fix(page): keep search bar within viewport on mobile

src/views/SearchView.vue

@@ -207,6 +207,7 @@ onMounted(() => {
 
 .search-input {
   flex: 1;
+  min-width: 0;
   padding: 10px 14px;
   border: 1px solid var(--ac-input-border);
   border-radius: var(--song-radius-l);
@@ -222,7 +223,9 @@ onMounted(() => {
 }
 
 .search-btn {
-  padding: 10px 22px;
+  flex-shrink: 0;
+  white-space: nowrap;
+  padding: 10px 18px;
   border: none;
   border-radius: var(--song-radius-l);
   background: var(--ac-primary-strong);