html - 为什么显示:none not work here?

Question

我认为问题在于#header img 不起作用。

#header img 
{
    border-style: solid;
         border-color: #000000;
         border-width: 5px;
         padding: 5px
}
    
@media only screen and (max-width: 840px) { #header img { display:none; } } 

<h1><a href="index.html" id="logo"><img src="images/platzhalter.jpg" </a></h1>

Answer 1

#header img 
{
    border-style: solid;
         border-color: #000000;
         border-width: 5px;
         padding: 5px
}
    
@media only screen and (max-width: 840px) { #header img { display:none; } } 

<h1><a href="index.html" id="logo"><img src="images/platzhalter.jpg" </a></h1>

你没有#header img，试试把#header换成#logo

@media only screen and (max-width: 840px) { #logo img { display:none; }