>>Attached please find the image. As I said, this is not true browser, it's the VFP application which generates HTML and it's displayed inside C++ form.
>
>Your master parent definitely has a fixed width. That might explain why the select at 100% would work.
>
>I am assuming you did the same for the input. However, it is not showing exactly the same.
>
>Do you have this in the CSS:
>
>

>*
>{
>   box-sizing: border-box;
>   -moz-box-sizing: border-box;
>   -webkit-box-sizing: border-box;
>}
>

The separate css file is simple:

body {font-family:Calibri;background-color:#363636;color:white;font-size:12.0pt}
a:link {color: #FF0000}
a:visited {color: #800000}
a:hover {color: #FF00FF}
a:active {color: #FF00FF}
hr {color: #666666;}

.heading {font-size:24.0pt;font-weight:bold;text-align:center;font-family:Calibri}
.subheading {font-size:14.0pt;font-weight:bold;text-align:center;font-family:Calibri}
.overdue {font-size:14.0pt;font-weight:bold;text-align:center;background-color:brown;font-family:Calibri}
.warning {font-size:14.0pt;font-weight:bold;text-align:center;color:orange;font-family:Calibri}
.warning_titles  {font-size:12.0pt;font-weight:bold;text-align:center;text-decoration:underline;color:black;font-family:Calibri}
.warning_data    {font-size:10.0pt;font-weight:normal;text-align:center;text-decoration:none;color:black;font-family:Calibri}

.columnheading {font-size:12.0pt;font-weight:bold;text-decoration:underline;font-family:Calibri}
.storereturnheading {background-color:#6c92b6;color: white; font-size:24.0pt;font-family:Calibri}
.datetext   {font-size:12.0pt;font-family:Calibri}
.helptext   {font-size:12.0pt;font-family:Calibri}
.tabletitle {font-size:12.0pt;font-weight:bold;font-family:Calibri}
.tabletext  {font-size:12.0pt;font-family:Calibri}
.normaltext {font-size:12.0pt;font-family:Calibri}
.formtext   {font-size:12.0pt;font-family:Calibri}
.errortext  {font-size:12.0pt;font-family:Calibri}
.button     {font-size:12.0pt;font-family:Calibri}
.fatbutton  {font-size:12.0pt;font-family:Calibri}
.fullwidth  {width: 100%;}

I think there is also code in VFP itself with some css, I need to look it up. The template for input doesn't use that class but uses size=60, I'm going to change to use that same class too.