manifest.json

{
    "manifest_version": 2,
    "name": "TAS-CAL",
    "version": "2.0",
    "description": "I want Tasukaru.",
    "icons": {
        "16": "icon16.png",
        "48": "icon48.png",
        "128": "icon128.png"
    },

    "content_scripts": [
        {
            "matches": ["https://www.youtube.com/*"],
            "css": ["style_youtube.css"],
            "js": ["jquery-3.4.1.min.js", "content_script_youtube.js"]
        },
        {
            "matches": ["https://www.pixiv.net/*"],
            "css": ["style_pixiv.css"],
            "js": ["jquery-3.4.1.min.js", "content_script_pixiv.js"]
        },
        {
            "matches": ["https://www.nicovideo.jp/*"],
            "css": ["style_niconico.css"]
        }
    ],


    "browser_action": {
        "default_popup": "popup.html"
    },

    "background": {
        "scripts": ["jquery-3.4.1.min.js", "background_youtube.js"],
        "persistent": false
    },

    "permissions": [
    "http://ext.nicovideo.jp/", "http://seiga.nicovideo.jp/"
  ],

    "web_accessible_resources": [
        "/*"
    ]
}