shrink standalone osd buttons

common/gtk-3.0/3.20/gtk-dark.css

@@ -295,8 +295,9 @@ button {
     background-color: rgba(53, 57, 69, 0.95);
     border-color: rgba(35, 38, 46, 0.95); }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/gtk-darker.css

@@ -294,8 +294,9 @@ button {
     background-color: rgba(53, 57, 69, 0.95);
     border-color: rgba(35, 38, 46, 0.95); }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/gtk-solid-dark.css

@@ -295,8 +295,9 @@ button {
     background-color: #353945;
     border-color: #23262e; }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/gtk-solid-darker.css

@@ -294,8 +294,9 @@ button {
     background-color: #353945;
     border-color: #23262e; }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/gtk-solid.css

@@ -294,8 +294,9 @@ button {
     background-color: #353945;
     border-color: #23262e; }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/gtk.css

@@ -294,8 +294,9 @@ button {
     background-color: rgba(53, 57, 69, 0.95);
     border-color: rgba(35, 38, 46, 0.95); }
     button.osd.image-button {
-      min-height: 48px;
-      min-width: 48px; }
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px; }
     button.osd:hover {
       color: #5294E2; }
     button.osd:active, button.osd:checked {

common/gtk-3.0/3.20/sass/_common.scss

@@ -362,8 +362,9 @@ button {
     border-color: darken($osd_bg_color, 8%);
 
     &.image-button {
-      min-height: 48px;
-      min-width: 48px;
+      padding: 0;
+      min-height: 36px;
+      min-width: 36px;
     }
 
     &:hover { color: $selected_bg_color; }