Radio Button style : demo 8

                        .radio-list{
                            width: 30px;
                            padding: 0;
                            margin: 0 auto;
                            list-style: none;
                        }
                        .radio-button{
                            margin: 0 0 5px;
                            position: relative;
                        }
                        .radio-button input[type=radio]{
                            margin: auto;
                            visibility: hidden;
                            position: absolute;
                            left: 0;
                            top: 0;
                        }
                        .radio-button label{
                            background: linear-gradient(to right, #9B59B6 50%, #8E44AD 50%);
                            width: 30px;
                            height: 30px;
                            margin: 0;
                            cursor: pointer;
                            overflow: hidden;
                            position: relative;
                            transition: all 0.25s linear;
                        }
                        .radio-button label:before,
                        .radio-button label:after{
                            content: "";
                            width: 0;
                            height: 50%;
                            border: 10px solid transparent;
                            border-top-color: #ffffff;
                            transform: translateX(-50%);
                            position: absolute;
                            top: -35%;
                            left: 50%;
                            transition: all 0.3s ease 0s;
                        }
                        .radio-button label:after{
                            border-top-color: transparent;
                            border-bottom-color: #fff;
                            top: auto;
                            bottom: -35%;
                        }
                        .radio-button input[type=radio]:checked+label:before{ 
                            opacity: 1;
                            top: 50%;
                        }
                        .radio-button input[type=radio]:checked+label:after{
                            opacity: 1;
                            bottom: 50%;
                        }