Change the size of Submit button

the button font remains the same size with small window size, such as on cellphone. I have to tried to put in calc(...) to do self-adjust. It fails to self-adjust. See this:

Greetings and thank you for your message.

In order to change the size of the text in the button only on phones, please add the following CSS to the bottom of your current custom CSS:

.form-all .qq-upload-button, .form-all .form-submit-button, .form-all .form-submit-reset, .form-all .form-submit-print{
      font-size: 9px !important;
}

You can adjust the site by changing the 9px to some other value.

If you are not sure how to inject this custom CSS, please click here to read more about it.

Please let us know if you have any other questions.

This won't be a good solution, as it will change it to a fixed font size, not adjustable. 

    font-size : calc(10px + (12 - 10) * (100vw - 450)/(800-450))!important;

should work in normal cases. I used it for many of other pages. But, for some reason, it just won't work for this. 

ok.. figure out  to change the font to fix size only for mobile: 

@media only screen and (max-width:480px)  {

 .form-all  .form-submit-button, .form-all .form-submit-reset, .form-all .form-submit-print { 

      font-size:14px !important; 

     font-weight:700!important;

   }

}

Glad to hear you were able to meet your requirements.

Let us know if you need further assistance.