独立的提示弹窗（类似layer）

function toast(msg, duration) {
    duration = isNaN(duration) ? 1000 : duration;
    var m = document.createElement('div');
    m.innerHTML = msg;
    m.style.cssText = "max-width:60%;min-width: 150px;padding:0 14px;height: 40px;color: rgb(255, 255, 255);line-height: 40px;text-align: center;border-radius:4px;position: fixed;top: 50%;left: 50%;transform: translate(-50%, -50%);z-index: 9999999999;background: rgba(0, 0, 0,.7);font-size: 20px;";
    document.body.appendChild(m);
    setTimeout(function () {
        var d = 0.5;
        m.style.webkitTransition = '-webkit-transform ' + d + 's ease-in, opacity ' + d + 's ease-in';
        m.style.opacity = '0';
        setTimeout(function () {
            document.body.removeChild(m)
        }, d * 1000);
    }, duration);
}

直接可以调用，使用效果如下