Make the login links easier to see

Changed the color of the three links under the login box to be easier to
read.  Also removed the underline unless it's being hovered over.

static/css/site.css

@@ -2,6 +2,7 @@
     --var-border: 1px solid #606060;
     --var-border-radius: 5px;
     --var-message-color: #f4f4f4;
+    --var-link-color: #a9c8c3;
     --var-contrast-color: #1bf7ec;
     --var-background-color: #0F0F11;
     --var-popout-color: #393940;
@@ -269,6 +270,15 @@ input[type=text] {
     margin: 5px auto;
 }
 
+#joinbox a {
+    text-decoration: none;
+    color: var(--var-link-color);
+}
+
+#joinbox a:hover {
+    text-decoration: underline;
+}
+
 #chat {
     display: grid;
     grid-template-rows: 1.5em min-content 1fr 6em 2.5em 1em;