<span class="bordered">Главная</span>

body {
  background-color: #000;
}

.bordered {
  display: inline-block;
  position: relative;
  padding: 2rem 3rem;
  font-family: sans-serif;
  font-size: 2rem;
  color: #fff;
}

.bordered::before,
.bordered::after {
  display: block;
  content: '';
  position: absolute;
  width: 50%;
  height: 50%;
  border: 0 solid #ff0;
}

.bordered::before {
  left: 0;
  top: 0;
  border-left-width: 2px;
  border-top-width: 2px;
}

.bordered::after {
  right: 0;
  bottom: 0;
  border-right-width: 2px;
  border-bottom-width: 2px;
}