Highlight :javascript and :css block in haml in Sublime Text

apply_syntax_config.json

// Sublime 3, comes installed with Rails package. This also provide "Ruby Haml". If you press ctrl + alt + p and type haml you will probably see two Set Syntax: Ruby Haml.

// The best solution for me was also install ApplySyntax and in it's user settings add the following:

// Put your custom syntax rules here:
"syntaxes": [
    {
        // This rule could be incorporated into the next one, but I prefer to be
        // more explicit rather than less
        "name": "Haml/Syntaxes/Ruby Haml",
        "extensions": ["haml"],
        "rules": [
            {"file_name": ".*\\.haml$"}
        ]
    }
]