Expand the timeline to 100% height in panel mode.

src/scss/card.scss

@@ -16,6 +16,11 @@
 :host([dark]) {
   filter: brightness(75%);
 }
+:host([panel]) {
+  // Card always extends to the full allowed height in panel mode (in non-panel
+  // mode this would cause the card to expand to the height of a column).
+  height: 100%;
+}
 
 div.main {
   position: relative;

src/scss/thumbnail-feature-event.scss

@@ -12,6 +12,10 @@ ha-icon {
   // Safari will occasionally not load thumbnails correctly with display block.
   display: inline-block;
 
+  // Ensure no whitespace around img with inline-block display.
+  vertical-align: top;
+  margin: 0;
+
   border-radius: var(--frigate-card-css-border-radius, var(--ha-card-border-radius, 4px));
 
   max-width: var(--frigate-card-thumbnail-size);

src/scss/timeline-core.scss

@@ -12,6 +12,11 @@
   position: relative;
 }
 
+:host(:not([mini])) {
+  // Timeline covers 100% of the parent unless it's in mini-mode.
+  height: 100%;
+}
+
 frigate-card-thumbnail {
   height: var(--frigate-card-thumbnail-size);
   width: var(--frigate-card-thumbnail-size);