.login_main { width: 1000px; margin: 0 auto;     overflow: hidden; position: relative; top: 20%;  }
.login_right { width: 500px; background: #fff; border: 1px solid #f0f0f0; padding: 20px; margin: 40px 0px;  padding: 20px; margin: 40px 0px;  margin: 0 auto;}