html - 侧边栏元素看起来像是主要内容的一部分。如何实现这种悬停效果？

Question

我试图在stackoverflow中寻找这种效果，但我不知道，开发人员如何调用这种悬停效果也不知道如何实现它。我尝试使用几种解决方案，但一切都失败了。是否有可能在纯 CSS 中做到这一点？

Link to image of this effect

我的意思是元素右侧的那种border-radius？

HTML:

    <div class="app">
      <nav class="navigation">
        <div class="nav-content">
          <ul>
            <span class="logo">Logoo</span>
            <hr />
            <a href="#">
              <li class="nav-item">
                Home
              </li>
            </a>
            <a href="#">
              <li class="nav-item">
                Rate plans
              </li>
            </a>
            <a href="#">
              <li class="nav-item">
                Bookings
              </li>
            </a>
            <a href="#">
              <li class="nav-item">
                Apartments
              </li>
            </a>
            <a href="#">
              <li class="nav-item">
                Pricing
              </li>
            </a>
            <hr />
            <a href="#">
              <li class="nav-item">
                Support
              </li>
            </a>
            <a href="#">
              <li class="nav-item">
                LogOut
              </li>
            </a>
          </ul>
        </div>
      </nav>
      <main>
        <div class="main-content"></div>
      </main>
    </div>

CSS:

.app {
  display: grid;
  grid-template-columns: 20% 80%;
  grid-template-rows: 100%;
  grid-template-areas: "nav main";
  height: 100%;
  width: 100%;
}

nav {
  grid-area: nav;
}

main {
  grid-area: main;
}

.navigation {
  padding: 0 0 0 40px;
  background-color: var(--primary-color);
}

.nav-item {
  padding: 20px 0 20px 0;
  color: white;
  cursor: pointer;
  transition: all 0.3s;
  background-color: var(--primary-color);
  border-radius: 0 20px 20px 0;
}

.nav-item:hover {
  background-color: var(--main-color);
  color: black;
}

ul {
  background-color: var(--main-color);
}

这是我目前得到的效果，但仅此而已......

Link to image of my work还有https://jsfiddle.net/q93mc8kz/

Answer 1

终于，我做到了。

-我使用了::before 和::after 来实现这一点。

Jsfiddle:https://jsfiddle.net/Rishabtyagi/hq078gdx/14

.app {
  display: grid;
  //commented//grid-template-columns: 20% 80%;
  grid-template-rows: 100%;
  grid-template-areas: "nav main";
  height: 100%;
  width: 100%;
}



nav {
  grid-area: nav;
}

main {
  grid-area: main;
}

.navigation {
  padding: 0 0 0 40px;
  background-color: brown;
}

.nav-item,.nav-item1,.nav-item2 {
  padding: 20px 0 20px 0;
  color: white;
  cursor: pointer;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  transition: all 0.3s;
  background-color: brown;
  
  
}

.nav-item::before,.nav-item1::before,.nav-item2::before{
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
  transition: all 0.5s;
  opacity: 0;
  content:'';
}

.nav-item::after,.nav-item1::after,.nav-item2::after{
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
  transition: all 0.5s;
  opacity: 0;
  content:'';
}

.nav-item:hover::before,.nav-item1:hover::before,.nav-item2:hover::before {
   content: "";
  position: absolute;
  opacity: 1;
  background-color: transparent;
  left:254px;
  height: 50px;
  width: 25px;
  margin-top:-70px;
  border-top-right-radius: 25px;
  box-shadow: 0 -25px 0 0 white;
  transform:rotate(-180deg); 
  transform:rotatex(-180deg); 
}

.nav-item:hover::after {
   content: "";
  position: absolute;
  opacity: 1;
  background-color: transparent;
  left:253px;
  height: 50px;
  width: 25px;
  margin-top:39.1px;
  border-top-right-radius: 25px;
  box-shadow: 0 -25px 0 0 white;
  
 
}

.nav-item1:hover::after{
  content: "";
  position: absolute;
  opacity: 1;
  background-color: transparent;
  left:253px;
  height: 50px;
  width: 25px;
  margin-top:38.7px;
  border-top-right-radius: 25px;
  box-shadow: 0 -25px 0 0 white;
 
  
}

.nav-item2:hover::after{
  content: "";
  position: absolute;
  opacity: 1;
  background-color: transparent;
  left:253px;
  height: 50px;
  width: 25px;
  margin-top:38.7px;
  border-top-right-radius: 25px;
  box-shadow: 0 -25px 0 0 white;
  
  
}
.nav-item:hover,.nav-item1:hover,.nav-item2:hover {
  background-color: brown;
  color: black;
 
  background-color: white;
  border-radius:40px 0 0 40px;
}



body {
    background: brown;
}

.main-content {
    
    border-radius: 20px 0px 0px 20px;
    height: 107%;
    background-color: white;
}

.new {
    background-color: brown;
}

ul {
  background-color: white;

  
}

@media all and (max-width:768px){
  .main-content{
  width:155%;
  margin-left:-49%;
  margin-right:-10%;
  }
  
  
}
@media all and (min-width:1280px){
  .main-content{
  
  width:200%;
  margin-left:-83%;
  height:120%;
  }
  
  
}

  <div class="app">
      <nav class="navigation">
        <div class="nav-content">
       
          <ul class="new">
            <span class="logo">Logo</span>
            <hr />
            
              <li class="nav-item">
              <a href="#"></a>
                Home
              </li>
            
            
              <li class="nav-item">
              <a href="#"> </a>
                Rate plans
              </li>
           
              <li class="nav-item"><a href="#"></a>
                Bookings
              </li>
          
           
              <li class="nav-item"><a href="#"></a>
                Apartments
              </li>
          
            
              <li class="nav-item"><a href="#"></a>
                Pricing
              </li>
           
            <hr />
            
              <li class="nav-item1"><a href="#"></a>
                Support
              </li>
         
            
              <li class="nav-item2"><a href="#"></a>
                LogOut
              </li>
           
          </ul>
        </div>
      </nav>
      <main>
        <div class="main-content"></div>
      </main>
    </div>