Remplacez la totalité de votre template index_box par :

Code:

<ul class="linklist top">
   <!-- BEGIN switch_user_logged_in -->
   <li>
      <a href="{U_SEARCH_NEW}"><i class="ion-ios-flame"></i>{L_SEARCH_NEW}</a>
   </li>
   <li>
      <a href="{U_SEARCH_SELF}"><i class="ion-ios-box-outline"></i>{L_SEARCH_SELF}</a>
   </li>
   <!-- END switch_user_logged_in -->
   <li>
      <a href="{U_SEARCH_UNANSWERED}"><i class="ion-ios-chatbubble-outline"></i>{L_SEARCH_UNANSWERED}</a>
   </li>
   <!-- BEGIN switch_user_logged_in -->
      <li class="rightside">
         <a href="{U_MARK_READ}" accesskey="m"><i class="ion-android-checkmark-circle"></i>{L_MARK_FORUMS_READ}</a>
      </li>
   <!-- END switch_user_logged_in -->
</ul>

<!-- BEGIN catrow -->
<!-- BEGIN tablehead -->

<div class="hl_cat_title">{catrow.tablehead.L_FORUM}<div class="hl_cat_sous_tit">I solemnly swear I am up to no good</div></div>

<!-- END tablehead -->
<!-- BEGIN forumrow -->


<div class="hl_total_cat" id="{catrow.forumrow.FORUM_NAME}">
  
  <div class="hl_cat_grotitle"><a href="{catrow.forumrow.U_VIEWFORUM}">{catrow.forumrow.FORUM_NAME}</a></div>
  
  <div class="hl_cat_icon" style="background:url({catrow.forumrow.FORUM_FOLDER_IMG}) no-repeat scroll 100%;">
    <div class="hl_cat_ava">
      <!-- BEGIN avatar -->
      <div class="hl_cat_ava_inside">{catrow.forumrow.avatar.LAST_POST_AVATAR}</div>
      <!-- END avatar -->
    </div>
  </div>
  
  <div class="hl_cat_desc">{catrow.forumrow.FORUM_DESC}</div>
  
  <div class="hl_cat_stats">
    <div>{catrow.forumrow.TOPICS}<br/><span>parchemins</span></div>
    <div class="hl_cat_stats_sep"></div>
    <div>{catrow.forumrow.POSTS}<br/><span>écrits</span></div>
  </div>
  
  <div class="hl_cat_lastpost">
    <div class="hl_cat_lastpost_icon"><img src="https://placehold.co/148x36"/></div>
    
    <div class="hl_cat_lastpost_total">
      <!-- BEGIN switch_topic_title -->
      <a href="{catrow.forumrow.U_LATEST_TOPIC}" title="{catrow.forumrow.LATEST_TOPIC_TITLE}">{catrow.forumrow.LATEST_TOPIC_NAME}</a><br />
      <!-- END switch_topic_title -->
    </div>
    
    <div class="hl_cat_lastpost_user">{catrow.forumrow.USER_LAST_POST}</div>
    
  </div>
  
  <div class="hl_cat_dec">{catrow.forumrow.L_LINKS}{catrow.forumrow.LINKS} <strong>{forumrow.L_SUBFORUM_STR}</strong> {forumrow.SUBFORUMS}</div>
  
</div>

<!-- END forumrow -->

<!-- BEGIN tablefoot -->
<!-- END tablefoot -->

<!-- END catrow -->


<!-- BEGIN switch_on_index -->
<ul class="linklist bottom">
   <li>
      <a href="{U_TODAY_ACTIVE}">{L_TODAY_ACTIVE}</a>
   </li>
   <li>
      <a href="{U_TODAY_POSTERS}">{L_TODAY_POSTERS}</a>
   </li>
   <li class="last">
      <a href="{U_OVERALL_POSTERS}">{L_OVERALL_POSTERS}</a>
   </li>
   <!-- BEGIN switch_delete_cookies -->
      <li class="rightside">
         <a href="{switch_on_index.switch_delete_cookies.U_DELETE_COOKIES}" rel="nofollow"><i class="ion-trash-a"></i>{switch_on_index.switch_delete_cookies.L_DELETE_COOKIES}</a>
      </li>
   <!-- END switch_delete_cookies -->
</ul>
<!-- END switch_on_index -->


Puis ajoutez votre CSS : Panneau d'administration > Affichage > Images et couleurs > Couleurs > Feuille de style CSS :

Code:

:root {
  --red:#9279b1;
  --text:#A6A6A6;
  --black:#151515;
  --deggris:#202020;
  --degnoir:#080808;
  --deentre:#242424;
  --pinkyred:#c29b88;
  --fondfo:#000;
  --fontcat:url(https://i.imgur.com/27HhuV6.png);
  --wrap:rgba(22, 22, 22, 0.8);
}
.hl_cat_title {
  width: 100%;
  padding: 10px;
  text-align: center;
  margin-bottom: 20px;
  position:relative;
}
.hl_cat_title:before {
  content:"";
  position:absolute;
  left:0;
  top:15px;
  background-image:url(https://cdn.discordapp.com/attachments/1087522908936622200/1088489451514245130/3.png);
  width:200px;
  height:100px;
  opacity:0.5;
  background-size:100%;
  background-repeat:no-repeat;
  background-position:top;
  z-index:-1;
}
.hl_cat_title::after {
  content: "";
  position: absolute;
  right: 0;
  top: 15px;
  background-image: url(https://cdn.discordapp.com/attachments/1087522908936622200/1088489451514245130/3.png);
  width: 200px;
  height: 100px;
  opacity: 0.5;
  background-size: 100%;
  background-repeat: no-repeat;
  background-position: top;
  transform: scaleX(-1);
  z-index: -1;
}
.hl_cat_title h2 {
  font: 35px goku;
  letter-spacing: 2px;
  word-spacing: 5px;
  background: linear-gradient(-225deg, var(--red) 0%, var(--pinkyred) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  border-bottom: 1px solid var(--deggris);
  width: 600px;
  margin: 0px auto 5px auto;
}
.hl_cat_sous_tit {
  letter-spacing: 6px;
  font: 9px Calibri;
  text-transform: uppercase;
  width: 100%;
  color: var(--pinkyred);
  text-align: center;
  text-shadow: 1px 1px 1px var(--black);
}
.hl_total_cat {
  background-color: var(--deggris);
  padding: 10px;
  border-radius: 8px;
  margin: 10px 0px 25px 0px;
  background-image:var(--fontcat);
  background-size: 100%;
  background-blend-mode: luminosity;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  border: solid 1px var(--deentre);
  position: relative;
}
.hl_cat_grotitle {
  width: 100%;
  margin: -30px 0px 0px 0px;
}
.hl_cat_grotitle a {
  color: var(--text);
  font: 28px goku;
  text-transform: lowercase;
  letter-spacing: 1px;
}
.hl_cat_icon {
  width: 167px;
  background-size: 109% !important;
  height: 135px;
  background-position: 50% 50% !important;
  margin: -17px -26px 0px -30px;
}
.hl_cat_ava {
  width: 75px;
  height: 75px;
  margin: 33px 0px 0px 46px;
  filter: grayscale(63%) contrast(90%);
}
.hl_cat_ava_inside {
  width: 75px;
  height: 75px;
  overflow: hidden;
  border-radius: 100%;
}
.hl_cat_ava_inside img {
  width:100%;
}
.hl_cat_desc {
  width: 270px;
  text-align: justify;
  border-radius: 6px;
  background: var(--black);
  padding: 10px;
  height: 118px;
  overflow: auto;
  color: var(--text);
  font: 13px Calibri;
}
.hl_cat_stats {
  width: 110px;
  margin: 0px 15px;
}
.hl_cat_stats div {
  text-align: center;
  margin: 6px 0px;
  font: 30px goku;
  letter-spacing: 2px;
}
.hl_cat_stats div span {
  letter-spacing: 4px;
  font: 8px Calibri;
  text-transform: uppercase;
  color: var(--pinkyred);
  text-align: center;
  text-shadow: 1px 1px 1px var(--black);
}
.hl_cat_stats_sep {
  width: 100%;
  height: 1px;
  background: var(--red);
}
.hl_cat_lastpost {
  width: 170px;
  padding: 10px;
  background: var(--black);
  border-radius: 8px;
  border: solid 1px var(--deentre);
}
.hl_cat_lastpost_icon {
  width: 100%;
  overflow: hidden;
  margin: 0px auto;
  height: 36px;
  text-align: center;
}
.hl_cat_lastpost_icon img {
  width: 150px;
  height: 32px;
}
.hl_cat_lastpost_total {
  width: 100%;
  color: var(--pinkyred);
  text-align: center;
  text-transform: uppercase;
  font: 12px Calibri;
  margin-top:8px;
}
.hl_cat_lastpost_total a {
  text-transform: uppercase;
  font: 12px Calibri;
  color: var(--pinkyred);
  border-bottom: 2px dotted var(--red);
}
.hl_cat_lastpost_total strong {
  font-style:italic;
}
.hl_cat_lastpost_user {
  text-align: center;
  font: 9px calibri;
  color: var(--text);
  margin-top: 5px;
}
.hl_cat_lastpost_user a {
  font: 16px goku;
  color:var(--text);
}
.hl_cat_dec {
  width: 188px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-evenly;
  height: 118px;
  overflow: auto;
  font-size: 0;
}
.hl_cat_dec a {
  text-align: center;
  background-image: linear-gradient(-225deg, var(--red) 0%, var(--pinkyred) 100%);
  padding: 2px 3px;
  margin: 5.2px 5px;
  width: 100%;
  font: 12px Calibri;
  color: var(--deentre);
  text-transform: uppercase;
  border-radius: 5px;
}

Icone "pas de nouveaux messages" :

Code:

https://i.imgur.com/ms6eWic.png

Icone "nouveaux messages" :

Code:

https://i.imgur.com/8m58Kqs.png

Enjoy