Added some button adjustments

lib/pages/heart_rate/heart_rate_screen.dart

@@ -9,7 +9,9 @@ class HeartRateScreen extends StatelessWidget {
       appBar: AppBar(
         title: Text('Heart Rate Detector'),
       ),
-      body: Column(
+      body: Container(
+        color: Colors.white,
+        child: Column(
           children: [
             Padding(
               padding: const EdgeInsets.all(8.0),
@@ -19,14 +21,29 @@ class HeartRateScreen extends StatelessWidget {
             Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-              ElevatedButton(
+                Padding(
+                  padding: const EdgeInsets.fromLTRB(8,70,8,8),
+                  child: SizedBox(
+                    height: 70,
+                    width: 350,
+                    child: ElevatedButton(
+                      style: ElevatedButton.styleFrom(
+                          primary: Colors.red[300],
+                          elevation: 15,
+                          shape: RoundedRectangleBorder(
+                              borderRadius: BorderRadius.circular(12)
+                          )
+                      ),
                       onPressed: () => Navigator.push(context, MaterialPageRoute(builder: (context) => HomePage(),)),
                       child: Text('Measure Heart Rate'),
                     ),
+                  ),
+                ),
               ],
             ),
           ],
         ),
+      ),
     );
   }
 }

lib/pages/mask_detect/invoker.dart

@@ -11,7 +11,9 @@ class invoker extends StatelessWidget {
       appBar: AppBar(
         title: Text('Face Mask Detector'),
       ),
-      body: Column(
+      body: Container(
+        color: Colors.white,
+        child: Column(
           children: [
             Padding(
               padding: const EdgeInsets.all(8.0),
@@ -21,14 +23,29 @@ class invoker extends StatelessWidget {
             Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-              ElevatedButton(
+                Padding(
+                  padding: const EdgeInsets.fromLTRB(8,70,8,8),
+                  child: SizedBox(
+                    height: 70,
+                    width: 350,
+                    child: ElevatedButton(
+                      style: ElevatedButton.styleFrom(
+                          primary: Colors.blue[300],
+                          elevation: 15,
+                          shape: RoundedRectangleBorder(
+                              borderRadius: BorderRadius.circular(12)
+                          )
+                      ),
                       onPressed: () => invokeCamera(),
                       child: Text('Detect Mask'),
                     ),
+                  ),
+                ),
               ],
             ),
           ],
         ),
+      ),
     );
   }