:root {
  color-scheme: dark;
  --bg: #0c0d0f;
  --panel: #141518;
  --panel-2: #1a1c20;
  --line: #26292e;
  --line-2: #33373d;
  --text: #e4e5e7;
  --muted: #8a8f98;
  --faint: #5c616a;
  --accent: #d9a55b;
  --accent-ink: #1b1409;
  --danger: #e2735f;
  --ok: #8fc79a;
  --radius: 8px;
  --mono: ui-monospace, "Cascadia Mono", "SF Mono", Consolas, monospace;
  font: 13px/1.4 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; background: var(--bg); color: var(--text); }
button, input, select { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.app { display: grid; grid-template-columns: 360px minmax(0, 1fr); grid-template-rows: minmax(0, 1fr); height: 100vh; }

/* ---------- settings panel ---------- */
.panel {
  background: var(--panel);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  padding: 18px 16px 40px;
  scrollbar-width: thin;
  scrollbar-color: var(--line-2) transparent;
}
.brand { display: flex; gap: 12px; align-items: center; margin-bottom: 18px; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 8px; flex: none;
  background:
    radial-gradient(circle at 30% 30%, #fff8 0 18%, transparent 19%),
    repeating-radial-gradient(circle at 70% 75%, #0000 0 3px, #0006 3px 5px),
    linear-gradient(135deg, #b9b9b9, #3b3b3b);
  box-shadow: inset 0 0 0 1px #fff2;
}
.brand h1 { font-size: 15px; margin: 0; letter-spacing: 0.01em; }
.brand p { margin: 2px 0 0; color: var(--muted); font-size: 11.5px; }

.seed-row { display: grid; grid-template-columns: auto 1fr auto; gap: 8px; align-items: center; }
.seed-row label { color: var(--muted); }
.seed-row input, .name-field input {
  background: var(--bg); border: 1px solid var(--line-2); border-radius: 6px;
  padding: 6px 8px; font-family: var(--mono); min-width: 0; width: 100%;
}
.action-row { display: flex; gap: 6px; margin: 10px 0 14px; flex-wrap: wrap; }

.btn {
  background: var(--panel-2); border: 1px solid var(--line-2); border-radius: 6px;
  padding: 6px 11px; cursor: pointer; white-space: nowrap;
  transition: background 0.12s, border-color 0.12s;
}
.btn:hover { background: #22252a; border-color: #454a52; }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn.ghost { background: transparent; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 600; }
.btn.primary:hover { background: #e6b56d; }
.btn.icon { padding: 5px; line-height: 0; }
.btn.icon svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.4; }
.btn.icon svg circle { fill: currentColor; stroke: none; }
.file-btn { position: relative; overflow: hidden; }
.file-btn input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }

/* sections */
details.section { border-top: 1px solid var(--line); }
details.section > summary {
  list-style: none; cursor: pointer; padding: 12px 2px; font-weight: 600;
  display: flex; align-items: center; gap: 8px; user-select: none;
}
details.section > summary::-webkit-details-marker { display: none; }
details.section > summary::before {
  content: ""; width: 6px; height: 6px; border-right: 1.5px solid var(--muted); border-bottom: 1.5px solid var(--muted);
  transform: rotate(-45deg); transition: transform 0.15s; margin-right: 2px;
}
details.section[open] > summary::before { transform: rotate(45deg); }
details.section > summary .sub { font-weight: 400; color: var(--faint); margin-left: auto; font-size: 11.5px; }
.section-body { padding: 0 2px 14px; display: grid; gap: 10px; }
.group-label { color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: 0.07em; margin-top: 4px; }
.note { color: var(--faint); font-size: 11.5px; margin: -2px 0 0; }

/* layer-type cards */
details.card { background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius); }
details.card > summary {
  list-style: none; cursor: pointer; padding: 8px 10px; display: flex; align-items: center; gap: 10px;
}
details.card > summary::-webkit-details-marker { display: none; }
details.card > summary .title { flex: 1; }
details.card > summary .chev { color: var(--faint); font-size: 11px; }
details.card[open] > summary .chev { transform: rotate(180deg); }
details.card.off > summary .title { color: var(--faint); }
.card-body { padding: 4px 10px 12px; display: grid; gap: 10px; }

/* controls */
.ctl { display: grid; gap: 4px; }
.ctl-head { display: flex; justify-content: space-between; gap: 8px; }
.ctl-head label, .ctl-head span.lbl { color: var(--muted); }
.val { font-family: var(--mono); font-variant-numeric: tabular-nums; color: var(--text); font-size: 12px; }

input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 18px; background: transparent; margin: 0;
}
input[type="range"]::-webkit-slider-runnable-track { height: 4px; background: var(--line-2); border-radius: 2px; }
input[type="range"]::-moz-range-track { height: 4px; background: var(--line-2); border-radius: 2px; }
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 14px; height: 14px; margin-top: -5px; border-radius: 50%;
  background: var(--text); border: 2px solid var(--panel); box-shadow: 0 0 0 1px #0008; cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 12px; height: 12px; border-radius: 50%; background: var(--text); border: 2px solid var(--panel); cursor: pointer;
}
.single input[type="range"] { --fill: 0%; }
.single input[type="range"]::-webkit-slider-runnable-track {
  background: linear-gradient(to right, var(--accent) var(--fill), var(--line-2) var(--fill));
}
.single input[type="range"]::-moz-range-progress { height: 4px; background: var(--accent); border-radius: 2px; }

/* dual-thumb range: two overlaid inputs, only the thumbs take pointer events */
.range2 { position: relative; height: 18px; }
.range2 .track { position: absolute; left: 0; right: 0; top: 7px; height: 4px; border-radius: 2px; background: var(--line-2); }
.range2 .fill { position: absolute; top: 0; bottom: 0; background: var(--accent); border-radius: 2px; }
.range2 input { position: absolute; inset: 0; pointer-events: none; }
.range2 input::-webkit-slider-runnable-track { background: transparent; }
.range2 input::-moz-range-track { background: transparent; }
.range2 input::-webkit-slider-thumb { pointer-events: auto; }
.range2 input::-moz-range-thumb { pointer-events: auto; }

/* toggle switch */
.switch { position: relative; width: 30px; height: 17px; flex: none; }
.switch input { position: absolute; inset: 0; opacity: 0; margin: 0; cursor: pointer; z-index: 1; }
.switch span { position: absolute; inset: 0; border-radius: 9px; background: var(--line-2); transition: background 0.15s; }
.switch span::after {
  content: ""; position: absolute; left: 2px; top: 2px; width: 13px; height: 13px; border-radius: 50%;
  background: var(--muted); transition: transform 0.15s, background 0.15s;
}
.switch input:checked + span { background: var(--accent); }
.switch input:checked + span::after { transform: translateX(13px); background: var(--accent-ink); }
.switch input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.row { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.row > label { color: var(--muted); }

/* hard/organic slider gets a two-ended label */
.ends { display: flex; justify-content: space-between; color: var(--faint); font-size: 11px; margin-top: -2px; }

/* chips (blend-mode sets) */
.chips { display: flex; flex-wrap: wrap; gap: 5px; }
.chip { position: relative; }
.chip input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.chip span {
  display: inline-block; padding: 3px 8px; border-radius: 999px; border: 1px solid var(--line-2);
  color: var(--muted); font-size: 11.5px; transition: all 0.12s;
}
.chip input:checked + span { background: #d9a55b22; border-color: var(--accent); color: var(--text); }
.chip input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 1px; }

/* segmented control */
.seg { display: inline-flex; background: var(--bg); border: 1px solid var(--line-2); border-radius: 7px; padding: 2px; }
.seg button { background: none; border: 0; padding: 4px 10px; border-radius: 5px; color: var(--muted); cursor: pointer; }
.seg button[aria-checked="true"] { background: var(--panel-2); color: var(--text); box-shadow: inset 0 0 0 1px var(--line-2); }

/* ---------- stage ---------- */
.stage { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.toolbar, .exportbar {
  display: flex; align-items: center; gap: 14px; padding: 10px 16px; flex-wrap: wrap;
  border-bottom: 1px solid var(--line); background: var(--panel);
}
.exportbar { border-bottom: 0; border-top: 1px solid var(--line); }
.check { display: inline-flex; gap: 6px; align-items: center; color: var(--muted); cursor: pointer; }
.check input { accent-color: var(--accent); }
.select-wrap { display: inline-flex; gap: 6px; align-items: center; color: var(--muted); }
select {
  background: var(--bg); border: 1px solid var(--line-2); border-radius: 6px; padding: 4px 6px; font-family: var(--mono);
}
.stats { margin-left: auto; color: var(--faint); font-family: var(--mono); font-size: 11.5px; }

.viewport {
  flex: 1; min-height: 0; position: relative;
  background: radial-gradient(circle at 50% 40%, #1a1c20 0, var(--bg) 70%);
}
#view {
  position: absolute; inset: 20px; width: calc(100% - 40px); height: calc(100% - 40px);
  object-fit: contain; display: block;
}
.fatal {
  position: absolute; inset: 20px; display: grid; place-items: center; text-align: center;
  color: var(--danger); background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; white-space: pre-wrap;
}
.fatal[hidden] { display: none; }

.name-field {
  display: inline-flex; align-items: center; background: var(--bg); border: 1px solid var(--line-2);
  border-radius: 6px; padding-left: 8px; font-family: var(--mono);
}
.name-field .affix { color: var(--faint); white-space: nowrap; }
.name-field .affix:last-child { padding-right: 8px; }
.name-field input { border: 0; background: none; width: 12ch; padding: 6px 2px; }
.name-field.invalid { border-color: var(--danger); }
.hint { color: var(--faint); font-size: 11.5px; }
.export-status { margin-left: auto; font-family: var(--mono); font-size: 11.5px; color: var(--muted); }
.export-status.ok { color: var(--ok); }
.export-status.err { color: var(--danger); }

@media (max-width: 900px) {
  .app { grid-template-columns: 1fr; height: auto; }
  .panel { border-right: 0; border-bottom: 1px solid var(--line); max-height: none; }
  .viewport { height: min(100vw, 80vh); }
  .stats, .export-status { margin-left: 0; }
}