t´es sur que tu l´as pas? c´est pas " stylle.css" le nom du fichier???
sinon, fait un copier collé de ca dans un fichier que tu renomme en EasyBlue.css:
< !--
/ *
Theme Easy Blue for phpBB version 2+
Created by Fly center
http://www.flycenter.fr.st
/ * General page style. The scroll bar colors only visible in IE5.5+ / Couleur de la scroll-bar visible seulement sur IE5.5 ou + */
body {
scrollbar-face-color: #D5E9FF;
scrollbar-highlight-color: #FFFFFF;
scrollbar-shadow-color: #DBEBF6;
scrollbar-3dlight-color: #FFFFFF;
scrollbar-arrow-color: #006699;
scrollbar-track-color: #E4F0FF;
scrollbar-darkshadow-color: #007EFF;
}
/ * General font families for common tags / Definition des polices et des liens */
font,th,td,p { font-family: Verdana, Arial, Helvetica, sans-serif }
a:link,a:active,a:visited { color : #006699; text-decoration: none; }
a:hover { color : #28CBF4; text-decoration: none; background-color: transparent; position: relative; top: 1.5px; left: 1.5px;}
hr { height: 0px; border: solid #CBE6F9 0px; border-top-width: 1px;}
/ * This is the border line & background colour round the entire page / c´est la ligne/bordure autour de toute la page */
. bodyline { background-color: #FFFFFF; border: 0px #AEBDC4 solid; }
/ * This is the outline round the main forum tables / Definition des classes forumlines les principaux tableaux de la page */
. forumline { background-color: #007EFF; border: 0px #0078D6 solid; }
. forumline1 { border: 0px #B8D7ED solid; }
/ * Main table cell colours and backgrounds / Couleur de fond des cellules des tableaux principaux */
td.row1 { background-color: #E4F0FF; }
td.row2 { background-color: #D5E9FF; }
td.row3 { background-color: #EAF5FD; }
/ *
This is for the table cell above the Topics, Post & Last posts on the index.php page
By default this is the fading out gradiated silver background.
However, you could replace this with a bitmap specific for each forum
td.rowpic {
background-color: #FFFFFF;
background-image: url(templates/EasyBlue/images/ebpic2.jpg);
background-repeat: repeat-y;
}
/ * Definition of the main table´s head cells properties / Definition des propriétés l´ en tête des tableaux principaux */
th {
color: #336699; font-size: 11px; font-weight : bold;
background-color: #8CB6D4; height: 25px;
background-image: url(templates/EasyBlue/images/h_m3.gif);
}
td.cat,td.catHead,td.catSides,td.catLeft,td.catRig
ht,td.catBottom {
background-image: url(templates/EasyBlue/images/ebpic1.gif);
background-color:#DBEBF6; border: #FFFFFF; border-style: solid; height: 28px;
}
/ *
Setting additional nice inner borders for the main table cells.
The names indicate which sides the border will be on.
Don´t worry if you don´t understand this, just ignore it 
Definition des propriétés des lignes interieures des cellules des tableaux principaux
Le nom indique de quel côté se trouvera la ligne
Ne vous inquietez pas, si vous ne le comprenez pas, Ignorez le
td.cat,td.catHead,td.catBottom {
height: 29px;
border-width: 0px 0px 0px 0px;
}
th.thHead,th.thSides,th.thLeft,th.thRight,th.thBot
tom {
font-weight: bold; border: #FFFFFF; border-style: solid; height: 28px;
}
th.thTop,th.thCornerL,th.thCornerR {
font-weight: bold; border: #FFFFFF; border-style: solid; height: 20px;
background-image: url(templates/EasyBlue/images/h_m3.gif);
}
td.row3Right,td.spaceRow {
background-color: #CBE6F9; border: #FFFFFF; border-style: solid;
}
th.thHead,td.catHead { font-size: 12px; border-width: 1px 1px 0px 1px; }
th.thSides,td.catSides,td.spaceRow { border-width: 0px 1px 0px 1px; }
th.thRight,td.catRight,td.row3Right { border-width: 0px 1px 0px 0px; }
th.thLeft,td.catLeft { border-width: 0px 0px 0px 1px; }
th.thBottom,td.catBottom { border-width: 0px 1px 1px 1px; }
th.thTop { border-width: 0px 0px 0px 0px; }
th.thCornerL { border-width: 0px 0px 0px 0px; }
th.thCornerR { border-width: 0px 0px 0px 0px; }
/ * The largest text used in the index page title and toptic title etc. / Le texte le plus large utilisé sur l´ index du Forum pour les titres etc. */
. maintitle {
font-weight: bold; font-size: 12px; font-family: " Trebuchet MS",Verdana, Arial, Helvetica, sans-serif;
text-decoration: none; line-height : 120%; color : #000000;
}
/ * General text / Texte general */
. gen { font-size : 11px; }
. genmed { font-size : 11px; }
. gensmall { font-size : 10px; }
. gen,.genmed,.gensmall { color : #000000; }
a.gen,a.genmed,a.gensmall { color: #006699; text-decoration: none; }
a.gen:hover,a.genmed:hover,a.gensmall:hover { color: #28CBF4; text-decoration: underline; }
/ * The register, login, search etc links at the top of the page / Propriétées des textes pour Login, Register, etc. ( en haut) */
. mainmenu { font-size : 11px; color : #000000 }
a.mainmenu { text-decoration: none; color : #006699; }
a.mainmenu:hover{ text-decoration: underline; color : #DD6900; }
/ * Forum category titles / Style des titres des Categories du Forum */
. cattitle { font-weight: bold; font-size: 11px; letter-spacing: 1px; color : #006699}
a.cattitle { text-decoration: none; color : #4A6E8A; }
a.cattitle:hover{ text-decoration: underline; }
/ * Forum title: Text and link to the forums used in: index.php */
. forumlink { font-weight: bold; font-size: 11px; color : #006699; }
a.forumlink { text-decoration: none; color : #006699; }
a.forumlink:hover{ text-decoration: underline; color : #28CBF4; }
/ * Used for the navigation text, ( Page 1,2,3 etc) and the navigation bar when in a forum */
. nav { font-weight: bold; font-size: 11px; color : #000000;}
a.nav { text-decoration: none; color : #006699; }
a.nav:hover { text-decoration: underline; text-decoration: none;}
/ * titles for the topics: could specify viewed link colour too / Propriétes des Liens vers les topics, visités etc. */
. topictitle,h1,h2 { font-weight: bold; font-size: 11px; color : #000000; }
a.topictitle:link { text-decoration: none; color : #006699; }
a.topictitle:visited { text-decoration: none; color : #5493B4; }
a.topictitle:hover { text-decoration: underline; color : #28CBF4; }
/ * Name of poster in viewmsg.php and viewtopic.php and other places / Propriétés du nom du Posteur */
. name { font-size : 11px; color : #000000;}
/ * Location, number of posts, post date etc / Propriétés des details sur le posteur */
. postdetails { font-size : 10px; color : #000000; }
/ * The content of the posts ( body of text) */
. postbody { font-size : 12px; line-height: 18px}
a.postlink:link { text-decoration: none; color : #006699 }
a.postlink:visited { text-decoration: none; color : #5493B4; }
a.postlink:hover { text-decoration: underline; color : #DD6900}
/ * Quote & Code blocks / Proprietés des Quotes et Codes */
. code {
font-family: Courier, ´Courier New´, sans-serif; font-size: 11px; color: #14719C;
background-color: #FAFAFA; border: #91C6EB; border-style: solid;
border-left-width: 1px; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px
}
. quote {
font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 11px; color: #14719C; line-height: 125%;
background-color: #FAFAFA; border: #91C6EB; border-style: solid;
border-left-width: 1px; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px
}
/ * Copyright and bottom info */
. copyright { font-size: 10px; font-family: Verdana, Arial, Helvetica, sans-serif; color: #444444; letter-spacing: -1px;}
a.copyright { color: #444444; text-decoration: none;}
a.copyright:hover { color: #000000; text-decoration: underline;}
/ * Form elements / Elements de Formulaires */
input,textarea, select {
color : color : #000000;
font: normal 11px Verdana, Arial, Helvetica, sans-serif;
border-color : #000000;
}
/ * The text input fields background colour */
input.post, textarea.post, select {
background-color : #FFFFFF;
}
input { text-indent : 2px; }
/ * The buttons used for bbCode styling in message post */
input.button {
background-color : #EFEFEF;
color : #000000;
font-size: 11px; font-family: Verdana, Arial, Helvetica, sans-serif;
}
/ * The main submit button option */
input.mainoption {
background-color : #FAFAFA;
font-weight : bold;
}
/ * None-bold submit button */
input.liteoption {
background-color : #FAFAFA;
font-weight : normal;
}
/ * This is the line in the posting page which shows the rollover
help line. This is actually a text box, but if set to be the same
colour as the background no one will know ; )
. helpline { background-color: #DBEBF6; border-style: none; }
. admin { font-size: 10px; font-family: Verdana, Arial, Helvetica, sans-serif; color: #006699; letter-spacing: -1px;}
/ * Background properties / Propriétés du Background */
body { background-color: #D5E9FF; background-image: url("templates/EasyBlue/images/background.gif"); background-attachment: fixed;
}
/ * Import the fancy styles for IE only ( NS4.x doesn´t use the @import function) */
@import url("templates/EasyBlue/formIE.css");
-->
