Why is the transform property not working - css

Question

So I know that two transforms don't apply at the same time. But at hover, they can replace each other?! Following is the code for a button I am trying to make, but when I hover, the properties don't seem to work! Also, the down-arrow I am trying to insert in there is also not exactly at the center. So due to which I have to use padding to center it!
.btn__bg {
position: absolute;
display: inline-block;
opacity: 0;
top: 75%;
left: 50%;
transform: translate(-50%, -50%);
height: 60px;
width: 60px;
background-color: #000;
border-radius: 50%;
text-align: center;
animation: fadeInTop 1.2s forwards ease-out 1.5s;
transition: all .2s;
box-shadow: 0 4px 40px rgba(0,0,0,.3);
}
.btn__content {
font-size: 30px;
color: #fff;
font-weight: 100;
text-decoration: none;
line-height: normal;
}
.btn__down--text {
display: inline-block;
vertical-align: middle;
}
.btn__bg:hover {
transform: translate(-50%, -50%) scale(1.5);
}
.btn__bg:hover ~ .btn__down--text {
vertical-align: middle;
}
<div class="header__main--text">
<h1 class="header__heading--primary usr-res">welcome</h1>
<a href="#" class="btn btn__bg btn__content usr-res">
<span class="btn__down--text">&downarrow;</span>
</a>
</div>
Any help would be appreciated!

Answer 1

It's not really clear what you mean: The scaling works (?)
The vertical position of the arrow can be adjusted with a margin-top on the span which contains it.
.btn__bg {
position: absolute;
display: inline-block;
opacity: 1;
top: 75%;
left: 50%;
transform: translate(-50%, -50%);
height: 60px;
width: 60px;
background-color: white;
border-radius: 50%;
text-align: center;
animation: fadeInTop 1.2s forwards ease-out 1.5s;
transition: all .2s;
box-shadow: 0 4px 40px rgba(0,0,0,.3);
}
.btn__content {
font-size: 30px;
color: #000;
font-weight: 100;
text-decoration: none;
line-height: normal;
}
.btn__down--text {
display: inline-block;
margin-top:0.3em;
}
.btn__bg:hover {
transform: translate(-50%, -50%) scale(1.5);
}
.btn__bg:hover ~ .btn__down--text {
vertical-align: middle;
}
<div class="header__main--text">
<h1 class="header__heading--primary usr-res">welcome</h1>
<a href="#" class="btn btn__bg btn__content usr-res">
<span class="btn__down--text">&downarrow;</span>
</a>
</div>