html,body {
font-size:12px;
font-family: Verdana, sans-serif;
}

#entete {
background-image: url("http://pmc.polytechnique.fr/image/img0011.gif");
background-position : center;
bottom-margin: 0px;
width:50em;
left:0.ex;
padding-top:0.5em;
margin-left: 0em;
margin-right: 0em;
padding-right:0ex;
padding-left:0ex;
height:9em;
Z-index:5;
vertical-align:center;

}
table {font:inherit;}
#maintext h1 {font-size:1.4em;}
#maintext h2 {font-size:1.4em;}



#entete h1{
position:absolute;
font-size: 2em;
background-color: #ffffff;
opacity: 0.6;
display:inline;
left:4em;
right:4em;
vertical-align:center;
text-align:center;
}
#entete a{opacity:0.85;
border: 0;}

#entete a:hover
{opacity:1.;
border: 0;}

#barregauche {
top:0%;
background-color:white;
width: 19em;
height:100%;
position:fixed;
left:0%;
margin: 0px;
margin-left:0em;
padding-left:1em;
margin-right:1em;
padding-top:1em;
overflow: auto;
Z-index:5;
border-right-style:solid;
border-right-width:3px;
border-right-color:lightgray;}

#submenu{
top-margin: 0px;
padding-top:1ex;
Z-index:5;
padding-bottom:1ex;}


#maintext {
text-align:justify;
top:0.ex;
width: 50em;
position: absolute;
left:22em;
margin-top:1em;
margin-left: 1.em;
margin-right: 1em;;
padding-left:2em;
padding-right:2em;
Z-index:4;
border-left-style:solid;
border-right-style:solid;
min-height:100%;
background-color:white;
border-color:gray;
borderwidth:2px;
}

#maintext h3{text-align:center;
font-size:1.4em;}

#barregauche a {
display: block;
margin-left: 2em;
margin-right: 0px;
margin-bottom: 7px;
margin-top: 7px;
text-align: left;
color: #000000;
text-decoration: none;
height: auto;
line-height: 110%;
}

#barregauche H3 {
text-transform:uppercase;
display: block;
margin-left: 2px;
margin-right: 2px;
margin-bottom: 4px;
margin-top:4px;
text-align: left;
color: #000000;
font-size: 1em;
text-decoration: underline;
height: auto;
line-height: 120%;
background-color:#CCCCFF;
}
#barregauche a {display:block;
width 86%;
padding-left:7%;
padding-right:7%;
}
#barregauche a:hover {
background-color: #eeeeee;
}
#barregauche hr{width:67%;color:lightgray;}
#galerie {text-align:center;font-size:1em;font-style:italic;}
#galerie td{text-align:center;font-size:1em;font-style:italic;width:50%;}
#maintext hr {width:67%;}

#barregauche a[href*="homepage.htm"]{font-weight:bolder;text-decoration:underline;}

#sommaireprop a
{background-color:white;display:block;padding-bottom:0.25em;text-decoration:none;color:black;font-size:1.em;height:3.25em;}

#sommaireprop a:hover
{background-color:#EEEEEE;display:block;padding-bottom:0.2em;font-size:1.25em;height:2.6em;overflow:hidden;}

#sommaireprop ul
{display:block;border-left:solid;border-color:lightgray;margin-left:-1em;padding-left:3em;border-width:thin;}

#maintext div.titreinter
{display:block;background-color:#DDDDFF;padding:2px;margin-top:0.5em;}
#maintext div.titreinter > h3
{text-align:center;font-size:1.2em;display:block;padding:0em;margin:5px;}
#maintext div.titreinter > h4  {padding-left:1em;font-size:1em;}