Checkbox style : demo 5

                        .demo{ background-color: #333; }
                        .checkbox{
                            width: 20px;
                            height: 20px;
                            margin: 0 auto;
                            border-radius: 20px;
                            overflow: hidden;
                            position: relative;
                        }
                        .checkbox input[type=checkbox]{
                            margin: 0;
                            visibility: hidden;
                            left: 7px;
                            top: 7px;
                        }
                        .checkbox label{
                            background: #bebebe;
                            width: 100%;
                            height: 100%;
                            transition: all 0.8s cubic-bezier(0.19, 1, 0.22, 1);
                        }
                        .checkbox label:after{
                            content: "";
                            width: 60%;
                            height: 35%;
                            border-left: 3px solid #fff;
                            border-bottom: 3px solid #fff;
                            margin: auto;
                            transform: rotate(-45deg);
                            position: absolute;
                            left: 0;
                            right: 0;
                            top: 20px;
                            transition: all 0.8s cubic-bezier(0.19, 1, 0.22, 1);
                        }
                        .checkbox input[type=checkbox]:checked+label{ background: linear-gradient(#FF512F, #DD2476); }
                        .checkbox input[type=checkbox]:checked+label:after{ top: 6px; }
                        @media only screen and (max-width:767px){
                            .checkbox{ margin: 0 0 20px; }
                        }