.custom_block_btn,
.acf-block-preview .custom_block_btn{
    color : #ffffff !important;
    background-color : #000000;
    border: 2px solid #000000;
    border-radius : 4px;
}
.custom_block_btn:hover{
    color : #ffffff !important;
    background-color : #1e73be;
    border-color: #000000;
}

@media only screen and (max-width: 500px){

}