add: message de bienvenue !!!

style/main.css

@@ -126,6 +126,77 @@ main{
         grid-template-columns: 2.5fr 2fr 1fr;
         grid-template-rows: 1fr 1.5fr;
 
+              aside{
+                grid-row: 2;
+                grid-column: 2;
+                align-self: end;
+                justify-self: end;
+                color: var(--main-color);
+
+                position: relative;
+
+                z-index: 33;
+
+                margin-bottom: 13.12px;
+                margin-right: 13.12px;
+
+                      #openMsg{
+                        width: 33px;
+                        height: 33px;
+                        animation: float 1.61s infinite;
+                        box-sizing: border-box;
+
+                        border-radius: 13.12px;
+                      }
+
+                      #openMsg:hover{
+                        animation: none;
+                      }
+
+                      #msgWindow{
+                        border-style: none;
+                        background-color: transparent;
+                        position: fixed;
+                        top: 117px;
+                        left: 33px;
+                        animation: none;
+                        z-index: 1312;
+                        margin: 0;
+
+                              .floatingWindow{
+                                width: 277px;
+                                height: auto;
+                                margin-top: 33px;
+
+                                text-transform: none;
+                                font-size: 15px;
+                                font-family: 'velvelyne';
+                                font-weight: bold;
+                                padding-bottom: 13.12px;
+                                border-width: 3.33px;
+                                border-style: double solid solid;
+
+                                      p{
+                                        padding: 7.77px;
+                                        padding-right: 16.1px;
+
+                                              strong{
+                                                font-family: 'karrik';
+                                                font-weight: normal;
+                                                text-transform: uppercase;
+                                                font-size: 16.1px;
+                                              }
+                                      }
+                              }
+                      }
+
+                      #msgWindow::backdrop{
+                        background-color: var(--back-color);
+                        opacity: .333;
+                      }
+
+              }
+
               #titleSection{
                 grid-column: 1;
                 grid-row: 1;
@@ -211,7 +282,7 @@ main{
                 grid-row: 2;
                 color: var(--back-color);
                 justify-self: end;
-                
+
                 display: flex;
                 flex-direction: row;
                 justify-content: center;
@@ -368,7 +439,7 @@ main{
                           justify-content: space-between;
                           align-items: center;
                           padding: 16.1px;
-                          
+
                         }
 
                         .solidBox:has(details[open]){
@@ -388,6 +459,10 @@ main{
                         .iconBtnStyle{
                           width: 33px;
                           height: 33px;
+
+                          .icon{
+                            transform: rotate(45deg);
+                          }
                         }
 
                         details{