/* CellSim Lab — visual language.
 *
 * The aesthetic follows professional CAE workbenches (SimScale, PrePoMax,
 * COMSOL): a dark viewport that the eye treats as the specimen, quiet
 * chrome around it, numbers in monospace so columns line up, and one
 * accent colour reserved for actions that actually do something.
 *
 * Borrowed: the look and the layout grammar — a single vertical workflow
 * on the left instead of tabs, which is the change SimScale made in 2018
 * precisely to help newcomers, and panels that float over the viewport so
 * the specimen keeps the space.
 *
 * Written here from scratch: every rule below. No third-party CSS is
 * copied, so nothing in this project carries someone else's copyright.
 */
:root {
  --bg:        #0e1317;
  --panel:     #161d23;
  --panel-2:   #1d262e;
  --line:      #2a3540;
  --text:      #e4ebf2;
  --muted:     #8d9cab;
  --accent:    #35b3a2;   /* actions */
  --accent-dim:#1f6b61;
  --warn:      #d8a23c;   /* "calibrated, not validated" */
  --bad:       #d3604f;   /* "fails its validation" */
  --good:      #5fb97a;
  --radius: 6px;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
* { box-sizing: border-box; }
/* [hidden] loses to any rule that sets display, which is how the
   'Nothing run yet' placeholder stayed on top of a finished plot.
   The viewer hit the same bug; this is the same fix. */
[hidden] { display: none !important; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--bg); color: var(--text);
  font: 14px/1.5 var(--sans);
  display: grid; grid-template-rows: 48px 1fr;
  overflow: hidden;
}

/* ── top bar ─────────────────────────────────────────────────── */
header {
  display: flex; align-items: center; gap: 16px;
  padding: 0 16px; background: var(--panel);
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 650; letter-spacing: .2px; }
.brand span { color: var(--accent); }
.subtitle { color: var(--muted); font-size: 12.5px; }
header .spacer { flex: 1; }

button {
  font: inherit; color: var(--text); cursor: pointer;
  background: var(--panel-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 7px 14px;
}
button:hover:not(:disabled) { border-color: #3b4a58; background: #243039; }
button:disabled { opacity: .45; cursor: not-allowed; }
button.primary {
  background: var(--accent); border-color: var(--accent); color: #06211d;
  font-weight: 600;
}
button.primary:hover:not(:disabled) { background: #3fc7b4; border-color: #3fc7b4; }

/* ── three-column workbench ──────────────────────────────────── */
main { display: grid; grid-template-columns: 300px 1fr 340px; min-height: 0; }
aside, .results { background: var(--panel); min-height: 0; overflow-y: auto; }
aside { border-right: 1px solid var(--line); }
.results { border-left: 1px solid var(--line); }

/* ── the workflow: one vertical list, not tabs ───────────────── */
.step { border-bottom: 1px solid var(--line); }
.step > summary {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 14px; cursor: pointer; user-select: none;
  list-style: none; font-weight: 550;
}
.step > summary::-webkit-details-marker { display: none; }
.step[open] > summary { background: var(--panel-2); }
.num {
  width: 21px; height: 21px; flex: none; border-radius: 50%;
  background: var(--panel-2); border: 1px solid var(--line);
  color: var(--muted); font: 600 11px/19px var(--mono); text-align: center;
}
.step[open] .num { background: var(--accent-dim); border-color: var(--accent); color: #d6fffa; }
.step-body { padding: 4px 14px 16px; }

label { display: block; margin: 12px 0 5px; color: var(--muted); font-size: 12px; }
select, input[type=text], input[type=number] {
  width: 100%; font: inherit; color: var(--text);
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 7px 9px;
}
select:focus, input:focus { outline: none; border-color: var(--accent); }
input[type=range] { width: 100%; accent-color: var(--accent); }
.row { display: flex; gap: 8px; align-items: center; }
.row > * { flex: 1; }
.hint { color: var(--muted); font-size: 11.5px; margin-top: 6px; line-height: 1.45; }
.val { font: 600 13px var(--mono); color: var(--text); min-width: 68px; text-align: right; flex: none; }

/* ── presets ─────────────────────────────────────────────────── */
.preset {
  display: block; width: 100%; text-align: left; margin-bottom: 7px;
  padding: 10px 12px; line-height: 1.35;
}
.preset b { display: block; font-weight: 600; margin-bottom: 2px; }
.preset small { color: var(--muted); font-size: 11.5px; }

/* ── viewport ────────────────────────────────────────────────── */
.stage { position: relative; background: #090d10; min-height: 0; }
.stage canvas { display: block; width: 100%; height: 100%; }
.overlay {
  position: absolute; left: 66px; bottom: 58px;
  background: rgba(14,19,23,.82); backdrop-filter: blur(6px);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 9px 12px; font: 12px var(--mono); color: var(--muted);
  pointer-events: none;
}
.overlay b { color: var(--text); font-weight: 600; }
.placeholder {
  position: absolute; inset: 0; display: grid; place-content: center;
  text-align: center; color: var(--muted); gap: 10px; padding: 24px;
}
.placeholder h2 { color: var(--text); font-size: 17px; margin: 0; font-weight: 600; }

/* ── progress ────────────────────────────────────────────────── */
.bar { height: 3px; background: var(--panel-2); overflow: hidden; }
.bar > i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .3s; }
.bar.indet > i { width: 35%; animation: slide 1.1s infinite ease-in-out; }
@keyframes slide { 0% { margin-left: -35%; } 100% { margin-left: 100%; } }

/* ── results ─────────────────────────────────────────────────── */
.results h3 {
  margin: 0; padding: 13px 14px; font-size: 13px; font-weight: 600;
  border-bottom: 1px solid var(--line);
}
.result-body { padding: 14px; }
.metric { margin-bottom: 16px; }
.metric .k { color: var(--muted); font-size: 12px; }
.metric .v { font: 600 22px/1.25 var(--mono); }
.metric .band { color: var(--muted); font: 12px var(--mono); }
.chip {
  display: inline-block; padding: 2px 7px; border-radius: 99px;
  font-size: 11px; font-weight: 600; border: 1px solid;
}
.chip.good { color: var(--good); border-color: #2f6b45; background: #15291d; }
.chip.warn { color: var(--warn); border-color: #6b5520; background: #292113; }
.chip.bad  { color: var(--bad);  border-color: #6b3028; background: #291715; }
.note {
  font-size: 11.5px; line-height: 1.5; color: var(--muted);
  border-left: 2px solid var(--line); padding-left: 10px; margin: 12px 0;
}
.note.warn { border-color: var(--warn); }
table.data { width: 100%; border-collapse: collapse; font: 12px var(--mono); }
table.data th, table.data td { padding: 5px 6px; text-align: right; }
table.data th { color: var(--muted); font-weight: 500; border-bottom: 1px solid var(--line); }
table.data td:first-child, table.data th:first-child { text-align: left; }
.empty { color: var(--muted); font-size: 12.5px; line-height: 1.55; }

@media (max-width: 1100px) {
  main { grid-template-columns: 260px 1fr; }
  .results { display: none; }
}