ctrl.dialog - how to setHeight of dialog in mobile view?

can anyone help me please?

I've used a custom button to Open dialog and take ask for mobile and dob. The dialog looks good in compter but while at mobile the dialog appears with full height. How can I change the height to just 200px while @media (max-width = 500px)?

I've used below code in the client Before event of a custom button:

return ctrl.dialog( {
title: 'Check IELTS - MockTest RESULT',
fields: [{
name: 'Mobile',
label: 'Your Mobile Number',
type: 'text',
required: true,
value: '9801224299'
},
{
name: 'DOB',
label: 'Date of Brith (AD)',
type: 'date',
datepicker: true,
required: true,
value: '2004-12-26'
}],
ok: 'Check',
cancel: 'Cancel'

});