html {
            height: 100%;
            background: url(https://www.iikx.com/skin/iikx/images/iikx.gif);
            background-size: 100% 100%;
        }

        header {
            width: 221px;
            height: 78px;
            margin: 15px auto 0;
        }

        main {
            width: 400px;
            margin: 15px auto 0;
            border: 2px solid #0aa770;
            border-radius: 20px;
            padding: 20px;
            background-color: #FFF;
        }

        footer {
            text-align: center;
            padding: 40px 0;
        }

        main .item {
            width: 100%;
            padding: 10px 0;
        }

        main .item div {
            width: 65px;
            height: 32px;
            line-height: 32px;
            float: left;
        }

        input, select {
            outline: none;
            border: 1px solid #d0ad9a;
            border-radius: 2px;
            height: 30px;
            line-height: 38px;
            padding: 0 4px;
        }

        #randomNumbers {
            color: #0aa770;
            width: 100%;
            line-height: 36px;
            font-size: 28px;
            text-align: left;
            background-color: #CCC;
            border-radius: 3px;
            padding: 5px;
            margin: 10px 0;
        }

        #randomGenerate {
            display: inline-block;
            height: 38px;
            line-height: 38px;
            padding: 0 18px;
            background-color: #009688;
            color: #fff;
            white-space: nowrap;
            text-align: center;
            font-size: 14px;
            border: none;
            border-radius: 2px;
            cursor: pointer;
        }

        @media (max-width: 1280px) {
            main {
                width: 80%;
                padding: 10px;
            }

            main .item {
                padding: 2px 0;
            }

            footer{
                padding: 10px 0;
            }

            #randomNumbers{
                padding: 2px;
            }
        }