圆角

        div{
            width: 100px;
            height: 100px;
            background-color: saddlebrown;
            border-radius: 5px;
        }

阴影

        div{
            width: 200px;
            height: 100px;
            background-color: saddlebrown;
            margin: 0 auto;
            box-shadow: 10px 10px 20px rgba(0, 0, 0, 0.5);
        }