table {
    width: 100%;
    border-collapse: collapse;
  }
  table, th, td {
    border: 1px solid black;
  }
  th {
    height: 50px;
    background-color: lightblue;
  }
  td {
    height: 50px;
    text-align: center;
  }
  /* 为奇数行设置交替背景色 */
  tr:nth-child(odd) {
    background-color: #f9f9f9;
  }
  /* 为偶数行设置交替背景色 */
  tr:nth-child(even) {
    background-color: #f0f0f0;
  }
.centered-btn {
    position: relative;
	width:200px;
	height:200px;
	display: block;
	margin: 0 auto;
	text-align: center;
	color:white;
	background-color:Deeppink;
	border-radius: 50%; /* Make the corners rounded */
	font-size: 32px; /* Set a font-size */
}
.left-btn {
    position: relative;
    top: 50px;
    left: -200px;
	background-color:Turquoise;
}
.positive {
    color: red; /* 红色背景表示正值 */
}
 
.negative {
    color: green; /* 绿色背景表示负值 */
}