[gtksourceview] map: tweak styling of slider over map

[Christian Hergert <chergert src gnome org>]

commit 60e27b4349d9c1ba0f818e367e0574d52de91933
Author: Christian Hergert <chergert redhat com>
Date:   Sat Jun 19 12:50:39 2021 -0700

    map: tweak styling of slider over map

 gtksourceview/gtksourcemap.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)
---
diff --git a/gtksourceview/gtksourcemap.c b/gtksourceview/gtksourcemap.c
index 37ee37c5..7207b4bf 100644
--- a/gtksourceview/gtksourcemap.c
+++ b/gtksourceview/gtksourcemap.c
@@ -400,19 +400,14 @@ gtk_source_map_rebuild_css (GtkSourceMap *map)
        if (background != NULL)
        {
                g_string_append_printf (gstr,
-                                       "slider {\n"
-                                       "\tbackground-color: alpha(%s,.3);\n"
-                                       "\tborder-radius: 3px;\n"
-                                       "\tborder: 1px solid alpha(shade(%s,.9),.3);\n"
-                                       "\tmargin-top: 1px;\n"
-                                       "\tmargin-bottom: 1px;\n"
+                                       "slider {"
+                                       " background-color: alpha(%s,.25);"
+                                       " transition-duration: 300ms;"
                                        "}\n"
-                                       "slider:hover {\n"
-                                       "\tbackground-color: alpha(%s,.5);\n"
+                                       "slider:hover {"
+                                       " background-color: alpha(%s,.35);"
                                        "}\n",
-                                       background,
-                                       background,
-                                       background);
+                                       background, background);
        }
 
        g_free (background);