Bulma Customization Concepts

What makes Bulma customizable

Bulma is a highly customizable CSS framework. From colors to typography, spacing and sizes, forms and layouts, all parts of Bulma can be customized by the user.

Bulma’s styles and variables are defined at several levels:

Global Sass variables
Component Sass variables
Global CSS variables
Component CSS variables
Helper classes

All Bulma components are styled using Sass variables and CSS Variables (which are also called CSS custom properties). Read more about them:

Global Sass Variables #

Bulma uses Sass variables globally defined in 2 files located in the utilities folder:

initial-variables.scss where you define variables by literal value
- colors like $blue: hsl(229, 53%, 53%)
- font sizes like $size-1: 3rem
- dimensions like $block-spacing: 1.5rem
- breakpoints like $tablet: 769px
- other values like $easing: ease-out or $radius-large: 0.75rem
derived-variables.scss where variables are calculated from the values set in the previous file
- primary colors:
  - $primary
  - $link
  - $success
  - $info
  - $warning
  - $dark
- utility colors:
  - $background
  - $border
  - $code and $pre
  - $shadow-color
- typography:
  - $family-primary
  - $family-secondary
  - $family-code
  - $size-small
  - $size-normal
  - $size-medium
  - $size-large
- color maps:
  - $colors
  - $shades
  - $sizes

Component Sass variables #

All Bulma components define its own Sass variables. For example, components/breadcrumb.scss define the following:

Sass and CSS variables #

Sass Variable	Value
`$breadcrumb-item-color`	`var(--bulma-link-text)`
`$breadcrumb-item-hover-color`	`var(--bulma-link-text-hover)`
`$breadcrumb-item-active-color`	`var(--bulma-link-text-active)`
`$breadcrumb-item-padding-vertical`	`0`
`$breadcrumb-item-padding-horizontal`	`0.75em`
`$breadcrumb-item-separator-color`	`var(--bulma-border)`

Global CSS Variables #

Bulma uses global CSS variables defined at the :root level. They are all prefixed with bulma-:

:root {
  /* Colors and Lightness values */
  --bulma-scheme-h: 221;
  --bulma-scheme-s: 14%;
  --bulma-light-l: 90%;
  --bulma-light-invert-l: 20%;
  --bulma-dark-l: 20%;
  --bulma-dark-invert-l: 90%;
  --bulma-soft-l: 90%;
  --bulma-bold-l: 20%;
  --bulma-soft-invert-l: 20%;
  --bulma-bold-invert-l: 90%;
  /* etc. */

  /* Color Palettes */
  --bulma-primary: hsla(var(--bulma-primary-h), var(--bulma-primary-s), var(--bulma-primary-l), 1);
  --bulma-primary-base: hsla(var(--bulma-primary-h), var(--bulma-primary-s), var(--bulma-primary-l), 1);
  --bulma-primary-rgb: 0, 209, 178;
  --bulma-primary-h: 171deg;
  --bulma-primary-s: 100%;
  --bulma-primary-l: 41%;
  --bulma-primary-00-l: 1%;
  --bulma-primary-05-l: 6%;
  --bulma-primary-10-l: 11%;
  --bulma-primary-15-l: 16%;
  --bulma-primary-20-l: 21%;
  /* etc. */

  /* Typography */
  --bulma-family-primary: Inter, SF Pro, Segoe UI, Roboto, Oxygen, Ubuntu, Helvetica Neue, Helvetica, Arial, sans-serif;
  --bulma-family-secondary: Inter, SF Pro, Segoe UI, Roboto, Oxygen, Ubuntu, Helvetica Neue, Helvetica, Arial, sans-serif;
  --bulma-family-code: Inconsolata, Hack, SF Mono, Roboto Mono, Source Code Pro, Ubuntu Mono, monospace;
  --bulma-size-small: 0.75rem;
  --bulma-size-normal: 1rem;
  --bulma-size-medium: 1.25rem;
  --bulma-size-large: 1.5rem;
  /* etc. */
}

You can overwrite them simply by setting a new value at the same scope (or even a more specific one):

:root {
  /* Set new values */
  --bulma-scheme-h: 35;
  --bulma-scheme-s: 20%;
}

Components CSS Variables #

Bulma is also styled at the component level. For example, here is how the .title element is styled:

.title {
  --bulma-title-color: var(--bulma-text-strong);
  --bulma-title-family: false;
  --bulma-title-size: var(--bulma-size-3);
  --bulma-title-weight: var(--bulma-weight-extrabold);
  --bulma-title-line-height: 1.125;
  --bulma-title-strong-color: inherit;
  --bulma-title-strong-weight: inherit;
  --bulma-title-sub-size: 0.75em;
  --bulma-title-sup-size: 0.75em;
}

.title {
  color: var(--bulma-title-color);
  font-size: var(--bulma-title-size);
  font-weight: var(--bulma-title-weight);
  line-height: var(--bulma-title-line-height);
}

You can overwrite this simply by setting new values under the same scope:

.title {
  --bulma-title-color: #fff;
  --bulma-title-line-height: 1.6;
}

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