Custom CSS

Jamdesk themes provide sensible defaults, but you can add custom CSS to match your brand or adjust specific styles.

Adding Custom CSS

Create a style.css file in your project root — the same folder as your docs.json. Jamdesk applies it to every page automatically; no docs.json entry is needed.

Any .css file in the project root works, not just style.css — handy when migrating from another tool. When there are several, Jamdesk combines them in alphabetical filename order.

Run jamdesk dev to preview the result locally — it renders your custom CSS the same way the published site does.

/* Your custom styles */
.content h1 {
  font-size: 2.5rem;
}

CSS Variables

Jamdesk exposes CSS variables for common customizations. Override them in your custom CSS:

:root {
  /* Typography */
  --font-family-sans: 'Inter', system-ui, sans-serif;
  --font-family-mono: 'JetBrains Mono', monospace;
  
  /* Spacing */
  --content-max-width: 900px;
  --sidebar-width: 280px;
  
  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

Color Variables

Primary colors are set in docs.json. For fine-grained control, override these variables:

:root {
  /* Light mode */
  --color-background: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #666666;
  --color-border: #e5e5e5;
  --color-code-bg: #f5f5f5;
}

[data-theme="dark"] {
  /* Dark mode */
  --color-background: #0a0a0a;
  --color-text: #fafafa;
  --color-text-muted: #a3a3a3;
  --color-border: #262626;
  --color-code-bg: #171717;
}

Common Customizations

Adjust Content Width

:root {
  --content-max-width: 1000px;  /* Default: 900px */
}

Change Code Block Font

:root {
  --font-family-mono: 'Fira Code', monospace;
}

/* Ensure ligatures work if your font supports them */
pre code {
  font-variant-ligatures: common-ligatures;
}

Customize Link Styles

.content a:not([class]) {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.content a:not([class]):hover {
  text-decoration-thickness: 2px;
}

Adjust Heading Spacing

.content h2 {
  margin-top: 3rem;
  margin-bottom: 1rem;
}

.content h3 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

Style Callouts

/* Make Note callouts more prominent */
[data-callout="note"] {
  border-left-width: 4px;
  background: var(--color-primary-subtle);
}

Dark Mode

Use the [data-theme="dark"] selector for dark mode styles:

/* Light mode */
.custom-banner {
  background: #f0f4ff;
  color: #1e3a5f;
}

/* Dark mode */
[data-theme="dark"] .custom-banner {
  background: #1e293b;
  color: #e2e8f0;
}

Targeting Components

Override styles for specific components:

/* Card component */
[data-component="card"] {
  border-radius: 16px;
}

/* Code blocks */
[data-component="code-block"] {
  border-radius: 8px;
}

/* Tabs */
[data-component="tabs"] [data-state="active"] {
  border-bottom-width: 3px;
}

External Fonts

Load custom fonts with @import or @font-face:

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --font-family-sans: 'Inter', system-ui, sans-serif;
}

Or self-host fonts:

@font-face {
  font-family: 'CustomFont';
  src: url('/fonts/custom-font.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}

Responsive Styles

Use media queries for responsive adjustments:

/* Mobile adjustments */
@media (max-width: 768px) {
  .content h1 {
    font-size: 1.75rem;
  }
  
  :root {
    --content-max-width: 100%;
  }
}

Debugging

Use browser dev tools to inspect elements and find the correct selectors. Jamdesk uses data attributes for component targeting:

• data-component="..." - Component type
• data-theme="light|dark" - Current theme
• data-state="..." - Component state (active, disabled, etc.)

Limitations

• CSS is applied globally; use specific selectors to avoid conflicts
• Some internal layout styles use !important and may require the same to override
• In local preview (jamdesk dev), edits to your CSS file(s) apply on browser refresh; on your published site, changes take effect on the next build

What's Next?