Resizing div before parent - html

Question

When I resize the page the searchbox starts resizing after the padding of the parent if zero. I want to resize the div with class-"searchbox", with resizing the page not after the parent's padding is off. Here is the code I'll be glad if you correct me anywhere.
.site-wrapper {
max-width: 86.5rem;
min-height: 28rem;
padding: 0 4.3rem;
margin: 0 auto;
overflow: hidden;
}
.navbar {
display: flex;
justify-content: end;
padding-top: 2.7rem;
}
#hamburger-button {
position: relative;
width: 32px;
height: 32px;
border-radius: 4px;
cursor: pointer;
}
#hamburger-button:hover {
background-color: #0000001f;
}
#hamburger {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
border: none;
background-color: transparent;
background-image: url(/assets/menuicon.svg);
background-repeat: no-repeat;
background-size: contain;
padding: 9.2px;
margin: 0 auto;
cursor: pointer;
}
.header-content {
margin: 0 auto;
}
.header-content {
display: flex;
flex-direction: column;
align-items: center;
justify-content: center;
}
.header-content-logo {
margin-top: 5rem;
margin-bottom: 2.3rem;
}
.header-content-logo svg {
width: 12.6rem;
}
.searchbox {
display: flex;
align-items: center;
border-radius: 6px;
width: 100%;
max-width: 38.7rem;
height: 2.7rem;
background-color: #fff;
box-shadow: 0px 2px 6px 1px rgba(0, 0, 0, 0.1);
overflow: hidden;
}
.searchbox:hover {
box-shadow: 0px 6px 20px 6px rgba(0, 0, 0, 0.1);
}
.searchbox input {
width: 92%;
border: none;
background-color: transparent;
font-size: 11.8pt;
font-family: inherit;
padding-left: 1rem;
}
.searchbox input:focus {
outline: none;
}
<div class="site-wrapper">
<div class="navbar">
<div id="hamburger-button">
<button id="hamburger"></button>
</div>
</div>
<div class="header-content">
<div class="header-content-logo">
<svg>
</div>
<div class="searchbox">
<input type="text" placeholder="Search without being tracked">
</div>
</div>
</div>
I have tried putting margin and even making another div before it and putting padding but seems that it didn't make it work. I am out of options.