Checkbox style : demo 7

                        .checkbox{
                            margin: 0;
                            border-radius: 50%;
                            display: inline-block;
                            overflow: hidden;
                            position: relative;
                        }
                        .checkbox input[type=checkbox]{
                            margin: 0;
                            visibility: hidden;
                            left: 7px;
                            top: 7px;
                        }
                        .checkbox label{
                            width: 30px;
                            height: 30px;
                            padding: 0;
                            margin: 0;
                            border-radius: 50%;
                            border: 5px solid #666;
                            box-shadow: 0 2px 4px rgba(0,0,0,0.2) inset;
                            cursor: pointer;
                            display: block;
                            position: relative;
                            transition: all 0.3s ease 0s;
                        }
                        .checkbox label:hover{ border-width: 7px; }
                        .checkbox input[type=checkbox]:checked+label{
                            background-color: #07d410;
                            border: 7px solid #07d410;
                            box-shadow: none;
                        }
                        .checkbox label:before,
                        .checkbox label:after{
                            content: "";
                            background: #fff;
                            width: 4px;
                            height: 18px;
                            opacity: 0;
                            transform: translateX(-50%) rotate(55deg);
                            position: absolute;
                            left: 160%;
                            top: -10px;
                            transition: all 0.2s ease 0s;
                        }
                        .checkbox label:after{
                            height: 10px;
                            transform: translateX(-50%) rotate(-33deg);
                            left: -35%;
                            top: -6px;
                        }
                        .checkbox input[type=checkbox]:checked+label:before{
                            opacity: 1;
                            transform: translateX(-50%) rotate(55deg);
                            left: 62%;
                            top: 0px;
                        }
                        .checkbox input[type=checkbox]:checked+label:after{
                            opacity: 1;
                            transform: translateX(-50%) rotate(-33deg);
                            left: 12%;
                            top: 6px;
                        }
                        @media only screen and (max-width:767px){
                            .checkbox{ margin: 0 0 20px; }
                        }