.header {
    height: 280px;
    background-image: url(https://files.cnblogs.com/files/Unknw/cal1.bmp);
    background-repeat: no-repeat;
    background-position: left;
    border: 0px dotted #000000;
    padding-left: 0px;
    padding-top: 0px;
    margin-left: 0px;
    width: 850px;
    padding-bottom: 0px;
}