; margin: 1.4rem 0 .4rem; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.2rem 1.4rem;
  margin: 0 0 1.2rem;
}
.num {
  display: inline-grid; place-items: center;
  width: 1.9rem; height: 1.9rem; border-radius: 50%;
  background: var(--accent); color: var(--accent-ink);
  font-size: 1rem; font-weight: 700; flex: none;
}
a { color: var(--accent); }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9em; }
code { background: var(--code); padding: .05em .3em; border-radius: 4px; }
pre { background: var(--code); padding: .7rem .9rem; border-radius: 6px; overflow-x: auto; }
.muted { color: var(--muted); }
.small { font-size: .9rem; }
ol, ul { padding-left: 1.3rem; }
li { margin: .2rem 0; }

.actions { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; margin: 1rem 0 .6rem; }
button {
  font: inherit; font-weight: 600;
  padding: .5rem 1rem; border-radius: 7px; cursor: pointer;
  border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink);
}
button.secondary { background: transparent; color: var(--accent); }
button:disabled { opacity: .45; cursor: not-allowed; }
button:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 45%, transparent); outline-offset: 2px; }
label.small { display: inline-flex; gap: .35rem; align-items: center; color: var(--muted); }

.note { padding: .7rem .9rem; border-radius: 7px; background: var(--code); margin: 0 0 1rem; }
.status:empty { display: none; }
.status { padding: .7rem .9rem; border-radius: 7px; margin: .6rem 0; background: var(--code); white-space: pre-line; overflow-wrap: anywhere; }
.ok { background: var(--ok-bg); color: var(--ok); }
.warn { background: var(--warn-bg); color: var(--warn); }
.error { background: var(--err-bg); color: var(--err); }
.status.ok, .status.warn, .status.error, .note.ok, .note.warn, .note.error { font-weight: 500; }

progress { width: 100%; height: 1rem; accent-color: var(--accent); margin: .3rem 0 .6rem; }
details { margin: .7rem 0; border-top: 1px solid var(--line); padding-top: .5rem; }
summary { cursor: pointer; font-weight: 600; color: var(--muted); }

dl.grid { display: grid; grid-template-columns: max-content 1fr; gap: .25rem 1rem; margin: 1rem 0; }
dl.grid dt { color: var(--muted); }
dl.grid dd { margin: 0; font-variant-numeric: tabular-nums; }
.form { display: flex; flex-wrap: wrap; gap: .8rem; align-items: flex-end; margin: .6rem 0; }
.form label { display: flex; flex-direction: column; gap: .2rem; font-size: .9rem; color: var(--muted); }
input, select { font: inherit; padding: .45rem .6rem; border: 1px solid var(--line); border-radius: 6px; background: var(--card); color: var(--ink); }
#f-freq { width: 9rem; }

table.settings { border-collapse: collapse; width: 100%; }
table.settings th { text-align: left; vertical-align: top; padding: .5rem 1rem .5rem 0; white-space: nowrap; }
table.settings td { padding: .5rem 0; }
table.settings tr + tr { border-top: 1px solid var(--line); }
@media (max-width: 36rem) {
  table.settings th, table.settings td { display: block; padding: .2rem 0; }
}

.meter { margin: .4rem 0 .8rem; }
.meter-bar { position: relative; height: 1.4rem; border-radius: 6px; background: var(--code); overflow: hidden; border: 1px solid var(--line); }
/* the target band, -18 to -9 dBFS on a -60 to 0 scale */
.meter-band { position: absolute; top: 0; bottom: 0; left: 70%; width: 15%; background: var(--ok-bg); border-left: 1px solid var(--ok); border-right: 1px solid var(--ok); }
.meter-fill { position: absolute; top: 25%; bottom: 25%; left: 0; width: 0; background: var(--muted); transition: width 60ms linear; }
.meter-fill.ok { background: var(--ok); }
.meter-fill.high, .meter-fill.clip { background: var(--err); }
.meter-rms { position: absolute; top: 0; bottom: 0; width: 2px; left: 0; background: var(--ink); opacity: .6; }
.meter-scale { position: relative; height: 1.2rem; }
.meter-scale span { position: absolute; transform: translateX(-50%); font-variant-numeric: tabular-nums; }
.meter-scale span:nth-child(1) { left: 0; transform: none; }
.meter-scale span:nth-child(2) { left: 70%; }
.meter-scale span:nth-child(3) { left: 85%; }
.meter-scale span:nth-child(4) { right: 0; transform: none; }
#meter-text { font-variant-numeric: tabular-nums; margin: .2rem 0; }
#meter-text.clip { color: var(--err); font-weight: 600; }