// ==UserScript==
// @name        Click To Top
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  click the arrow-up pic to jump to the top of page.
// @author       kilin
// @include      *
// @match        *
// @grant        none
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';
    window.onload = function(){
        var aNode = document.createElement('a');
        aNode.href = 'javascript:;';
        aNode.id = 'click-to-top';
        aNode.title = 'Click it to go to the top';
        var css = '#click-to-top{ position: fixed; right: 5%; bottom: 20%; opacity: 0.2; z-index: 99; } #click-to-top:hover{ position: fixed; right: 5%; bottom: 20%; opacity: 1; z-index: 99; }';
        //图片相关
        var img = document.createElement('img');
        img.src = 'https://ooo.0o0.ooo/2017/05/23/59245c636b321.png';
        img.style = 'width: 30px; height: 30px;';
        //样式相关
        var style = document.createElement('style');
        if (style.styleSheet) {
            style.styleSheet.cssText = css;
        } else {
            style.appendChild(document.createTextNode(css));
        }
        document.getElementsByTagName('head')[0].appendChild(style);
        aNode.append(img);
        aNode.addEventListener('click', function(){document.documentElement.scrollIntoView();}, false);
        var body = document.querySelector('body');
        body.append(aNode);
    };
})();