三角形及选中取消按钮的css代码

.triangle{
  background:blue transparent transparent  transparent;
  border-width:100px 60px 0 60px;
  border-style:solid ;
  height:0 ;width:0;      
}
  <div class="triangle">
    </div>

.svg-triangle{
    margin:0 auto; width:10px;height:100px;
}
.svg-triangle polygon{
    fill:blue;stroke:yellow; stroke-width:2px;
}

  <svg xmlns="http://www.w3.org/2000/svg" version="1.1" class="svg-triangle">
        <polygon points="0,0 100,0 50,100"></polygon>
    </svg>

 .mui-switch {
            width: 52px;
            height: 31px;
            position: relative;
            border: 1px solid #dfdfdf;
            background-color: #fdfdfd;
            box-shadow: #dfdfdf 0 0 0 0 inset;
            border-radius: 20px;
            border-top-left-radius: 20px;
            border-top-right-radius: 20px;
            border-bottom-left-radius: 20px;
            border-bottom-right-radius: 20px;
            background-clip: content-box;
            display: inline-block;
            -webkit-appearance: none;
            user-select: none;
            outline: none;
        }

            .mui-switch:before {
                content: ‘‘;
                width: 29px;
                height: 29px;
                position: absolute;
                top: 0px;
                left: 0;
                border-radius: 20px;
                border-top-left-radius: 20px;
                border-top-right-radius: 20px;
                border-bottom-left-radius: 20px;
                border-bottom-right-radius: 20px;
                background-color: #fff;
                box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
            }

            .mui-switch:checked {
                border-color: #64bd63;
                box-shadow: #64bd63 0 0 0 16px inset;
                background-color: #64bd63;
            }

                .mui-switch:checked:before {
                    left: 21px;
                }
 .mui-switch.mui-switch-anim {
                transition: border cubic-bezier(0, 0, 0, 1) 0.4s, box-shadow cubic-bezier(0, 0, 0, 1) 0.4s;
            }

                .mui-switch.mui-switch-anim:before {
                    transition: left 0.3s;
                }

                .mui-switch.mui-switch-anim:checked {
                    box-shadow: #64bd63 0 0 0 16px inset;
                    background-color: #64bd63;
                    transition: border ease 0.4s, box-shadow ease 0.4s, background-color ease 1.2s;
                }

                    .mui-switch.mui-switch-anim:checked:before {
                        transition: left 0.3s;
                    }

<label>
<input class="mui-switch mui-switch-anim" type="checkbox">
</label>