.ms-block-theme-clean form {

}

.ms-block-theme-clean form .ms-input,
.ms-block-theme-clean form .ms-select,
.ms-block-theme-clean form .ms-textarea {
    background: #fafafa;
    padding: 15px;
    border-radius: 7px;
}

.ms-block-theme-clean form .ms-input:focus,
.ms-block-theme-clean form .ms-select:focus,
.ms-block-theme-clean form .ms-textarea:focus {
    border-color:  var(--ms-color-primary);
}