Update style.css

style.css

@@ -4,6 +4,69 @@
     margin: 0;
     font-family: sans-serif;
 }
+body {
+  min-height: 100vh;
+  min-height: -webkit-fill-available;
+}
+
+html {
+  height: -webkit-fill-available;
+}
+
+main {
+  height: 100vh;
+  height: -webkit-fill-available;
+  max-height: 100vh;
+  overflow-x: auto;
+  overflow-y: hidden;
+}
+
+.dropdown-toggle { outline: 0; }
+
+.btn-toggle {
+  padding: .25rem .5rem;
+  font-weight: 600;
+  color: var(--bs-emphasis-color);
+  background-color: transparent;
+}
+.btn-toggle:hover,
+.btn-toggle:focus {
+  color: rgba(var(--bs-emphasis-color-rgb), .85);
+  background-color: var(--bs-tertiary-bg);
+}
+
+.btn-toggle::before {
+  width: 1.25em;
+  line-height: 0;
+  content: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='rgba%280,0,0,.5%29' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M5 14l6-6-6-6'/%3e%3c/svg%3e");
+  transition: transform .35s ease;
+  transform-origin: .5em 50%;
+}
+
+[data-bs-theme="dark"] .btn-toggle::before {
+  content: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='rgba%28255,255,255,.5%29' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M5 14l6-6-6-6'/%3e%3c/svg%3e");
+}
+
+.btn-toggle[aria-expanded="true"] {
+  color: rgba(var(--bs-emphasis-color-rgb), .85);
+}
+.btn-toggle[aria-expanded="true"]::before {
+  transform: rotate(90deg);
+}
+
+.btn-toggle-nav a {
+  padding: .1875rem .5rem;
+  margin-top: .125rem;
+  margin-left: 1.25rem;
+}
+.btn-toggle-nav a:hover,
+.btn-toggle-nav a:focus {
+  background-color: var(--bs-tertiary-bg);
+}
+
+.scrollarea {
+  overflow-y: auto;
+}
 
 html,
 body {