CSS Styling Skill
Instructions
When writing CSS:
1. Modern CSS Reset
*, *::before, *::after {
box-sizing: border-box;
}
* {
margin: 0;
padding: 0;
}
html {
-webkit-text-size-adjust: none;
text-size-adjust: none;
}
body {
min-height: 100vh;
line-height: 1.5;
-webkit-font-smoothing: antialiased;
}
img, picture, video, canvas, svg {
display: block;
max-width: 100%;
}
input, button, textarea, select {
font: inherit;
}
p, h1, h2, h3, h4, h5, h6 {
overflow-wrap: break-word;
}2. CSS Custom Properties (Variables)
:root {
/* Colors */
--color-primary: #2563eb;
--color-primary-dark: #1d4ed8;
--color-secondary: #64748b;
--color-success: #22c55e;
--color-error: #ef4444;
/* Typography */
--font-sans: system-ui, -apple-system, sans-serif;
--font-mono: ui-monospace, monospace;
--text-xs: 0.75rem;
--text-sm: 0.875rem;
--text-base: 1rem;
--text-lg: 1.125rem;
--text-xl: 1.25rem;
--text-2xl: 1.5rem;
--text-3xl: 1.875rem;
/* Spacing */
--space-1: 0.25rem;
--space-2: 0.5rem;
--space-3: 0.75rem;
--space-4: 1rem;
--space-6: 1.5rem;
--space-8: 2rem;
--space-12: 3rem;
--space-16: 4rem;
/* Borders */
--radius-sm: 0.25rem;
--radius-md: 0.375rem;
--radius-lg: 0.5rem;
--radius-full: 9999px;
/* Shadows */
--shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
--shadow-md: 0 4px 6px rgba(0,0,0,0.1);
--shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
/* Transitions */
--transition-fast: 150ms ease;
--transition-normal: 300ms ease;
}
/* Dark mode */
@media (prefers-color-scheme: dark) {
:root {
--color-bg: #0f172a;
--color-text: #f1f5f9;
}
}3. Flexbox Layouts
/* Center anything */
.center {
display: flex;
justify-content: center;
align-items: center;
}
/* Space between */
.space-between {
display: flex;
justify-content: space-between;
align-items: center;
}
/* Stack vertically */
.stack {
display: flex;
flex-direction: column;
gap: var(--space-4);
}
/* Wrap items */
.flex-wrap {
display: flex;
flex-wrap: wrap;
gap: var(--space-4);
}4. Grid Layouts
/* Auto-fit responsive grid */
.grid-auto {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
gap: var(--space-6);
}
/* Fixed columns */
.grid-3 {
display: grid;
grid-template-columns: repeat(3, 1fr);
gap: var(--space-4);
}
/* Sidebar layout */
.with-sidebar {
display: grid;
grid-template-columns: 300px 1fr;
gap: var(--space-8);
}
/* Holy grail layout */
.holy-grail {
display: grid;
grid-template:
"header header header" auto
"nav main aside" 1fr
"footer footer footer" auto
/ 200px 1fr 200px;
min-height: 100vh;
}5. Responsive Design
/* Mobile-first breakpoints */
/* Base: Mobile */
@media (min-width: 640px) {
/* Tablet */
}
@media (min-width: 1024px) {
/* Desktop */
}
@media (min-width: 1280px) {
/* Large desktop */
}
/* Container queries */
.card-container {
container-type: inline-size;
}
@container (min-width: 400px) {
.card {
display: flex;
}
}
/* Clamp for fluid typography */
h1 {
font-size: clamp(2rem, 5vw, 4rem);
}6. Common Components
Buttons:
.btn {
display: inline-flex;
align-items: center;
justify-content: center;
gap: var(--space-2);
padding: var(--space-3) var(--space-6);
font-weight: 500;
border-radius: var(--radius-md);
border: none;
cursor: pointer;
transition: all var(--transition-fast);
}
.btn-primary {
background: var(--color-primary);
color: white;
}
.btn-primary:hover {
background: var(--color-primary-dark);
}
.btn:focus-visible {
outline: 2px solid var(--color-primary);
outline-offset: 2px;
}Cards:
.card {
background: white;
border-radius: var(--radius-lg);
box-shadow: var(--shadow-md);
overflow: hidden;
}
.card-body {
padding: var(--space-6);
}
.card-title {
font-size: var(--text-xl);
font-weight: 600;
margin-bottom: var(--space-2);
}Forms:
.input {
width: 100%;
padding: var(--space-3) var(--space-4);
border: 1px solid #e2e8f0;
border-radius: var(--radius-md);
font-size: var(--text-base);
transition: border-color var(--transition-fast);
}
.input:focus {
outline: none;
border-color: var(--color-primary);
box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
.input:invalid {
border-color: var(--color-error);
}7. Animations
/* Fade in */
@keyframes fadeIn {
from { opacity: 0; }
to { opacity: 1; }
}
.fade-in {
animation: fadeIn var(--transition-normal) ease-out;
}
/* Slide up */
@keyframes slideUp {
from {
opacity: 0;
transform: translateY(20px);
}
to {
opacity: 1;
transform: translateY(0);
}
}
.slide-up {
animation: slideUp var(--transition-normal) ease-out;
}
/* Respect user preferences */
@media (prefers-reduced-motion: reduce) {
*, *::before, *::after {
animation-duration: 0.01ms !important;
transition-duration: 0.01ms !important;
}
}8. Utility Classes
/* Visually hidden (accessible) */
.visually-hidden {
position: absolute;
width: 1px;
height: 1px;
padding: 0;
margin: -1px;
overflow: hidden;
clip: rect(0, 0, 0, 0);
white-space: nowrap;
border: 0;
}
/* Truncate text */
.truncate {
overflow: hidden;
text-overflow: ellipsis;
white-space: nowrap;
}
/* Line clamp */
.line-clamp-2 {
display: -webkit-box;
-webkit-line-clamp: 2;
-webkit-box-orient: vertical;
overflow: hidden;
}9. Best Practices
- Use CSS custom properties for theming
- Mobile-first responsive approach
- Avoid!important
- Use logical properties (margin-inline, padding-block)
- Prefer classes over IDs for styling
- Use BEM or similar naming convention
- Minimize nesting depth
- Group related properties
10. Performance Tips
- Avoid expensive selectors
- Use
will-changesparingly - Prefer
transformandopacityfor animations - Use
containfor isolated components - Lazy load non-critical CSS
WordPress-Specific CSS
11. Enqueueing Styles Properly
// In functions.php or plugin file
function theme_enqueue_styles() {
// Main stylesheet
wp_enqueue_style(
'theme-style',
get_stylesheet_uri(),
array(),
wp_get_theme()->get('Version')
);
// Additional CSS
wp_enqueue_style(
'theme-custom',
get_template_directory_uri() . '/assets/css/custom.css',
array('theme-style'),
'1.0.0'
);
}
add_action('wp_enqueue_scripts', 'theme_enqueue_styles');
// Admin styles
function theme_admin_styles() {
wp_enqueue_style(
'theme-admin',
get_template_directory_uri() . '/assets/css/admin.css',
array(),
'1.0.0'
);
}
add_action('admin_enqueue_scripts', 'theme_admin_styles');12. RTL Support
// Register RTL stylesheet
wp_enqueue_style('theme-style', get_stylesheet_uri());
wp_style_add_data('theme-style', 'rtl', 'replace');
// Or with suffix
wp_style_add_data('theme-style', 'rtl', get_template_directory_uri() . '/assets/css/style-rtl.css');/* Use logical properties for automatic RTL */
.element {
margin-inline-start: 1rem; /* margin-left in LTR, margin-right in RTL */
padding-inline-end: 1rem; /* padding-right in LTR, padding-left in RTL */
text-align: start; /* left in LTR, right in RTL */
}
/* Or use [dir] attribute */
[dir="rtl"] .element {
margin-left: 0;
margin-right: 1rem;
}13. Block Editor (Gutenberg) Styles
// Editor styles
function theme_editor_styles() {
add_theme_support('editor-styles');
add_editor_style('assets/css/editor-style.css');
}
add_action('after_setup_theme', 'theme_editor_styles');
// Block styles
function theme_block_styles() {
wp_enqueue_block_style('core/button', array(
'handle' => 'theme-button-style',
'src' => get_template_directory_uri() . '/assets/css/blocks/button.css',
));
}
add_action('init', 'theme_block_styles');14. theme.json Integration
{
"version": 2,
"settings": {
"color": {
"palette": [
{ "slug": "primary", "color": "#2563eb", "name": "Primary" },
{ "slug": "secondary", "color": "#64748b", "name": "Secondary" }
]
},
"spacing": {
"units": ["px", "rem", "%"],
"spacingScale": { "steps": 7 }
},
"typography": {
"fontFamilies": [
{ "slug": "system", "fontFamily": "system-ui, sans-serif", "name": "System" }
]
}
}
}/* Use WordPress CSS variables from theme.json */
.element {
color: var(--wp--preset--color--primary);
font-family: var(--wp--preset--font-family--system);
padding: var(--wp--preset--spacing--40);
}15. WordPress Admin Compatibility
/* Match WordPress admin colors */
.wp-admin .my-plugin-box {
background: #f0f0f1;
border: 1px solid #c3c4c7;
border-radius: 4px;
}
/* Use admin color scheme variables */
.wp-admin .my-button {
background: var(--wp-admin-theme-color, #2271b1);
color: var(--wp-admin-theme-color-darker-10, #135e96);
}
/* Responsive admin */
@media screen and (max-width: 782px) {
.wp-admin .my-plugin-box {
padding: 12px;
}
}16. WordPress CSS Best Practices
- Prefix classes with theme/plugin slug to avoid conflicts
- Use
wp_add_inline_style()for dynamic CSS - Avoid!important - use specificity instead
- Support RTL with logical properties or RTL stylesheet
- Test in Gutenberg editor view
- Use theme.json for design tokens when possible
- Minify for production using build tools