Skip to main content

​
CSS Format

​
Simple Utilities

Write one property per utility class: 
.text-large {
  font-size: 24px;
}
.bg-primary {
  background-color: #3b82f6;
}
.p-4 {
  padding: 16px;
}

​
Multiple Properties

You can include multiple properties in one class: 
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 6px;
  font-weight: 500;
}

​
Directional Properties

Use separate properties for directional values: 
.px-4 {
  padding-left: 16px;
  padding-right: 16px;
}

.py-2 {
  padding-top: 8px;
  padding-bottom: 8px;
}

​
Value Requirements

​
Always Include Units

Add units to numeric values: 
/* Correct */
.text-lg {
  font-size: 18px;
}
.w-64 {
  width: 256px;
}
.m-4 {
  margin: 16px;
}

/* Incorrect */
.text-lg {
  font-size: 18;
}
.w-64 {
  width: 256;
}
.m-4 {
  margin: 16;
}

​
Exceptions (No Units Needed)

These properties don’t need units:
  • opacity: opacity: 0.5;
  • z-index: z-index: 10;
  • line-height: line-height: 1.5;

​
Naming Conventions

​
Use Descriptive Names

Choose clear, descriptive class names: 
/* Good */
.text-heading {
  font-size: 32px;
}
.bg-brand {
  background-color: #your-brand-color;
}
.spacing-section {
  margin: 48px;
}

/* Avoid */
.text1 {
  font-size: 32px;
}
.bg1 {
  background-color: #your-brand-color;
}
.m1 {
  margin: 48px;
}

​
Follow Patterns

Use consistent naming patterns: 
/* Size-based */
.text-xs {
  font-size: 12px;
}
.text-sm {
  font-size: 14px;
}
.text-lg {
  font-size: 18px;
}

/* Color-based */
.text-primary {
  color: #3b82f6;
}
.bg-primary {
  background-color: #3b82f6;
}
.border-primary {
  border-color: #3b82f6;
}

​
Best Practices

​
Keep Classes Focused

Each class should have a single purpose: 
/* Good: Single purpose */
.text-center {
  text-align: center;
}
.font-bold {
  font-weight: 700;
}
.p-4 {
  padding: 16px;
}

/* Avoid: Multiple purposes */
.text-center-bold {
  text-align: center;
  font-weight: 700;
}

​
Use Semantic Values

Choose values that make sense: 
/* Good: Semantic spacing */
.spacing-sm {
  margin: 8px;
}
.spacing-md {
  margin: 16px;
}
.spacing-lg {
  margin: 32px;
}

/* Avoid: Arbitrary values */
.spacing-7 {
  margin: 7px;
}
.spacing-13 {
  margin: 13px;
}

​
Test Incrementally

Import and test small batches: 
/* Import 5-10 classes at a time */
.text-xs {
  font-size: 12px;
}
.text-sm {
  font-size: 14px;
}
.text-base {
  font-size: 16px;
}
.text-lg {
  font-size: 18px;
}
.text-xl {
  font-size: 20px;
}

​
Common Mistakes

​
Missing Semicolons

Always end properties with semicolons: 
/* Correct */
.text-lg {
  font-size: 18px;
}

/* Incorrect */
.text-lg {
  font-size: 18px;
}

​
Invalid Values

Use valid CSS values: 
/* Correct */
.items-center {
  align-items: center;
}

/* Incorrect */
.items-center {
  align-items: flex-center;
}

​
Reserved Names

Avoid reserved class names: 
/* Avoid */
.container {
  max-width: 1200px;
}

/* Use instead */
.cont {
  max-width: 1200px;
}
.wrapper {
  max-width: 1200px;
}

​
Advanced Techniques

​
CSS Custom Properties

Use CSS variables for consistency: 
:root {
  --primary-color: #3b82f6;
  --spacing-unit: 4px;
}

.text-primary {
  color: var(--primary-color);
}
.spacing-1 {
  margin: var(--spacing-unit);
}
.spacing-2 {
  margin: calc(var(--spacing-unit) * 2);
}

​
Logical Properties

Use modern CSS logical properties: 
/* These are automatically converted */
.text-start {
  text-align: start;
}
.text-end {
  text-align: end;
}
.items-start {
  align-items: start;
}
.items-end {
  align-items: end;
}

Supported Properties

Complete property reference

Reserved Names

Names to avoid