Web Design Patterns

CSS implementation patterns for production-grade interfaces. For design fundamentals and decision-making, see ui-design. This skill focuses on code.

See also: ui-design for typography/color/spacing theory, frontend-design for creative aesthetics.

Installation

OpenClaw / Moltbot / Clawbot

npx clawhub@latest install web-design

Layout Principles

Use CSS Grid for two-dimensional layouts and Flexbox for one-dimensional flow. Choose the right tool for each context.

Spatial Composition

Go beyond predictable layouts. Intentional asymmetry, overlapping elements, and grid-breaking accents create visual interest. Use grid stacking (grid-area: 1/1) instead of position: absolute for overlapping elements. Choose generous negative space for luxury/editorial aesthetics, or controlled density for data-rich interfaces — the choice must be intentional.

Typography

Typography carries 90% of a design's personality. Choose fonts that match the interface's purpose.

Type Scale

Use a consistent ratio. A 1.25 (major third) scale works for most interfaces: text-xs 0.64rem, text-sm 0.8rem, text-base 1rem, text-lg 1.25rem, text-xl 1.563rem, text-2xl 1.953rem, text-3xl 2.441rem, text-4xl 3.052rem. Set body text to 1rem (16px minimum), line-height 1.5 for body, 1.1–1.2 for headings. Limit line length to 60–75ch.

Color

Building a Palette

Every palette needs five functional roles:

Contrast and Depth

Create depth through surface layering, not just shadows:

:root {
  --surface-0: hsl(220 15% 8%);    /* page background */
  --surface-1: hsl(220 15% 12%);   /* card */
  --surface-2: hsl(220 15% 16%);   /* raised element */
  --surface-3: hsl(220 15% 20%);   /* popover / modal */
}

Use HSL or OKLCH for perceptually uniform color manipulation. Dominant color with sharp accents outperforms evenly-distributed palettes. Always verify WCAG contrast: 4.5:1 for normal text, 3:1 for large text.

Spacing

Consistent spacing creates rhythm. Use an 8px base unit (or 4px for dense UIs):

Apply spacing consistently: use gap on Grid/Flexbox containers instead of margins on children. This eliminates margin-collapse bugs and simplifies responsive adjustments.

Visual Hierarchy

Guide the eye through deliberate contrast in size, weight, color, and space.

Hierarchy Techniques

Practical Pattern — Card Hierarchy

Layer hierarchy within cards: eyebrow (xs, uppercase, muted) → title (xl, semibold) → body (base, secondary color, 1.6 line-height) → action (spaced apart with margin-top). Use surface color for separation and consistent padding from spacing tokens.

Responsive Design

Breakpoint Strategy

Fluid Techniques

Prefer fluid sizing over rigid breakpoints where possible:

/* Fluid typography — scales between 640px and 1440px viewport */
h1 { font-size: clamp(2rem, 1.5rem + 2.5vw, 3.5rem); }

/* Fluid spacing */
section { padding-block: clamp(2rem, 1rem + 4vw, 6rem); }

/* Intrinsic grid — no media queries needed */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 20rem), 1fr)); gap: var(--space-6); }

Use container queries (@container) for component-level responsiveness when a component's layout should respond to its container, not the viewport.

Accessibility

Accessibility is not optional. Build it in from the start.

/* Robust focus indicator */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Respect motion preferences */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

Component Design

Anatomy of a Well-Designed Component

Every UI component should have clear states, consistent spacing, and predictable behavior:

Design Token Architecture

Structure tokens in three layers for maintainability:

/* Layer 1: Primitive values */
--blue-500: oklch(0.55 0.2 250);
--gray-100: oklch(0.95 0.005 250);
--radius-md: 0.5rem;

/* Layer 2: Semantic aliases */
--color-primary: var(--blue-500);
--color-surface: var(--gray-100);
--radius-button: var(--radius-md);

/* Layer 3: Component-specific */
--btn-bg: var(--color-primary);
--btn-radius: var(--radius-button);
--btn-padding: var(--space-2) var(--space-4);

This three-layer approach allows theme switching by remapping Layer 2 without touching components.

Interaction Patterns

Motion and Animation

Use motion to communicate state changes, not to decorate. Focus on high-impact moments:

/* Staggered entrance animation */
.stagger-item {
  opacity: 0;
  translate: 0 1rem;
  animation: reveal 0.5s ease-out forwards;
}
.stagger-item:nth-child(1) { animation-delay: 0ms; }
.stagger-item:nth-child(2) { animation-delay: 60ms; }
.stagger-item:nth-child(3) { animation-delay: 120ms; }

@keyframes reveal {
  to { opacity: 1; translate: 0 0; }
}

Scroll-Driven Effects

Use native animation-timeline: scroll() (behind @supports) for parallax and reveal effects without JavaScript. Wrap in feature detection to gracefully degrade.

Design Quality Checklist

Before shipping, verify against these criteria:

• Typography: Intentional font pairing, consistent scale, readable line lengths
• Color: Cohesive palette, WCAG contrast met, semantic feedback colors defined
• Spacing: Consistent rhythm using spacing tokens, no ad-hoc pixel values
• Hierarchy: Clear visual flow — eye path follows intended reading order
• Responsiveness: Tested at mobile, tablet, desktop; no horizontal overflow
• Accessibility: Keyboard navigable, focus visible, screen-reader tested, motion-safe
• States: All interactive elements have hover, active, focus, disabled, and loading states
• Personality: Design has a clear point-of-view — not generic template aesthetic
• Performance: Images optimized, fonts subset, animations GPU-accelerated (transform, opacity)
• Dark mode: If supported, surfaces use layered lightness, not inverted colors