* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Arial", sans-serif;
  line-height: 1.6;
}
ul {
  list-style: none;
}
.mb10 {
  margin-bottom: 10px;
}
.mb20 {
  margin-bottom: 20px;
}
.main-content {
  margin-top: 70px;
}
.flex {
  display: flex;
}
.flex-1 {
  flex: 1;
}