/*
 * Dark by default: the renderer draws additive light on a dark ground, so a
 * light chrome around it would make the canvas look like a hole in the page.
 *
 * The Python/Browser tags on each panel are load-bearing, not decoration —
 * the point of this demo is which half of the work happens where, and the
 * colour split is the fastest way to read that.
 */

:root {
  --bg: #0b0d12;
  --bg-panel: #12151d;
  --bg-inset: #0e1117;
  --line: #232838;
  --line-soft: #1a1e2a;
  --text: #e6e9f0;
  --text-dim: #949bad;
  --text-faint: #646c80;
  --accent: #5b8cff;
  --accent-soft: rgba(91, 140, 255, 0.14);
  --py: #6fd08c;
  --js: #f0c674;
  --danger: #ff6b6b;
  --radius: 10px;
  --rail-width: 340px;
}

* {
  box-sizing: border-box;
}

/*
 * The `hidden` attribute is only a `display: none` in the UA stylesheet, so
 * any author rule that sets `display` outranks it. Both overlays below are
 * `display: grid`, which left them painted on top of a finished render even
 * after the script had set `hidden`. Restore the attribute's meaning once,
 * globally, rather than remembering it per rule.
 */
[hidden] {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.5 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
}

code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
  font-size: 0.92em;
  color: var(--text-dim);
}

/* ── Top bar ─────────────────────────────────────────────────────── */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-panel);
  flex: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 2.5px solid var(--accent);
  border-right-color: transparent;
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 13px;
  height: 2.5px;
  background: var(--accent);
  transform: translateY(-50%);
}

.topbar h1 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.brand-sub {
  margin: 0;
  font-size: 11.5px;
  color: var(--text-faint);
}

.topbar-status {
  display: flex;
  align-items: center;
  gap: 8px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  font-size: 11.5px;
  color: var(--text-dim);
  background: var(--bg-inset);
  white-space: nowrap;
}

.pill-ok {
  color: var(--py);
  border-color: rgba(111, 208, 140, 0.3);
}

.pill-bad {
  color: var(--danger);
  border-color: rgba(255, 107, 107, 0.35);
}

.pill-link {
  text-decoration: none;
}

.pill-link:hover {
  color: var(--text);
  border-color: var(--accent);
}

/* ── Layout ──────────────────────────────────────────────────────── */

.layout {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: var(--rail-width) 1fr;
}

.rail {
  border-right: 1px solid var(--line);
  overflow-y: auto;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--bg);
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 13px;
}

.panel-title {
  margin: 0 0 8px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel-note {
  margin: -2px 0 12px;
  font-size: 11.5px;
  color: var(--text-faint);
  line-height: 1.45;
}

.tag {
  font-size: 9.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
}

.tag-py {
  color: var(--py);
  background: rgba(111, 208, 140, 0.12);
}

.tag-js {
  color: var(--js);
  background: rgba(240, 198, 116, 0.12);
}

/* ── Dropzone ────────────────────────────────────────────────────── */

.dropzone {
  position: relative;
  border: 1.5px dashed var(--line);
  border-radius: var(--radius);
  background: var(--bg-inset);
  min-height: 116px;
  display: grid;
  place-items: center;
  cursor: pointer;
  overflow: hidden;
  transition: border-color 0.15s, background 0.15s;
}

.dropzone:hover,
.dropzone:focus-visible,
.dropzone.is-over {
  border-color: var(--accent);
  background: var(--accent-soft);
  outline: none;
}

.dropzone-hint {
  display: grid;
  gap: 4px;
  text-align: center;
  padding: 16px;
  pointer-events: none;
}

.dropzone-hint strong {
  font-size: 13px;
  font-weight: 600;
}

.dropzone-hint span {
  font-size: 11px;
  color: var(--text-faint);
}

.preview {
  width: 100%;
  max-height: 190px;
  object-fit: contain;
  display: block;
  /* Letterbox in the panel colour, not black: a black surround around a
     light image reads as part of the artwork. */
  background: var(--bg-inset);
}

.file-meta {
  margin: 8px 0 0;
  font-size: 11px;
  color: var(--text-faint);
  word-break: break-all;
  min-height: 1em;
}

/* ── Controls ────────────────────────────────────────────────────── */

.controls {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.group {
  border-top: 1px solid var(--line-soft);
  padding-top: 10px;
  margin-top: 6px;
}

.group:first-child {
  border-top: 0;
  padding-top: 0;
  margin-top: 0;
}

.group-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 2px;
}

.group-help {
  font-size: 10.5px;
  color: var(--text-faint);
  margin-bottom: 8px;
  line-height: 1.4;
}

.field {
  display: grid;
  gap: 3px;
  padding: 5px 0;
}

.field-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.field label {
  font-size: 12px;
  color: var(--text);
  cursor: pointer;
}

.field-value {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 11px;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.field-help {
  font-size: 10.5px;
  color: var(--text-faint);
  line-height: 1.4;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  height: 18px;
  cursor: pointer;
}

select,
input[type="number"],
input[type="text"] {
  width: 100%;
  background: var(--bg-inset);
  border: 1px solid var(--line);
  color: var(--text);
  border-radius: 6px;
  padding: 5px 7px;
  font: inherit;
  font-size: 12px;
}

select:focus,
input:focus {
  outline: 1.5px solid var(--accent);
  outline-offset: -1px;
}

input[type="color"] {
  width: 100%;
  height: 26px;
  background: var(--bg-inset);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 2px;
  cursor: pointer;
}

.field-check {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
}

.field-check input {
  accent-color: var(--accent);
  width: 15px;
  height: 15px;
  cursor: pointer;
}

.field-inline {
  display: flex;
  gap: 6px;
  align-items: center;
}

.field-inline input[type="number"] {
  flex: 1;
}

.btn-tiny {
  font-size: 10.5px;
  padding: 4px 8px;
  border-radius: 5px;
  border: 1px solid var(--line);
  background: var(--bg-inset);
  color: var(--text-dim);
  cursor: pointer;
  white-space: nowrap;
}

.btn-tiny:hover {
  color: var(--text);
  border-color: var(--accent);
}

.loading {
  font-size: 11.5px;
  color: var(--text-faint);
  margin: 0;
}

/* ── Stage ───────────────────────────────────────────────────────── */

.stage {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.stage-canvas-wrap {
  position: relative;
  flex: 1;
  min-height: 0;
  background: radial-gradient(ellipse at 50% 45%, #10131b 0%, #07080c 75%);
}

#stage {
  display: block;
  width: 100%;
  height: 100%;
}

.stage-empty,
.stage-busy {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 8px;
  text-align: center;
  padding: 24px;
  pointer-events: none;
}

.stage-empty p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
}

.stage-empty-sub {
  max-width: 40ch;
  font-size: 12px !important;
  color: var(--text-faint) !important;
  line-height: 1.5;
}

.stage-busy {
  background: rgba(7, 8, 12, 0.6);
  color: var(--text-dim);
  font-size: 13px;
  grid-auto-flow: column;
  align-content: center;
}

.spinner {
  width: 15px;
  height: 15px;
  border: 2px solid var(--line);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .spinner {
    animation-duration: 2.4s;
  }
}

.stage-bar {
  flex: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding: 10px 16px;
  border-top: 1px solid var(--line);
  background: var(--bg-panel);
}

.actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn {
  border: 1px solid var(--line);
  background: var(--bg-inset);
  color: var(--text);
  border-radius: 7px;
  padding: 7px 14px;
  font: inherit;
  font-size: 12.5px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, opacity 0.15s;
}

.btn:hover:not(:disabled) {
  border-color: var(--accent);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #08111f;
  font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
  background: #6f9bff;
}

.btn-quiet {
  color: var(--text-dim);
}

.stats {
  display: flex;
  gap: 18px;
  margin: 0;
}

.stats div {
  display: grid;
  gap: 1px;
}

.stats dt {
  font-size: 9.5px;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-faint);
}

.stats dd {
  margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12.5px;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

/* ── Messages ────────────────────────────────────────────────────── */

.message {
  flex: none;
  padding: 10px 16px;
  font-size: 12.5px;
  border-top: 1px solid var(--line);
  background: rgba(255, 107, 107, 0.08);
  color: #ffb3b3;
}

.message.is-info {
  background: var(--accent-soft);
  color: #b8ccff;
}

.message ul {
  margin: 6px 0 0;
  padding-left: 18px;
}

/* ── Narrow screens ──────────────────────────────────────────────── */

@media (max-width: 860px) {
  .layout {
    grid-template-columns: 1fr;
    overflow-y: auto;
  }

  .rail {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    overflow-y: visible;
    order: 2;
  }

  .stage {
    order: 1;
  }

  .stage-canvas-wrap {
    min-height: 58vh;
  }
}