diff --git a/web/src/components/SessionList.tsx b/web/src/components/SessionList.tsx
index c5ca3697..4849ea1e 100644
--- a/web/src/components/SessionList.tsx
+++ b/web/src/components/SessionList.tsx
@@ -290,11 +290,11 @@ export function SessionList(props: {
                 {groups.map((group) => {
                     const isCollapsed = isGroupCollapsed(group)
                     return (
-                        <div key={group.directory} className="border-b border-[var(--app-divider)]">
+                        <div key={group.directory}>
                             <button
                                 type="button"
                                 onClick={() => toggleGroup(group.directory, isCollapsed)}
-                                className="flex w-full items-center gap-2 px-3 py-2 text-left transition-colors hover:bg-[var(--app-secondary-bg)]"
+                                className="sticky top-0 z-10 flex w-full items-center gap-2 px-3 py-2 text-left bg-[var(--app-bg)] border-b border-[var(--app-divider)] transition-colors hover:bg-[var(--app-secondary-bg)]"
                             >
                                 <ChevronIcon
                                     className="h-4 w-4 text-[var(--app-hint)]"
@@ -310,7 +310,7 @@ export function SessionList(props: {
                                 </div>
                             </button>
                             {!isCollapsed ? (
-                                <div className="flex flex-col divide-y divide-[var(--app-divider)]">
+                                <div className="flex flex-col divide-y divide-[var(--app-divider)] border-b border-[var(--app-divider)]">
                                     {group.sessions.map((s) => (
                                         <SessionItem
                                             key={s.id}