delete focus border button css code example
Example 1: diable focus button css
*:focus {
outline: 0 !important;
}
Example 2: remove button outlines
<button class="btn shadow-none">Bootstrap (4.1) button without shadow</button>
*:focus {
outline: 0 !important;
}
<button class="btn shadow-none">Bootstrap (4.1) button without shadow</button>