Default Close Button
Provide an option to dismiss or close a component with .btn-close. Default styling is limited, but highly customizable. Modify the Sass variables to replace the default background-image. Be sure to include text for screen readers, as we’ve done with aria-label.
Disabled state
Disabled close buttons change their opacity. We’ve also applied pointer-events: none and user-select: none to preventing hover and active states from triggering.
Dark variant
Add data-bs-theme="dark" to the .btn-close, or to its parent element, to invert the close button. This uses the filter property to invert the background-image without overriding its value.