diff --git a/style.css b/style.css
index b2e9ce2..b19181f 100644
--- a/style.css
+++ b/style.css
@@ -8,6 +8,14 @@ body {
 
 #v5shoutbox {
   height: 100vh;
+  --shoutbox-color: #333333;
+  --shoutbox-border-color: rgba(0, 0, 0, .15);
+  --shoutbox-header-bg: #ececec;
+  --shoutbox-link-color: #ce1919;
+  --shoutbox-tab-activity-color: #ce1919;
+  --shoutbox-tab-current-color: #097ba1;
+  --shoutbox-message-date-color: #949494;
+  --shoutbox-message-author-color: #777777;
 }
 
 /* Shoutbox-only style */
@@ -16,15 +24,15 @@ body {
   display: flex;
   flex-flow: column;
   font-size: 12px;
-  color: #333;
+  color: var(--shoutbox-color);
 }
 
 #v5shoutbox header {
   height: 2em;
   display: flex;
   align-items: center;
-  background: #ececec;
-  border: 1px solid rgba(0, 0, 0, .15);
+  background: var(--shoutbox-header-bg);
+  border: 1px solid var(--shoutbox-border-color);
   gap: 4px;
   padding: 0 4px;
 }
@@ -33,11 +41,11 @@ body {
 }
 
 #v5shoutbox a {
-  color: #ce1919;
+  color: var(--shoutbox-link-color);
 }
 
 #v5shoutbox a:active, #v5shoutbox a:hover, #v5shoutbox a:focus {
-  color: #ce1919;
+  color: var(--shoutbox-link-color);
   text-decoration: underline;
   outline: 0;
 }
@@ -52,7 +60,7 @@ body {
 }
 
 #v5shoutbox .channel-buttons button {
-  border: 1px solid rgba(0, 0, 0, .15);
+  border: 1px solid var(--shoutbox-border-color);
   border-radius: 3px;
 }
 
@@ -71,10 +79,10 @@ body {
 }
 
 #v5shoutbox .channel-buttons *.bg-activity {
-  color: #ce1919;
+  color: var(--shoutbox-tab-activity-color);
 }
 #v5shoutbox .channel-buttons *.current {
-  color: #097ba1;
+  color: var(--shoutbox-tab-current-color);
 }
 
 #v5shoutbox .channels {
@@ -92,7 +100,7 @@ body {
 #v5shoutbox .channels .login-form {
   height: 30%;
   width: 40%;
-  border: 1px solid rgba(0, 0, 0, .15);
+  border: 1px solid var(--shoutbox-border-color);
   padding: 0 2%;
   display: flex;
   flex-flow: column;
@@ -110,13 +118,13 @@ body {
 #v5shoutbox .message {
   line-height: 1.5;
   display: flex;
-  border-top: 1px solid rgba(0, 0, 0, .15);
+  border-top: 1px solid var(--shoutbox-border-color);
 }
 
 #v5shoutbox .message .message-author {
   margin-right: 6px;
   font-size: 0.9em;
-  color: #777777;
+  color: var(--shoutbox-message-author-color);
   min-width: 70px;
   text-align: right;
   flex-shrink: 0;
@@ -131,7 +139,7 @@ body {
 }
 
 #v5shoutbox .message .message-date {
-  color: #949494;
+  color: var(--shoutbox-message-date-color);
   margin-left: 5px;
   font-size: 0.8em;
   order: 3;
@@ -144,7 +152,7 @@ body {
 
 #v5shoutbox .shoutbox-form input[type=text] {
   width: 95%;
-  border: 1px solid rgba(0, 0, 0, .15);
+  border: 1px solid var(--shoutbox-border-color);
   border-left: 0;
   border-right: 0;
   border-radius: 0;
@@ -152,6 +160,6 @@ body {
 
 #v5shoutbox .shoutbox-form button[type=submit] {
   width: 5%;
-  border: 1px solid rgba(0, 0, 0, .15);
+  border: 1px solid var(--shoutbox-border-color);
   border-radius: 0;
 }