Remove unnecessary spacer and adjust margins in the hosts manager UI for improved layout consistency.

src/hosts/tui/app.py

@@ -71,9 +71,6 @@ class HostsManagerApp(App):
         yield Header()
         yield Footer()
 
-        # Spacer
-        yield Static("", classes="spacer")
-
         # Search bar above the panes
         with Horizontal(classes="search-container") as search_container:
             search_container.border_title = "Search"

src/hosts/tui/styles.py

@@ -11,7 +11,8 @@ HOSTS_MANAGER_CSS = """
     border: round $primary;
     height: 3;
     padding: 0 1;
-    margin-bottom: 1;
+    margin-top: 1;
+    margin-bottom: 0;
 }
 
 .search-input {
@@ -21,20 +22,21 @@ HOSTS_MANAGER_CSS = """
 }
 
 .hosts-container {
-    height: 1fr;
+    # height: 1fr;
+    margin-top: 0;
 }
 
 .left-pane {
     width: 60%;
     border: round $primary;
-    margin: 1;
+    margin: 0;
     padding: 1;
 }
 
 .right-pane {
     width: 40%;
     border: round $primary;
-    margin: 1;
+    margin: 0;
     padding: 1;
 }