画面サイズによってページ下に白い空白ができる

HTML
<!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">
    <title>Document</title>
    <link rel="stylesheet" href="web.css">
    <script   src="https://code.jquery.com/jquery-3.6.0.js"   integrity="sha256-H+K7U5CnXl1h5ywQfKtSj8PCmoN9aaq30gDh27Xc0jk="   crossorigin="anonymous"></script>

</head>
<body id='dosukoi'>
    <header class="webheader pageheader">
<h1><a href="web.html"></a>文房具の魅力</h1>



<nav class="hambarger">
    
    <ul class="pagenav">
<li class="tamtam menu "><a href="pencil.html">ペンシル</a></li>
<li class="tamtam menu "><a href="ballpen.html">ボールペン</a></li>
<li class="tamtam menu "><a href="fountain.html">万年筆</a></li>
<li class="tamtam menu "><a href="pencase.html">ペンケース</a></li>

    </ul>
</nav>
    </header>
 
    <div class="hambarger tamtam">
<span class="icon"></span>
<span class="icon"></span>
<span class="icon"></span>
    </div>

    <div class="stationary pageheader">
    <h2 class="gold">Stationary is beautiful</h2>
    <p class="sub">〜文房具で日常を優雅に〜</p>

    </div>
  

 
    <script src="web.js"></script>
</body>
</html>

CSS
html {
    font-size: 100%;
}
h2{font-size: 18px;}
.pagenav{
    
    font-size: 1.35remrem;
    text-transform: uppercase;
    list-style: none;

}
h1{
    font-weight: bold;
}
body{

    background-image: url(images/background.jpg);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center top;

   
}


.pagenav a {  
    color: #32605a;
  
    
}
a{
    text-decoration: none;
}


.pagenav li{
    left: 20px;
}



 header h1{margin-top: 15px;
    margin-left: 80px;
    font-size: 35px;
}
 .pageheader{
     max-width: 1100px;
     margin: 0 auto;
     padding: 0 4%;
 }
 .stationary{
     text-align: center;
     margin-top: 10%;
 }
 .gold{
     font-size: 3.5rem;
     text-transform: none;
     font-weight: normal;
     font-family: serif;
    
 }
 @media(max-width:750px){
     .gold{
         font-size: 2.0rem;}
     .sub{
         font-size: 1.5rem;
     }    
     header h1{
         font-size: 2.0rem;
     }
 }
 .sub{
     font-family: fantasy;
     font-size: 1.0rem;
 }
body{
    color: white;
}
.menu{

   display: block;
   transition: all 0.5s;
   
   opacity: 0;
   border-bottom: 1px solid black;

}

.hambarger{
    display: block;
    font-size: 18px;
    position: fixed;
top: 30px;
left: 30px;
width: 30px;
height: 32px;
cursor: pointer;
}
.hambarger span{
    position: absolute;
    display: block;
    left: 0;
    width: 30px;
    height: 2px;
    background-color: black;
    transition: all 0.5s;
    border-radius: 4px;
}

.hambarger span:nth-child(1){
    top: 4px;
    
}
.hambarger span:nth-child(2){
    top: 15px;
    
}
.hambarger span:nth-child(3){
    bottom: 4px;
}

.pagenav a:nth-child(1){
    top: 10px;
    }
    .pagenav a:nth-child(2){
        top: 20px;
    }



    ul{
        position: absolute;
        top: 20px;
        left: 0;
        width: 120px;
        padding: 0;
    }
.open{
    opacity: 1;
    left: 5px;
  }