I use .header > div:nth-child (2). Div _ other wants to set the div background color and top of the class name navigation_other
but this write has not been set correctly, how to deal with it?
.navigation_other {
background-color: rgba( 0, 0, 0, 0.9 );
color: rgba(255,255,255,1);
height: 50px;
line-height: 50px;
display: none;
position: absolute;
width: 100%;
top: 50px;
}
/*640px*/
@media only screen and (max-width: 640px) {
.header>div:nth-child(2) .navigation_other {
display: block
position: absolute;
width: 100%;
top: 50px;
}
}
<header id="header" class="header">
<div id="head_describe">
<div id="head_describe_uu">
<ul>
<li class="head_li header_login">
<div id="head_li_please"><a href="login.html" class="login_a"><span id="user_describe"></span></a></div>
<div id="head_li_information">
<ul>
<div class="clear"></div>
<li class="head_li_li" id="head_li_change"><a href="information_change.html"></a></li>
<div class="clear"></div>
<li class="head_li_li" id="head_li_logout"><a href="php/logout.php"></a></li>
</ul>
</div>
</li>
<li class="head_li" id="head_li_free_register"><a href="register.html"><span id="free_register"></span></a></li>
</ul>
<!---->
<div class="mobile_phone_navigation">
<div>
<!--//-->
</div>
</div>
<div class="navigation_other navigation_index">
</div>
<div class="navigation_other navigation_index">
</div>
</header>