minor improvements

src/components/notifications/notifications.scss

@@ -36,7 +36,7 @@
     width: var(--__panel-heading-height);
     height: var(--__panel-heading-height);
     margin: calc(-1 * var(--panel-heading-height-padding)) 0;
-    margin-right: -0.5em;
+    margin-right: calc(-1 * var(--__panel-heading-gap));
 
     > button {
       box-sizing: border-box;

src/components/timeline/timeline.scss

@@ -19,7 +19,7 @@
     width: var(--__panel-heading-height);
     height: var(--__panel-heading-height);
     margin: calc(-1 * var(--panel-heading-height-padding)) 0;
-    margin-right: -0.5em;
+    margin-right: calc(-1 * var(--__panel-heading-gap));
 
     > button {
       box-sizing: border-box;
@@ -38,7 +38,7 @@
     align-self: stretch;
     text-align: center;
     width: var(--__panel-heading-height);
-    margin-right: -0.5em;
+    margin-right: calc(-1 * var(--__panel-heading-gap));
 
     svg {
       font-size: 1.2em;

src/components/timeline/timeline.vue

@@ -5,9 +5,11 @@
         v-if="!embedded"
         :timeline-name="timelineName"
       />
-      <div class="timeline-header-button">
+      <div
+        class="timeline-header-button"
+        v-if="showScrollTop && !embedded"
+      >
         <button
-          v-if="showScrollTop"
           class="button-unstyled scroll-to-top-button"
           type="button"
           @click="scrollToTop"

src/panel.scss

@@ -45,6 +45,7 @@
 .panel-heading,
 .panel-footer {
   --panel-heading-height-padding: 0.6em;
+  --__panel-heading-gap: 0.5em;
   --__panel-heading-height: 3.2em;
   --__panel-heading-height-inner: calc(var(--__panel-heading-height) - 2 * var(--panel-heading-height-padding, 0));
 
@@ -54,7 +55,7 @@
   grid-auto-flow: column;
   grid-template-columns: minmax(50%, 1fr);
   grid-auto-columns: auto;
-  grid-column-gap: 0.5em;
+  grid-column-gap: var(--__panel-heading-gap);
   flex: none;
   background-size: cover;
   padding: var(--panel-heading-height-padding);