CSS Grid布局中高度继承与fr单位的深度解析与实践

.profile-card {
  width: 150px;
  height: 255px; /* 父容器有明确高度 */
  /* ... 其他样式 ... */
}

.profile-grid {
  display: grid;
  grid-template-columns: 100%;
  grid-template-rows: 150px 1fr; /* 1fr 无法正确计算 */
  /* 缺少 height: 100% */
}

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&display=swap');
body {
  font-family: roboto;
}

p {
  display: block;
  margin: auto;
}

.profile-card {
  margin-top: 0px;
  width: 150px;
  height: 255px; /* 父容器有明确高度 */
  border: none;
  box-shadow: 0px 0px 5px 3px rgba(73, 73, 73, 0.301);
}

.profile-grid {
  display: grid;
  height: 100%; /* 关键修正：使 profile-grid 继承父容器高度 */
  grid-template-columns: 100%;
  grid-template-rows: 150px 1fr; /* 1fr 现在可以正确计算 */
}

/* 其他样式保持不变 */
.social-ava {
  width: 100%;
  height: 100%;
  background-color: gray;
  transition: opacity 0.15s;
}

.social-ava:hover {
  opacity: 0.8;
}

.social-text {
  height: 100%; /* 如果内部元素也需要填满其 Grid 单元格高度，同样需要设置 100% */
  padding: 8px;
}

.social-name {
  margin-top: 0px;
  cursor: pointer;
  transition: color 0.15s;
}

.social-name:hover {
  color: rgb(52, 98, 167);
}

.mutual-grid {
  display: grid;
  grid-template-columns: 20px 1fr;
  margin-top: 6px;
  align-items: center;
}

.mutual-pic {
  width: 20px;
  height: 20px;
  background-color: gray;
  border-radius: 10px;
  cursor: pointer;
}

.mutual-friend {
  font-size: 12px;
  color: rgb(80, 80, 80);
  cursor: pointer;
}

.mutual-friend:hover {
  text-decoration: underline;
}

.social-add {
  margin-top: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: 4px;
  color: white;
  background-color: rgb(25, 118, 240);
  font-size: 12px;
  cursor: pointer;
  transition: opacity 0.1s;
}

.social-add:hover {
  opacity: 0.8;
}

<!-- profile card start -->
<div class="profile-card">

  <!-- profile grid start -->
  <div class="profile-grid">

    <!-- row 1: picture start -->
    <div class="image-container">
      <div class="social-ava"></div>
      <!-- placeholder for profile picture -->
    </div>
    <!-- row 1: picture end -->

    <!-- row 2: info start -->
    <div class="social-text">
      <p class="social-name"><strong>Name</strong></p>

      <div class="mutual-grid">
        <!-- grid for mutual friends info start -->
        <div class="mutual-pic"></div>
        <!-- placeholder for mutual's profile picture -->
        <p class="mutual-friend">2 mutual friends</p>
      </div>
      <!-- grid for mutual friends info end -->

      <button class="social-add">Add Friend</button>
    </div>
    <!-- row 2: info end -->

  </div>
  <!-- profile grid end -->

</div>
<!-- profile card end -->