Consistent announcement and module style

_layouts/announcement.html

 <div class="announcement">
+  <h2 class="announcement-header">{% if page.date %}<strong class="announcement-meta">{{ page.date | date: '%b %e' }}</strong> {% endif %}{{ page.title }}</h2>
   <div class="announcement-body">
-    <h2>{{ page.title }}{% if page.date %} <strong class="announcement-meta">{{ page.date | date: '%b %e' }}</strong>{% endif %}</h2>
     {{ content }}
   </div>
 </div>

_layouts/module.html

 <div class="module">
-  <h3 class="module-header"><strong class="module-meta">{{ page.week }}</strong> {{ page.title }}</h3>
+  <h2 class="module-header">{% if page.week %}<strong class="module-meta">Week {{ page.week }}</strong> {% endif %}{{ page.title }}</h2>
   {% if page.days %}
   <dl class="module-days">
     {% for day in page.days %}

_sass/custom/announcement.scss

@@ -2,6 +2,10 @@
   @extend %card;
 }
 
+.announcement-header {
+  @extend %card-header;
+}
+
 .announcement-body {
   @extend %card-body;
 

_sass/custom/card.scss

@@ -19,6 +19,10 @@
   @include mq(lg) {
     flex: 1 0 0%;
   }
+
+  >:first-child {
+    border-top: none;
+  }
 }
 
 %card-header {
@@ -33,6 +37,7 @@
   @extend %card-header;
 
   flex: 1 1 auto;
+  border-top: $border $border-color;
 }
 
 %card-meta {

_sass/custom/module.scss

@@ -2,6 +2,7 @@
   @extend %card;
 
   .module-days {
+    border-top: $border $border-color;
     display: grid;
     grid-template-columns: max-content 1fr;
     margin: 0;
@@ -45,6 +46,14 @@
         border-top: $border $border-color;
       }
 
+      &:first-child {
+        border-top: none;
+
+        +.module-event {
+          border-top: none;
+        }
+      }
+
       &::after {
         content: ":";
       }