.tool-section { padding-top: 0; padding-bottom: 80px; }

.tool-hero {
  position: relative;
  overflow: hidden;
  padding: 96px 0 48px;
}

.tool-hero-bg {
  position: absolute;
  inset: -20%;
  z-index: 0;
  background:
    radial-gradient(circle at 25% 30%, color-mix(in srgb, var(--accent) 18%, transparent), transparent 55%),
    radial-gradient(circle at 75% 60%, color-mix(in srgb, var(--accent-2) 18%, transparent), transparent 55%);
  background-size: 140% 140%;
  filter: blur(20px);
}

@media (prefers-reduced-motion: no-preference) {
  .tool-hero-bg { animation: toolBgDrift 20s ease-in-out infinite; }
}

@keyframes toolBgDrift {
  0%, 100% { background-position: 0% 0%, 100% 100%; }
  50% { background-position: 15% 10%, 85% 90%; }
}

.tool-intro { position: relative; z-index: 1; text-align: center; }
.tool-intro h1 {
  font-size: clamp(2rem, 4vw, 2.5rem);
  margin: 0 0 10px;
  letter-spacing: -0.02em;
}
.tool-intro .section-sub { margin-left: auto; margin-right: auto; margin-bottom: 0; }

#app {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
  height: min(72vh, 680px);
  min-height: 480px;
}

#sidebar {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 20px;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* Themed scrollbars for the tool panels, instead of the default white/system ones */
#sidebar,
#colorList {
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
#sidebar::-webkit-scrollbar,
#colorList::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
#sidebar::-webkit-scrollbar-track,
#colorList::-webkit-scrollbar-track {
  background: transparent;
}
#sidebar::-webkit-scrollbar-thumb,
#colorList::-webkit-scrollbar-thumb {
  background-color: var(--border);
  border-radius: 8px;
}

.tool-panel {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px 0;
}
.tool-panel:first-child { padding-top: 0; }
.tool-panel:last-child { padding-bottom: 0; }
.tool-panel + .tool-panel { border-top: 1px solid var(--border); }

.panel-title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 700;
}

.tool-empty { color: var(--text-muted); font-size: 0.85rem; }

#dropzone {
  border: 2px dashed var(--border);
  border-radius: 8px;
  padding: 16px 12px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease, color 0.15s ease, transform 0.15s ease;
}
#dropzone:hover {
  border-color: var(--accent);
  color: var(--text);
}
#dropzone.drag {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  color: var(--text);
  transform: scale(1.01);
}
#fileInput { display: none; }

.row { display: flex; gap: 8px; align-items: flex-end; }
.row .field { flex: 1; min-width: 0; margin-bottom: 0; }
.row .btn { width: auto; flex: 0 0 auto; padding: 8px 16px; }

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

label.field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}

input[type="number"] {
  background: var(--bg-alt);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  font: inherit;
  font-size: 0.85rem;
  width: 100%;
  transition: border-color 0.15s ease;
}
input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
}
input[type="number"]:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.checkbox-field {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text);
  cursor: pointer;
}

input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-alt);
  cursor: pointer;
  position: relative;
  transition: border-color 0.15s ease, background 0.15s ease;
}
input[type="checkbox"]:hover { border-color: var(--accent); }
input[type="checkbox"]:checked {
  background: var(--accent);
  border-color: var(--accent);
}
input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 1px;
  width: 4px;
  height: 8px;
  border: solid var(--card-bg);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}
input[type="checkbox"]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.slider-field { gap: 6px; }
.slider-row { display: flex; align-items: center; gap: 10px; }
.slider-value {
  font-size: 0.8rem;
  color: var(--text);
  min-width: 38px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  flex: 1;
  appearance: none;
  -webkit-appearance: none;
  height: 4px;
  border-radius: 2px;
  background: var(--border);
  outline: none;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--card-bg);
  box-shadow: 0 0 0 1px var(--accent);
  cursor: pointer;
  transition: transform 0.15s ease;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.15); }
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--card-bg);
  cursor: pointer;
}
input[type="range"]::-moz-range-track {
  height: 4px;
  border-radius: 2px;
  background: var(--border);
}

#app .btn {
  width: 100%;
  text-align: center;
  padding: 10px 16px;
  font-size: 0.85rem;
}
#app .btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.export-note {
  margin: -2px 0 0;
  color: var(--text-muted);
  font-size: 0.72rem;
  line-height: 1.45;
}

#colorList {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 260px;
  overflow-y: auto;
}

.color-row {
  display: grid;
  grid-template-columns: 18px 1fr 68px;
  align-items: center;
  gap: 8px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 8px;
  transition: border-color 0.15s ease, transform 0.15s ease;
  cursor: pointer;
}
.color-row:hover {
  border-color: var(--accent);
  transform: translateX(2px);
}
.color-row.selected {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, var(--bg-alt));
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 24%, transparent);
}
.color-row:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.swatch {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.color-label {
  font-size: 0.7rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.color-row input[type="number"] {
  padding: 4px 6px;
  font-size: 0.75rem;
  text-align: right;
}

#status { font-size: 0.8rem; color: var(--text-muted); min-height: 32px; line-height: 1.4; }
#status.error { color: #d9534f; }
#status.ok { color: var(--accent); }

#viewer {
  position: relative;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
#viewer canvas { display: block; cursor: grab; }
#viewer canvas:active { cursor: grabbing; }

#viewerHint {
  position: absolute;
  top: 12px;
  left: 14px;
  font-size: 0.75rem;
  color: var(--text-muted);
  pointer-events: none;
  background: color-mix(in srgb, var(--bg-alt) 70%, transparent);
  padding: 4px 8px;
  border-radius: 6px;
}

@media (max-width: 900px) {
  .tool-hero { padding: 40px 0 28px; }
  #app {
    grid-template-columns: 1fr;
    height: auto;
    gap: 16px;
  }
  #sidebar { max-height: none; }
  #viewer { height: 420px; }
  #colorList { max-height: 200px; }
}