diff --git a/timetracker.c b/timetracker.c
index 70a4c98..4d225e3 100644
--- a/timetracker.c
+++ b/timetracker.c
@@ -1,10 +1,10 @@
 //////////////////////////////////////////////////////////////////////////
 // TODOS:                                                               //
 // [X] Lower the the time text lower below the activity title.          //
-// [ ] On timeline, hower, display additional activity chunk info.      //
+// [X] On timeline, hower, display additional activity chunk info.      //
 // [X] Display distribution timeline below the activity line.           //
 // [ ] Better file save error handling.                                 //
-// [ ] Make Linux and MacOS libraries for RayLib; store locally.        //
+// [X] Make Linux and MacOS libraries for RayLib; store locally.        //
 //////////////////////////////////////////////////////////////////////////
 
 
@@ -78,9 +78,7 @@ U64 now()
     return (U64)time(NULL);
 }
 
-B32 activity_button(Rectangle rect, char *title, char *subtitle,
-                    F32 font_size, Color font_color,
-                    Color background_color)
+B32 activity_button(Rectangle rect, char *title, char *subtitle, F32 font_size, Color font_color, Color background_color)
 {
     B32 button_pressed = false;
 
@@ -274,7 +272,7 @@ void save_activities(FILE *f, char *file_path, U32 current_activity, activity *a
     // NOTE: We use "w+" because want to clear file contents before the next write.
     f = freopen(file_path, "w+", f);
     if(f) {
-        char write_buffer[128];
+        local_persist char write_buffer[128];
         for(U32 i = 0; i <= current_activity; i++) {
             snprintf(write_buffer, sizeof(write_buffer), "%s %llu %llu\n", activity_type_string_representation[activities[i].type], activities[i].began, activities[i].ended);
 
@@ -290,6 +288,10 @@ void save_activities(FILE *f, char *file_path, U32 current_activity, activity *a
     }
 }
 
+#define ACTIVE_FPS 60
+#define IDLE_FPS 1
+#define IDLE_TIME 5 /* seconds */
+
 int main(int argc, char *argv[])
 {
     // TODO: Move into global state.
@@ -321,7 +323,7 @@ int main(int argc, char *argv[])
     InitWindow(state.window_w, state.window_h, "Time Tracker");
     SetWindowState(FLAG_MSAA_4X_HINT|FLAG_WINDOW_RESIZABLE);
 
-    SetTargetFPS(30);
+    SetTargetFPS(ACTIVE_FPS);
 
     state.font = LoadFontFromMemory(".ttf", opensans_ttf, opensans_ttf_len, 96, NULL, 0);
     if(!IsFontValid(state.font)) {
@@ -338,11 +340,20 @@ int main(int argc, char *argv[])
 
     state.font_size = 30;
 
-    //DisableEventWaiting();
-    //EnableEventWaiting();
+    double last_input_s = now();
+
     while(!WindowShouldClose()) {
         U64 now_s = now();
 
+        if(GetMouseDelta().x != 0 || GetMouseDelta().y != 0 || GetMouseWheelMove() != 0 || GetKeyPressed() != 0 || IsMouseButtonPressed(MOUSE_LEFT_BUTTON) || IsMouseButtonPressed(MOUSE_RIGHT_BUTTON)) {
+            last_input_s = now_s;
+            SetTargetFPS(ACTIVE_FPS);
+        }
+
+        if(now_s - last_input_s > IDLE_TIME) {
+            SetTargetFPS(IDLE_FPS);
+        }
+
         if(now_s >= upper_bound_s) {
             t = today();
             ts = start_of_day_seconds(t);