html{
				height: 100%;
			}
			body{
				height: 100%;
				margin: 0px;
				/* 上下左右居中 */
				display: flex;
				align-items: center;
				justify-content: center;
				background-color: aliceblue;
			}
			#guess_box{
				/* 两种设置模式：border-box包括内边距，content-box刨去内边距 */
				box-sizing: border-box;
				width: 400px;
				height: 200px;
				/* 圆角 */
				border-radius: 14px;
				/* 背景颜色 */
				background-color: white;
				/* 阴影 */
				box-shadow: 0px 0px 10px rgba(0,0,0,0.2);
				padding:40px;
			}
			#num_input{
				height: 34px;
				border:1px solid #999999;
				border-radius: 5px;
				width: 140px;
			}
			#start_game{
				border: 0px;
				background-color: #00aa00;
				height: 38px;
				border-radius: 5px;
				color: white;
				width: 80px;	
				cursor: pointer;/*鼠标是手型*/
			}
			#guess_btn{
				border: 0px;
				background-color: #0055ff;
				height: 38px;
				border-radius: 5px;
				color: white;
				width: 80px;
				cursor: pointer;/*鼠标是手型*/
			}
			#guess_div{
				display: flex;
				gap:10px;
			}