Не используйте div для стилизации, вместо этого используйте псевдоэлементы .topic_text
div.
.topic_text:before,
.topic_text:after {
content: "";
border-bottom: 2px solid #fdb239;
position: absolute;
width: calc(100% + 2em); /* adjust as required */
left: -1em;
}
.topic_text:before {
top: -.25em;
/* adjust as required */
}
.topic_text:after {
bottom: -.25em;
}
.topic {
display: flex;
font-family: Tahoma, Geneva, sans-serif;
justify-content: center;
align-items: center;
font-weight: 700;
font-size: calc(0.8em + 2.3vw);
margin-top: 1em;
}
.topic_symbols {
color: #ee290b;
}
.topic_text {
text-align: center;
color: #3cae3f;
position: relative;
}
<div class="topic">
<div class="topic_symbols">@</div>
<div class="topic_text">THIS IS THE SAMPLE TEXT</div>
<div class="topic_symbols">@</div>
</div>