#app {
  display: grid;
  grid-template-rows: 48px 1fr;
  grid-template-columns: 1fr 320px;
  grid-template-areas:
    "topbar topbar"
    "main   inspector";
  height: 100vh;
  overflow: hidden;
}

[data-region="topbar"] {
  grid-area: topbar;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 0 var(--sp-3);
  height: 48px;
  flex-shrink: 0;
  overflow: hidden;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-shrink: 0;
}

.topbar-center {
  flex: 1;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-shrink: 0;
}

.app-title {
  font-size: var(--fs-4);
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}

.project-name {
  font-size: var(--fs-3);
  color: var(--text2);
  white-space: nowrap;
  max-width: 180px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sep {
  width: 1px;
  height: 20px;
  background: var(--line);
  flex-shrink: 0;
}

#main-area {
  grid-area: main;
  display: grid;
  grid-template-rows: 1fr var(--timeline-height, 340px);
  overflow: hidden;
}

[data-region="canvas"] {
  background: var(--stage);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--faint);
  font-size: var(--fs-2);
}

[data-region="timeline"] {
  background: var(--tl);
  border-top: 1px solid var(--line);
  overflow: hidden;
  display: grid;
  grid-template-rows: 40px 1fr;
  min-height: 200px;
  max-height: 600px;
}

.timeline-head {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 0 var(--sp-3);
  border-bottom: 1px solid var(--line);
  background: var(--tl);
  flex-shrink: 0;
}

.timeline-body {
  display: grid;
  grid-template-columns: 260px 1fr;
  overflow: hidden;
}

.timeline-layers {
  border-right: 1px solid var(--line);
  overflow-y: auto;
  overflow-x: hidden;
}

.timeline-tracks {
  overflow: auto;
}

[data-region="inspector"] {
  grid-area: inspector;
  background: var(--panel);
  border-left: 1px solid var(--line);
  overflow-y: auto;
}

.resize-handle {
  position: absolute;
  left: 0;
  right: 0;
  height: 4px;
  cursor: ns-resize;
  background: transparent;
  z-index: 10;
}

.resize-handle:hover,
.resize-handle.dragging {
  background: var(--acc);
  opacity: 0.5;
}