Check Availability this room pop-up form

Hi, i need your help to know how can i fix the problem with the pop-up form, after click on the check availability this room button. There are two problems, first when you try to put the dates of arrival and departure, the calendar table are showing on the back of the pop up, and dont allow to select any date. How can i fix that?
And the second problem is this pop-up form doesnt have responsive design, on the mobile site, the check available button is showing incomplete. Please can you help me with that?

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