/* One instrument panel, phone first. No framework, no build step, no CDN. */
:root {
  --bg: #0b0e13;
  --panel: #121824;
  --panel-2: #0e141e;
  --line: #222d3d;
  --line-2: #1a2331;
  --ink: #e6edf3;
  --ink-dim: #8b98a8;
  --ink-faint: #5b6676;
  --cyan: #22d3ee;
  --amber: #f5b23b;
  --green: #34d399;
  --red: #f87171;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --r: 10px;
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  overscroll-behavior: none;
}
#app { min-height: 100dvh; display: flex; flex-direction: column; }

/* ---------- chrome ---------- */
.topbar {
  display: flex; align-items: center; gap: 10px;
  padding: max(10px, env(safe-area-inset-top)) 14px 10px;
  border-bottom: 1px solid var(--line-2);
  background: linear-gradient(180deg, #101723, #0b0e13);
  position: sticky; top: 0; z-index: 5;
}
.topbar .back {
  font: 600 14px/1 system-ui; color: var(--ink-dim);
  background: none; border: 0; padding: 8px 8px 8px 0; cursor: pointer;
}
.topbar .back:active { color: var(--ink); }
.topbar h1 { font-size: 15px; font-weight: 650; margin: 0; letter-spacing: .2px; }
.topbar .sub { font-size: 12px; color: var(--ink-faint); margin-top: 1px; }
.topbar .grow { flex: 1; }
.chip {
  font: 600 11px/1 var(--mono); letter-spacing: .6px; text-transform: uppercase;
  padding: 5px 8px; border-radius: 999px; border: 1px solid var(--line);
  color: var(--ink-dim); white-space: nowrap;
}
.chip.on { color: var(--green); border-color: #1d4638; background: #0f2019; }

.stage { flex: 1; display: flex; flex-direction: column; gap: 10px; padding: 12px; min-height: 0; }
.stage.menu { padding-bottom: max(12px, env(safe-area-inset-bottom)); }
.wrap { width: 100%; max-width: 1000px; margin: 0 auto; display: flex; flex-direction: column; gap: 10px; flex: 1; min-height: 0; }

/* ---------- menu ---------- */
.hero { padding: 14px 4px 4px; }
.hero h2 { margin: 0 0 6px; font-size: clamp(26px, 7vw, 40px); line-height: 1.05; letter-spacing: -.5px; }
.hero h2 em { font-style: normal; color: var(--cyan); }
.hero p { margin: 0; color: var(--ink-dim); max-width: 48ch; }
.cards { display: grid; gap: 8px; grid-template-columns: 1fr; }
@media (min-width: 620px) { .cards { grid-template-columns: 1fr 1fr; } }
.card {
  display: flex; align-items: center; gap: 12px; text-align: left;
  padding: 12px 14px; border: 1px solid var(--line-2); border-radius: var(--r);
  background: var(--panel); color: inherit; font: inherit; cursor: pointer;
}
.card:active { background: #162031; }
.card .n {
  flex: none; width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center;
  font: 700 13px/1 var(--mono); color: var(--ink-faint); background: var(--panel-2); border: 1px solid var(--line-2);
}
.card.done .n { color: var(--green); border-color: #1d4638; }
.card .t { flex: 1; min-width: 0; }
.card .t b { display: block; font-weight: 620; }
.card .t span { display: block; font-size: 12.5px; color: var(--ink-faint); }
.card .s { font: 600 12px/1 var(--mono); color: var(--amber); }
.menu-foot { color: var(--ink-faint); font-size: 12.5px; padding: 8px 4px 0; }
.menu-foot a { color: var(--ink-dim); }

/* ---------- level ---------- */
.objective {
  padding: 10px 12px; border-radius: var(--r); border: 1px solid var(--line-2);
  background: var(--panel-2); font-size: 13.5px;
}
.objective b { color: var(--cyan); font-weight: 650; }
.hint { margin-top: 6px; font-size: 12.5px; color: var(--amber); display: none; }
.hint.show { display: block; }

.budget { display: flex; align-items: center; gap: 10px; font: 600 12px/1 var(--mono); color: var(--ink-dim); }
.budget .bar { flex: 1; height: 6px; border-radius: 3px; background: var(--line-2); overflow: hidden; }
.budget .bar i { display: block; height: 100%; background: var(--cyan); transition: width .18s ease; }
.budget.low .bar i { background: var(--amber); }
.budget.out .bar i { background: var(--red); }

.plot { position: relative; flex: 1 1 0; min-height: 140px; border-radius: var(--r); background: var(--panel-2); border: 1px solid var(--line-2); overflow: hidden; }
.plot canvas { display: block; }
.plots { display: flex; flex-direction: column; gap: 10px; flex: 1; min-height: 0; }

.panel { padding: 10px 12px; border-radius: var(--r); background: var(--panel); border: 1px solid var(--line-2); }
.rowline { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

.readouts { display: flex; gap: 16px; flex-wrap: wrap; align-items: flex-end; }
.ro { min-width: 58px; }
.ro label { display: block; font: 600 10px/1.4 var(--mono); letter-spacing: .7px; text-transform: uppercase; color: var(--ink-faint); }
.ro output { display: block; font: 500 17px/1.25 var(--mono); color: var(--ink); font-variant-numeric: tabular-nums; }
.ro.big output { font-size: clamp(24px, 7.5vw, 32px); color: var(--cyan); }
.ro.warn output { color: var(--amber); }

.slider { margin: 6px 0 0; }
.slider .lab { display: flex; justify-content: space-between; font: 600 10px/1.4 var(--mono); letter-spacing: .7px; text-transform: uppercase; color: var(--ink-faint); }
input[type=range] { -webkit-appearance: none; appearance: none; width: 100%; height: 34px; background: none; margin: 0; }
input[type=range]::-webkit-slider-runnable-track { height: 4px; border-radius: 2px; background: var(--line); }
input[type=range]::-moz-range-track { height: 4px; border-radius: 2px; background: var(--line); }
input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; width: 26px; height: 26px; margin-top: -11px; border-radius: 50%; background: var(--ink); border: 4px solid #1d2636; }
input[type=range]::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%; background: var(--ink); border: 4px solid #1d2636; }
input[type=range]:active::-webkit-slider-thumb { background: var(--cyan); }

.btns { display: flex; gap: 8px; flex-wrap: wrap; }
button.b {
  flex: 1 1 auto; min-height: 46px; padding: 0 14px;
  border-radius: 9px; border: 1px solid var(--line); background: #182234; color: var(--ink);
  font: 600 14px/1 system-ui; cursor: pointer;
}
button.b:active { background: #1f2c42; }
button.b[disabled] { opacity: .4; }
button.b.primary { background: #0e3d47; border-color: #1a5b68; color: #b8f1fb; }
button.b.primary:active { background: #12505d; }
button.b.ghost { background: transparent; }
.seg { display: flex; border: 1px solid var(--line); border-radius: 9px; overflow: hidden; }
.seg button { flex: 1; min-height: 40px; border: 0; background: transparent; color: var(--ink-dim); font: 600 13px/1 var(--mono); cursor: pointer; }
.seg button + button { border-left: 1px solid var(--line); }
.seg button.on { background: #1b2739; color: var(--ink); }
.seglab { font: 600 10px/1.4 var(--mono); letter-spacing: .7px; text-transform: uppercase; color: var(--ink-faint); margin-bottom: 4px; }

/* ---------- result sheet ---------- */
.sheet {
  position: fixed; inset: 0; z-index: 20; display: flex; align-items: flex-end; justify-content: center;
  background: rgba(6,9,14,.72); backdrop-filter: blur(3px);
}
.sheet .box {
  width: 100%; max-width: 560px; max-height: 90dvh; overflow: auto;
  background: var(--panel); border: 1px solid var(--line); border-radius: 16px 16px 0 0;
  padding: 18px 18px max(18px, env(safe-area-inset-bottom));
}
@media (min-width: 620px) { .sheet { align-items: center; } .sheet .box { border-radius: 16px; } }
.sheet .verdict { font: 700 12px/1 var(--mono); letter-spacing: 1.4px; text-transform: uppercase; color: var(--green); }
.sheet .verdict.bad { color: var(--amber); }
.sheet h3 { margin: 8px 0 2px; font-size: 22px; }
.sheet .score { font: 600 13px/1 var(--mono); color: var(--amber); margin-bottom: 12px; }
.sheet .reveal { border-left: 2px solid var(--cyan); padding: 2px 0 2px 12px; margin: 0 0 14px; color: var(--ink-dim); font-size: 13.5px; }
.sheet .reveal b { color: var(--ink); font-weight: 620; }
.sheet .reveal code { font: 500 13px/1.5 var(--mono); color: var(--cyan); }
.sheet .reveal p { margin: 0 0 8px; }
.sheet .reveal p:last-child { margin: 0; }

.note { font-size: 12.5px; color: var(--ink-faint); }
.note a { color: var(--cyan); }
.imgpair { display: flex; gap: 10px; }
.imgpair > div { flex: 1; }
.imgpair canvas { width: 100%; height: auto; display: block; border-radius: 6px; border: 1px solid var(--line-2); image-rendering: auto; }
.imgpair .cap { font: 600 10px/1.4 var(--mono); letter-spacing: .6px; text-transform: uppercase; color: var(--ink-faint); margin-bottom: 4px; }

/* ---------- interaction feedback ---------- */
.plot.tuning { border-color: #2b4a5c; box-shadow: inset 0 0 0 1px rgba(34,211,238,.18); }
.plot { cursor: ew-resize; }

.meter { display: flex; align-items: center; gap: 8px; margin-top: 8px; }
.meter .mlab { font: 600 10px/1 var(--mono); letter-spacing: .7px; color: var(--ink-faint); white-space: nowrap; }
.meter .mbar { position: relative; flex: 1; height: 8px; border-radius: 4px; background: var(--line-2); overflow: hidden; }
.meter .mbar i { display: block; height: 100%; width: 0%; background: var(--cyan); transition: width .08s linear; }
.meter .mbar i.warm { background: var(--amber); }
.meter .mbar i.hot { background: var(--green); }
.meter .mbar u { position: absolute; top: 0; bottom: 0; width: 2px; background: rgba(230,237,243,.5); transition: left .12s ease; }

.flash { position: fixed; inset: 0; pointer-events: none; z-index: 30; opacity: 0; transition: opacity .22s ease; }

.toast {
  position: fixed; left: 50%; transform: translate(-50%, 20px); z-index: 40;
  bottom: max(18px, env(safe-area-inset-bottom));
  padding: 10px 16px; border-radius: 999px; max-width: 88vw; text-align: center;
  background: #1b2739; border: 1px solid var(--line); color: var(--ink);
  font: 600 13px/1.3 system-ui; opacity: 0; transition: opacity .18s ease, transform .18s ease;
  pointer-events: none;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

.stars { display: inline-flex; gap: 2px; vertical-align: middle; }
.stars span { color: var(--line); font-size: 14px; }
.stars span.on { color: var(--amber); }