Fix: Sidebar stays expanded on option selection

coscine/issues#662

src/assets/css/_custom.css

+:root {
+  --navbar-height: 2.5rem;
+  --loading-indicator-height: 3px;
+  --loading-indicator-margin: 1rem;
+  --sidebar-offset-top: calc(var(--navbar-height) + var(--loading-indicator-height) + var(--loading-indicator-margin));
+  --sidebar-height: calc(100vh - var(--navbar-height) - calc(var(--loading-indicator-height) + var(--loading-indicator-margin)))
+}
\ No newline at end of file