CSS
.lumise-customize-button, 
a.lumise-button {
display: block !important;
width: 100% !important;
margin-top: 10px !important;
text-align: center !important;
box-sizing: border-box !important;
}
CSS .single-product .cart {
display: flex !important;
flex-direction: column !important;
align-items: flex-start !important;
}
.single-product .cart .button,
.single-product .cart a[href*="lumise"],
.lumise-customize-button {
width: 100% !important;
max-width: 300px !important;
margin-top: 10px !important;
margin-left: 0 !important;
display: block !important;
text-align: center !important;
}