Image not showing animation after hover - html

Question

I'm trying to show an animation whenever the cursor both hovers & leaves an image link, but for some reason whenever my cursor leaves the image, no animation occurs:
.soc {
display: block;
font-size: 0;
list-style: none;
margin: 0;
text-align: center;
}
.soc li {
display: inline-block;
margin: 12px;
margin: 1.2rem;
}
.soc a, .soc svg {
display: block;
}
.soc a {
position: relative;
height: 50px;
height: 5.0rem;
width: 50px;
width: 5.0rem;
}
.soc svg {
height: 100%;
width: 100%;
}
.soc em {
font-size: 14px;
line-height: 1.5;
margin-top: -0.75em;
position: absolute;
text-align: center;
top: 50%;
right: 0;
bottom: 0;
left: 0;
}
.icon-twitter:hover {
border-radius: 100%;
color: #fff;
fill: #fff;
-webkit-transform: scale(1.25);
transform: scale(1.25);
-webkit-transition: background-color 0.5s, -webkit-transform 0.5s ease-out;
transition: background-color 0.5s, -webkit-transform 0.5s ease-out;
transition: background-color 0.5s, transform 0.5s ease-out;
transition: background-color 0.5s, transform 0.5s ease-out, -webkit-transform 0.5s ease-out;
}
.icon-twitter
{
color: #000;
fill: #000;
}
.icon-twitter:hover {
background: #00aced;
}
<ul class="soc">
<li><a href="#" class="icon-twitter" title="Twitter">
<svg viewBox="0 0 512 512">
<path d="M419.6 168.6c-11.7 5.2-24.2 8.7-37.4 10.2 13.4-8.1 23.8-20.8 28.6-36 -12.6 7.5-26.5 12.9-41.3 15.8 -11.9-12.6-28.8-20.6-47.5-20.6 -42 0-72.9 39.2-63.4 79.9 -54.1-2.7-102.1-28.6-134.2-68 -17 29.2-8.8 67.5 20.1 86.9 -10.7-0.3-20.7-3.3-29.5-8.1 -0.7 30.2 20.9 58.4 52.2 64.6 -9.2 2.5-19.2 3.1-29.4 1.1 8.3 25.9 32.3 44.7 60.8 45.2 -27.4 21.4-61.8 31-96.4 27 28.8 18.5 63 29.2 99.8 29.2 120.8 0 189.1-102.1 185-193.6C399.9 193.1 410.9 181.7 419.6 168.6z"/>
</svg>
<!--[if lt IE 9]><em>Twitter</em><![endif]--></a></li>
</ul>

Answer 1

Put the transition property on the element itself, not on the hover state. Otherwise it won't affect the element when it is not hovered.
.soc {
display: block;
font-size: 0;
list-style: none;
margin: 0;
text-align: center;
}
.soc li {
display: inline-block;
margin: 12px;
margin: 1.2rem;
}
.soc a,
.soc svg {
display: block;
}
.soc a {
position: relative;
height: 50px;
height: 5.0rem;
width: 50px;
width: 5.0rem;
}
.soc svg {
height: 100%;
width: 100%;
}
.soc em {
font-size: 14px;
line-height: 1.5;
margin-top: -0.75em;
position: absolute;
text-align: center;
top: 50%;
right: 0;
bottom: 0;
left: 0;
}
.icon-twitter {
color: #000;
fill: #000;
border-radius: 100%;
transition: background-color 0.5s, -webkit-transform 0.5s ease-out;
transition: background-color 0.5s, transform 0.5s ease-out;
transition: background-color 0.5s, transform 0.5s ease-out, -webkit-transform 0.5s ease-out;
-webkit-transition: background-color 0.5s, -webkit-transform 0.5s ease-out;
}
.icon-twitter:hover {
color: #fff;
fill: #fff;
-webkit-transform: scale(1.25);
transform: scale(1.25);
background: #00aced;
}
<ul class="soc">
<li>
<a href="#" class="icon-twitter" title="Twitter">
<svg viewBox="0 0 512 512">
<path d="M419.6 168.6c-11.7 5.2-24.2 8.7-37.4 10.2 13.4-8.1 23.8-20.8 28.6-36 -12.6 7.5-26.5 12.9-41.3 15.8 -11.9-12.6-28.8-20.6-47.5-20.6 -42 0-72.9 39.2-63.4 79.9 -54.1-2.7-102.1-28.6-134.2-68 -17 29.2-8.8 67.5 20.1 86.9 -10.7-0.3-20.7-3.3-29.5-8.1 -0.7 30.2 20.9 58.4 52.2 64.6 -9.2 2.5-19.2 3.1-29.4 1.1 8.3 25.9 32.3 44.7 60.8 45.2 -27.4 21.4-61.8 31-96.4 27 28.8 18.5 63 29.2 99.8 29.2 120.8 0 189.1-102.1 185-193.6C399.9 193.1 410.9 181.7 419.6 168.6z"/>
</svg>
<!--[if lt IE 9]><em>Twitter</em><![endif]--></a>
</li>
</ul>