[gnome-calculator] style: Drop padding around the display

[Robert Roth <robertroth src gnome org>]

commit 0f62ed65d804bad3b5782515c10bacd83cb86f34
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Fri Jan 10 15:19:15 2020 +0100

    style: Drop padding around the display
    
    This maximizes the available space and better visualy split the display
    from the buttons. It modernizes the style a bit.

 src/calculator.css      | 27 +++++++++++++++++++++++++--
 src/math-converter.vala |  4 ++++
 2 files changed, 29 insertions(+), 2 deletions(-)
---
diff --git a/src/calculator.css b/src/calculator.css
index a97b1e8c..3291cae5 100644
--- a/src/calculator.css
+++ b/src/calculator.css
@@ -15,10 +15,33 @@
   padding: 0px 12px;
 }
 
-window > grid {
-  padding: 12px;
+window > grid > .frame {
+  border-left-width: 0;
+  border-right-width: 0;
 }
 
+/* It isn't first in keyboard mode */
+window > grid > .frame:first-child {
+  border-top-width: 0;
+}
+
+/* It is last in keyboard mode */
+window > grid > .frame:last-child {
+  border-bottom-width: 0;
+}
+
+window > grid > box {
+  padding-left: 12px;
+  padding-right: 12px;
+  padding-bottom: 12px;
+}
+
+/* This affects the keyboard mode */
+window > grid > mathconverter {
+  padding-left: 12px;
+  padding-right: 12px;
+  padding-top: 12px;
+}
 
 .math-buttons button {
 }
diff --git a/src/math-converter.vala b/src/math-converter.vala
index ee335891..802a069a 100644
--- a/src/math-converter.vala
+++ b/src/math-converter.vala
@@ -29,6 +29,10 @@ public class MathConverter : Gtk.Grid
 
     public signal void changed ();
 
+    static construct {
+        set_css_name ("mathconverter");
+    }
+
     construct
     {
         from_combo.set_cell_data_func (from_renderer, from_cell_data_func);