Rendre compatible mon css pour tous les navigateur

 ul {
 width:500px;
 padding:0;
 margin:0;
 list-style-type:none;
 }
li {
 margin-left:0px;
 float:left; /*pour IE*/
 }
ul li a {
 display:block;
 float:left;   
 width:150px;
 background-color:#6495ED;
 color:black;
 text-decoration:none;
 text-align:center;
 padding:3px;
 border:0px solid;
 /*pour avoir un effet "outset" avec IE :*/
 border-color:#DCDCDC #696969 #696969 #DCDCDC;
 border-radius:5px;
 }
ul li a:hover {
 background-color:#D3D3D3;
 border-color:#696969 #DCDCDC #DCDCDC #696969;
 }  
#searchbutton {
 background-color:#6495ED;
 padding: 7px 0px 6px;
 width:165px;
 text-align:center;
 border-radius:5px;
 border:1px none;
 cursor: pointer;
 bottom: 0px;
 right: 0px;
 }  

 input, select {
    margin-top: 0px;
    margin-left: 0px;
}
 
 #texte {
 border-radius:5px;
 }
 #plan {
 border-radius:5px;
 }