Quill Forms gives you the ability to add custom css easily.
To add custom css, you should pass customCSS
property to your formObj
prop like the following
<Form
formObj={{
...formObj,
customCSS: `
input {
border: 1px solid #e3e3e3 !important;
box-shadown: none !important;
border-radius: 4px !important;
padding: 8px !important;
}
`
}}
/>