[libadwaita/wip/exalm/borders: 36/40] stylesheet: Replace scrollbar border with an inset box-shadow

[Alexander Mikhaylenko <alexm src gnome org>]

commit 9ec38541dfe2fadab865618d479c04a5928a7382
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Jul 26 21:15:47 2021 +0500

    stylesheet: Replace scrollbar border with an inset box-shadow
    
    Avoid problems later when $border_color will be transparent.

 src/stylesheet/widgets/_scrolling.scss | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/src/stylesheet/widgets/_scrolling.scss b/src/stylesheet/widgets/_scrolling.scss
index 8d18e64f..172fee64 100644
--- a/src/stylesheet/widgets/_scrolling.scss
+++ b/src/stylesheet/widgets/_scrolling.scss
@@ -8,10 +8,10 @@ scrollbar {
   transition: $_scrollbar_transition;
 
   // scrollbar border
-  &.top { border-bottom: 1px solid $borders_color; }
-  &.bottom { border-top: 1px solid $borders_color; }
-  &.left { border-right: 1px solid $borders_color; }
-  &.right { border-left: 1px solid $borders_color; }
+  &.top    { box-shadow: inset 0 -1px $borders_color; padding-bottom: 1px; }
+  &.bottom { box-shadow: inset 0  1px $borders_color; padding-top:    1px; }
+  &.left   { box-shadow: inset -1px 0 $borders_color; padding-right:  1px; }
+  &.right  { box-shadow: inset  1px 0 $borders_color; padding-left:   1px; }
 
   > range > trough > slider {
     min-width: $_slider_width;
@@ -43,7 +43,7 @@ scrollbar {
 
   &.overlay-indicator {
     &:not(.dragging):not(.hovering) {
-      border-color: transparent;
+      box-shadow: none;
       opacity: 0.4;
       background-color: transparent;