.main {
  width: 1100px;
  height: 900px;
  margin: 30px;
  background: #eee;
  margin: 0 auto;
}
.main aside {
  margin: 10px;
  float: right;
  width: 150px;
  padding: 20px;
  text-align: center;
  line-height: 25px;
  font-size: 15px;
}
.main aside div {
  padding: 10px 0;
}
.main aside #start {
  width: 80px;
  height: 30px;
  margin: 10px;
}
.main aside .tips {
  padding: 0;
}
.main aside .tips ol {
  padding-left: 5px;
}
.main aside .number {
  color: red;
  font-size: 2em;
  padding: 10px;
}
.main section {
  float: left;
  width: 800px;
  height: 850px;
  display: -webkit-flex;
  -webkit-align-items: center;
  -webkit-justify-content: center;
  display: flex;
  align-items: center;
  justify-content: center;
  display: -moz-flex;
  -moz-align-items: center;
  -moz-justify-content: center;
}
.main section .sweep {
  background: #aaa;
  padding: 0;
  margin: 0;
  -moz-user-select: none;
  -o-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
.main section .sweep .brick {
  background: #c4c4c4;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  margin: 1px;
  float: left;
  border-left: 1px solid #ffffff;
  border-top: 1px solid #ffffff;
  border-right: 1px solid #aaaaaa;
  border-bottom: 1px solid #aaaaaa;
}
.main section .sweep .no-mine {
  background: #eee;
  text-align: center;
  border-left: 1px solid grey;
  border-left: 1px solid #bbbbbb;
  border-top: 1px solid #bbbbbb;
  border-right: 1px solid #e7e7e7;
  border-bottom: 1px solid #e7e7e7;
}
.main section .sweep .flag {
  background-image: url("../img/flag40.png");
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  background-position: center;
}
.main section .sweep .bomb {
  background: #eee;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  background-image: url("../img/bomb40.png");
  background-position: center;
  border-left: 1px solid #bbbbbb;
  border-top: 1px solid #bbbbbb;
  border-right: 1px solid #e7e7e7;
  border-bottom: 1px solid #e7e7e7;
}
.main section .sweep .wrong-flag {
  background-image: url("../img/wrong.png");
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  background-position: center;
}
.background-size {
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}
.in-center {
  display: -webkit-flex;
  -webkit-align-items: center;
  -webkit-justify-content: center;
  display: flex;
  align-items: center;
  justify-content: center;
  display: -moz-flex;
  -moz-align-items: center;
  -moz-justify-content: center;
}