How to center div element in mobile devices by CSS media queries - html

Question

I need to center div's element for mobile devices. This is my website: http://transporttest.cba.pl/
On mobile devices description div goes to the left.I try to use media queries but it didnt works. What I'm doing wrong? On PC everything is ok. This is fragment of my code:
HTML:
<div id="opis">
<h2>
<p style="line-height: 3cm; ">
♦ Od 1991 roku w branży. <br/>
♦ 9 zestawów (ciągnik+ naczepa firanka, colimulde). <br/>
♦ Uprawnienia ADR u każdego kierowcy.<br/>
♦ Warsztat obsługujący auta ciężarowe.<br/>
</p>
</div>
CSS:
#opis
{
font-size: 25px;
font-family:"Lucida Sans Unicode", "Lucida Grande", sans-serif;
background-color: #F2F3F7;
height: auto;
width:72%;
display:inline-block;
text-align:center;
}
#container
{
text-align: center;
width:100%;
}
#media all and (max-width: 768px) {
#container{
wiidth:100%;
}
#opis,#opis_onas,#opis_dok,#opis_praca,#oskup,#opis_warsztat,#okredyt
{
left:25%;
top:25%;
position:absolute;
width:50%;
text-align:center;
}
#menudol{
text-align:center;
display: block;
margin: 0 auto;
}
}
#media all and (max-width:640px){
#container{
wiidth:100%;
}
#opis,#opis_onas,#opis_dok,#opis_praca,#oskup,#opis_warsztat,#okredyt
{
width:72%;
height:auto;
display:inline-block;
text-align:center;
margin: 0 auto;
}
#menudol{
text-align:center;
display: block;
margin: 0 auto;
}
}

Answer 1

For media queries to work, you need to include:
<meta name="viewport" content="width=device-width, initial-scale=1.0">
Between the tags.
https://www.w3schools.com/css/css_rwd_viewport.asp

Answer 2

Firstly, use <meta name="viewport" content="width=device-width, initial scale= 1.0">
As it will automatically fit you webpage to the width of the Device.
Secondly, you should use margin-left=auto;
margin-right=auto;
This will make the contents if your webpage to the center of the screen of the device.
You can also use text-align="center"
if that works for you.
P.S. The <meta name=viewport> should be definitely used in webpages as it helps the designer to format the webpage automatically to the screen width.