Add a dark mode, fixes #7

html/content.css

@@ -10,6 +10,11 @@ body {
     font-weight: lighter;
 }
 
+body.nightmode {
+    background: #111;
+    color: #aaa;
+}
+
 h1 {
     font-weight: lighter;
     font-size: 1.4em;
@@ -24,6 +29,10 @@ h1 {
     display: block;
 }
 
+.nightmode #date {
+    border-bottom-color: #333;
+}
+
 .starred:after {
     content: "*";
 }
@@ -35,6 +44,10 @@ header p {
     font-size: 0.8em;
 }
 
+.nightmode header p {
+    color: #888;
+}
+
 a {
     color: inherit;
     text-decoration: none;