See next code:
<div style="width:800px;display:flex;">
<div style="margin:2px;flex-grow:1;border:1px solid red;">
<input type="text" style="width:100%;min-width:0;" />
</div>
<div style="margin:2px;flex-grow:1;border:1px solid blue;">
<input type="text" style="width:100%;min-width:0;" />
</div>
</div>
<div style="width:800px;display:flex;">
<div style="margin:2px;flex-grow:1;border:1px solid red;">
<input class="easyui-datebox" data-options="" style="width:100%;">
</div>
<div style="margin:2px;flex-grow:1;border:1px solid blue;">
<input class="easyui-datebox" data-options="" style="width:100%;">
</div>
</div>
in first row, two input each space 50% width as experted.
but in second row, textbox not show correctly
it seams some bug in textbox render...