improve font specification in CSS

server-extras/error.css

@@ -4,7 +4,7 @@
 }
 
 body {
-    font-family: "Source Code Pro";
+    font-family: "Source Code Pro", "Menlo", "Consolas", monospace;
     padding: 1em;
 }
 
@@ -24,7 +24,7 @@ pre {
     padding: 0.8em;
     line-height: 1.5;
     font-size: 80%;
-    font-family: "Source Code Pro";
+    font-family: "Source Code Pro", "Menlo", "Consolas", monospace;
     white-space: pre-wrap;       
     overflow: auto;
     max-height: 240px;

server-extras/poldash.css

@@ -5,7 +5,7 @@
 
 body {
     padding: 1em;
-    font-family: "Source Code Pro";
+    font-family: "Source Code Pro", "Menlo", "Consolas", monospace;
 }
 
 div#pollen-logo {
@@ -30,7 +30,7 @@ tr > td:first-child {
 }
 
 th, tr > td:first-child {
-    font-family: "Source Code Pro";
+    font-family: "Source Code Pro", "Menlo", "Consolas", monospace;
     background: #f6f6f6;
     text-align: left; 
 }
@@ -92,7 +92,7 @@ a:active {
 
 
 tt {
-    font-family: "Source Code Pro";
+    font-family: "Source Code Pro", "Menlo", "Consolas", monospace;
     font-size: 100%;
     white-space: pre-wrap;
 }