overflow scroll not adjusting height of div - html

Question

My issue:
I'm making somewhat of a Zillow clone. I need the page to not expand beyond 100% of the viewport height however, I'm making a section with the intentions of having the overflow property set to scroll. When I do this, the section expands beyond the viewport height and leaves a large whitespace at the bottom of my page. I can adjust the height to fill up to 100vh however, if I adjust the screen vertically the div with the scroll overflow doesn't adjust to the viewport height. Thanks for any and all help!
Here's a screenshot of my issue:
The circled section is the section that I need the overflow to scroll:
This is my HTML for the entire 'popup' portion:
<div class="home__popup--backdrop">
<div class="home__popup--container">
<div class="home__popup--left">
<div class="home__popup--img--container">
<div class="home__popup--img--main--container">
<img src="./src/img/home-0.jpg" alt="home-0" class="home__popup--img--main">
</div>
<div class="home__popup--img--sub--container">
<img src="./src/img/home-1.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-2.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-3.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-4.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-5.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-0.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-1.jpg" alt="home-0" class="home__popup--img--sub">
<img src="./src/img/home-2.jpg" alt="home-0" class="home__popup--img--sub">
</div>
</div>
</div>
<div class="home__popup--right">
<div class="home__popup--header--container">
<div class="home__popup--logo--container">
<div class="logo__container--home">
<img src="./src/img/logo__house.svg" alt="logo-homes" class="logo logo__homes logo__homes--small">
</div>
<div class="logo__container--txt">
<img src="./src/img/logo__txt.svg" alt="logo-homes" class="logo logo__homes logo__txt--small">
</div>
</div>
<div class="home__popup--social--container">
<div class="home__popup--social">
<img src="./src/img/like.svg" alt="logo like" class="popup__logo logo__like">
<p>Save</p>
</div>
<div class="home__popup--share">
<div class="home__popup--social">
<img src="./src/img/next.svg" alt="logo next" class="popup__logo logo__next">
<p>Share</p>
</div>
</div>
<div class="home__popup--more">
<div class="home__popup--social">
<img src="./src/img/more.svg" alt="logo more" class="popup__logo logo__more">
<p>More</p>
</div>
</div>
</div>
</div>
<div class="home__popup--details--container">
<div class="home__popup--details">
<p class="home__popup--price">$500,000</p>
<p class="home__popup--beds home__popup--details--home">3 <span>bds</span></p>
<p class="home__popup--baths home__popup--details--home">2 <span>ba</span></p>
<p class="home__popup--sqft home__popup--details--home">2,245 <span>sqft</span></p>
</div>
<div class="home__popup--address--container">
<p class="home__popup--address">
4210 sharman rd<span>,&nbsp</span>
</p>
<p class="home__popup--city">Madison<span>,&nbsp</span></p>
<p class="home__popup--state">WI</p>
</div>
<div class="home__popup--btn--container">
<button class="btn__agent">Contact Agent</button>
</div>
</div>
<div class="home__popup--overview--container">
<div class="home__popup--overview--container--links">
<img src="./src/img/001-left-arrow.svg" alt="arrow-left" class = 'arrow-small arrow-small--left'>
<div class="home__popup--overview home__popup--overview--active home__popup--overview--container--links--text--container" data-list-section = 0>
<p class="home__popup--overview--text home__popup--overview--container--links--text">Overview</p>
</div>
<div class="home__popup--facts home__popup--overview--container--links--text--container">
<p class="home__popup--facts--text home__popup--overview--container--links--text">Facts and features</p>
</div>
<div class="home__popup--value home__popup--overview--container--links--text--container">
<p class="home__popup--value--text home__popup--overview--container--links--text">Home value</p>
</div>
<div class="home__popup--history home__popup--overview--container--links--text--container" data-list-section = 1>
<p class="home__popup--history--text home__popup--overview--container--links--text">Price and tax history</p>
</div>
<div class="home__popup--monthly home__popup--overview--container--links--text--container">
<p class="home__popup--monthly--text home__popup--overview--container--links--text">Monthly cost</p>
</div>
<div class="home__popup--rental home__popup--overview--container--links--text--container">
<p class="home__popup--rental--text home__popup--overview--container--links--text">Rental Value</p>
</div>
<div class="home__popup--schools home__popup--overview--container--links--text--container" data-list-section = 2>
<p class="home__popup--schools--text home__popup--overview--container--links--text">Nearby schools</p>
</div>
<div class="home__popup--similar home__popup--overview--container--links--text--container">
<p class="home__popup--similar--text home__popup--overview--container--links--text">Similar homes</p>
</div>
<div class="home__popup--neighborhood home__popup--overview--container--links--text--container">
<p class="home__popup--neighborhood--text home__popup--overview--container--links--text">Neighborhood</p>
</div>
<div class="home__popup--homes-for-you home__popup--overview--container--links--text--container">
<p class="home__popup--homes-for-you--text home__popup--overview--container--links--text">Homes for you</p>
</div>
<img src="./src/img/002-right-arrow.svg" alt="arrow-right" class = 'arrow-small arrow-small--right'>
</div>
<div class="home__popup--scroll">
<div class="home__popup--home--detail--container">
<div class="home__popup--map--container">
<div class="test" id = "home__popup--map"></div>
</div>
<div class="home__popup--text--container">
<div class="home__popup--text--stats">
<P class="home__popup--text--header">Overview</P>
<div class="home__popup--text--user-activity">
<p class="home__popup--text--time">Time on Home Finder &nbsp<span> --</span></p>
<p class="home__popup--text--views">Views <span>64</span></p>
<p class="home__popup--text--saves">Saves <span>1</span></p>
</div>
<p class="home__popup--text--description">
No showings until 8/22 OH.....
</p>
<p class="home__popup--text--read-more">Read more</p>
</div>
<p class="home__popup--text--open-house--header">Open House</p>
<p class="home__popup--text--open-house--day">Sun, Aug 22</p>
<p class="home__popup--text--open-house--time">12:00 PM - 2:00 PM</p>
<ul class="home__popup--text--agent--container">
<li class="home__popup--text--agent">Kavita Biyani</li>
<li class="home__popup--text--agent">Nik Tantardini</li>
<li class="home__popup--text--agent">First Weber INC</li>
<li class="home__popup--text--agent">Lena Oberwetter</li>
<li class="home__popup--text--agent">Prince Michael</li>
</ul>
<div class="home__popup--overview--text">
</div>
<div class="home--popup--overview--specs">
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
Here's the HTML for the overflowed portion:
<div class="home__popup--scroll">
<div class="home__popup--home--detail--container">
<div class="home__popup--map--container">
<div class="test" id = "home__popup--map"></div>
</div>
<div class="home__popup--text--container">
<div class="home__popup--text--stats">
<P class="home__popup--text--header">Overview</P>
<div class="home__popup--text--user-activity">
<p class="home__popup--text--time">Time on Home Finder &nbsp<span> --</span></p>
<p class="home__popup--text--views">Views <span>64</span></p>
<p class="home__popup--text--saves">Saves <span>1</span></p>
</div>
<p class="home__popup--text--description">
No showings until 8/22 OH. Amazing opportunity ...
</p>
<p class="home__popup--text--read-more">Read more</p>
</div>
<p class="home__popup--text--open-house--header">Open House</p>
<p class="home__popup--text--open-house--day">Sun, Aug 22</p>
<p class="home__popup--text--open-house--time">12:00 PM - 2:00 PM</p>
<ul class="home__popup--text--agent--container">
<li class="home__popup--text--agent">Kavita Biyani</li>
<li class="home__popup--text--agent">Nik Tantardini</li>
<li class="home__popup--text--agent">First Weber INC</li>
<li class="home__popup--text--agent">Lena Oberwetter</li>
<li class="home__popup--text--agent">Prince Michael</li>
</ul>
<div class="home__popup--overview--text">
</div>
<div class="home--popup--overview--specs">
</div>
</div>
</div>
Here is the relevant css:
.home__popup {
&--home--detail--container {
}
&--text {
&--description{
font-size: 1.8rem;
font-weight: 300;
color: $color-grey-text;
line-height: 1.3;
}
&--user-activity{
display: flex;
margin-bottom: 2rem;
font-size: 1.4rem;
color: $color-grey-text;
& span{
color: black;
}
}
&--time{
margin-right: 2rem;
border-right: 1px solid $color-grey-medium;
& span{
font-weight: bold;
margin-right: 2rem;
}
}
&--saves{
margin-left: 2rem;
& span{
font-weight: bold;
}
}
&--views{
margin-right: 2rem;
border-right: 1px solid $color-grey-medium;
& span{
font-weight: bold;
margin-right: 2rem;
}
}
&--header {
font-size: 2rem;
font-weight: 700;
letter-spacing: 0.5px;
margin-bottom: 2rem;
}
&--container {
margin-top: 2rem;
display: flex;
flex-direction: column;
margin-left: 1rem;
}
}
&--btn {
&--container {
margin-top: 1rem;
margin-left: 1rem;
display: flex;
justify-content: space-between;
width: 100%;
position: relative;
}
}
&--address {
&--container {
display: flex;
font-weight: 300;
font-size: 1.6rem;
margin-left: 1rem;
margin-top: 1rem;
}
}
&--baths {
margin-left: 0.5rem;
}
&--beds {
margin-left: 2rem;
}
&--price {
margin-top: 3rem;
font-size: 2.5rem;
font-weight: 500;
margin-left: 1rem;
}
&--social {
cursor: pointer;
&--container {
display: flex;
align-items: center;
width: 45%;
justify-content: space-around;
}
}
&--backdrop {
width: 100vw;
height: 100vh;
z-index: 2999;
position: absolute;
top: 0;
left: 0;
backdrop-filter: blur(2px);
background-color: rgba(0, 0, 0, 0.671);
}
&--container {
position: absolute;
top: 0;
left: 50%;
height: 100vh;
width: 65vw;
background-color: white;
transform: translateX(-50%);
z-index: 3000;
backdrop-filter: blur(2px);
display: flex;
flex-direction: row;
}
&--left {
position: relative;
width: 60%;
overflow-y: scroll;
}
&--right {
width: 40%;
position: relative;
}
&--img {
&--main {
height: auto;
object-fit: cover;
width: 100%;
}
&--sub {
height: 25rem;
object-fit: cover;
width: 49.5%;
margin-bottom: 0.4rem;
&--container {
display: flex;
flex-wrap: wrap;
justify-content: space-between;
align-items: center;
}
}
}
&--header {
&--container {
display: flex;
justify-content: space-between;
position: relative;
border-bottom: 1px solid #6060607a;
margin-left: 1rem;
margin-right: 1rem;
}
}
&--logo {
&--container {
display: flex;
transform: translateY(1rem);
}
&__homes {
&--small {
height: 6rem;
width: 7rem;
}
}
}
&--details {
display: flex;
align-items: flex-end;
&--container {
display: flex;
flex-direction: column;
position: relative;
}
&--home {
font-size: 1.6rem;
font-weight: 400;
& span {
border-right: 1px solid $color-grey-text;
padding-right: 0.5rem;
font-weight: 300;
}
}
}
&--sqft {
margin-left: 0.5rem;
& span {
border-right: none;
}
}
&--overview {
color: $color-primary;
border-bottom: 2px solid $color-primary;
&--container {
display: flex;
flex-direction: column;
position: relative;
&--links {
display: flex;
overflow-x: scroll;
font-size: 14px;
font-weight: 300;
height: 5rem;
align-items: center;
margin-top: 2rem;
border-top: 1px solid $color-grey-medium;
border-bottom: 1px solid $color-grey-medium;
margin-left: 0.5rem;
margin-right: 0.5rem;
&::-webkit-scrollbar {
display: none;
}
&--text {
margin-left: 1rem;
margin-right: 1rem;
width: max-content;
&--container {
cursor: pointer;
height: 100%;
display: flex;
align-items: center;
transition: .2s all;
&:hover {
color: $color-primary-light;
}
}
}
}
}
}
}

Answer 1

I was having way too many issues out of pure stubbornness of not wanting to change my css however, I finally gave in and refactored the section as a grid. I'm now able to get it to function properly. Here's what it looks like:
And here's the css for the grid-layout:
&--right {
width: 40%;
position: relative;
display: grid;
grid-template-columns: repeat(2, 1fr);
grid-template-rows: 5rem 20rem 5rem auto;
}
here's the CSS for the updated div containing the scroll bar:
&--scroll{
grid-column: 1/-1;
grid-row: 4/5;
overflow-y: scroll;
overflow-x: hidden;
}