'use strict'
;(function (win, doc) {
    // 设计稿宽度
    var designWidth = 720
    // 屏幕旋转事件：orientationchange
    var resizeEvt   = 'orientationchange' in win ? 'orientationchange' : 'resize'
    // 重计算方法
    var recalc      = function () {
        var docEl       = doc.documentElement
        // window.orientation 已从Web标准中删除
        var orientation = (win.screen.orientation && win.screen.orientation.angle) || win.orientation
        var clientWidth = docEl.clientWidth
        if (orientation === 0 || orientation === 180) {
            // 竖屏 portrait
            clientWidth = docEl.clientWidth
        } else if (orientation === 90 || orientation === - 90) {
            // 横屏 landscape
            clientWidth = docEl.clientHeight
        }
        // 以设计稿宽度为最大限制
        clientWidth          = clientWidth > designWidth ? designWidth : clientWidth
        var fontSize         = clientWidth / designWidth * 100
        docEl.style.fontSize = fontSize + 'px'
    }
    // 绑定事件
    win.addEventListener(resizeEvt, recalc, false)
    doc.addEventListener('DOMContentLoaded', recalc, false)
})(window, document)