Right at the end of your head tag, you have:
#themeswitcher ul {
list-style: none;
}</style>
</head>
But you opened a comment with <!-- at the start of that style tag. Add --> at the end to close the comment. Like this:
#themeswitcher ul {
list-style: none;
}
--> </style>
</head>
It then works in Safari, and should work in other browsers.