Add this code to the Custom CSS box and Save
/* Newsletter */
.newsletter-block .newsletter-form-body {
background: #fff;
border: 1px solid #eee;
border-radius: 50px;
display: inline-block;
padding: 0px 5px !important;
}
.newsletter-block .newsletter-form-fields-wrapper,.newsletter-block .newsletter-form-button-wrapper {
margin: 0px !important
}
@media only screen and (max-width: 767px) {
.newsletter-block .newsletter-form-button-wrapper,.newsletter-block .newsletter-form-button,.newsletter-block .newsletter-form-fields-wrapper,.newsletter-block .newsletter-form-field-wrapper,.newsletter-block .newsletter-form-wrapper--layoutStack .newsletter-form-field-wrapper,.newsletter-block .newsletter-form-wrapper--layoutStack .newsletter-form-name-fieldset {
width:100% !important;
max-width: 100%;
display: block !important
}
.newsletter-form-body {
display: flex !important;
align-items: center;
}
}
.newsletter-block .newsletter-form-field-element {
border: none !important;
padding-top: 0px !important;
padding-bottom: 0px !important;
padding-left: 5px !important;
}
button.newsletter-form-button.sqs-system-button {
padding-top: 5px !important;
padding-bottom: 5px !important;
}
.newsletter-block .newsletter-form-field-wrapper, .newsletter-block .newsletter-form-button-wrapper {
padding-top: 5px !important;
padding-bottom: 5px !important;
}
Result:
