how-to-clear/book.json

{
    "gitbook": ">=3.0.0",
    "plugins": ["autocover", "download-pdf-link"],
    "title": "How to Clear",
    "author": "T",
    "pluginsConfig": {
        "autocover": {
            "font": {
                "size": null,
                "family": "Impact",
                "color": "#FFF"
            },
            "size": {
                "w": 1800,
                "h": 2360
            },
            "background": {
                "color": "#09F"
            }
        }
    }
}