SASS优化边框成一行代码

.box {
  border: {
    top: 1px solid #000;
    right: 1px solid #000;
    bottom: 1px solid #000;
    left: 1px solid #000;
  }
}

.box {
  border-top: 1px solid #000;
  border-right: 1px solid #000;
  border-bottom: 1px solid #000;
  border-left: 1px solid #000;
}

.box {
  border: 1px solid #000;
}

.box {
  border: 1px solid #000;
}