unify panel-heading markup and use h1 for header label

src/components/announcements_page/announcements_page.vue

 <template>
   <div class="panel panel-default announcements-page">
     <div class="panel-heading">
-      <span>
+      <h1 class="title">
         {{ $t('announcements.page_header') }}
-      </span>
+      </h1>
     </div>
     <div class="panel-body">
       <section

src/components/bookmark_folder_edit/bookmark_folder_edit.vue

@@ -13,7 +13,7 @@
           icon="chevron-left"
         />
       </button>
-      <div class="title">
+      <h1 class="title">
         <i18n-t
           v-if="id"
           keypath="bookmark_folders.editing_folder"
@@ -26,7 +26,7 @@
           v-else
           keypath="bookmark_folders.creating_folder"
         />
-      </div>
+      </h1>
     </div>
     <div class="panel-body">
       <div class="input-wrap">

src/components/bookmark_folders/bookmark_folders.vue

 <template>
   <div class="Bookmark-folders panel panel-default">
     <div class="panel-heading">
-      <div class="title">
+      <h1 class="title">
         {{ $t('nav.bookmark_folders') }}
-      </div>
+      </h1>
       <router-link
         :to="{ name: 'bookmark-folder-new' }"
         class="button-default btn new-folder-button"

src/components/chat_list/chat_list.vue

@@ -7,9 +7,9 @@
     class="chat-list panel panel-default"
   >
     <div class="panel-heading -sticky">
-      <span class="title">
+      <h1 class="title">
         {{ $t("chats.chats") }}
-      </span>
+      </h1>
       <button
         class="button-default"
         @click="newChat"

src/components/conversation/conversation.vue

@@ -9,7 +9,9 @@
       v-if="isExpanded"
       class="panel-heading conversation-heading -sticky"
     >
-      <span class="title"> {{ $t('timeline.conversation') }} </span>
+      <h1 class="title">
+        {{ $t('timeline.conversation') }}
+      </h1>
       <button
         v-if="collapsable"
         class="button-unstyled -link"

src/components/dialog_modal/dialog_modal.vue

@@ -8,9 +8,9 @@
       @click.stop=""
     >
       <div class="panel-heading dialog-modal-heading">
-        <div class="title">
+        <h1 class="title">
           <slot name="header" />
-        </div>
+        </h1>
       </div>
       <div class="panel-body dialog-modal-content">
         <slot name="default" />

src/components/edit_status_modal/edit_status_modal.vue

@@ -6,7 +6,9 @@
   >
     <div class="edit-form-modal-panel panel">
       <div class="panel-heading">
-        {{ $t('post_status.edit_status') }}
+        <h1 class="title">
+          {{ $t('post_status.edit_status') }}
+        </h1>
       </div>
       <PostStatusForm
         class="panel-body"

src/components/features_panel/features_panel.vue

@@ -2,9 +2,9 @@
   <div class="features-panel">
     <div class="panel panel-default base01-background">
       <div class="panel-heading timeline-heading base02-background base04">
-        <div class="title">
+        <h1 class="title">
           {{ $t('features_panel.title') }}
-        </div>
+        </h1>
       </div>
       <div class="panel-body features-panel">
         <ul>

src/components/follow_requests/follow_requests.vue

 <template>
   <div class="settings panel panel-default">
     <div class="panel-heading">
-      <div class="title">
+      <h1 class="title">
         {{ $t('nav.friend_requests') }}
-      </div>
+      </h1>
     </div>
     <div class="panel-body">
       <FollowRequestCard

src/components/interactions/interactions.vue

 <template>
   <div class="panel panel-default">
     <div class="panel-heading">
-      <div class="title">
+      <h1 class="title">
         {{ $t("nav.interactions") }}
-      </div>
+      </h1>
     </div>
     <tab-switcher
       ref="tabSwitcher"

src/components/lists/lists.vue

@@ -2,7 +2,9 @@
   <div class="Lists panel panel-default">
     <div class="panel-heading">
       <div class="title">
-        {{ $t('lists.lists') }}
+        <h1 class="title">
+          {{ $t('lists.lists') }}
+        </h1>
       </div>
       <router-link
         :to="{ name: 'lists-new' }"

src/components/login_form/login_form.vue

@@ -3,7 +3,7 @@
     <!-- Default panel contents -->
 
     <div class="panel-heading">
-      <span class="title">{{ $t('login.login') }}</span>
+      <h1 class="title">{{ $t('login.login') }}</h1>
     </div>
 
     <div class="panel-body">

src/components/mfa_form/recovery_form.vue

@@ -3,7 +3,9 @@
     <!-- Default panel contents -->
 
     <div class="panel-heading">
-      {{ $t('login.heading.recovery') }}
+      <h1 class="title">
+        {{ $t('login.heading.recovery') }}
+      </h1>
     </div>
 
     <div class="panel-body">

src/components/mfa_form/totp_form.vue

@@ -3,7 +3,9 @@
     <!-- Default panel contents -->
 
     <div class="panel-heading">
-      {{ $t('login.heading.totp') }}
+      <h1 class="title">
+        {{ $t('login.heading.totp') }}
+      </h1>
     </div>
 
     <div class="panel-body">

src/components/mobile_nav/mobile_nav.vue

@@ -50,13 +50,13 @@
       @touchmove.stop="notificationsTouchMove"
     >
       <div class="panel-heading mobile-notifications-header">
-        <span class="title">
+        <h1 class="title">
           {{ $t('notifications.notifications') }}
           <span
             v-if="unseenCountBadgeText"
             class="badge -notification unseen-count"
           >{{ unseenCountBadgeText }}</span>
-        </span>
+        </h1>
         <span class="spacer" />
         <button
           v-if="notificationsAtTop"

src/components/notifications/notifications.vue

@@ -14,13 +14,13 @@
           v-if="!noHeading"
           class="notifications-heading panel-heading -sticky"
         >
-          <div class="title">
+          <h1 class="title">
             {{ $t('notifications.notifications') }}
             <span
               v-if="unseenCountBadgeText"
               class="badge -notification unseen-count"
             >{{ unseenCountBadgeText }}</span>
-          </div>
+          </h1>
           <div
             v-if="showScrollTop"
             class="rightside-button"

src/components/password_reset/password_reset.vue

 <template>
   <div class="settings panel panel-default">
     <div class="panel-heading">
-      <span class="title">{{ $t('password_reset.password_reset') }}</span>
+      <h1 class="title">
+        {{ $t('password_reset.password_reset') }}
+      </h1>
     </div>
     <div class="panel-body">
       <form

src/components/post_status_modal/post_status_modal.vue

@@ -7,7 +7,9 @@
   >
     <div class="post-form-modal-panel panel">
       <div class="panel-heading">
-        {{ $t('post_status.new_status') }}
+        <h1 class="title">
+          {{ $t('post_status.new_status') }}
+        </h1>
       </div>
       <PostStatusForm
         class="panel-body"

src/components/registration/registration.vue

 <template>
   <div class="settings panel panel-default">
     <div class="panel-heading">
-      <span class="title">{{ $t('registration.registration') }}</span>
+      <h1 class="title">
+        {{ $t('registration.registration') }}
+      </h1>
     </div>
     <div
       v-if="!hasSignUpNotice"

src/components/remote_user_resolver/remote_user_resolver.vue

 <template>
   <div class="panel panel-default">
     <div class="panel-heading">
-      {{ $t('remote_user_resolver.remote_user_resolver') }}
+      <h1 class="title">
+        {{ $t('remote_user_resolver.remote_user_resolver') }}
+      </h1>
     </div>
     <div class="panel-body">
       <p>