UI Design Patterns

Practical guidelines for creating polished, professional user interfaces without relying on graphic design talent. These patterns work for any web project, including TYPO3 frontend development.

Acknowledgements

These patterns are adapted from two excellent resources:

• Refactoring UI by Adam Wathan & Steve Schoger — The definitive guide to practical UI design for developers
• Practical UI (2nd Edition) by Adham Dannaway — Quick and practical UI design guidelines for intuitive, accessible, and beautiful interfaces

We highly recommend both works for deepening your UI design knowledge.

0. Core Principles (from Practical UI)

Before diving into specific patterns, internalize these foundational principles:

Minimize Usability Risks

Base design decisions on risk assessment—the risk that someone could have difficulty using an interface:

• Light grey text may look sleek but risks readability issues
• Icons without labels risk confusion about meaning
• Colored heading text risks being mistaken for links

Always consider: people with poor eyesight, low computer literacy, reduced dexterity, and cognitive differences.

Have a Logical Reason for Every Design Detail

Every UI element should have a rationale. "That looks nice" is not constructive feedback. Be able to articulate why each design decision was made.

Minimize Interaction Cost

Interaction cost = physical + mental effort to complete a task. Reduce it by:

1. Keep related actions close (Fitts's Law—closer/larger targets are faster to click)
2. Reduce distractions (avoid attention-grabbing elements that pull focus)
3. Use progressive disclosure (reveal complexity only when needed)

Minimize Cognitive Load

Cognitive load is the mental effort required to use an interface. Reduce it by:

• Breaking information into smaller, digestible chunks
• Using familiar patterns people already understand
• Removing unnecessary elements and decisions
• Grouping related items visually

Design System First

Create a system of reusable guidelines before designing:

• Color palette with usage rules
• Typography scale
• Spacing system
• Component patterns
• Interaction states

This ensures consistency and speeds up decision-making.

Accessibility is Non-Negotiable

Meet WCAG 2.1 Level AA at minimum:

Never rely on color alone—always pair with icons, patterns, or text for color blind users.

Use Common Design Patterns

Per Jakob's Law, stick with patterns people already know:

• Conventional form fields (not custom/unfamiliar styles)
• Standard navigation patterns
• Expected icon meanings
• Familiar button behaviors

Save creativity for your product's unique value proposition, not basic UI conventions.

The 80/20 Rule

Roughly 80% of users use 20% of features. Prioritize the common paths:

• Optimize for frequent tasks, not edge cases
• Focus design effort where it has the largest impact
• Don't over-engineer rarely-used features

1. Starting from Scratch

Start with a Feature, Not a Layout

Don't begin by designing the shell (navigation, sidebar, footer). Start with actual functionality.

Wrong approach:

• "Should it have a top nav or sidebar?"
• "Where should the logo go?"

Right approach:

• Design the core feature first (search form, product card, user profile)
• The navigation will reveal itself as you design features

Detail Comes Later

In early stages, ignore typefaces, shadows, and icons. Use thick markers or low-fidelity wireframes to explore layouts quickly.

Hold the Color

Design in grayscale first. This forces you to use spacing, contrast, and size to create hierarchy. Color comes later as enhancement.

Work in Cycles

1. Design a simple version of the next feature
2. Build it
3. Iterate on the working design
4. Move to the next feature

Be a Pessimist

Design the smallest useful version first. Don't design features you can't build yet—ship what works.

2. Hierarchy is Everything

Not All Elements Are Equal

Visual hierarchy makes interfaces feel "designed". When everything competes for attention, nothing stands out.

The key: Deliberately de-emphasize secondary and tertiary information while highlighting what matters most.

Size Isn't Everything

Don't rely solely on font size for hierarchy. Use:

Color guidelines for text:

• Primary content: Dark color (e.g., slate-900)
• Secondary content: Medium grey (e.g., slate-600)
• Tertiary content: Light grey (e.g., slate-400)

Don't Use Grey Text on Colored Backgrounds

Grey text on colored backgrounds looks washed out. Instead, pick a color with the same hue as the background, adjusting saturation and lightness.

/* Bad: Grey on blue background */
background: hsl(220, 80%, 50%);
color: #888888; /* Looks dull */

/* Good: Tinted text matching background hue */
background: hsl(220, 80%, 50%);
color: hsl(220, 60%, 85%); /* Harmonious and readable */

Emphasize by De-emphasizing

If a primary element doesn't stand out, don't make it louder—make competing elements quieter.

/* Instead of making active nav item bolder... */
/* ...make inactive items softer */
.nav-item { color: var(--slate-400); }
.nav-item.active { color: var(--slate-900); }

Labels Are a Last Resort

Context often eliminates the need for labels:

When labels are necessary, de-emphasize them—the data is what matters.

Balance Weight and Contrast

Heavy elements (icons, bold text) can be de-emphasized with softer colors. Light elements (thin borders) can be emphasized with increased weight.

/* Icon feels too heavy? Reduce contrast */
.icon { color: var(--slate-400); } /* Instead of slate-900 */

/* Border too subtle? Increase width */
border: 2px solid hsl(210, 23%, 95%); /* Instead of 1px darker */

Button Hierarchy

Design buttons based on hierarchy, not just semantics:

Destructive actions aren't automatically red and bold. If "Delete" isn't the primary action, style it as secondary or tertiary, then use bold red styling in the confirmation modal.

3. Layout and Spacing

Start with Too Much White Space

Begin with excessive space, then remove until satisfied. This ensures elements breathe properly.

Establish a Spacing System

Use a constrained scale with meaningful jumps (~25% between values):

4px, 8px, 12px, 16px, 24px, 32px, 48px, 64px, 96px, 128px

Base on 16px (default browser font size, divides nicely).

You Don't Have to Fill the Screen

If content only needs 600px, don't stretch it to 1200px. Extra space around edges never hurts.

Shrink the Canvas

Designing for mobile first often reveals better solutions. Start with ~400px width, then expand.

Grids Are Overrated

Not all elements should be fluid. Sidebars, icons, and avatars often work better with fixed sizes while main content flexes.

/* Better than percentage-based sidebar */
.sidebar { width: 280px; flex-shrink: 0; }
.main { flex: 1; min-width: 0; }

Relative Sizing Doesn't Scale

Headlines shouldn't stay proportional to body text across screen sizes. Large elements should shrink faster than small ones on mobile.

/* Desktop: 45px headline, 18px body (2.5x ratio) */
/* Mobile: 24px headline, 14px body (1.7x ratio) */

Avoid Ambiguous Spacing

When elements are grouped without visible separators, the spacing between groups must be greater than spacing within groups.

/* Form labels should be closer to their inputs than to previous inputs */
.form-group { margin-bottom: 24px; }
.form-label { margin-bottom: 8px; }

4. Designing Text

Establish a Type Scale

Hand-pick sizes rather than using mathematical ratios:

12px, 14px, 16px, 18px, 20px, 24px, 30px, 36px, 48px, 60px, 72px

Use px or rem, not em (to avoid compounding issues with nesting).

Use Good Fonts

Safe choices:

• System font stack for familiarity
• Fonts with 5+ weights indicate quality craftsmanship
• High x-height fonts for UI text (better legibility at small sizes)

Filter by weight count on Google Fonts to find quality options.

Keep Line Length in Check

Optimal: 45-75 characters per line (20-35em width).

.prose { max-width: 65ch; } /* Character-based width */

Baseline, Not Center

When mixing font sizes on one line, align by baseline, not vertical center.

.header-row { align-items: baseline; } /* Not center */

Line Height Is Proportional

Wider paragraphs need taller line heights.

Not Every Link Needs a Color

In link-heavy interfaces, use subtle differentiation (font weight, darker color) instead of blue underlines everywhere. Reserve bold link styling for important navigation.

Align with Readability in Mind

• Left-align most text
• Center only short, independent blocks (headings, CTAs)
• Right-align numbers in tables for easy comparison
• Hyphenate justified text

Use Letter-Spacing Effectively

• Tighten headlines slightly: letter-spacing: -0.02em;
• Widen all-caps text: letter-spacing: 0.05em;
• Leave body text alone

5. Working with Color

Ditch Hex for HSL

HSL (Hue, Saturation, Lightness) makes color relationships intuitive:

/* HSL is easier to reason about */
--primary-500: hsl(220, 80%, 50%);
--primary-600: hsl(220, 80%, 40%); /* Just darken lightness */
--primary-400: hsl(220, 80%, 60%); /* Just lighten */

You Need More Colors Than You Think

A complete palette includes:

Define Shades Up Front

Don't use lighten() or darken() functions. Pre-define all shades:

1. Pick your base color (good for button backgrounds)
2. Pick your darkest shade (for text on light backgrounds)
3. Pick your lightest shade (for tinted backgrounds)
4. Fill in 6-7 shades between them

Don't Let Lightness Kill Saturation

As lightness approaches 0% or 100%, increase saturation to maintain vibrancy.

Perceived Brightness Varies by Hue

Yellow appears brighter than blue at the same lightness. To make a color lighter without washing it out, rotate hue toward yellow, cyan, or magenta. To darken, rotate toward red, green, or blue.

Greys Don't Have to Be Grey

Saturate greys slightly for personality:

• Cool greys: Add blue (hue ~210)
• Warm greys: Add yellow/orange (hue ~40)

--grey-500: hsl(210, 10%, 50%); /* Cool grey */
--grey-500-warm: hsl(40, 10%, 50%); /* Warm grey */

Accessible Contrast

Flip the contrast when colored backgrounds make white text too dark—use dark colored text on light colored backgrounds instead.

Don't Rely on Color Alone

Always pair color with another indicator (icons, patterns, text) for colorblind users.

System Colors for Status

Use traffic light colors with familiar meanings:

Always pair with icons for color blind accessibility.

APCA: The Future of Contrast Measurement

WCAG 3 introduces the Accessible Perceptual Contrast Algorithm (APCA)—a more accurate contrast measurement:

Key difference: APCA handles dark backgrounds better than WCAG 2, and swapping text/background colors affects the score.

Transparent Colors for Flexibility

Use transparent colors (with alpha values) for:

• Hover states that work on any background
• Overlays that adapt to underlying content
• Subtle backgrounds that maintain harmony

/* Transparent overlays that work on any background */
--hover-overlay: hsla(0, 0%, 0%, 0.05);
--active-overlay: hsla(0, 0%, 0%, 0.1);
--disabled-overlay: hsla(0, 0%, 100%, 0.5);

6. Creating Depth

Emulate a Light Source

Light comes from above. Apply this consistently:

• Raised elements: Lighter top edge, shadow below
• Inset elements: Shadow at top, lighter bottom edge

/* Raised button */
.button {
  box-shadow: 
    inset 0 1px 0 hsl(220, 80%, 70%), /* Light top edge */
    0 1px 3px hsla(0, 0%, 0%, 0.2);    /* Shadow below */
}

/* Inset input */
.input {
  box-shadow: inset 0 2px 4px hsla(0, 0%, 0%, 0.1);
}

Use Shadows to Convey Elevation

Define 5 shadow levels and stick to them.

Shadows Can Have Two Parts

Combine a large soft shadow (direct light) with a small tight shadow (ambient occlusion):

box-shadow: 
  0 4px 6px rgba(0, 0, 0, 0.07),   /* Large, soft */
  0 1px 3px rgba(0, 0, 0, 0.1);    /* Small, tight */

The tight shadow fades at higher elevations.

Flat Designs Can Have Depth

Without shadows:

• Use lighter colors for raised elements
• Use darker colors for inset elements
• Use solid offset shadows (no blur) for flat aesthetic with depth

Overlap Elements to Create Layers

Let cards cross background boundaries. Overlap images with invisible borders to prevent clashing.

7. Working with Images

Use Good Photos

Bad photos ruin designs. Hire professionals or use quality stock (Unsplash, etc.). Don't use smartphone placeholders.

Text on Images Needs Consistent Contrast

When placing text over images:

1. Add overlay: Semi-transparent black (for light text) or white (for dark text)
2. Lower contrast: Reduce image contrast, adjust brightness
3. Colorize: Desaturate + multiply blend with brand color
4. Text shadow: Large blur radius, no offset (glow effect)

Everything Has an Intended Size

• Don't scale up icons designed for 16-24px—they look chunky
• Don't scale down screenshots—details become illegible
• Redraw logos for small sizes (favicons)

Wrap small icons in colored shapes to fill larger spaces:

<div class="w-12 h-12 bg-blue-100 rounded-lg flex items-center justify-center">
  <svg class="w-6 h-6 text-blue-600"><!-- Icon --></svg>
</div>

User-Uploaded Content

• Force consistent aspect ratios with object-fit: cover
• Prevent background bleed with subtle inner shadows
• Control dimensions with fixed containers

.user-image {
  object-fit: cover;
  aspect-ratio: 16/9;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.1);
}

8. Copywriting for UI

Clear interface text is as important as visual design. Poor copy creates confusion and increases cognitive load.

Be Concise

Remove unnecessary words. Every word should earn its place.

Use Sentence Case

Sentence case is easier to read than Title Case or ALL CAPS:

• Good: "Create new account"
• Avoid: "Create New Account"
• Never: "CREATE NEW ACCOUNT"

Front-Load Text

Put the most important information first. Users scan—don't bury key info.

Use Plain Language

Write at an 8th-grade reading level. Avoid jargon and technical terms.

Write Clear Error Messages

Good error messages:

1. Explain what happened (not just "Error")
2. Suggest how to fix it (actionable guidance)
3. Use human language (not error codes)

Consistent Vocabulary

Use the same words for the same concepts throughout:

• Pick "Sign in" or "Log in"—not both
• Pick "Settings" or "Preferences"—not both
• Pick "Delete" or "Remove"—not both

Button Labels

Use action verbs that describe what happens:

9. Forms and Buttons

Button Weights

Define three distinct button styles based on importance:

Form Field Best Practices

1. Use conventional styles—don't reinvent form fields
2. Visible borders—minimum 3:1 contrast ratio
3. Clear focus states—visible keyboard focus indicators
4. Inline validation—show errors as users type, not only on submit
5. Helpful placeholders—example input, not labels

Form Layout

• One column for most forms (faster to complete)
• Group related fields with clear visual separation
• Labels above inputs (faster scanning than left-aligned labels)
• Required field indicators—mark optional fields, not required ones

Avoid Disabled Buttons

Disabled buttons create confusion. Instead:

• Hide buttons until they're usable
• Show buttons but explain why action isn't available
• Use inline validation to guide users

/* If you must use disabled buttons */
.button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

10. Finishing Touches

Supercharge the Defaults

Add Color with Accent Borders

A 4px colored border adds polish without design skills:

/* Top of cards */
.card { border-top: 4px solid var(--primary-500); }

/* Side of alerts */
.alert { border-left: 4px solid var(--warning-500); }

/* Under headlines */
.headline::after { 
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--primary-500);
  margin-top: 12px;
}

Decorate Backgrounds

Break monotony with:

• Subtle background color changes between sections
• Gradients (keep hues within 30° of each other)
• Low-contrast repeating patterns
• Simple geometric shapes or illustrations

Don't Overlook Empty States

Empty states are first impressions. Include:

• Illustrations or icons
• Clear call-to-action
• Hide filters/tabs until content exists

Use Fewer Borders

Instead of borders for separation:

Think Outside the Box

Challenge assumptions about component design:

• Dropdowns can have multiple columns, icons, and descriptions
• Tables can combine columns and add hierarchy
• Radio buttons can be selectable cards
• Forms can use creative layouts

11. Leveling Up

Look for Decisions You Wouldn't Have Made

Study designs you admire. Notice unconventional choices:

• Inverted datepicker colors
• Buttons inside inputs
• Two-color headlines

Rebuild Favorite Interfaces

Recreate designs from scratch without inspecting code. Discovering why your version differs teaches lasting lessons.

Quick Reference: System Recommendations

Spacing Scale

--space-1: 4px;
--space-2: 8px;
--space-3: 12px;
--space-4: 16px;
--space-6: 24px;
--space-8: 32px;
--space-12: 48px;
--space-16: 64px;
--space-24: 96px;
--space-32: 128px;

Type Scale

--text-xs: 12px;
--text-sm: 14px;
--text-base: 16px;
--text-lg: 18px;
--text-xl: 20px;
--text-2xl: 24px;
--text-3xl: 30px;
--text-4xl: 36px;
--text-5xl: 48px;
--text-6xl: 60px;

Shadow Scale

--shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
--shadow-md: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
--shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
--shadow-xl: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
--shadow-2xl: 0 20px 25px rgba(0, 0, 0, 0.15), 0 10px 10px rgba(0, 0, 0, 0.04);

Border Radius Scale

--radius-sm: 2px;
--radius-md: 4px;
--radius-lg: 8px;
--radius-xl: 12px;
--radius-2xl: 16px;
--radius-full: 9999px;

Interaction States

Every interactive element needs clear state feedback:

/* Button states example */
.button {
  background: var(--primary-500);
  transition: all 0.15s ease;
}
.button:hover {
  background: var(--primary-600);
}
.button:active {
  background: var(--primary-700);
  transform: translateY(1px);
}
.button:focus-visible {
  outline: 2px solid var(--primary-500);
  outline-offset: 2px;
}
.button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

WCAG 2.1 AA Checklist

For deeper learning, study the source materials: Refactoring UI and Practical UI