This is a small note about how we can change the class attribute of body tag using typoscript.
# bodyTag
page.bodyTag >page.bodyTagCObject = TEXT
page.bodyTagCObject.data = levelfield:-1 :, myfeildname, slide
page.bodyTagCObject.wrap = <body class="myclass_|">
Well here I am using a custom field added to pages table. If you wish to use the page id you may try using this code below:
# bodyTag
page.bodyTag >
page.bodyTagCObject = TEXT
page.bodyTagCObject.data = field:id
page.bodyTagCObject.wrap = <body class="myclass_|">
This way you may expect body tags like:
<body class="myclass_1">
<body class="myclass_2">