CSS Variable

About

This is an advanced CSS topic that you can use while creating your theme.

You can set CSS variables:

to have a global set of CSS values
to customize the bootstrap stylesheet

How to customize CSS Variables?

If you want to customize Bootstrap CSS Variables or add your own, they are in the partial head-partials.hbs.

Combostap uses them when you change the branding colors.

Example:

{{#if primary-color}}
    <style>
        :root {
            --bs-primary: {{primary-color}};
        }
        .btn-primary {
            --bs-btn-bg: {{primary-color}};
            --bs-btn-border-color: {{primary-color}};
        }
    </style>
{{/if}}

Bootstrap CSS Variables

Bootstrap allows customizing its stylesheet via its own CSS variables (from version 5.1)

It offers CSS variables:

on the root
and for each component

Root variables

:root {
    --bs-blue: #0d6efd;
    --bs-indigo: #6610f2;
    --bs-purple: #6f42c1;
    --bs-pink: #d63384;
    --bs-red: #dc3545;
    --bs-orange: #fd7e14;
    --bs-yellow: #ffc107;
    --bs-green: #198754;
    --bs-teal: #20c997;
    --bs-cyan: #0dcaf0;
    --bs-black: #000;
    --bs-white: #fff;
    --bs-gray: #6c757d;
    --bs-gray-dark: #343a40;
    --bs-gray-100: #f8f9fa;
    --bs-gray-200: #e9ecef;
    --bs-gray-300: #dee2e6;
    --bs-gray-400: #ced4da;
    --bs-gray-500: #adb5bd;
    --bs-gray-600: #6c757d;
    --bs-gray-700: #495057;
    --bs-gray-800: #343a40;
    --bs-gray-900: #212529;
    --bs-primary: #0d6efd;
    --bs-secondary: #6c757d;
    --bs-success: #198754;
    --bs-info: #0dcaf0;
    --bs-warning: #ffc107;
    --bs-danger: #dc3545;
    --bs-light: #f8f9fa;
    --bs-dark: #212529;
    --bs-primary-rgb: 13,110,253;
    --bs-secondary-rgb: 108,117,125;
    --bs-success-rgb: 25,135,84;
    --bs-info-rgb: 13,202,240;
    --bs-warning-rgb: 255,193,7;
    --bs-danger-rgb: 220,53,69;
    --bs-light-rgb: 248,249,250;
    --bs-dark-rgb: 33,37,41;
    --bs-white-rgb: 255,255,255;
    --bs-black-rgb: 0,0,0;
    --bs-body-color-rgb: 33,37,41;
    --bs-body-bg-rgb: 255,255,255;
    --bs-font-sans-serif: system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue","Noto Sans","Liberation Sans",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";
    --bs-font-monospace: SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;
    --bs-gradient: linear-gradient(180deg, rgba(255, 255, 255, 0.15), rgba(255, 255, 255, 0));
    --bs-body-font-family: var(--bs-font-sans-serif);
    --bs-body-font-size: 1rem;
    --bs-body-font-weight: 400;
    --bs-body-line-height: 1.5;
    --bs-body-color: #212529;
    --bs-body-bg: #fff;
    --bs-border-width: 1px;
    --bs-border-style: solid;
    --bs-border-color: #dee2e6;
    --bs-border-color-translucent: rgba(0, 0, 0, 0.175);
    --bs-border-radius: 0.375rem;
    --bs-border-radius-sm: 0.25rem;
    --bs-border-radius-lg: 0.5rem;
    --bs-border-radius-xl: 1rem;
    --bs-border-radius-2xl: 2rem;
    --bs-border-radius-pill: 50rem;
    --bs-link-color: #0d6efd;
    --bs-link-hover-color: #0a58ca;
    --bs-code-color: #d63384;
    --bs-highlight-bg: #fff3cd;
}

Components Variables

The CSS Variables are (from version 5.2) scoped to the component

Example for a primary button

.btn-primary {
    --bs-btn-color: #fff;
    --bs-btn-bg: #0d6efd;
    --bs-btn-border-color: #0d6efd;
    --bs-btn-hover-color: #fff;
    --bs-btn-hover-bg: #0b5ed7;
    --bs-btn-hover-border-color: #0a58ca;
    --bs-btn-focus-shadow-rgb: 49,132,253;
    --bs-btn-active-color: #fff;
    --bs-btn-active-bg: #0a58ca;
    --bs-btn-active-border-color: #0a53be;
    --bs-btn-active-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.125);
    --bs-btn-disabled-color: #fff;
    --bs-btn-disabled-bg: #0d6efd;
    --bs-btn-disabled-border-color: #0d6efd;
}
.btn {
    --bs-btn-padding-x: 0.75rem;
    --bs-btn-padding-y: 0.375rem;
    --bs-btn-font-family: ;
    --bs-btn-font-size: 1rem;
    --bs-btn-font-weight: 400;
    --bs-btn-line-height: 1.5;
    --bs-btn-color: #212529;
    --bs-btn-bg: transparent;
    --bs-btn-border-width: 1px;
    --bs-btn-border-color: transparent;
    --bs-btn-border-radius: 0.375rem;
    --bs-btn-hover-border-color: transparent;
    --bs-btn-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.15),0 1px 1px rgba(0, 0, 0, 0.075);
    --bs-btn-disabled-opacity: 0.65;
    --bs-btn-focus-box-shadow: 0 0 0 0.25rem rgba(var(--bs-btn-focus-shadow-rgb), .5);
}