Il faut rajouter :

font-family:Arial,

dans le body du css.

de rien

font-size:12px

toujours dans le body du css.

Ben pour faire plus simple voici le css 
Il et long

/**


@import url(layout.css);
@import url(menue.css);
@import url(forms.css);
@import url(news.css);   
a {
   background-color: transparent;
   color: #4e4e4e;
   text-decoration: underline;
}

a img,
a:hover
a:focus,
a:hover,
a:active {
   background-color: transparent;
   color: #4f6719;
   text-decoration: underline;
}

acronym, abbr {
   border-bottom: 1px solid #86b042;
   cursor: help;
}

br {
   line-height: 8px;
}

body, html {
    background:#2E2E2E url(../images/bg.jpg) repeat-x;    top:0px;
    margin:0;
    font-family:Arial, Helvetica, sans-serif;;
             font-size : 14px
    }   

fieldset {
   margin: 0 0 2em 0;
   padding: 1em .5em .5em .5em;
}

fieldset,
legend {
   background-color: #fdfefa;
   border: 1px solid #e7f2cc;
   color: #4e4e4e;
}

/* headers */
h1 *, h2 *, h3 *, h4 *, h5 *, h6 *, .title *, .option * {
   background-color: transparent;
   color: #3b4d17;
   line-height: normal;
   text-decoration: none;
}

h1, h2, h3, h4, h5, h6, .title, .option, legend {
   background-color: transparent;
   color: #3b4d17;
   font-weight: bold;
   text-align: left;
   white-space: normal; /* z.B. Your_Account&op=edithome, der Userblock */
}

h2, h1, .title {
   font-size: 14px; /* h2 ist die gleiche Definition wie .title !! */
}

h3, .option {
   font-size: 13px; /* h3 ist die gleiche Definition wie .option, ausser block und margin !! */
}

h4, h5, h6 {

}

hr {
   background-color: #e9f2cb; /* Mozilla 1.4 */
   border: #e8f2ce; /* Opera 7.11 */
   color: #e7f2cc; /* IE 6 */
   /* In Opera ist eine feste Höhe für die Anzeige
   notwedig, hingegen in Mozilla für eine
   einheitliche Darstellung wichtig. */
   height: 1px;
   margin: 5px 0 5px 0;

}

/* images */
img.align-left,
img.align-left.border {
   float: left;
   margin: 5px 12px 5px 0px;
}

img.align-right,
img.align-right.border {
   float: right;
   margin: 5px 0px 5px 12px;
}

img.border {
   border-bottom-color: #98bc63;
   border-left-color: #86b042;
   border-right-color: #98bc63;
   border-style: solid;
   border-top-color: #86b042;
   border-width: 2px;
   margin: 3px 10px 3px 10px;
}

img.margin {
   margin: 5px 12px 5px 12px;
}

legend {
   font-weight: bold;
   padding: 2px 6px;
   text-align: left;
}

p {
   margin: 0 0 0.5em 0;
}

/* start - table */
table.list {
   background-color: #ffffff;
   border: none;
   border-collapse: collapse;
   border-spacing: 0;
   color: inherit;
   font-size: 1em;
   margin: 15px 0;
}

.ident{
    margin: 0px;
    padding: 0px;
    text-indent: -50000px;
    color: #333333;
}

table.list th,
table.list td {
   border: 1px solid #e7f2cc;
   line-height: normal;
   padding: 2px 3px;
}

table.list th,
table.list tr.head,
table.list td.head {
   background-color: #a6d243;
   background-image: url(../images/table_bg.jpg);
   background-position: 0 0;
   background-repeat: repeat-x;
   color: #4e4e4e;
   font-weight: bold;
}

table.list tr.alternate-a,
table.list td.alternate-a {
   background-color: #f5fbec;
   color: inherit;
}

table.list tr.alternate-b,
table.list td.alternate-b {
   background-color: #eef8e0;
   color: inherit;
}

table.list tr.alternate-c,
table.list td.alternate-c {
   background-color: #dbebad;
   color: inherit;
}

/* ### Lists | Listen  #### */
ul, ol, dl {
   background-color: transparent;
   color: #3b4d17;
   margin: 2px 2px;
   padding: 0 15px;
}

.base-color {
   background-color: transparent;
   color: #3b4d17;
}

.box {
   background-color: #fbfef8;
   border: 1px solid #bada77;
   color: inherit;
   display: block;
   margin: .3em;
   padding: .3em .3em;
}

.code * {
   font-size: 9px; /* zur Sicherheit, damit wirklich alles gleich gross ist */
}

.code pre {
   border: none; /* dieser Selector hebt die vorherigen Definitionen auf, damit es im Forum keine Probleme gibt, wo diese Verschachtelung vorkommt! */
   font-size: 9px; /* zu Sicherheit doppelgemoppelt!! */
   margin: auto;
   padding: 0;
}

.code, pre, code {
   background-color: #fbfef8;
   border: 1px solid #ececec;
   color: #3b4d17;
   display: block;
   font-family:Arial, Helvetica, sans-serif;
   font-size: 9px;
   line-height: 1.2em;
   margin: 1px auto 0.3em auto;
   max-height: 22em;
   overflow: auto;
   padding: 0 0 0 5px;
   text-align: left;
   white-space: pre;
   width: auto;
}

.content {
   font-size: 11px;
   line-height: 1.4em;
}

.highlight {
   background-color: #ffffcc;
   border-bottom: 1px solid #cccccc;
   color: #ba2e15;
   padding: 0 0.3em 0 0.3em;
}

.important {
   background-color: #ffffcc;
   border-bottom: 1px #ddddbb dotted;
   border-top: 1px #ddddbb dotted;
   color: inherit;
}

.important,
.messagescreen,
.note,
.warning {
   display: block;
   margin: .3em 1em;
   padding: .6em;
}

.indent {
   display: block;
   margin-left: 125px;
}

.note {
   background-color: #fbfef8;
   border-bottom: 1px #86b042 dotted;
   border-top: 1px #86b042 dotted;
   color: inherit;
}

.quote, cite, blockquote {
   background-color: #fbfef8;
   border: 1px solid #ececec;
   color: #3b4d17;
   display: block;
   font-style: italic;
   margin: 1px auto 0.3em 1em;
   overflow: auto;
   padding: 5px;
   width: auto;
}

.smaller {
   font-size: 85%;
}

.tiny, small {
   font-size: 9px;
}

.warning {
   background-color: #ffdddd;
   border-bottom: 1px #ddbbbb dotted;
   border-top: 1px #ddbbbb dotted;
   color: inherit;
}

#logo {
    background-image:url(../images/logo.png);
    background-repeat:no-repeat;
    height: 135px;
    width:1000px;
   
}

#header-right{
    clear:both;
    float:right;
    background-image:url(../images/header-right.png);
    background-repeat:no-repeat;
    height: 135px;
    width: 584px;
}




#menutop{
    background-image:url(../images/menu.png);
    background-repeat:no-repeat;
    height: 36px;
    width: 1000px;
}

/* Menu Header */
#MainMenu
{
    height:30px;
    background:#000 url(../images/menu.png);
    border:0;
    padding-left:10px;
}
#tab
{
    top:0;
    height:0;
    background:repeat-x top;
    margin:0;
}
#tab ul
{
    list-style:none;
    float:left;
    margin:0;
    padding:0;
    display: inline; /* (en|de) Bugfix: IE - Doubled Float Margin Bug */

}
#tab li
{
    display:inline;
    float:left;
    margin:0;
    padding:0;
}
#tab a
{
    background:transparent;
    text-decoration:none;
    border:0;
    display:block;
    float:left;
    margin:0;
    padding:0;
}
#tab a span
{
    display:block;
    font-family:Arial, Helvetica, sans-serif;
    font-size:11px;
    color:#fff;
    font-weight:bold;
    line-height:30px;
    padding:0 15px;
}
#tab a:hover,#tab li.item_active a
{
    background-position:right bottom;
    border-color:#FF9300;
    background:url(../images/hover.jpg) repeat-x;
}
#tab a:hover span,#tab li.item_active a span
{
    background-position:left bottom;
    color:#FFF;
    padding-top: 2px;
    font-weight: bold;
    font-style:normal;
    text-decoration:none;
}
.dropmenudiv
{
    position:absolute;
    top:0;
    float:left;
    display:block;
    visibility:hidden;
    border:0 #FDB300;
    background:#FFF ;
    color:#000;
    z-index:100;
    text-decoration:none;
    padding:0;
}
.dropmenudiv ul
{
    list-style:none;
    margin:0;
    padding:0;
}
.dropmenudiv li
{
    display:inline;
    margin:0;
    padding:0;
}
.dropmenudiv a:link,.dropmenudiv a:visited
{
    width:150px;
    display:block;
    border:0;
    color:#000;;
    font-weight:normal;
    font-style:normal;
    text-decoration:none;
    margin:0;
    padding:0;
}
.dropmenudiv a span
{
    display:block;
    line-height:25px;
    background-color:#000;
    font-family:Tahoma,century gothic,Georgia,  sans-serif;
    font-size:10px;
    color: #E8E8E8;
    border-bottom: 1px solid #666;
    float:none;
    padding:0 12px;
}
.dropmenudiv a:hover
{
    border:0 #FF9300;
    background-position:left bottom;
    font-weight:normal;
    font-style:normal;
    text-decoration:none;
    color:#CCC;
}
.dropmenudiv a:hover span
{
    background-position:right bottom;
    background-color:#333;
    color:#CCC;
    font-weight:normal;
}

#block-top{
    background:#fff url(../images/block-top.jpg);
    height: 230px;
    width: 1000px;
}

#lastthemes{
    float:left;
    height: 230px;
    width: 430px;
    padding-left: 10px;
    padding-top: 15px
}

#lastmessage {
    float:right;
    width: 550px;
    padding-top: 5px;
    padding-right: 2px;
}

#lastmessage .block-title{
       font-size: 13px;
   font-weight: bold;
   line-height: 10px;
   background-image:url(../images/title-message.jpg);
   background-position:bottom;
   background-repeat:repeat-x;
   height: 18px;
   padding-left: 4px;
}

#bg-top{
    background-image:url(../images/border-top.jpg);
    background-repeat:no-repeat;
    width: 1000px;
    height: 26px;
}

.wrapper{
        width:1000px;
    margin:0 auto;
   
}