* {
  /* 清除默认的外边距和内边距 */
  margin: 0;
  padding: 0;
}
body {
  background-color: #ececec;
  /* 初始化select标签的样式 */
  /* 其中的-xx-xx是浏览器的私有前缀，这么写可以保证兼容性
    也就是各个浏览器下样式表现一致
     */
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  -khtml-user-select: none;
  user-select: none;
}
#ground {
  /* 设置棋盘外部容器的大小，并为其添加绝对定位以及溢出隐藏 */
  width: 100%;
  height: 100%;
  position: absolute;
  overflow: hidden;
}
#board {
  /* 添加棋盘样式并通过绝对定位固定其位置 */
  width: 401px;
  height: 451px;
  padding: 30px;
  background-color: #8f7a66;
  position: relative;
  top: 45%;
  left: 0;
  right: 0;
  margin: -220px auto;
  border: 3px solid rgb(192, 166, 137);
  border-radius: 2px;
  box-shadow: 0 0 25px rgba(143, 97, 76, 0.35);
}
#board #line {
  /* 设置棋盘中的格子线的样式 */
  width: 100%;
  height: 100%;
}
#board #line #rows {
  width: 100%;
  height: 100%;
  overflow: hidden;
}
#board #line #lines {
  width: 100%;
  height: 100%;
  position: relative;
  top: -100%;
  overflow: hidden;
}
#board #line .row {
  width: 100%;
  height: 1px;
  background-color: #571b16;
  margin-bottom: 49px;
}
#board #line .line {
  width: 1px;
  height: 100%;
  background-color: #571b16;
  margin-right: 49px;
  float: left;
}
#board #line .end {
  margin: 0;
}
#board #line #river {
  width: 461px;
  height: 100%;
  position: relative;
  top: -200%;
  left: -30px;
}
#board #line #river article {
  position: relative;
  top: 201px;
  width: 100%;
  height: 49px;
  background-color: rgba(143, 122, 102, 0.95);
  /*background-image: url("ass/Riv.png");*/
  box-shadow: inset 0 0 25px rgba(79, 139, 191, 0.55);
  font-family: Arial, sans-serif;
  font-size: 45px;
  text-align: center;
  letter-spacing: 1px;
  color: #817c77;
  opacity: 0.95;
}
#board #flower {
  width: 100%;
  height: 100%;
  position: relative;
  top: -300%;
  overflow: hidden;
}
#board #flower article {
  width: 25px;
  height: 25px;
  position: relative;
  left: 37px;
  top: 37px;
  float: left;
  border: 1px solid rgba(134, 42, 3, 0.55);
  transform: rotate(45deg);
}
#board #flower .L2 {
  width: 100%;
  height: 50px;
}
#board #flower .L5 {
  width: 100%;
  height: 50px;
}
/* 使用子代选择器设置.L2中第二个article的样式 */
#board #flower .L2 article:nth-child(2) {
  margin-left: 273px;
}
#board #flower .L5 article:nth-child(1n + 2) {
  margin-left: 73px;
}
#board #flower .L5 article:nth-child(1) {
  margin-left: -50px;
}
#board #flower .L5 article:nth-child(2) {
  margin-left: 50px;
}
#board #flower #F {
  margin-top: 50px;
  height: 200px;
}
#board #cross {
  width: 100%;
  height: 100%;
  position: relative;
  top: -400%;
}
#board #cross #T {
  width: 100%;
  height: 200px;
  margin-bottom: 51px;
}
#board #cross #B {
  width: 100%;
  height: 200px;
}
#board #cross article {
  margin: 0 auto;
  width: 140px;
  height: 1px;
  position: relative;
  top: 50px;
  background-color: #752e2b;
}
#board #cross article:nth-child(1) {
  transform: rotate(45deg);
}
#board #cross article:nth-child(2) {
  margin-top: -1px;
  transform: rotate(-45deg);
}
#board #cross #B article {
  position: relative;
  top: 149px;
}