wide mode initial implementation + cleanup

src/components/about/about.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="sidebar">
+  <div class="column-inner">
     <instance-specific-panel v-if="showInstanceSpecificPanel" />
     <staff-panel />
     <terms-of-service-panel />

src/components/mobile_nav/mobile_nav.vue

@@ -96,7 +96,6 @@
     grid-template-rows: 50px;
     grid-template-columns: 2fr auto;
     width: 100%;
-    position: fixed;
     box-sizing: border-box;
   }
 

src/components/user_card/user_card.vue

@@ -289,6 +289,7 @@
 
 .user-card {
   position: relative;
+  z-index: 1;
 
   &:hover {
     --_still-image-img-visibility: visible;