CSS id is passing to the rest of the website - php

Question

I´m trying to do a navigation menu on a website and for some reason what i defined in the id topnav_ubid is getting applied to the rest of the site, especially on a:link and a:visited. I just wanted the style to be applied to the menu. I tried wraping inside a div but still no luck. What's wrong with my code? Can someone help?
I defined this on my style.css
#topnav_ubid ul li {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
}
#topnav_ubid li {
float: left;
}
#topnav_ubid a:link, a:visited {
display: block;
width: 85px;
height: 20px;
font-weight: bold;
color: #FFFFFF;
background-color: orange;
text-align: center;
padding: 4px;
text-decoration: none;
text-transform: uppercase;
}
#topnav_ubid a:hover, a:active {
background-color: #7A991A;
And had this in HTML:
<div id="topnav_ubid">
<ul>
<li><? print $MSG_501; ?></li>
<?php
if($_SESSION["BPLowbidAuction_LOGGED_IN"]) {
/* user is logged in, give link to edit data or log out */
?>
<li class="<?=$user_menu_style;?>"><? print $MSG_622; ?></li>
<li><? print $MSG_245; ?></li>
<?php
} else {
/* user not logged in, give link to register or login */
?>
<li class="<?=$user_login_style;?>"><? print $MSG_259; ?></li>
<?php
}
?>
<li><? echo $MSG_5085 ;?></li>
<li><? echo $MSG_31_0048; ?></li>
<li> <? print $MSG_164; ?></li>
</ul>
</div>

Answer 1

#topnav_ubid a:link, a:visited { actually are two selectors: #topnav_ubid a:link and a:visited. The second one applies to every visited link, regardless of its parent.
I think you meant this to be #topnav_ubid a:link, #topnav_ubid a:visited {. The same mistake is made in the next selector: #topnav_ubid a:hover, a:active.
I usually add a break after a comma in a list of selectors, so it would be written as:
#topnav_ubid a:link,
#topnav_ubid a:visited {
That way, it's much easier to instantly see all the selectors and you are less likely to make this mistake.
Also note, that in your developer tools (F12) in your browser, you can inspect which styles are applied and which selector caused that. That should help you find any invalid selectors pretty easily.