body {
  margin: 0;
  height: 100vh;
  width: 100vw;
  box-sizing: border-box;
  font-size: 12px;
  font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  overflow: hidden;
}

.main-layout {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

.toolbar {
  background: #23272b;
  padding: 6px 10px 6px 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  box-sizing: border-box;
  border-bottom: 4px solid #444;
  flex: 0 0 auto;
}

.toolbar button {
  background: #2d3238;
  color: #eee;
  border: 2px solid #444;
  border-radius: 4px;
  padding: 5px 14px;
  margin: 0;
  font-size: 1em;
  cursor: pointer;
  outline: none;
  transition: background 0.15s, border 0.15s;
  user-select: none;
}

.toolbar button:hover {
  background: #3a4047;
  border-color: #666;
}

.tool-btn.selected {
  background: #4a90e2;
  color: #fff;
  border-color: #357ab8;
}

.toolbar button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.panel-container {
  display: grid;
  position: relative;
  grid-template-columns: 0.5fr 0.5fr;
  grid-template-rows: 0.5fr 0.5fr;
  gap: 4px;
  background: #444;
  flex: 1 1 0;
  width: 100%;
  height: 100%;
  min-height: 0;
  min-width: 0;
}

.panel-container.tool-pan {
  cursor: grab;
}

.panel-container.tool-create-vertex {
  cursor: crosshair;
}

.panel {
  position: relative;
  background: #181818;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

canvas {
  flex: 1 1 auto;
  width: 100%;
  height: 100%;
  display: block;
  background: #111;
}

.panel-label {
  position: absolute;
  top: 6px;
  left: 10px;
  color: #ccc;
  background: rgba(30,30,30,0.7);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.95em;
  user-select: none;
  z-index: 1;
  text-wrap: nowrap;
  white-space: nowrap;
}

.reset-camera-btn,
.movement-constraint-btn {
  margin-left: 8px;
  padding: 0 6px;
  font-size: 1em;
  background: #23272b;
  color: #aaf;
  border: 2px solid #357ab8;
  border-radius: 3px;
  cursor: pointer;
  vertical-align: middle;
  line-height: 1;
  height: 18px;
  min-width: 18px;
  transition: background 0.15s, border 0.15s;
}

.movement-constraint-btn {
  margin: 0;
}

.reset-camera-btn:hover,
.movement-constraint-btn:hover,
.movement-constraint-btn.active {
  background: #4a90e2;
  color: #fff;
  border-color: #357ab8;
}

.help-modal {
  padding: 24px;
  min-width: 400px;
  max-width: 600px;
  min-height: 400px;
  border: none;
  border-radius: 8px;
  background: #2d3238;
  color: #eee;
}

.help-modal::backdrop {
  background: rgba(0, 0, 0, 0.5);
}

.help-modal .close-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 22px;
  height: 22px;
  border: none;
  background: transparent;
  color: #888;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: background-color 0.2s, color 0.2s;
}

.help-modal .close-btn:hover {
  background: #444;
  color: #fff;
}

.help-modal .help-content {
  margin-right: 20px;
}

.resize-handle {
  position: absolute;
  background: #444;
  transition: background-color 0.2s, color 0.2s;
}

.resize-handle:hover,
.resize-handle.active {
  background-color: #4a90e2;
}

.resize-handle-vertical {
  cursor: col-resize;
  width: 4px;
  height: 100%;
  top: 0;
  left: calc(50% - 2px);
}

.resize-handle-horizontal {
  cursor: row-resize;
  width: 100%;
  height: 4px;
  top: calc(50% - 2px);
  left: 0;
}

.resize-handle-center {
  cursor: move;
  width: 12px;
  height: 12px;
  top: calc(50% - 6px);
  left: calc(50% - 6px);
  border-radius: 50%;
}

.dg li.folder .dg.selected > ul > li.title {
  background-color: #042;
}

.dg li.cr span.property-name.selected {
  background-color: #042;
}