scroll option button doesn't work as expected

Question

Could you please check and advise why my scroll button doesn't work as expected?

It's my first project, so I believe there may be some mistakes, but have no idea why my scrolling "crashes".

I was expecting it to be only a pink one and have the smooth scroll option on the whole page, but it breaks into two lines. Unfortunately, I can't post the image, but basically, this "second" line is like the line in the standard browser and behind that line, I have my pink one.

{
    font-family: 'Poppings', sans-serif;
    margin: 0;
    padding: 0;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
    outline: none;
    border: none;
    text-decoration: none;
    text-transform: capitalize;
    -webkit-transition: all .2s linear;
    transition: all .2s linear;

}

html {
    font-size: 62.5%;
    overflow-x: hidden;
    scroll-behavior: smooth;
    scroll-padding-top: 9rem;

}

html::-webkit-scrollbar {
    width: 0.5rem;
}

html::-webkit-scrollbar-thumb {
    background: #d9296f;
}

body {
    padding: 0;
    margin: 0;
    background: #08122f;
    overflow-x: hidden;
}

section {
    padding: 3rem 9%;
}

.heading{
    text-align: center;
    margin-bottom: 2rem;
}

.heading span{
    color: #d9296f;
    font-size: 2rem;
}

.heading h1{
    font-size: 4rem;
    color: #8f7fa2;
}


.btn {
    margin-top: 1rem;
    display: inline-block;
    padding: 1rem 3rem;
    font-size: 1.7rem;
    color: #d9296f;
    border: 0.2rem solid #d9296f;
    border-radius: 5rem;
    cursor: pointer;
    background: none;
}


.btn:hover {
    background: #d9296f;
    color: #08122f;

}

/*---header---*/

.header{
    position: fixed;
    top:0;
    left: 0;
    right: 0;
    z-index: 1100;
    background: #08122f;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    -webkit-boxpack: justify;
    -ms-flex-pack: justify;
    justify-content: space-between;
    padding: 1.5rem 9%;
    box-shadow: 0 1px 6px 0 rgba(193, 193, 212, 0.28);
}

.header .navbar a{
    font-size: 2rem;
    color: #8f7fa2;
    display: inline-block;
    margin: 0 1rem;
}

.header .navbar a:hover{
    color: #d9296f;

}

.logo{
    font-size: 2.5rem;
    color: #8f7fa2;
    font-weight: bolder;

}

.logo span{
    color: #d9296f;
}

#menu-btn{
    font-size: 2.5rem;
    color:#8f7fa2;
    cursor: pointer;
    display: none;
}


/*--home---*/

.home{
    margin: auto;
    margin-top: auto;
    width: 80%;
    display: -webkit-box;
    display: -ms-webkit-box;
    display: flex;
    min-height: 80vh;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    padding-bottom: 5rem;
}

.home .content{
    text-align: center;
}

.home .content span{
    margin-top: 100px;
    font-weight: bolder;
    color: transparent;
    -webkit-text-stroke: 0.1rem #8f7fa2;
    font-size: 4vw;
    display: block;
    }

.home .content h3{
    font-size: 6vw;
    color: #8f7fa2;
}

.home .content p{
    max-width: 60rem;
    margin: 1rem auto;
    font-size: 1.4rem;
    color: #8f7fa2;
    margin-top: 18px;
    line-height: 2;
    letter-spacing: 1px;
}

/*--about--*/

.about{
    display: -webkit-box;
    -display: -ms-flexbox;
    display: flex;
    -webkit-boxalign: center;
    -ms-flex-align: center;
    align-items: center;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
    gap: 4rem;
    margin-top: 5rem;
}

.about .img-container{
    -webkit-box-flex: 1;
    -ms-flex: 1 1 42rem;
    flex: 1 1 42rem;
    width: 50%;
}

.about .img-container img{
    border-radius: 1rem;
    width: 40%;
    
}

.about .content{
    -webkit-box-flex: 1;
    -ms-flex: 1 1 42rem;
    flex: 1 1 42rem;
    margin-bottom: 10rem;
}

.about .content span{
    color: #d9296f;
    font-size: 2rem;
}

.about .content h3{
    color: #8f7fa2;
    font-size: 4rem;
    margin-top: .5rem;
}

.about .content p{
    padding: 1rem 0;
    font-size: 1.4rem;
    color: #8f7fa2;
    line-height: 2;
}

/*--Services--*/

.services .box-container{
    display: -ms-grid;
    display: grid;

    -ms-grid-column: (minmax(25rem, 1fr)) [auto-fit];
    grid-column: (minmax(25rem, 1fr)) [auto-fit];

    grid-template-columns: repeat(auto-fit, minmax(32rem, 1fr));
    gap: 1.5rem;
}

.services .box-container .box{
    background: #08122f;
    border-radius: 1rem;
    padding: 1rem;
    text-align: center;
    box-shadow: #8f7fa2;
}

.services .box-container .box:hover{
    transform: scale(1.05);
    background: #8f7fa2;
}

.services .box-container .box i{
    font-size: 4rem;
    color: #d9296f;
    margin-bottom: 3scrolrem;
}


.services .box-container .box h3{
    font-size: 2rem;
    color: #d9296f;[enter image description here][1]
}