1# Spatial Design
2 
3## Spacing Systems
4 
5### Use 4pt Base, Not 8pt
6 
78pt systems are too coarse; you'll frequently need 12px (between 8 and 16). Use 4pt for granularity: 4, 8, 12, 16, 24, 32, 48, 64, 96px.
8 
9### Name Tokens Semantically
10 
11Name by relationship (`--space-sm`, `--space-lg`), not value (`--spacing-8`). Use `gap` instead of margins for sibling spacing; it eliminates margin collapse and cleanup hacks.
12 
13## Grid Systems
14 
15### The Self-Adjusting Grid
16 
17Use `repeat(auto-fit, minmax(280px, 1fr))` for responsive grids without breakpoints. Columns are at least 280px, as many as fit per row, leftovers stretch. For complex layouts, use named grid areas (`grid-template-areas`) and redefine them at breakpoints.
18 
19## Visual Hierarchy
20 
21### The Squint Test
22 
23Blur your eyes (or screenshot and blur). Can you still identify:
24- The most important element?
25- The second most important?
26- Clear groupings?
27 
28If everything looks the same weight blurred, you have a hierarchy problem.
29 
30### Hierarchy Through Multiple Dimensions
31 
32Don't rely on size alone. Combine:
33 
34| Tool | Strong Hierarchy | Weak Hierarchy |
35|------|------------------|----------------|
36| **Size** | 3:1 ratio or more | <2:1 ratio |
37| **Weight** | Bold vs Regular | Medium vs Regular |
38| **Color** | High contrast | Similar tones |
39| **Position** | Top/left (primary) | Bottom/right |
40| **Space** | Surrounded by white space | Crowded |
41 
42**The best hierarchy uses 2-3 dimensions at once**: A heading that's larger, bolder, AND has more space above it.
43 
44### Cards Are Not Required
45 
46Cards are overused. Spacing and alignment create visual grouping naturally. Use cards only when content is truly distinct and actionable, items need visual comparison in a grid, or content needs clear interaction boundaries. **Never nest cards inside cards.** Use spacing, typography, and subtle dividers for hierarchy within a card.
47 
48## Container Queries
49 
50Viewport queries are for page layouts. **Container queries are for components**:
51 
52```css
53.card-container {
54  container-type: inline-size;
55}
56 
57.card {
58  display: grid;
59  gap: var(--space-md);
60}
61 
62/* Card layout changes based on its container, not viewport */
63@container (min-width: 400px) {
64  .card {
65    grid-template-columns: 120px 1fr;
66  }
67}
68```
69 
70**Why this matters**: A card in a narrow sidebar stays compact, while the same card in a main content area expands automatically, without viewport hacks.
71 
72## Optical Adjustments
73 
74Text at `margin-left: 0` looks indented due to letterform whitespace; use negative margin (`-0.05em`) to optically align. Geometrically centered icons often look off-center; play icons need to shift right, arrows shift toward their direction.
75 
76### Touch Targets vs Visual Size
77 
78Buttons can look small but need large touch targets (44px minimum). Use padding or pseudo-elements:
79 
80```css
81.icon-button {
82  width: 24px;  /* Visual size */
83  height: 24px;
84  position: relative;
85}
86 
87.icon-button::before {
88  content: '';
89  position: absolute;
90  inset: -10px;  /* Expand tap target to 44px */
91}
92```
93 
94## Depth & Elevation
95 
96Create semantic z-index scales (dropdown → sticky → modal-backdrop → modal → toast → tooltip) instead of arbitrary numbers. For shadows, create a consistent elevation scale (sm → md → lg → xl). **Key insight**: Shadows should be subtle. If you can clearly see it, it's probably too strong.
97 
98---
99 
100**Avoid**: Arbitrary spacing values outside your scale. Making all spacing equal (variety creates hierarchy). Creating hierarchy through size alone - combine size, weight, color, and space.
101