Dark theme minor fixes

This CL improves the dark theme by:
- Styling the original thread box in escalations correctly.
- Styling the bug and cases popup correctly.
- Fixing the star button yellow color in thread lists.

Fixed: twpowertools:126
Bug: twpowertools:138
Change-Id: I92351fe1fc7109abe65a47a9544343accab24090
diff --git a/src/static/css/ccdarktheme.css b/src/static/css/ccdarktheme.css
index ddc4b3f..a35dc0b 100644
--- a/src/static/css/ccdarktheme.css
+++ b/src/static/css/ccdarktheme.css
@@ -16,6 +16,7 @@
   --TWPT-button-background: #3c3e42;
   --TWPT-subtle-button-background: rgba(255, 255, 255, .54);
   --TWPT-input-underline: rgba(255, 255, 255, .28);
+  --TWPT-starred: #fbbc04;
   --TWPT-blue-100: #BBDEFB;
   --TWPT-blue-A100: #82B1FF;
   --TWPT-bad-text: #f6aea9;
@@ -242,7 +243,7 @@
 }
 
 .material-content .action-bar material-button.starred {
-  color: #fbbc04!important;
+  color: var(--TWPT-starred)!important;
 }
 
 /* ec-work-state-picker and ec-symptom-picker */
@@ -310,7 +311,7 @@
  * The following section changes the styles of the checkboxes in thread lists,
  * based in the styles defined in the "Checkbox input" section.
  **/
-ec-thread-summary material-expansionpanel .action material-button,
+ec-thread-summary material-expansionpanel .action material-button:not(.starred),
     ec-thread-list material-checkbox material-icon,
     ec-thread-summary material-expansionpanel .star-button:not(.starred),
     ec-thread-summary material-expansionpanel .mdc-button.mdc-icon-button material-icon {
@@ -318,6 +319,10 @@
   opacity: 1!important;
 }
 
+ec-thread-summary material-expansionpanel .action material-button.starred {
+  color: var(--TWPT-starred)!important;
+}
+
 ec-thread-list material-checkbox material-icon.filled {
   color: #62a5ff!important; /* Custom value to contrast well with the background */
 }
@@ -347,6 +352,20 @@
   border-color: var(--TWPT-subtle-border)!important;
 }
 
+/* "Original thread" box inside escalations */
+sc-tailwind-thread-question-thread-summary .scTailwindThreadQuestionThreadsummarythread-summary {
+  background: var(--TWPT-active-background)!important;
+  border-color: var(--TWPT-card-border)!important;
+}
+
+sc-tailwind-thread-question-thread-summary .scTailwindThreadQuestionThreadsummarydetails {
+  color: var(--TWPT-secondary-text)!important;
+}
+
+sc-tailwind-thread-question-thread-summary .scTailwindThreadQuestionThreadsummarytitle {
+  color: var(--TWPT-primary-text)!important;
+}
+
 /* Review bar shown above the main message or replies */
 ec-review-bar {
   background-color: var(--TWPT-active-background)!important;
@@ -2260,6 +2279,15 @@
   border-bottom-color: var(--TWPT-subtle-border)!important;
 }
 
+/* Bug/case links dialog */
+.bug-case-links-dialog material-button.add-button {
+  color: var(--TWPT-blue-A100)!important;
+}
+
+ec-bug-case-link material-button {
+  color: var(--TWPT-secondary-text)!important;
+}
+
 /* Reply button */
 material-fab.reply-button,
     material-fab.reply-fab {