Fix on hover expands element - html

Question

I don't know how to solve this problem: on hover of 'a' elements the div enlarges and the other 'a' move.
Thanks for help
https://jsfiddle.net/0r2v2qyp/
Here html:
<a id="btn_agency" class="btn_presentation">Agenzia</a>
<a id="btn_student" class="btn_presentation">Studente</a>
<a id="btn_prof" class="btn_presentation">Docente</a>
<a id="btn_admin" class="btn_presentation">Segreteria</a>
And css:
.btn_presentation {
float: left;
margin: 10px;
color: royalblue;
font-size: 20px;
position: relative;
letter-spacing: 0;
text-transform: uppercase;
transition: all .2s ease-out;
}
.btn_presentation:after {
content: '';
position: relative;
display: block;
margin: 0 auto;
width: 0;
height: 0;
background: red;
transition: all .2s ease-out;
}
.btn_presentation:hover {
letter-spacing: 5px;
transition: all .3s ease-in;
}
.btn_presentation:hover:after {
width: 100%;
height: 2px;
transition: all .2s ease-in-out;
}

Answer 1

To be able to animate the letter-spacing, you have to give the div a fixed width wide enough to make up for the text when expanded.
div {
display: inline-block;
margin: 10px;
width: 120px;
}
.btn_presentation {
display: inline-block;
color: royalblue;
font-size: 20px;
position: relative;
letter-spacing: 0;
text-transform: uppercase;
transition: all .2s ease-out;
}
.btn_presentation:after {
content: '';
position: relative;
display: block;
margin: 0 auto;
width: 0;
height: 0;
background: red;
transition: all .2s ease-out;
}
.btn_presentation:hover {
letter-spacing: 5px;
transition: all .3s ease-in;
}
.btn_presentation:hover:after {
width: 100%;
height: 2px;
transition: all .2s ease-in-out;
}
<div>
<a id="btn_agency" class="btn_presentation">Agenzia</a>
</div>
<div>
<a id="btn_student" class="btn_presentation">Studente</a>
</div>
<div>
<a id="btn_prof" class="btn_presentation">Docente</a>
</div>
<div>
<a id="btn_admin" class="btn_presentation">Segreteria</a>
</div>
An option could instead be to scale it using transform
div {
display: inline-block;
margin: 10px;
}
.btn_presentation {
display: inline-block;
color: royalblue;
font-size: 20px;
position: relative;
letter-spacing: 0;
text-transform: uppercase;
transition: transform .2s ease-out;
}
.btn_presentation:after {
content: '';
position: relative;
display: block;
margin: 0 auto;
width: 0;
height: 2px;
background: red;
transition: width .2s ease-out;
}
.btn_presentation:hover {
transform: scale(1.2);
transition: transform .3s ease-in;
}
.btn_presentation:hover:after {
width: 100%;
transition: width .2s ease-in-out;
}
<div>
<a id="btn_agency" class="btn_presentation">Agenzia</a>
</div>
<div>
<a id="btn_student" class="btn_presentation">Studente</a>
</div>
<div>
<a id="btn_prof" class="btn_presentation">Docente</a>
</div>
<div>
<a id="btn_admin" class="btn_presentation">Segreteria</a>
</div>
Updated based on comment
This stretch the word only side ways
div {
display: inline-block;
margin: 10px;
}
.btn_presentation {
display: inline-block;
color: royalblue;
font-size: 20px;
position: relative;
letter-spacing: 0;
text-transform: uppercase;
transition: transform .2s ease-out;
}
.btn_presentation:after {
content: '';
position: relative;
display: block;
margin: 0 auto;
width: 0;
height: 2px;
background: red;
transition: width .2s ease-out;
}
.btn_presentation:hover {
transform: scaleX(1.2);
transition: transform .3s ease-in;
}
.btn_presentation:hover:after {
width: 100%;
transition: width .2s ease-in-out;
}
<div>
<a id="btn_agency" class="btn_presentation">Agenzia</a>
</div>
<div>
<a id="btn_student" class="btn_presentation">Studente</a>
</div>
<div>
<a id="btn_prof" class="btn_presentation">Docente</a>
</div>
<div>
<a id="btn_admin" class="btn_presentation">Segreteria</a>
</div>