基于现有代码，如何用CSS/Bootstrap实现导航栏中间圆形缺口？

安全阿岳

2026-7-23

实现导航栏中间的圆形缺口

需要在底部导航栏的中间位置制作一个圆形缺口，匹配Figma原型样式，现有HTML和CSS代码如下，请教如何用CSS实现该效果。

现有代码

CSS代码

@import url("https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600;700&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Quicksand:wght@300;400;500;600;700&display=swap");

.wrapper {
  border: solid 0.25rem black;
  box-shadow: 0 0 6vmin rgba(0, 0, 0, 0.2);
  border-radius: 2vmin;
  position: relative;
  width: 40vh;
  height: 80vh;
  margin: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  overflow: hidden;
}

.navbar img {
  margin: 0 10px;
}

.navbar a[href="/search"] {
  margin-right: 40px;
}

.navbar a[href="/notes"] {
  margin-left: 40px;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  height: 60px;
  background-color: #ffffff;
  box-shadow: 0px 0px 10px rgba(128, 131, 255, 0.75);
  border-radius: 10px;
  position: absolute;
  bottom: 0;
  left: 0;
  padding: 0;
  border: 20px solid var(-clr);
}

.circle {
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  top: -25px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: linear-gradient(
      270deg,
      rgba(227, 224, 243, 0.245) 0%,
      rgba(128, 131, 255, 0.255) 100%
    ),
    #8083ff;
}

a[href="/feeds/buckets?show=inprogress"] img {
  width: 40px;
  height: 40px;
}

.top_buttons {
  margin-top: 45px;
  display: flex;
  justify-content: space-between;
  gap: 35px;
}

.friends,
.for_you {
  font-family: "Opens Sans", sans-serif;
  font-size: 14px;
  font-weight: 400;
  line-height: 20px;
  border: 3px solid #8083ff;
  border-radius: 30px;
  width: 100px;
  padding: 4px 8px;
  text-align: center;
}

.friends {
  background-color: #8083ff;
  color: #ffffff;
}

.for_you {
  background-color: #ffffff;
  color: #8083ff;
}

.post {
  background-color: #ffffff;
  border-radius: 10px;
  padding: 15px;
  margin-bottom: 20px;
  margin-top: 10px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  position: relative;
}

.post p {
  font-family: "Opens Sans", sans-serif;
  font-size: 14px;
  margin: 0 0 10px;
  line-height: 15px;
  font-style: normal;
  word-wrap: break-word;
}

.post p:last-child {
  margin-bottom: 0;
}

.user-info {
  display: flex;
  align-items: center;
}
.user-picture {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  margin-right: 10px;
  background-color: #b1b1b1;
  position: absolute;
  top: 10px;
  left: 10px;
}

.username {
  font-weight: normal;
  margin: 0;
  line-height: 19px;
}

.post p:nth-child(2) {
  margin-top: 20px;
}

.post-content {
  margin-left: 60px;
  margin-top: 10px;
  font-family: "Open Sans";
  font-style: normal;
  font-weight: 400;
  font-size: 14px;
  line-height: 19px;
  padding-right: 10px;
}

.posts-container {
  overflow-y: auto;
  max-height: calc(80vh - 230px);
  width: 100%;
  padding: 0 15px;
  margin-top: 10px;
}

.create_post {
  background-color: #d9d9d9;
  border-radius: 10px;
  width: 100%;
  height: 220px;
  padding: 6px 14px;
  font-size: 18px;
  box-sizing: border-box;
  margin-bottom: 20px;
  padding-left: 60px;
  border: none;
  position: relative;
  top: 10px;
  padding-top: 10%;
}

.user-input-wrapper {
  position: relative;
  width: 100%;
}

.user-avatar {
  position: absolute;
  top: 15%;
  left: 15px;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: #b1b1b1;
  z-index: 1;
}

.create_post::placeholder {
  font-size: 14px;
  font-family: "Open Sans";
  font-style: normal;
}

HTML代码

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="../styles/style_friendspost.css" />
    <script defer src="myscripts.js"></script>
    <title>Main Feed</title>
  </head>
  <body>
    <div class="wrapper">
      <div class="top_buttons">
        <p>Cheer Your Friends!</p>
      </div>
      <div class="posts-container">
        <% feed.forEach(post => { %>
        <div class="post">
          <div class="user-picture"></div>
          <div class="post-content">
            <p class="username">@<%=post.username%></p>
            <p><%= post.completed[0] %></p>
            <p><%= post.bucketName[0] %></p>
            <p><%= post.messages %></p>
          </div>
        </div>
        <% }) %>
      </div>
      <div class="navbar">
        <a href="/feeds/home">
          <img
            src="../styles/images/home_icon_noBackground.png"
            alt="Home"
            width="40"
            height="40"
          />
        </a>
        <a href="/search">
          <img
            src="../styles/images/search_icon_noBackground.png"
            alt="Search"
            width="40"
            height="40"
          />
        </a>
        <div class="circle">
          <a href="/feeds/buckets?show=inprogress">
            <img
              src="../styles/images/bucket_icon_noBackground.png"
              alt="Bucket"
              width="50"
              height="50"
            />
          </a>
        </div>
        <a href="/notes">
          <img
            src="../styles/images/note_icon_noBackground.png"
            alt="Notes"
            width="40"
            height="40"
          />
        </a>
        <a href="/profile">
          <img
            src="../styles/images/profile_icon_noBackground.png"
            alt="Profile"
            width="40"
            height="40"
          />
        </a>
      </div>
    </div>
  </body>
</html>

实现方案

通过CSS的clip-path属性裁剪导航栏，同时调整中间圆形按钮的位置，即可实现原型中的圆形缺口效果，具体修改如下：

1. 修改导航栏样式，裁剪圆形缺口

替换原有.navbar的CSS代码，添加clip-path实现缺口，同时优化布局：

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  height: 60px;
  background-color: #ffffff;
  box-shadow: 0px 0px 10px rgba(128, 131, 255, 0.75);
  border-radius: 10px 10px 0 0; /* 仅保留顶部圆角 */
  position: absolute;
  bottom: 0;
  left: 0;
  padding: 0 20px; /* 增加左右内边距，避免图标贴边 */
  /* 裁剪中间圆形缺口，参数可根据实际尺寸调整 */
  clip-path: circle(32px at 50% -22px);
}

clip-path: circle(32px at 50% -22px)表示在导航栏顶部中间位置，裁剪一个半径32px的圆形缺口，垂直位置设为负数让缺口延伸到导航栏外。

2. 调整中间圆形按钮的位置，嵌入缺口

修改.circle的样式，让按钮刚好嵌入缺口：

.circle {
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  top: -32px; /* 调整偏移距离，让按钮与缺口完全贴合 */
  left: 50%;
  transform: translateX(-50%);
  width: 64px; /* 增大按钮尺寸，匹配缺口大小 */
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(
      270deg,
      rgba(227, 224, 243, 0.245) 0%,
      rgba(128, 131, 255, 0.255) 100%
    ),
    #8083ff;
  box-shadow: 0 0 10px rgba(128, 131, 255, 0.75); /* 添加阴影增强层次感 */
}

3. 优化导航栏链接布局

移除原有链接的自定义margin，改用flex:1让图标均匀分布：

.navbar a {
  flex: 1;
  display: flex;
  justify-content: center;
}

.navbar a[href="/search"],
.navbar a[href="/notes"] {
  margin: 0; /* 移除原有margin */
}

将以上修改替换原有代码对应的部分，即可实现与原型一致的导航栏圆形缺口效果。

内容的提问来源于stack exchange，提问作者Fernando Daumichen

基于现有代码，如何用CSS/Bootstrap实现导航栏中间圆形缺口？

现有代码 #

CSS代码 #

HTML代码 #

实现方案 #

1. 修改导航栏样式，裁剪圆形缺口 #

2. 调整中间圆形按钮的位置，嵌入缺口 #

3. 优化导航栏链接布局 #