Fix Font Responsiveness - html

Question

When you hover over the image, you will see that it will be replaced by the text block.
When you shrink the browser, you will see that the font size remains the same, although I specified it in EMs which should have made the font responsive.
I need the layout of the hover element remain the same in mobile view, i.e. I need to avoid the scrollbar that appears if you shrink the size of the browser. Any ideas how to achieve this?
/*Programs*/
ul.img-list {
list-style-type: none;
margin: 0;
padding: 0;
text-align: center;
}
ul.img-list li {
display: inline-block;
width: 100%;
height: 100%;
margin: 0;
position: relative;
}
div.text-content {
background: rgba(26,33,43,0.9);
color: white;
cursor: pointer;
left: 0;
position: absolute;
top: 0;
bottom: 0;
width: 100%;
height: 100%;
opacity: 0;
font-size: 1.250em;
font-family: Roboto;
line-height: 1em;
font-weight: 300;
text-align: center;
overflow-y: auto;
box-sizing: border-box;
padding-right: 25px;
padding-left: 25px;
padding-top: 25px;
padding-bottom: 25px;
-webkit-transition: opacity 500ms;
-moz-transition: opacity 500ms;
-o-transition: opacity 500ms;
transition: opacity 500ms;
text-align: center;
vertical-align: middle;
}
ul.img-list li:hover div.text-content {
opacity: 1;
}
/* Events page */
/*Event link button*/
.btn {
background-color: transparent;
border-radius: 42px;
border: 2px solid #ffffff;
display: inline-block;
cursor: pointer;
font-family: Roboto;
line-height: 1.750em;
font-size: 1.500em;
padding: 5px 15px 5px 15px;
margin-right: 45px;
margin-left: 45px;
}
.btn:link {
color: #ffffff;
text-decoration: none;
}
.btn:visited {
color: #1b1c16;
text-decoration: none;
}
.btn:hover {
background-color: #ffffff;
color: #1b1c16 !important;
}
.btn:active {
position: relative;
top: 1px;
}
/*All events button*/
.evens_btn {
background: ;
}
.events_btn>span{
color: #f9c70f;
font-family: Roboto;
color: #ffffff;
font-size: 1.5em !important;
background: ;
text-decoration: none !important;
padding: 10px 0px 10px 0px;
}
.events_btn>i{
color: #ffffff;
margin-right: 15px;
font-size: 3.125em;
}
.events_btn:link>i {
color: #f9c70f;
}
.events_btn:visited>i {
color: #ffffff;
text-decoration: none;
}
.events_btn:hover>i {
color: #f9c70f;
}
.events_btn:active>i {
color: #f9c70f;
}
.events_btn:link>span {
color: #f9c70f;
}
.events_btn:visited>span {
color: #ffffff;
text-decoration: none;
}
.events_btn:hover>span {
color: #f9c70f ;
}
.events_btn:active>span {
color: #f9c70f;
}
<ul class="img-list">
<li><img style="width: 100%; height: 100%;" src="http://www.sflsupport.org/wp-content/uploads/2016/06/Programs-11.jpg" />
<div class="text-content">
<div>
<h5 style="color: white; font-size: 2.375em; font-family: Montserrat; font-weight: 600; line-height: 1em; letter-spacing: 0.125em;">WEBINAR<br/>ARCHIVE</h5>
<hr style="border-top: 0.125em solid #ffffff; width: auto; margin: 0.625em 1.875em;"/>Throughout the years SFL has ammased the library of recorded webinars from some of the leading libertarian voices about numerous topics in philosophy, politics, and economics. How can the government fix the higher education bubble? What is Ayn Rand's theory of natural rights? Tune in to our videos for answers to these questions and many more.
<br>
<a class="btn" style="color: white; text-align: center; margin-top: 0.625em; padding-top: 0.313em; padding-bottom: 0.313em; padding-left: 1.875em; padding-right: 1.875em; text-decoration: none; font-size: 1.500em; font-weight: 600; border: 3px solid white; letter-spacing: 0.125em;" href="http://www.google.com/" target="_blank">READ MORE</a>
</div>
</div>
</li>
</ul>

Answer 1

You can simply set the font size in vw instead of em
/*Programs*/
ul.img-list {
list-style-type: none;
margin: 0;
padding: 0;
text-align: center;
}
ul.img-list li {
display: inline-block;
width: 100%;
height: 100%;
margin: 0;
position: relative;
}
div.text-content {
background: rgba(26,33,43,0.9);
color: white;
cursor: pointer;
left: 0;
position: absolute;
top: 0;
bottom: 0;
width: 100%;
height: 100%;
opacity: 0;
font-size: 3vw;
font-family: Roboto;
line-height: 1em;
font-weight: 300;
text-align: center;
overflow-y: auto;
box-sizing: border-box;
padding-right: 25px;
padding-left: 25px;
padding-top: 25px;
padding-bottom: 25px;
-webkit-transition: opacity 500ms;
-moz-transition: opacity 500ms;
-o-transition: opacity 500ms;
transition: opacity 500ms;
text-align: center;
vertical-align: middle;
}
ul.img-list li:hover div.text-content {
opacity: 1;
}
/* Events page */
/*Event link button*/
.btn {
background-color: transparent;
border-radius: 42px;
border: 2px solid #ffffff;
display: inline-block;
cursor: pointer;
font-family: Roboto;
line-height: 1.750em;
font-size: 1.500em;
padding: 5px 15px 5px 15px;
margin-right: 45px;
margin-left: 45px;
}
.btn:link {
color: #ffffff;
text-decoration: none;
}
.btn:visited {
color: #1b1c16;
text-decoration: none;
}
.btn:hover {
background-color: #ffffff;
color: #1b1c16 !important;
}
.btn:active {
position: relative;
top: 1px;
}
/*All events button*/
.evens_btn {
background: ;
}
.events_btn>span{
color: #f9c70f;
font-family: Roboto;
color: #ffffff;
font-size: 1.5em !important;
background: ;
text-decoration: none !important;
padding: 10px 0px 10px 0px;
}
.events_btn>i{
color: #ffffff;
margin-right: 15px;
font-size: 3.125em;
}
.events_btn:link>i {
color: #f9c70f;
}
.events_btn:visited>i {
color: #ffffff;
text-decoration: none;
}
.events_btn:hover>i {
color: #f9c70f;
}
.events_btn:active>i {
color: #f9c70f;
}
.events_btn:link>span {
color: #f9c70f;
}
.events_btn:visited>span {
color: #ffffff;
text-decoration: none;
}
.events_btn:hover>span {
color: #f9c70f ;
}
.events_btn:active>span {
color: #f9c70f;
}
<ul class="img-list">
<li><img style="width: 100%; height: 100%;" src="http://www.sflsupport.org/wp-content/uploads/2016/06/Programs-11.jpg" />
<div class="text-content">
<div>
<h5 style="color: white; font-size: 2.375em; font-family: Montserrat; font-weight: 600; line-height: 1em; letter-spacing: 0.125em;">WEBINAR<br/>ARCHIVE</h5>
<hr style="border-top: 0.125em solid #ffffff; width: auto; margin: 0.625em 1.875em;"/>Throughout the years SFL has ammased the library of recorded webinars from some of the leading libertarian voices about numerous topics in philosophy, politics, and economics. How can the government fix the higher education bubble? What is Ayn Rand's theory of natural rights? Tune in to our videos for answers to these questions and many more.
<br>
<a class="btn" style="color: white; text-align: center; margin-top: 0.625em; padding-top: 0.313em; padding-bottom: 0.313em; padding-left: 1.875em; padding-right: 1.875em; text-decoration: none; font-size: 1.500em; font-weight: 600; border: 3px solid white; letter-spacing: 0.125em;" href="http://www.google.com/" target="_blank">READ MORE</a>
</div>
</div>
</li>
</ul>