Ich kann nichts auf dem Bildschirm zentrieren

Question

Ich folge einem YouTube-Tutorial darüber, wie man mit CSS eine responsive Navigationsleiste in HTML erstellt, und alles lief gut, bis ich versuchte, Text in der Mitte des Bildschirms hinzuzufügen, und dieser auf der linken Seite des Bildschirms erschien (nur wenn der Die Fensterauflösung ist höher als 952 Pixel (Breite Stunde). Ich bin CSS-Neuling und alles, was ich zu beheben versuche, scheint nicht zu funktionieren. Der Code lautet wie folgt

* {
  padding: 0;
  margin: 0;
  text-decoration: none;
  list-style: none;
  box-sizing: border-box;
}

body {
  font-family: montserrat;
}

nav {
  background: #0082e6;
  height: 80px;
  width: 100%;
}

label.logo {
  color: white;
  font-size: 35px;
  line-height: 80px;
  padding: 100px;
  font-weight: bold;
}

nav ul {
  float: right;
  margin-right: 20px;
}

nav ul li {
  display: inline-block;
  line-height: 80px;
  margin: 0 5px;
}

nav ul li a {
  color: white;
  font-size: 17px;
  padding: 7px 13px;
  border-radius: 3px;
  text-transform: uppercase;
}

a.active,
a:hover {
  background: #1b9bff;
  transition: .5s;
}

.checkbtn {
  font-size: 30px;
  color: white;
  float: right;
  line-height: 80px;
  margin-right: 40px;
  cursor: pointer;
  display: none;
}

#check {
  display: none;
}

@media (max-width: 952px) {
  label.logo {
    font-size: 30px;
    padding-left: 50px;
  }
  nav ul li a {
    font-size: 16px;
  }
}

@media (max-width: 858px) {
  .checkbtn {
    display: block;
  }
  ul {
    position: fixed;
    width: 100%;
    height: 100vh;
    background: #2c3e50;
    top: 80px;
    left: -100%;
    text-align: center;
    transition: all .5s;
  }
  nav ul li {
    display: block;
  }
  nav ul li a {
    font-size: 20px;
  }
  a:hover,
  a.active {
    background: none;
    color: #0082e6;
  }
  #check:checked~ul {
    left: 0;
  }
}

section {
  background: url(bg1.jpeg) no-repeat;
  background-size: cover;
  height: calc(100vh - 80px);
  opacity: 20%;
}

<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Montserrat">
<meta charset="utf-8">
<meta name="viewport" content="width=device-widht,initial-sclae=1.0">
<link rel="stylesheet" href="style.css">
<script src="https://kit.fontawesome.com/.js" crossorigin="anonymous"></script>
<nav>
  <input type="checkbox" id="check">
  <label for="check" class="checkbtn">
                <i class="fas fa-bars"></i>
            </label>
  <label class="logo">Air</label>
  <ul>
    <li><a href='home.html'>Home</a></li>
    <li><a href='About.html'>About</a></li>
    <li><a href='Flights.html'>Flights</a></li>
    <li><a href='Contact.html'>Contact</a></li>
  </ul>
</nav>
<section>
  <h1 style="text-align:center;">test</h1>
</section>

Answer 1

这解决了问题：将宽度设置为仅文本的宽度，然后通过 margin 0 auto 将容器对齐到中心。

test

Answer 2

添加 section { 边框：1px 实心透明； } 也解决了这个问题。

请参阅下面的代码片段。

* {
  padding: 0;
  margin: 0;
  text-decoration: none;
  list-style: none;
  box-sizing: border-box;
}

body {
  font-family: montserrat;
}

nav {
  background: #0082e6;
  height: 80px;
  width: 100%;
}

label.logo {
  color: white;
  font-size: 35px;
  line-height: 80px;
  padding: 100px;
  font-weight: bold;
}

nav ul {
  float: right;
  margin-right: 20px;
}

nav ul li {
  display: inline-block;
  line-height: 80px;
  margin: 0 5px;
}

nav ul li a {
  color: white;
  font-size: 17px;
  padding: 7px 13px;
  border-radius: 3px;
  text-transform: uppercase;
}

a.active,
a:hover {
  background: #1b9bff;
  transition: .5s;
}

.checkbtn {
  font-size: 30px;
  color: white;
  float: right;
  line-height: 80px;
  margin-right: 40px;
  cursor: pointer;
  display: none;
}

#check {
  display: none;
}

@media (max-width: 952px) {
  label.logo {
    font-size: 30px;
    padding-left: 50px;
  }
  nav ul li a {
    font-size: 16px;
  }
}

@media (max-width: 858px) {
  .checkbtn {
    display: block;
  }
  ul {
    position: fixed;
    width: 100%;
    height: 100vh;
    background: #2c3e50;
    top: 80px;
    left: -100%;
    text-align: center;
    transition: all .5s;
  }
  nav ul li {
    display: block;
  }
  nav ul li a {
    font-size: 20px;
  }
  a:hover,
  a.active {
    background: none;
    color: #0082e6;
  }
  #check:checked~ul {
    left: 0;
  }
}

section {
  background: url(bg1.jpeg) no-repeat;
  background-size: cover;
  height: calc(100vh - 80px);
  opacity: 20%;
  border: 1px solid transparent;
}

  
  
  
  
  
  



  

    
    
        
      
    Air
    

      
Home
      
About
      
Flights
      
Contact
    
  
  

    
test