Can't click on right half of field to select it

I am trying to approximate an order form.  I tightened up the margins via CSS code but it seems to have affected the ability to click on a field to select it.  Works fine if you click on the left side, does not work if you click the far right side.

How can I fix this?

Also, is there a way to have the cursor in a particular field when the form is first loaded? (I want it in the quantity1 field)

This issue happened due to the CSS code injected to your form, you're using "margin-left" and a negative value to move the fields, get rid of that in order to fix the issue, instead, you may reduce the element's padding like this: 

li#id_3 {

    padding-left: 0px;

    padding-right: 0px;

}

I hope this helps.