How to make a button show on mobile - php

Question

Good day everyone.
Just started working in Firm that has given me task to optimize their website (nigeria-friends(dot)com/staging.academix) responsively, which I have been doing gradually and am not all that proficient with PHP, HTML and CSS. But, I can confidently read and understand some couple of stuff in them. Thus;
I have been trying to center all the contents on the frontpage image banner
Reveal or make a particular button "How Academix can benefit you" appear on mobile devices of max-width:380px with no success and that has got me perplexed.
I have searched all through the CSS and couldn't get my head around any to fix it. Hence, me calling for help. And having looked into the index.html from the based folder I found something, the aforementioned buttons were in a loop sort of, which I don't understand.
Here is the index code:
<div class="col-sm-12 col-xs-10 col-centered">
<?php if(!isset($_SESSION["acc_identifier"])){ ?>
<!--
<div class="col-sm-4 col-centered">
<a href="<?php echo $URLMAIN; ?>/access/signup.html">
<div id="fb-login" class="social-login">
<div class="social-text">Sign up for free</div>
</div>
</a>
</div>
-->
<div class="col-sm-6 col-centered">
<a href="<?php echo $URLMAIN; ?>/about/benefits.html">
<div id="yahoo-login" class="social-login">
<div class="social-text">How <?php echo $web_shortName; ?> can benefit you</div>
</div>
</a>
</div>
<div class="col-sm-6 col-centered">
<a href="<?php echo $URLMAIN; ?>/access/host.html">
<div id="g-login" class="social-login">
<div class="social-text">Host your journal on <?php echo $web_shortName; ?></div>
</div>
</a>
</div>
<?php }else{ ?>
<div class="col-sm-6 col-centered">
<a href="<?php echo $URLMAIN; ?>/about/benefits.html">
<div id="yahoo-login" class="social-login">
<div class="social-text">How <?php echo $web_shortName; ?> can benefit you</div>
</div>
</a>
</div>
<div class="col-sm-6 col-centered">
<a href="<?php echo $URLMAIN; ?>/access/host.html">
<div id="g-login" class="social-login">
<div class="social-text">Host your journal on <?php echo $web_shortName; ?></div>
</div>
</a>
</div>
<?php } ?>
</div>
I can't paste in all the index.html code here as is quite long and length, which is generating error format when I try to, which is mixed php and html, where PHP starts the index.html. So also is the CSS file.

Answer 1

#media (min-width: 380px){
#yahoo-login .social-text {
display: none;
}
}
OR
#media (max-width: 380px){
#yahoo-login .social-text {
display: block;
}
}