Alisson, I recommend studying the vision structure (Grid system) you should follow when using bootstrap.
http://getbootstrap.com/css/#grid
By declaring your HTML following this structure, your screens will be able to adjust according to the size of the device you are accessing.
A simple example:
Here, I want for small screens, my button occupy the whole screen. For large screens, only 1/4 of the screen:
<div class='row'>
<div class='col-lg-3 col-xs-12'>
<button type='button' class='btn btn-primary' style='width:100%'>Botão 1 </button>
</div>
<div class='col-lg-3 col-xs-12'>
<button type='button' class='btn btn-primary' style='width:100%'>Botão 2 </button>
</div>
<div class='col-lg-3 col-xs-12'>
<button type='button' class='btn btn-primary' style='width:100%'>Botão 3 </button>
</div>
<div class='col-lg-3 col-xs-12'>
<button type='button' class='btn btn-primary' style='width:100%'> Botão 4 </button>
</div>
</div>
Remember that you should never change the position of the elements on your page using fixed CSS styles like position:Absolute and top/left. This will produce a distorted effect when used in conjunction with bootstrap.
Adriano answered while I typed. That’s it.
– Joel Rodrigues