getComputedStyle.js

// example: 
// phantomjs getComputedStyle.js "http://www.iqiyi.com/" ".usrTxGeneral-box_hover" "position,display,visibility,overflow"

var TIMEOUT = 60 * 1000;
 
var webPage = require('webpage');
var system = require('system');
 
var page = webPage.create();
page.settings.loadImages = false;
 
var args = system.args;
if (args.length < 4) {
  console.log('usage: phantomjs getComputedStyle.js url elementSelector styleNames');
  phantom.exit();
}
var url = args[1];
var elementSelector = args[2];
var styleNames = args[3].split(',');
 
var getStyles = function(status) {
  var styleValues = page.evaluate(function(elementSelector, styleNames) {
    var element = document.querySelector(elementSelector);
    var computedStyle = window.getComputedStyle(element);
    var styleValues = [];
    styleNames.forEach(function(styleName) {
      styleValues.push(computedStyle.getPropertyValue(styleName));
    });
    return styleValues;
  }, elementSelector, styleNames);
  console.log(styleValues.join('\t'));
  phantom.exit();
};

page.open(url, getStyles);
setTimeout(getStyles, TIMEOUT);