:root {
  --bg: #f5f5f5;
  --panel: #ffffff;
  --ink: #1e1e21;
  --muted: #6b6b73;
  --line: #dcdce1;
  --accent: #b4541f;
  --accent-soft: #fbe9dd;
  --error: #a3261c;
  --stage: #ececed;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17171a;
    --panel: #1f1f23;
    --ink: #e8e8ea;
    --muted: #9b9ba4;
    --line: #33333a;
    --accent: #e8823f;
    --accent-soft: #3a2618;
    --error: #ef7c72;
    --stage: #232328;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

#app {
  display: grid;
  grid-template-columns: 340px 1fr;
  height: 100vh;
  height: 100dvh;
}

/* ------------------------------------------------------------------- panel */

#panel {
  overflow-y: auto;
  background: var(--panel);
  border-right: 1px solid var(--line);
  padding: 22px 22px 32px;
}

#panel header h1 {
  margin: 0;
  font-size: 20px;
  letter-spacing: -0.01em;
}

/* the wordmark doubles as the reset: the arrow only turns up once there is
   something to reset, which is also what tells you the title is a control */
#reset {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 0;
  padding: 0;
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  border-radius: 4px;
  cursor: pointer;
}

#reset .mark span { color: var(--accent); }

#reset svg {
  flex: none;
  color: var(--muted);
  opacity: 0;
  transition: opacity 0.15s, color 0.15s;
}

#reset[data-dirty] svg { opacity: 1; }
#reset[data-dirty]:hover svg,
#reset:focus-visible svg { color: var(--accent); opacity: 1; }
#reset:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

@media (prefers-reduced-motion: reduce) { #reset svg { transition: none; } }

.sub {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.group {
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.group h2, summary {
  margin: 0 0 12px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
}

summary { cursor: pointer; margin-bottom: 0; }
details[open] summary { margin-bottom: 12px; }

.row {
  display: grid;
  grid-template-columns: 78px 1fr 46px;
  align-items: center;
  gap: 10px;
  margin-bottom: 9px;
  font-size: 13px;
}

.row output {
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--muted);
  text-align: right;
}

.row select { grid-column: 2 / 3; }

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

select {
  width: 100%;
  padding: 5px 7px;
  font: inherit;
  font-size: 13px;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 5px;
}

.check {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  margin-bottom: 9px;
  font-size: 13px;
  line-height: 1.35;
}

.check input { margin-top: 2px; accent-color: var(--accent); }

.check:has(input:disabled) { color: var(--muted); opacity: 0.55; }

.note {
  margin: 8px 0 0;
  font-size: 12px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------- cell tiles */

.cells {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.cells label {
  display: block;
  cursor: pointer;
  text-align: center;
}

.cells input { position: absolute; opacity: 0; pointer-events: none; }

.cells svg {
  width: 100%;
  display: block;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel);
}

.cells rect { fill: var(--line); }

.cells label span {
  display: block;
  margin-top: 4px;
  font-size: 11px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.cells input:checked + svg {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.cells input:checked + svg rect { fill: var(--accent); }
.cells input:focus-visible + svg { outline: 2px solid var(--accent); outline-offset: 2px; }

/* -------------------------------------------------------------------- stage */

#stage { position: relative; background: var(--stage); min-width: 0; }

#viewer { position: absolute; inset: 0; }
#viewer canvas { display: block; }

#view-toggle {
  position: absolute;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 2px;
  padding: 3px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
}

#view-toggle label {
  cursor: pointer;
  padding: 5px 13px;
  font-size: 13px;
  border-radius: 5px;
  color: var(--muted);
  white-space: nowrap;
}

#view-toggle input { position: absolute; opacity: 0; pointer-events: none; }
#view-toggle label:has(input:checked) { background: var(--accent-soft); color: var(--accent); }
#view-toggle label[hidden] { display: none; }

#status {
  position: absolute;
  bottom: 16px;
  left: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: min(520px, calc(100% - 32px));
  padding: 6px 12px;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 7px;
}

#status[data-state="error"] { color: var(--error); white-space: pre-wrap; }
#status[data-state="idle"] .spinner { display: none; }

.spinner {
  flex: none;
  width: 11px;
  height: 11px;
  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: none; } }

#downloads {
  position: absolute;
  right: 16px;
  bottom: 16px;
  display: flex;
  gap: 8px;
}

#downloads button {
  padding: 8px 15px;
  font: inherit;
  font-size: 13px;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 7px;
  cursor: pointer;
}

#downloads button:disabled { opacity: 0.4; cursor: default; }
#downloads button:not(:disabled):hover { filter: brightness(1.08); }

#panel footer {
  margin-top: 26px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

#panel footer a { color: var(--muted); }

/* ------------------------------------------------------------------ narrow */

@media (max-width: 820px) {
  #app { grid-template-columns: 1fr; height: auto; }
  #panel { border-right: none; border-bottom: 1px solid var(--line); order: 2; }
  #stage { order: 1; height: 60vh; }
}