Como arrumar esse CSS ? é o que eu acho

BOm galera, eu tenho um menu,

ele é um menu daquele q quando vc passar o mouse ele aparece, (desculpem eu esqueci o nome) '-'

mais enfim, coloquei o link, porém o link esta aparecendo em outras paginas e quando tiro o link as paginas ficam normais, enfim, eu acho que é o css, tem como vc's verem??

vou postar o codigo do CSS, e a pagina com o link

CSS:

*{

margin: 0px;
padding: 0px;
}

body{

background-color: #FFF;
}

/Configuração do topo /

header{

width: 100%;
height: 145px;
float: left;
background-color: #5ba452;
}

header #topo{

width: 1120px;
height: 155px;
margin: 0 auto;
}

#logo{
width: 231px;
height: 53px;
float: left;
margin-top: 10px;
}

#topo-right{
 width: 455px;
 height: 144px;
 float: right;
}

#topo-right p{

width: 455px;
margin-top: 25px;
margin-bottom: 20px;
font-family: Tahoma;
color: #FFF;
font-size: 14px;
text-align: right;
}

#topo-right p a{

 color: #073e00;
 text-decoration: none;
}

#topo-right #busca-organica{

 width: 400px;
 height: 40px;
 border: none;
 background: #fff;
 float: right;
 box-shadow: inset 0px 0px 5px 1px #cfcdcd;
 font-family: Tahoma;
 font-size: 16px;
 color: #073e00;
 text-align: right;
 padding: 0px 10px 0px 10px;
}

/ Configurações do Menu /

#menu{
 width: 100%;
 height: 50px;
 float: left;
 background-color: #0e7501;

}

#menu nav{

 width: 1120px;
 height: 50px;
 margin: 0 auto;
}

nav ul#menu-screen{

 list-style: none;
 margin: 0;
 padding: 0;
}

nav ul#menu-screen li{

 width: auto;
 height: 90px;
 display: inline;
 padding: 15px 15px 16px 15px;
 text-align: center;
 float: left;
 margin-right: 7px;
 font-family: Tahoma;
 font-size: 16px;
 color: #FFF;

 }

 nav a{
 color: #0e7501;
 text-decoration: none;

 }

 ul#menu-screen li ul li:hover a{
 color: #FFF;
 text-decoration: none
 }

 ul#menu-screen li a:hover {
 color: #FFF;
 text-decoration: none
 }

 nav ul#menu-screen li:first-child{
 width: 130px;
 height: 19px;
 }
 nav ul#menu-screen li:hover{
 background-color: #fff;
 color: #0e7501;
 cursor: pointer;
 }
 nav ul#menu-screen li ul{
 display: none;
 }

 nav ul#menu-screen li:hover ul{
 display: block;
 ;
 margin-top: 16px;
 width: 1080px;
 height: auto;
 padding: 20px;
 float: left;
 background-color: #fff;
 box-shadow: 0px 3px 4px 1px #ccc;
 border-radius: 0px 0px 4px 4px;
 position: relative;
 z-index: 3;

 }

 nav ul#menu-screen li:hover ul li{
 width: auto;
 height: auto;
 color: #121212;
 display: block;
 padding: 0px;
 margin-right: 10px;
 padding: 5px;
 border-radius: 2px;

}

nav ul#menu-screen li:hover ul li:hover{

 background-color: #0e7501;
 color: #fff;

}

/ Configuração do Conteúdo /

main{

 width: 100%;
 height: auto;
 float: left;
 position: relative;
 z-index: 1;
 margin-bottom: 30px;
}

section#content{

 width: 1120px;
 height: auto;
 margin: 0 auto;
 }

 section#conteudo{
 width: 700px;
 height: auto;
 float: left;
 }

 section.banner{
 width: 690px;
 height: 270px;
 float: left;
 margin-top: 20px;

 }

 section.banner ul li a img{
 max-width: 690px;
 max-height: 270px;
 min-width: 690px;
 min-height: 270px;
 }

 section#artigos{
 width: 700px;
 height: auto;
 float: left;
 margin-top: 20px;
 }

 section#artigos article{
 width: 218px;
 height: 270px;
 float: left;
 font-family: Tahoma;
 color: #0e7501;
 margin-left: 12px;
 margin-bottom: 15px;

 }

 section#artigos article h1{
 width: 218px;
 height: auto;
 float: left;
 font-size: 18px;
 text-align: left;
 padding: 0;

 }

 section#artigos article h1 a{
 color: #000000;
 text-decoration: none

 }

 section#artigos article img{
 width: 210px;
 height: 160px;
 float: left;
 margin-top: 5px;

 }

 section#artigos article h2{
 width: 218px;
 height: 55px;
 float: left;
 font-size: 14px;
 text-align: center;
 padding: 0;
 }

 section#artigos article h2 a{
 color: #000000;
 text-decoration: none
 }

 section#publicidade-conteudo{
 width: 700px;
 height: 90px;
 float: left;
 margin-top: 10px;
 background-color: #ccc

 }

 /* Configuração da Sidebar */

 section#sidebar{
 width: 400px;
 height: auto;
 margin-top: 20px;
 float: right;

 }

 section#publicidade-sidebar{
 width: 400px;
 height: 250px;
 float: right;
 background: #ddd;
 margin-bottom: 15px;
 }

 section#widget-ultimas-noticias, section#widget-categorias-portal{
 width: 400px;
 height: auto;
 float: right;
 font-family: Tahoma;
 font-size: 14px;

 }

 section#widget-categorias-portal{
 margin-top: 15px;
 }

 section#widget-ultimas-noticias h1, #widget-categorias-portal h1{
 font-size: 16px;
 background-color: #0e7501;
 color: #fff;
 padding: 7px 12px 7px 12px;
 width: 376px;
 height: auto;
 float: right;
 border-radius: 2px;
 position: relative;
 z-index: 2;
 }

 section#widget-ultimas-noticias ul, #widget-categorias-portal ul{
 list-style: none;
 margin: 0;
 padding: 0;
 height: auto;
 float: right;
 margin-top: 5px;
 }

 #widget-categorias-portal ul{
 display: inline
 }

 section#widget-ultimas-noticias ul li, #widget-categorias-portal ul li{
 color: #5ba452;
 width: 386px;
 height: auto;
 padding: 5px 7px 5px 7px;
 float: right;
 -webkit-transition: all 0.3s ease-in-out;
 -moz-transition: all 0.3s ease-in-out;
 -o-transition: all 0.3s ease-in-out
 }

 section#widget-ultimas-noticias ul li a, #widget-categorias-portal ul li a {
 color: #000000;
 text-decoration: none;

 }

 section#widget-ultimas-noticias ul li:hover a, #widget-categorias-portal ul li:hover a{
 color: #FFF;
 text-decoration: none;
 }

 #widget-categorias-portal ul li{
 width: auto;
 height: auto;
 padding: 7px 5px 7px 5px;
 float: right;

 }

 section#widget-ultimas-noticias ul li:hover, #widget-categorias-portal ul li:hover{
 background-color: #0e7501;
 color: #fff;
 cursor: pointer;

 }

 /* Configuração Noticias Interna */

section#banner-noticia{

	width: 690px;
	height: 270px;
	float: left;
	margin-top: 10px;
	overflow: hidden;
}

section#banner-noticia img{

	width: 690px;
	height: 270px;
}

section#info-noticias{

	margin-top: 20px;
	float: left;
	text-align: left;
}

section#info-noticias h1{

	width: 679px;
	height: auto;
	text-align: left;
	padding: 0;
	margin: 0;
	margin-bottom: 5px;
}

section#conteudo-noticia{

	width: 690px;
	height: auto;
	margin-top: 20px;
	float: left;
	text-align: justify;
}

section#tags{

	width: 670px;
	height: auto;
	float: left;
	background-color: #E2E2E2;
	color: #121212;
	padding: 10px;
	margin-top: 10px;
	text-align: left;
	border: 2px dashed #BBBBBB;
}

/Configuração página de Categoria /

section#categoria-news, section#categoria-news-error{

	width: 650px;
	height: auto;
	float: left;
	margin-top: 20px;
	padding-bottom: 10px;
}

section#categoria-news h1, section#categoria-news-error h1{

	width: 100%;
	height: auto;
	text-align:left;
	font-size: 20px;
	font-family: Tahoma;
	padding: 10px 0px;
	border-bottom: 1px solid #BCBCBC;
	margin-bottom: 10px;
}

section#categoria-news-error h1{

	border: none;
	font-size: 24px;
}

section#categoria-news h1 a{

	color: #121212;
	text-decoration: none;
}

section#imagem-noticia{

	width: 160px;
	height: 160px;
	float: left;
	border: 5px solid #fff;
	box-shadow: 0px 0px 2px 1px #999999;
	margin-right: 20px;
	margin-bottom: 3px;
	margin-top: 8px;
	overflow: hidden;
}

section#imagem-noticia img{

	width: 160px;
	height: 100%;
	float: left;
}

section#categoria-news p{

	text-align: justify;
	font-size: 14px;
	font-family: Tahoma;
	color: #121212;
}

section#categoria-news p a{

	color: #1C4788;
	text-decoration: none;
}

 /* Configuração do Footer */

 footer{
 width: 100%;
 height: auto;
 float: left;
 margin-bottom: 20px;
 background: #5ba452

 }

 footer #center-ft{
 width: 1120px;
 height: auto;
 float: center;
 margin: 0 auto;
 border-top: 2px solid #75b66c
 }

 footer #logo2{
 float: left;
 margin-top: 20px;
 }

 footer #center-ft p{
 font-family: Tahoma;
 font-size: 14px;
 color: #fff;
 float: right;
 margin-top: 25px;
 }

agora da pagina do menu:

<?php require_once "configuration.php"; ?>

<!DOCTYPE html>

<html lang="py-br">
 <head>
 <meta charset="utf-8" />
 <title>Esportes Geral</title>
 <link rel="stylesheet" type="text/css" href="css/categoria.css" media="screen" />
 <link rel="stylesheet" type="text/css" href="css/noticia.css" media="screen" />
 <link rel="stylesheet" type="text/css" href="css/default.css" media="screen" />
 <script src="js/jquery-2.1.4.js" type="text/javascript"></script>
 <script type="text/javascript" src="js/easySlider1.7.js"></script>
	<script type="text/javascript">
 $(document).ready(function(){
 $("#slider").easySlider({
 auto: true,
 continuous: true
 });
 });
	</script>

<link href="css/screen.css" rel="stylesheet" type="text/css" media="screen" />

 </head>

 <body>

 <header>

 <div id="topo">

 <div id="logo">
 <a href="index.php">
 <img src="imagens/Logo.png" alt="Esportes Geral Logo" />
 </a>
 </div>

 <div id="topo-right">

 <p>Olá, Seja Bem Vindo <a href="paineldecontrole/index.php">Faça login</a> ou <a href="cadastrar.php">Cadastre-se</a>. </p>

 <form action="busca.php" method="GET">

 <input type="text" name="busca-organica" id="busca-organica" />

 <p><embed quality="high" src="http://www.cryd.com.br/relogios-feitos-em-flash/swf/01-10/481.swf" type="application/x-shockwave-flash" width="300" height="20" wmode="transparent"></embed></p>
 </form>
 </div>

 </div>

 </header>

 <div id="menu">

 <nav>
 <ul id="menu-screen">

 <li>Categorias do site
 <ul>
 <?php

 $SQL = mysql_query("SELECT * FROM categoria");

 while($ln = mysql_fetch_assoc($SQL)){

 ?>
 <li><a href="categoria.php?id=<?php echo $ln["id_categoria"]; ?>"/><?php echo $ln["nome_categoria"]; ?></li>
 <?php } ?>
 </ul>
 </li>
 <li>Publicidade</li>
 <li>Quem somos</li>
 <li>Parceiros</li>
 <li>atendimento</li>
 </ul>
 </nav>

 </div>

estou com o problema nesse link:

<li><a href="categoria.php?id=<?php echo $ln["id_categoria"]; ?>"/><?php echo $ln["nome_categoria"]; ?></li>