ปุ่มปิด

<button type="button" class="btn-close" aria-label="Close"></button>

<button type="button" class="btn-close" disabled aria-label="Close"></button>

<button type="button" class="btn-close btn-close-white" aria-label="Close"></button>
<button type="button" class="btn-close btn-close-white" disabled aria-label="Close"></button>

$btn-close-width:            1em;
$btn-close-height:           $btn-close-width;
$btn-close-padding-x:        .25em;
$btn-close-padding-y:        $btn-close-padding-x;
$btn-close-color:            $black;
$btn-close-bg:               url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$btn-close-color}'><path d='M.293.293a1 1 0 011.414 0L8 6.586 14.293.293a1 1 0 111.414 1.414L9.414 8l6.293 6.293a1 1 0 01-1.414 1.414L8 9.414l-6.293 6.293a1 1 0 01-1.414-1.414L6.586 8 .293 1.707a1 1 0 010-1.414z'/></svg>");
$btn-close-focus-shadow:     $input-btn-focus-box-shadow;
$btn-close-opacity:          .5;
$btn-close-hover-opacity:    .75;
$btn-close-focus-opacity:    1;
$btn-close-disabled-opacity: .25;
$btn-close-white-filter:     invert(1) grayscale(100%) brightness(200%);