Nov 4, 2025 • css, design, frontend

CSS Utilities You'll Reuse in Every Project

CSS Utilities You'll Reuse in Every Project

Stop reinventing the wheel. Here's a production-ready collection of CSS utilities that work across every project.

Why Reusable CSS Utilities?

  • Speed: Copy-paste and ship faster
  • Consistency: Same look and feel across projects
  • Maintainability: Update once, benefit everywhere
  • Accessibility: Baked-in focus states and ARIA-friendly

Setup: CSS Variables

Start every project with this foundation:

:root {
  /* Colors */
  --color-primary: #0066ff;
  --color-secondary: #8b5cf6;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;

  /* Neutrals */
  --color-bg: #ffffff;
  --color-bg-subtle: #f9fafb;
  --color-text: #111827;
  --color-text-muted: #6b7280;
  --color-border: #e5e7eb;

  /* Spacing (8pt grid) */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
  --font-mono: 'SF Mono', 'Monaco', 'Consolas', monospace;
}

Component 1: Buttons

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.5;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Variants */
.btn-primary {
  background: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background: #0052cc;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--color-bg-subtle);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: #f3f4f6;
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
}

.btn-ghost:hover {
  background: var(--color-bg-subtle);
}

/* Sizes */
.btn-sm {
  padding: 6px 12px;
  font-size: 13px;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 16px;
}

/* States */
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

Usage

<button class="btn btn-primary">Primary Button</button>
<button class="btn btn-secondary btn-lg">Large Secondary</button>
<button class="btn btn-ghost btn-sm">Small Ghost</button>

Component 2: Cards

.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

.card-title {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
}

.card-subtitle {
  margin: var(--space-xs) 0 0;
  font-size: 14px;
  color: var(--color-text-muted);
}

.card-body {
  color: var(--color-text);
  line-height: 1.6;
}

.card-footer {
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
  display: flex;
  gap: var(--space-sm);
  justify-content: flex-end;
}

/* Variants */
.card-elevated {
  border: none;
  box-shadow: var(--shadow-lg);
}

.card-interactive {
  cursor: pointer;
}

.card-interactive:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

Component 3: Grid System

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.grid {
  display: grid;
  gap: var(--space-md);
}

/* Auto-fit responsive */
.grid-auto {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Fixed columns */
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Responsive breakpoints */
@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* Flexbox utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

Component 4: Form Controls

.form-group {
  margin-bottom: var(--space-md);
}

.form-label {
  display: block;
  margin-bottom: var(--space-xs);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
}

.form-helper {
  margin-top: var(--space-xs);
  font-size: 13px;
  color: var(--color-text-muted);
}

.form-error {
  color: var(--color-error);
}

/* Checkbox and Radio */
.form-check {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.form-check-input {
  width: 18px;
  height: 18px;
  cursor: pointer;
}

Component 5: Badges & Pills

.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1;
}

.badge-primary {
  background: #dbeafe;
  color: #1e40af;
}

.badge-success {
  background: #d1fae5;
  color: #065f46;
}

.badge-warning {
  background: #fef3c7;
  color: #92400e;
}

.badge-error {
  background: #fee2e2;
  color: #991b1b;
}

.badge-neutral {
  background: var(--color-bg-subtle);
  color: var(--color-text-muted);
}

Component 6: Loading States

.skeleton {
  background: linear-gradient(
    90deg,
    #f0f0f0 25%,
    #e0e0e0 50%,
    #f0f0f0 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes skeleton-loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.skeleton-text {
  height: 16px;
  margin-bottom: var(--space-sm);
}

.skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
}

/* Spinner */
.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(0, 0, 0, 0.1);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

Component 7: Utility Classes

/* Spacing */
.m-0 { margin: 0; }
.mt-1 { margin-top: var(--space-sm); }
.mb-1 { margin-bottom: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mb-2 { margin-bottom: var(--space-md); }

.p-1 { padding: var(--space-sm); }
.p-2 { padding: var(--space-md); }
.p-3 { padding: var(--space-lg); }

/* Typography */
.text-sm { font-size: 13px; }
.text-base { font-size: 14px; }
.text-lg { font-size: 16px; }
.text-xl { font-size: 20px; }

.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-normal { font-weight: 400; }

.text-center { text-align: center; }
.text-right { text-align: right; }

.text-muted { color: var(--color-text-muted); }
.text-primary { color: var(--color-primary); }
.text-error { color: var(--color-error); }

/* Display */
.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

/* Borders */
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

/* Shadows */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

Dark Mode Support

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #111827;
    --color-bg-subtle: #1f2937;
    --color-text: #f9fafb;
    --color-text-muted: #9ca3af;
    --color-border: #374151;
  }
}

Pro Tips

  1. Organize by category: Keep utilities in separate files
  2. Use CSS layers: @layer base, components, utilities;
  3. Purge unused CSS: Use PurgeCSS in production
  4. Version your system: Track changes in a design tokens file

Download the Complete Library

Get all utilities in a single file:

→ Download utilities.css

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