*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

:root {
  --bg: #1a1a2e;
  --surface: #16213e;
  --surface2: #0f3460;
  --accent: #e94560;
  --accent-hover: #ff6b81;
  --text: #eee;
  --text-muted: #888;
  --border: #2a2a4a;
  --radius: 6px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  overflow: hidden;
}

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

/* Toolbar */
#toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 13px;
  transition: all 0.15s;
  white-space: nowrap;
}

.btn:hover {
  background: #1a4a7a;
  border-color: #3a5a8a;
}

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  margin-left: auto;
}

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

.tool-btn.active {
  background: var(--accent);
  border-color: var(--accent);
}

#tool-group, #zoom-group {
  display: flex;
  align-items: center;
  gap: 4px;
  padding-left: 12px;
  border-left: 1px solid var(--border);
}

.toggle-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 8px;
  font-size: 13px;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
  border-left: 1px solid var(--border);
  height: 100%;
}

.toggle-label input[type="checkbox"] {
  accent-color: var(--accent);
  width: 14px;
  height: 14px;
  cursor: pointer;
}

.toggle-label:has(input:checked) span {
  color: var(--text);
}

#zoom-level {
  font-size: 12px;
  color: var(--text-muted);
  min-width: 45px;
  text-align: center;
}

/* Main layout */
#main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Canvas */
#canvas-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: #111;
  background-image:
    linear-gradient(45deg, #1a1a1a 25%, transparent 25%),
    linear-gradient(-45deg, #1a1a1a 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #1a1a1a 75%),
    linear-gradient(-45deg, transparent 75%, #1a1a1a 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

#canvas {
  position: absolute;
  top: 0;
  left: 0;
  cursor: crosshair;
}

#canvas-container.panning #canvas {
  cursor: grab;
}

#canvas-container.panning-active #canvas {
  cursor: grabbing;
}

/* Drop zone */
#drop-zone {
  position: absolute;
  inset: 0;
  display: none;
  place-items: center;
  z-index: 5;
  background: rgba(0,0,0,0.6);
}

#drop-zone.visible {
  display: grid;
}

#drop-zone-content {
  text-align: center;
  color: var(--text-muted);
}

#drop-zone-content p {
  margin-top: 12px;
  font-size: 15px;
}

/* Sidebar */
#sidebar {
  width: 300px;
  background: var(--surface);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}

#sidebar-header h2 {
  font-size: 15px;
  font-weight: 600;
}

#region-count {
  background: var(--surface2);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
  color: var(--text-muted);
}

#region-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

#sidebar-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
  padding: 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

/* Region cards */
.region-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 6px;
  overflow: hidden;
  transition: border-color 0.15s;
}

.region-card:hover,
.region-card.active {
  border-color: var(--accent);
}

.region-card-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
}

.region-color {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}

.region-name-input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 13px;
  outline: none;
  padding: 2px 4px;
  border-radius: 3px;
}

.region-name-input:focus {
  background: var(--surface2);
}

.region-dims {
  font-size: 11px;
  color: var(--text-muted);
  flex-shrink: 0;
}

.region-delete {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 2px;
  border-radius: 3px;
  display: flex;
  align-items: center;
}

.region-delete:hover {
  color: var(--accent);
  background: rgba(233, 69, 96, 0.15);
}

.region-preview {
  height: 60px;
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.region-preview canvas {
  max-width: 100%;
  max-height: 60px;
  object-fit: contain;
}

/* Scrollbar */
#region-list::-webkit-scrollbar {
  width: 6px;
}

#region-list::-webkit-scrollbar-track {
  background: transparent;
}

#region-list::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}