我正在关注 YouTube 教程，了解如何使用 CSS 在 HTML 上制作响应式导航栏，一切都很顺利，直到我尝试在屏幕中央添加文本，它出现在屏幕左侧（仅当窗口分辨率高于 952px 宽时）。我对 CSS 很陌生，我尝试修复它的所有内容似乎都不起作用。代码如下

* {
  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>