The text align not work in mobile

Hello I have try use the background image with text with background color and I use margin to align the text over the image, in desktop works well but in mobile have not work …
<div style=”height: 30px; width: 350px; background-color: #ffdead; opacity: 0.5; margin: 200px 0px 0px 100px; color: #0000ff;”>
<p align=”center”>Slide content Teste texto na imagem do slide</p>
</div>
I try use …
<meta name=”viewport” content=”initial-scale=1, width=device-width“/>
but haven’t effet …
If have option to use text why that not work properly .. because some texts need align left, others right, or top etc…
Thanks