The workspace

┌─ Menu bar (File · Edit · View · Arrange · Verify · Help) ─────┐
├─ Tab strip (one per open document, click [+] for new) ───────┤
├─ Toolbar (Draw · Transform (incl. Align) · Boolean · Modify · History) ┤
├───────────┬────────────────────────────────┬─────────────────┤
│ Layers    │                                │ Properties      │
│ Cells     │           Canvas               │ (selected obj)  │
│           │                                │                 │
└───────────┴────────────────────────────────┴─────────────────┘
│ x, y   │   N shapes · N refs · N selected   │ measure │ zoom │
└──────────────────────────────────────────────────────────────┘

• Menu bar (top): File / Edit / View / Arrange / Verify / Help.
• Tab strip: one tab per open file. [+] spawns a blank document; × closes. Switch tabs to edit a different document; the clipboard is shared across tabs so you can copy/paste between them.
• Toolbar: grouped into Draw, Transform (which holds the Align dropdown), Boolean, Modify, History. Each group has a small label above it. The Boolean group is a single flyout icon listing Union / Difference / Intersect / XOR with their hotkeys — select 2+ shapes, then click a row, press U/D/I/X directly, right-click for the context menu, or use Edit in the menu bar.
• Left panels: layers above, cell hierarchy below.
• Canvas (center): the drawing surface.
• Right panel: editable numeric properties of whatever is selected.
• Hint line (just above the status bar): what the current tool expects next, and — while you are inside a cell — an Editing <cell> — Esc to go back breadcrumb.
• Status bar (bottom): cursor coords, save target, counts, live measurement, and the ORTHO / POLAR / hierarchy-level toggles. The cursor x, y read-out shows exactly the precision the current zoom can resolve — the decimals follow the zoom, so a wafer-wide view reads 2740 µm rather than a false 2740.11 µm, and at 1 nm per pixel the same read-out shows fractional nanometres. Ruler tick labels follow the same rule.
• Scale bar (bottom-left corner of the canvas): a live yardstick that spans a whole number of grid cells — as many as fit in about 60–100 screen pixels — and states that length in your display unit; the rule is always an exact multiple of the current snap step. When one grid cell is already wider than the bar, the bar shows that single cell.

Keyboard / accessibility. Press Tab once from a fresh page load and the first stop is a Skip to canvas link — activating it moves keyboard focus straight to the drawing surface, bypassing the menu bar and the toolbar. The canvas shows a visible orange focus ring while it holds keyboard focus, so you can always tell whether a key press will reach the drawing. Below about 1024 px of window width the toolbar scrolls horizontally; a soft fade at its right edge means there are more buttons (including Open and Save) further along — scroll the strip, or use Ctrl+O / Ctrl+S. The Open and Save toolbar buttons name their shortcuts in their tooltips, and follow any remap made in Edit → Keyboard shortcuts….