Form Control
Example
Form controls are styled with a mix of Sass and CSS variables, allowing them to adapt to color modes and support any customization method.
Sizing
Set heights using classes like .form-control-lg and .form-control-sm.
Form text
Block-level or inline-level form text can be created using .form-text.
aria-labelledby (for mandatory information such as data format) or aria-describedby (for complementary information) attribute. This will ensure that assistive technologies—such as screen readers—will announce this form text when the user focuses or enters the control.
Form text below inputs can be styled with .form-text. If a block-level element will be used, a top margin is added for easy spacing from the inputs above.
Inline text can use any typical inline HTML element (be it a <span>, <small>, or something else) with nothing more than the .form-text class.
Disabled
Add the disabled boolean attribute on an input to give it a grayed out appearance, remove pointer events, and prevent focusing.
Readonly
Add the readonly boolean attribute on an input to prevent modification of the input’s value. readonly inputs can still be focused and selected, while disabled inputs cannot.
Readonly plain text
If you want to have <input readonly> elements in your form styled as plain text, replace .form-control with .form-control-plaintext to remove the default form field styling and preserve the correct margin and padding.
File input
Color
Set the type="color" and add .form-control-color to the <input>. We use the modifier class to set fixed heights and override some inconsistencies between browsers.
Datalists
Datalists allow you to create a group of <option>s that can be accessed (and autocompleted) from within an <input>. These are similar to <select> elements, but come with more menu styling limitations and differences. While most browsers and operating systems include some support for <datalist> elements, their styling is inconsistent at best.
Learn more about support for datalist elements.
CSS
Sass variables
$input-* are shared across most of our form controls (and not buttons).
$input-padding-y: $input-btn-padding-y; //0.6875rem;
$input-padding-x: 1.125rem;
$input-font-family: $input-btn-font-family;
$input-font-size: $input-btn-font-size;
$input-font-weight: $font-weight-base;
$input-line-height: $input-btn-line-height;
$input-padding-y-sm: $input-btn-padding-y-sm;
$input-padding-x-sm: $input-btn-padding-x-sm;
$input-font-size-sm: $input-btn-font-size-sm;
$input-padding-y-lg: 0.649rem;
$input-padding-x-lg: $input-btn-padding-x-lg;
$input-font-size-lg: $input-btn-font-size-lg;
$input-bg: var(--#{$prefix}form-control-bg);
$input-disabled-color: null;
$input-disabled-bg: var(--#{$prefix}form-control-disabled-bg);
$input-disabled-border-color: null;
$input-color: var(--#{$prefix}body-color);
$input-border-color: var(--#{$prefix}border-color);
$input-border-width: $input-btn-border-width;
$input-box-shadow: 0 0;
$input-border-radius: $border-radius;
$input-border-radius-sm: $border-radius-sm;
$input-border-radius-lg: $border-radius-lg;
$input-focus-bg: $input-bg;
$input-focus-border-color: tint-color($component-active-bg, 50%);
$input-focus-color: $input-color;
$input-focus-width: $input-btn-focus-width;
$input-focus-box-shadow: $input-btn-focus-box-shadow;
$input-placeholder-color: var(--#{$prefix}secondary-color);
$input-plaintext-color: var(--#{$prefix}body-color);
$input-height-border: calc(var(--#{$prefix}border-width) * 2); // stylelint-disable-line function-disallowed-list
$input-height-inner: add($input-line-height * 1em, $input-padding-y * 2);
$input-height-inner-half: add($input-line-height * .5em, $input-padding-y);
$input-height-inner-quarter: add($input-line-height * .25em, $input-padding-y * .5);
$input-height: add($input-line-height * 1em, add($input-padding-y * 2, $input-height-border, false));
$input-height-sm: add($input-line-height * 1em, add($input-padding-y-sm * 2, $input-height-border, false));
$input-height-lg: add($input-line-height * 1em, add($input-padding-y-lg * 2, $input-height-border, false));
$input-transition: border-color .15s ease-in-out, box-shadow .15s ease-in-out;
$form-color-width: 3rem;
$form-label-* and $form-text-* are for our <label>s and .form-text component.
$form-label-margin-bottom: .5rem;
$form-label-font-size: null;
$form-label-font-style: null;
$form-label-font-weight: null;
$form-label-color: null;
$form-text-margin-top: .25rem;
$form-text-font-size: $small-font-size;
$form-text-font-style: null;
$form-text-font-weight: null;
$form-text-color: $text-muted;
$form-file-* are for file input.
$form-file-button-color: $input-color;
$form-file-button-bg: var(--#{$prefix}tertiary-bg);
$form-file-button-hover-bg: var(--#{$prefix}secondary-bg);