<div class="mainimage">
    <p class="mainimage-text">
      <span>Beautiful sunset</span>
    </p>
    <p class="mainimage-sub-text">Nice gradient sky</p>
  </div>

@import url('https://fonts.googleapis.com/css2?family=Caveat&family=Paytone+One&display=swap');
* {
  margin: 0;
  padding: 0;
  line-height: 1;
  box-sizing: border-box;
}
body {
  background: #05243c;
  height:100%;
}
.mainimage {
  max-width: 600px;
  min-height: 200px;
  margin: 0 auto;
  position: absolute;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.mainimage-text {
  margin: 0 auto;
  text-align: center;
  font-family: 'Paytone One', sans-serif;
  font-size: 100px;
  line-height: 1em;
  color: transparent;
}

.mainimage span {
  display: block;
  max-width: 600px;
  height: 200px;
  background: url("https://picsum.photos/id/980/600/400") no-repeat center center;
  -webkit-background-clip: text;
  background-clip: text;
  background-size: cover ;
}

.mainimage::before {
  content: "";
  display: block;
  width: 60px;
  height: 60px;
  position: absolute;
  top: -60px;
  left: -100px;
  border-style: solid;
  border-width: 1px 0 0 1px;
  border-color: rgba(255, 255, 255, 0.5);
}

.mainimage-text::after {
  content: "";
  display: block;
  width: 60px;
  height: 60px;
  position: absolute;
  bottom: -60px;
  right: -100px;
  border-style: solid;
  border-width: 0 1px 1px 0;
  border-color: rgba(255, 255, 255, 0.5);
}

.mainimage span::before {
  content: "";
  display: block;
  width: 20px;
  height: 20px;
  position: absolute;
  top: -80px;
  left: -120px;
  border-style: solid;
  border-width: 0 1px 1px 0;
  border-color: rgba(255, 255, 255, 0.5);
}

.mainimage span::after {
  content: "";
  display: block;
  width: 20px;
  height: 20px;
  position: absolute;
  bottom: -80px;
  right: -120px;
  border-style: solid;
  border-width: 1px 0 0 1px;
  border-color: rgba(255, 255, 255, 0.5);
}

.mainimage-sub-text {
  display:block;
  font-family: 'Caveat', cursive;
  font-size: 75px;
  line-height:1em;
  color: rgba(255, 255, 255, 0.2);
  position: absolute;
  bottom: -25px;
  right: -100px;
  transform: rotate(-7deg);
  z-index: -10;
}