:root {
  --bg: #1b1e24;
  --panel-bg: #262a33;
  --panel-border: #3a3f4b;
  --text: #e8eaed;
  --text-dim: #9aa0ac;
  --accent: #4fa3ff;
  --accent-hover: #6cb4ff;
  --danger: #e2554f;
  --danger-hover: #ec6d67;
  --resting: #cccccc;
  --excited: #ff5028;
  --refractory: #333333;
  --connective: #8b5e34;
  --pacemaker-rest: #e8b84b;
  --slow-rest: #9e96c7;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-bottom: 1px solid var(--panel-border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.heart-icon {
  height: 40px;
  width: auto;
  flex-shrink: 0;
}

.app-header h1 {
  font-size: 1.6rem;
  margin: 0;
  font-weight: 700;
}

.status {
  font-size: 0.85rem;
  color: var(--text-dim);
  padding: 4px 10px;
  border: 1px solid var(--panel-border);
  border-radius: 4px;
}

.app-main {
  display: flex;
  flex: 1;
  gap: 16px;
  padding: 16px;
  align-items: flex-start;
}

.canvas-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.canvas-scroll {
  overflow: auto;
  border: 1px solid var(--panel-border);
  background: #000;
  max-width: 100%;
  max-height: 80vh;
  line-height: 0;
}

#grid {
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  cursor: crosshair;
  display: block;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  border: 1px solid #000a;
  display: inline-block;
}

.swatch-resting { background: var(--resting); }
.swatch-excited { background: var(--excited); }
.swatch-refractory { background: var(--refractory); }
.swatch-connective { background: var(--connective); }
.swatch-pacemaker { background: var(--pacemaker-rest); }

.slow-legend {
  flex-direction: column;
  gap: 6px;
  margin-top: -4px;
}

.slow-legend-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.slow-legend-label {
  white-space: nowrap;
}

.slow-gradient-bar {
  width: 90px;
  height: 12px;
  border-radius: 3px;
  border: 1px solid #000a;
  display: inline-block;
}

.slow-legend-minmax {
  white-space: nowrap;
}

.slow-erp-sample {
  width: 16px;
  height: 16px;
  border-radius: 3px;
  background: var(--slow-rest);
  border-color: var(--text-dim);
  border-style: solid;
  display: inline-block;
}

.slow-erp-tier-label {
  margin-right: 4px;
}

.panel {
  width: 300px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.panel-section {
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  padding: 10px 12px 14px;
  background: var(--panel-bg);
}

.panel-section legend {
  padding: 0 6px;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-dim);
}

.field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.85rem;
  margin: 8px 0;
}

.field input[type="number"] {
  width: 100%;
}

.field-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 0.85rem;
  margin: 8px 0;
}

.field-row label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}

input[type="number"] {
  background: #1b1e24;
  border: 1px solid var(--panel-border);
  color: var(--text);
  border-radius: 4px;
  padding: 5px 6px;
}

input[type="range"] {
  width: 100%;
}

input[type="range"]:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.btn-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 6px;
}

.btn {
  flex: 1;
  min-width: 70px;
  padding: 7px 10px;
  border-radius: 5px;
  border: 1px solid var(--panel-border);
  background: #333844;
  color: var(--text);
  cursor: pointer;
  font-size: 0.85rem;
  transition: background 0.15s, border-color 0.15s;
}

.btn:hover {
  background: #3d4350;
}

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

.btn:disabled:hover {
  background: #333844;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #0c1420;
  font-weight: 600;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-danger {
  background: transparent;
  border-color: var(--danger);
  color: var(--danger);
  width: 100%;
}

.btn-danger:hover {
  background: var(--danger);
  color: #fff;
}

.tool-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #0c1420;
  font-weight: 600;
}

.type-accordion {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.type-item {
  border: 1px solid var(--panel-border);
  border-radius: 5px;
  overflow: hidden;
}

.type-header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 0;
  background: #333844;
}

.type-swatch-btn {
  display: flex;
  align-items: center;
  padding: 8px 10px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.type-swatch-btn:hover {
  background: #3d4350;
}

.type-toggle {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 10px 8px 2px;
  background: transparent;
  border: none;
  color: var(--text);
  cursor: pointer;
  font-size: 0.85rem;
  text-align: left;
}

.type-toggle:hover {
  background: #3d4350;
}

.type-item.open .type-toggle {
  color: var(--accent);
  font-weight: 600;
}

.type-chevron {
  font-size: 0.7rem;
  color: var(--text-dim);
  transition: transform 0.15s;
}

.type-item.open .type-chevron {
  transform: rotate(180deg);
  color: var(--accent);
}

.type-swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  border: 2px solid #0006;
  flex-shrink: 0;
  box-sizing: border-box;
}

.type-swatch.selected {
  border-color: var(--danger);
  box-shadow: 0 0 0 1px var(--danger);
}

.type-body {
  display: none;
  padding: 10px 12px;
  background: var(--panel-bg);
}

.type-item.open .type-body {
  display: block;
}

.type-body .field {
  margin: 8px 0;
}

.hint {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin: 8px 0 0;
  line-height: 1.4;
}

#brushSizeValue {
  font-size: 0.78rem;
  color: var(--text-dim);
  align-self: flex-end;
}

.app-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
  padding: 10px 20px;
  border-top: 1px solid var(--panel-border);
  font-size: 0.78rem;
  color: var(--text-dim);
}

.app-footer a,
.legal a {
  color: var(--accent);
  text-decoration: none;
}

.app-footer a:hover,
.legal a:hover {
  text-decoration: underline;
}

.legal {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 20px 48px;
  line-height: 1.6;
}

.legal h1 {
  font-size: 1.6rem;
  margin: 0 0 18px;
}

.legal h2 {
  font-size: 1.05rem;
  margin: 26px 0 8px;
}

.legal p,
.legal ul {
  margin: 0 0 12px;
}

.legal ul {
  padding-left: 22px;
}

.legal .back {
  display: inline-block;
  margin-bottom: 16px;
  font-size: 0.85rem;
}

.legal .note {
  padding: 12px 14px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
}

.todo {
  background: #5a3300;
  color: #ffd9a8;
  padding: 1px 6px;
  border-radius: 3px;
}

@media (max-width: 900px) {
  .app-main {
    flex-direction: column;
  }
  .panel {
    width: 100%;
  }
}