.change-font-size-btn {
            position: fixed;
            top: 0;
            bottom: 0;
            right: 0;
            width: 50px;
            height: 150px;
            margin: auto;
            opacity: .7;
            z-index: 1000
        }

        .change-font-size-btn .change-font-size-item {
            display: inline-block;
            width: 50px;
            height: 50px;
            text-align: center;
            line-height: 50px;
            background: #8d0007;
            color: #fff;
            border-bottom: 1px dashed #eee;
            outline: 0;
            cursor: pointer
        }

        .change-font-size-btn .change-font-size-item:hover {
            opacity: .6
        }

        .change-font-size-btn .change-font-size-item:nth-child(2) {
            border-bottom: none;
            background: #dc101a
        }