[improvement] Add button style for emails

Author: sman591

app/views/layouts/mailer.html.erb

@@ -146,45 +146,20 @@
       }
 
       /* -------------------------------------
-          BUTTONS
+          BUTTON
       ------------------------------------- */
-      .btn {
-        box-sizing: border-box;
-        width: 100%; }
-        .btn > tbody > tr > td {
-          padding-bottom: 15px; }
-        .btn table {
-          width: auto;
-      }
-        .btn table td {
-          background-color: #ffffff;
-          border-radius: 5px;
-          text-align: center;
-      }
-        .btn a {
-          background-color: #ffffff;
-          border: solid 1px #3498db;
-          border-radius: 5px;
-          box-sizing: border-box;
-          color: #3498db;
-          cursor: pointer;
-          display: inline-block;
-          font-size: 14px;
-          font-weight: bold;
-          margin: 0;
-          padding: 12px 25px;
-          text-decoration: none;
-          text-transform: capitalize;
-      }
-
-      .btn-primary table td {
-        background-color: #3498db;
-      }
-
-      .btn-primary a {
-        background-color: #3498db;
-        border-color: #3498db;
+      .button {
+        background: #3498db;
+        border: 1px solid #3498db;
+        display: inline-block;
+        padding: 0.6em 1.3em;
+        font-size: 15px;
+        letter-spacing: 0.07em;
         color: #ffffff;
+        font-weight: 600;
+        margin: 0.25em 0 0.25em;
+        text-decoration: none;
+        border-radius: 3px;
       }
 
       /* -------------------------------------