ui-design（用户界面设计）

UI Design Skill

Practical design principles for creating professional, polished user interfaces without formal design training.

Core Philosophy

Design is not about artistic talent—it's about making deliberate decisions. Focus on these fundamentals:

1. Visual hierarchy - Guide attention to what matters
2. Spacing systems - Create consistent rhythm
3. Constraint-based design - Limit choices to speed decisions

Starting a Design

Feature First, Not Layout

Never start with the shell (navbar, sidebar). Start with actual functionality:

• Design the core feature first (e.g., search form, not the page layout)
• The shell emerges from feature needs, not vice versa

Progressive Fidelity

1. Sketch first - Use low-fidelity to explore ideas fast
2. Grayscale second - Force hierarchy through spacing, contrast, size
3. Color last - Add color only after hierarchy is established

Design the Minimum

• Don't design features you won't build yet
• Expect implementation to be hard—design the smallest useful version
• Work in cycles: design → build → iterate

Hierarchy

The most important skill. When everything competes for attention, nothing stands out.

Establish Hierarchy With

• Size - But don't rely on it alone
• Weight - 400-500 for normal, 600-700 for emphasis. Avoid <400 for UI text
• Color - Dark for primary, grey for secondary, lighter grey for tertiary

De-emphasize to Emphasize

When the main element doesn't stand out, don't add more to it—reduce emphasis on competing elements.

Labels

• Often unnecessary—format and context communicate meaning (email, phone, price)
• Combine with values: "12 left in stock" not "In stock: 12"
• When needed, de-emphasize labels (smaller, lighter, lower contrast)

Actions

• Primary - Solid, high contrast background
• Secondary - Outline or lower contrast background
• Tertiary - Style like links
• Destructive ≠ always red and bold. Use hierarchy first, confirm with bold styling.

Spacing & Layout

White Space

Start with too much, then remove. Elements need breathing room.

Spacing System

Use a constrained scale where adjacent values differ by ~25%:

4, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, 256, 384, 512

Base on 16px (browser default). Don't nitpick between 120px and 125px—grab from your scale.

Layout Principles

• Don't fill the screen - If you need 600px, use 600px
• Grids are overrated - Not everything should be fluid. Sidebars often work better with fixed widths.
• Relative sizing doesn't scale - Large elements shrink faster than small ones on small screens
• Avoid ambiguous spacing - More space *around* groups than *within* them

Typography

Type Scale

Hand-pick a constrained set:

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

Use px or rem, never em (nesting breaks the system).

Line Length

45-75 characters per line (20-35em). Constrain paragraphs even in wide layouts.

Line Height

• Inversely proportional to font size - Taller for small text, shorter for large
• Proportional to line length - Wider content needs taller line-height
• Headlines at large sizes can use line-height: 1

Alignment

• Left-align most text
• Center only headlines or short blocks (<3 lines)
• Right-align numbers in tables

Letter Spacing

• Tighten for large headlines
• Increase for ALL CAPS text

Color

Use HSL

Hue (0-360°), Saturation (0-100%), Lightness (0-100%). More intuitive than hex/RGB.

Build a Palette

You need far more than 5 colors:

• Greys - 8-10 shades. Start dark grey (not pure black), end white.
• Primary - 5-10 shades for buttons, links, active states
• Accents - Semantic colors (red=destructive, yellow=warning, green=success)

Creating Shades

1. Pick base color (good for button background)
2. Pick darkest (for text on light bg) and lightest (for tinted backgrounds)
3. Fill gaps: 100, 200, 300, 400, 500, 600, 700, 800, 900

Advanced Techniques

• Increase saturation as lightness moves away from 50%
• Rotate hue toward bright hues (60°, 180°, 300°) to lighten, dark hues (0°, 120°, 240°) to darken
• Saturate greys with blue (cool) or yellow/orange (warm)

Colored Backgrounds

Don't use grey text on colored backgrounds—hand-pick a color with same hue, adjusted saturation/lightness.

Accessibility

• 4.5:1 contrast for normal text, 3:1 for large text
• Flip contrast: dark text on light colored background instead of white on dark
• Never rely on color alone—add icons, patterns, or contrast differences

Depth & Shadows

Light Source

Light comes from above. Raised elements: lighter top edge, shadow below. Inset elements: shadow at top, lighter bottom edge.

Shadow System

Define 5 shadows from subtle to dramatic:

• Small - Buttons, subtle elevation
• Medium - Dropdowns, cards
• Large - Modals, dialogs

Two-Part Shadows

1. Large, soft shadow (direct light source)
2. Tight, dark shadow (ambient light blocked underneath)

Flat Design Depth

• Lighter = closer, darker = further
• Solid shadows (no blur) work for flat aesthetics
• Overlap elements to create layers

Images

Quality Matters

Bad photos ruin good designs. Use professional photography or quality stock (Unsplash).

Text Over Images

• Add semi-transparent overlay
• Lower image contrast and adjust brightness
• Add subtle text shadow (large blur, no offset)

Sizing

• Don't scale icons up (they look chunky) or down (they look muddy)
• Don't shrink full screenshots—use partial screenshots or simplified illustrations
• Control user-uploaded images with fixed containers (background-size: cover)

Finishing Touches

Supercharge Defaults

• Replace bullets with icons
• Promote quotes into visual elements
• Style links distinctively
• Use custom checkboxes/radios with brand colors

Add Polish

• Accent borders - Top of cards, side of alerts, under headlines
• Background decoration - Color changes, subtle patterns, geometric shapes
• Empty states - Design them! Include illustrations and clear CTAs.

Reduce Borders

Use instead:

• Box shadows
• Different background colors
• Extra spacing

Think Outside the Box

Dropdowns can have columns, icons, sections. Tables can combine columns and add hierarchy. Radio buttons can be selectable cards.

Reference Files

For deeper guidance:

• Hierarchy & Spacing - Visual hierarchy, spacing systems, layout
• Typography & Color - Type scales, font selection, color systems
• Depth & Polish - Shadows, images, finishing touches