<div class="card-container">
  <div class="card">Card 1</div>
  <div class="card">Card 2</div>
  <div class="card">Card 3</div>
  <div class="card">Card 4</div>
  <div class="card">Card 5</div>
  <div class="card">Card 6</div>
</div>

.card-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-gap: 10px;
}

.card {
  background-color: #f0f0f0;
  padding: 10px;
}

（多列则将 repeat(2,1fr) ，2 替换成想显示的列数） 

.card-container {
  display: flex;
  flex-wrap: wrap;
}

.card {
  width: 50%;
  box-sizing: border-box;
  padding: 10px;
}

.card-container {
  width: 100%;
  overflow: hidden;
}

.card {
  width: 50%;
  float: left;
  box-sizing: border-box;
  padding: 10px;
  background-color: #f0f0f0;
}