Dark theme: fix forum checkboxes in the drawer

Checkboxes are now shown in their corresponding color, and no longer all
in white.

Fixed: twpowertools:41
Change-Id: Ide1c2ea00a0486d67b3c7d00cbbf2fd1e4a88700
diff --git a/src/static/css/ccdarktheme.css b/src/static/css/ccdarktheme.css
index 1ee5e11..3b580e7 100644
--- a/src/static/css/ccdarktheme.css
+++ b/src/static/css/ccdarktheme.css
@@ -829,14 +829,14 @@
   border-color: var(--TWPT-input-underline)!important;
 }
 
-/* Checkbox input */
-material-checkbox material-icon,
-    material-checkbox .content {
+/* Checkbox input (except for forum checkboxes in the drawer) */
+material-checkbox material-icon:not(ec-forum-drawer-item material-icon),
+    material-checkbox .content:not(ec-forum-drawer-item material-icon) {
   color: var(--TWPT-secondary-text)!important;
 }
 
 /* .gm-icons is added by the SMEI_GOOGLE_MATERIAL_ICONS experiment. */
-material-checkbox material-icon.filled {
+material-checkbox material-icon.filled:not(ec-forum-drawer-item material-icon) {
   color: var(--TWPT-blue-A100)!important;
 }