P4TB-390: Provide fallback colour for privacy status dialogue fields so it works better in TB 68.

addon/content/dialogs/common.css

@@ -37,8 +37,8 @@
 
 .trustwords {
     text-transform: uppercase;
-    background-color: var(--field-background-color);
-    border: 1px solid var(--field-border-color);
+    background-color: var(--field-background-color, white);
+    border: 1px solid var(--field-border-color, lightgray);
     border-radius: 2px;
     color: var(--field-text-color);
     padding: 0.5em;

addon/content/dialogs/options.css

@@ -48,7 +48,7 @@ textarea#disclaimer {
 
 #accountlist {
     /* background-color: -moz-Dialog; */
-    border: 1px solid var(--field-border-color);
+    border: 1px solid var(--field-border-color, ThreeDFace);
     overflow: auto;
 }
 

addon/content/dialogs/privacy_status.css

@@ -31,12 +31,13 @@
 
 .tabs button {
     float: left;
-    border: 1px solid var(--field-border-color);
+    border: 1px solid var(--field-border-color, lightgray);
     border-bottom: none;
     cursor: pointer;
     margin-bottom: 0;
     padding: 4px 6px;
     transition: 0.3s;
+    font-size: 1em;
 }
 
 :root[lwt-tree-brighttext] .tabs button {
@@ -44,13 +45,13 @@
 }
 
 .tabs button.active {
-    background-color: var(--field-background-color);
+    background-color: var(--field-background-color, white);
 }
 
 .fpr {
     white-space: pre;
-    background-color: var(--field-background-color);
-    border: 1px solid var(--field-border-color);
+    background-color: var(--field-background-color, white);
+    border: 1px solid var(--field-border-color, lightgray);
     border-radius: 2px;
     color: var(--field-text-color);
     padding: 0.5em;

addon/content/dialogs/privacy_status.xhtml

@@ -30,11 +30,11 @@
           <html:span data-field="full-name">full-name</html:span>
         </html:div>
         <html:div id="Tabs" class="tabs">
-          <html:button id="buttonTrustwords" class="tablinks"
+          <html:button id="buttonTrustwords"
                        data-localekey="privacyStatusTrustwords"
                        onclick="pEpPrivacyStatus.openTab(event, 'Trustwords')">
           </html:button>
-          <html:button id="buttonFingerprint" class="tablinks"
+          <html:button id="buttonFingerprint"
                        data-localekey="privacyStatusFingerprint"
                        onclick="pEpPrivacyStatus.openTab(event, 'Fingerprint')">
           </html:button>