How to create a vertical line on top of the text when it is active?-CodePudding

I want my active element to have a vertical line on top of it and I was given a hint to use either :before or :after in CSS to make this line. However, I'm not really familiar with those two tags and I have tried a bit using :after but it doesn't seem to work. Can you give me some advice/suggestions for this? Below is the design example of what it should look like.

.nav-menu{
    background: var(--unnamed-color-ffffff);
    flex: 1;
    justify-content: space-between;
    padding-top: 2.3rem;
    width: 91.5rem;
}

.nav-menu .icon{
    width: 2.0rem;
    height: 2.0rem;
    margin-right: 1.5rem;
}

.nav-menu .nav-list {
    margin: 0;
    padding: 0;
    list-style: none;
}

.nav-menu .nav-list .nav-item{
    display: inline-block;
}

.nav-menu .nav-list .nav-item .nav-link {
    display: inline-block;
    text-decoration: none;
    color: black;
}

.nav-menu .nav-list .nav-item .active {
    color: red;
}

.nav-menu .nav-list .nav-item .active ::after {
    content: '';
    border-left: 0.1rem solid red;
    height: 1.5rem;
    position: absolute;
    left: 50%;
    top: 0;
}

        <nav  id="nav-menu">
            <ul >
                <li >
                    <a href="#home" >one</a>
                </li>
                <li >
                    <a href="#about" >two</a>
                </li>
                <li >
                    <a href="#service" >three</a>
                </li>
                <li >
                    <a href="#promotion" >four</a>
                </li>
                <li >
                    <a href="#customer" >five</a>
                </li>
                <li >
                    <a href="#contact" >six</a>
                </li>
            </ul>

        </nav>

CodePudding user response：

Use active:before and use position:relative on the parent where you used position:absolute. here an example with your code:

.nav-menu{
    background: var(--unnamed-color-ffffff);
    flex: 1;
    justify-content: space-between;
    padding-top: 2.3rem;
    width: 91.5rem;
}

.nav-menu .icon{
    width: 2.0rem;
    height: 2.0rem;
    margin-right: 1.5rem;
}

.nav-menu .nav-list {
    margin: 0;
    padding: 0;
    list-style: none;
}

.nav-menu .nav-list .nav-item{
    display: inline-block;
}

.nav-menu .nav-list .nav-item .nav-link {
    display: inline-block;
    text-decoration: none;
    color: black;
}

.nav-menu .nav-list .nav-item .active {
    color: red;
    position: relative;
}

.nav-menu .nav-list .nav-item .active:before {
    content: '';
    border-left: 0.1rem solid red;
    height: 1.5rem;
    position: absolute;
    left: 50%;
    bottom: 100%;
}

<nav  id="nav-menu">
            <ul >
                <li >
                    <a href="#home" >one</a>
                </li>
                <li >
                    <a href="#about" >two</a>
                </li>
                <li >
                    <a href="#service" >three</a>
                </li>
                <li >
                    <a href="#promotion" >four</a>
                </li>
                <li >
                    <a href="#customer" >five</a>
                </li>
                <li >
                    <a href="#contact" >six</a>
                </li>
            </ul>

        </nav>

CodePudding user response：

You can use something like this.

*,
*::before,
*::after {
  box-sizing: border-box;
}


body {
  min-height: 100vh;
  margin: 0;
  background-color: bisque;
  display: grid;
  place-content: center;
}


.box{
  width: 10rem;
  height: 5rem;
  border: 1px solid black;
}

.box::before{
  display: block;
  position: relative;
  left: 50%;
  transform: translate(-50%);
  content: '';
  height: 1.5rem;
  width: 2px;
  background-color: brown;
}

<body>
    <div ></div>
  </body>

CodePudding user response：

It looks like you're using Bootstrap? If so, the majority of the CSS may not work. The example below has Bootstrap 5 loaded, and your custom CSS was too complex to follow so I had to remove it (BS styles would inhibit most of it anyway), and the following CSS was added:

    .active {
      position: relative
    }
    
    .active::before {
      content: '|';
      position: absolute;
      left: calc(50% - 0.25ch);
      top: -1ch;
      color: tomato;
    }

This style will appear whenever a link is assigned .active. If the | is too tall, try decreasing font-size directly on the .active::before selector -- use Dev Tools to find the computed font-size of .active::before to get an idea of how much you should decrease it by. Also, I changed some of the BS classes according to BS suggested use.

<!DOCTYPE html>
<html lang="en">

<head>
  <title></title>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet">
  <style>
    .active {
      position: relative
    }
    
    .active::before {
      content: '|';
      position: absolute;
      left: calc(50% - 0.25ch);
      top: -1ch;
      color: tomato;
    }
  </style>
</head>

<body>
  <main >
    <section >
      <nav >
        <ul >
          <li >
            <a href="#home" >one</a>
          </li>
          <li >
            <a href="#about" >two</a>
          </li>
          <li >
            <a href="#service" >three</a>
          </li>
          <li >
            <a href="#promotion" >four</a>
          </li>
          <li >
            <a href="#customer" >five</a>
          </li>
          <li >
            <a href="#contact" >six</a>
          </li>
        </ul>
      </nav>
    </section>
  </main>
  <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>
  <script></script>
</body>

</html>