Thank you for your input.
I didn't know that most phones are ~400 pixels wide.
My dilemma right now is what to specify for label and text box fonts and sizes. My first version does not specify them at all. But I think (guess) that this should be set to some values that will make it work on most mobile devices.

>The ViewPort tag should be added to just about every Web page and you should design the page assuming a 1:1 ratio. ViewPort 1.0 means that the page won't scale down to fix the size of the content.
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>I think you always want to use 1 because that'll get you the size you'd expect. Anything else is to weird to keep straight IMHO. IOW, make 1.0 scale work. You know how wide the phone screen is (~400pixels) so make sure you don't have any elements that exceed that size with physical widths. Whenever possible use flex sizing (ie. width=100%) so it adjusts to the width of the document automatically, or - for inline text - wraps around.
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>+++ Rick ---
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>
>>Hi,
>>
>>I am working on an asp.net page that will be viewed on a mobile device (not on the desktop).
>>
>>I can view the page on my iPhone but all labels and text boxes look very small. Basically the entire form fits into the small upper-right corner. I can enlarge the form, by pinching the form with fingers. But this is not an acceptable approach.
>>
>>My question: Should I implement the page with a Bootstrap? Or should I simply try to increase the fonts of the ASP.NET page controls? If I increase the fonts, it may work on my iPhone. But I am not sure how well it will look on an Android or some other mobile device.
>>
>>What would you recommend?
>>
>>TIA
>>
>>UPDATE: Adding the viewport meta makes the page look better. Still, not perfect. Should I change the value of the initial-scale?
>>

>><meta name="viewport" content="width=device-width, initial-scale=1.0">
>>

>>
>>UPDATE 2. Value of 1.2 gives the best result on my "old" iPhone 6. But I need to find a way to set this value dynamically so that it works on any mobile device.