add calculation module and fix many bugs

assets/admin/sass/admin.scss

@@ -127,7 +127,7 @@ $panelBg: #fff;
       padding: 0 15px;
       position: fixed;
       top: 56px;
-      left: 15px;
+      left: 0;
       z-index: 5;
 
       h2 {
@@ -177,10 +177,11 @@ $panelBg: #fff;
   }
 
   .admin--sidebar {
-    min-height: calc(100vh - 55px);
+    height: calc(100vh - 55px);
     background: $sidebar;
     flex-basis: 300px;
     border-left: 1px solid $borders;
+    overflow: auto;
 
     ul {
       width: 100%;
@@ -231,6 +232,23 @@ $panelBg: #fff;
     .admin-user {
       padding: 20px 15px;
       color: $usernameColor;
+      display: flex;
+      flex-direction: row;
+      justify-content: flex-start;
+      align-items: center;
+      flex-wrap: nowrap;
+
+      .el-avatar {
+        display: block;
+        width: 50px;
+        height: 50px;
+
+        img {
+          width: 100%;
+          height: 100%;
+          object-fit: cover;
+        }
+      }
 
       h2 {
         font-size: 25px !important;
@@ -254,6 +272,11 @@ $panelBg: #fff;
         }
       }
     }
+
+    .sidebar--content {
+      height: 100%;
+      overflow: auto;
+    }
   }
 
   .admin--header {
@@ -320,6 +343,11 @@ $panelBg: #fff;
     text-align: center;
   }
 
+  .err {
+    color: red;
+    font-size: 13px;
+  }
+
 }
 
 pre {
@@ -382,11 +410,6 @@ html:lang(fa) {
     margin-top: 50px;
   }
 
-  .err {
-    color: red;
-    font-size: 13px;
-  }
-
   .el-upload__input {
     display: none !important;
   }