Fix bug main page

sg-frontend/src/app.css

@@ -54,6 +54,11 @@ h1 {
     text-align: center;
 }
 
+#app {
+    width: 100vw;
+    height: 100vh;
+}
+
 button {
     border-radius: 8px;
     border: 1px solid transparent;

sg-frontend/src/components/SoftwareSelect.svelte

@@ -35,6 +35,7 @@
 		padding: 20px;
 		border-radius: 4px;
 		color: black;
+		margin: auto;
 	}
 
 	label {

sg-frontend/src/routes/SigmaCustom.svelte

@@ -197,13 +197,6 @@
         text-align: center;
     }
 
-    #app {
-        margin: 0 auto;
-        text-align: center;
-        max-width: none;
-        padding: 0 !important;
-    }
-
     html,
     body,
     #sigma-container {