style.css

* {
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
}

body {
  padding: 0;
  margin: 0;
}

#notfound {
  position: relative;
  height: 100vh;
}

#notfound .notfound {
  position: absolute;
  left: 50%;
  top: 50%;
  -webkit-transform: translate(-50%, -50%);
      -ms-transform: translate(-50%, -50%);
          transform: translate(-50%, -50%);
}

.notfound {
  max-width: 410px;
  width: 100%;
  text-align: center;
}

.notfound .notfound-404 {
  height: 280px;
  position: relative;
  z-index: -1;
}

.notfound .notfound-404 h1 {
  font-family: 'Montserrat', sans-serif;
  font-size: 230px;
  margin: 0px;
  font-weight: 900;
  position: absolute;
  left: 50%;
  -webkit-transform: translateX(-50%);
      -ms-transform: translateX(-50%);
          transform: translateX(-50%);
  background: url('../img/bg.jpg') no-repeat;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-size: cover;
  background-position: center;
}


.notfound h2 {
  font-family: 'Montserrat', sans-serif;
  color: #000;
  font-size: 24px;
  font-weight: 700;
  text-transform: uppercase;
  margin-top: 0;
}

.notfound p {
  font-family: 'Montserrat', sans-serif;
  color: #000;
  font-size: 14px;
  font-weight: 400;
  margin-bottom: 20px;
  margin-top: 0px;
}

.notfound a {
  font-family: 'Montserrat', sans-serif;
  font-size: 14px;
  text-decoration: none;
  text-transform: uppercase;
  background: #0046d5;
  display: inline-block;
  padding: 15px 30px;
  border-radius: 40px;
  color: #fff;
  font-weight: 700;
  -webkit-box-shadow: 0px 4px 15px -5px #0046d5;
          box-shadow: 0px 4px 15px -5px #0046d5;
}


@media only screen and (max-width: 767px) {
    .notfound .notfound-404 {
      height: 142px;
    }
    .notfound .notfound-404 h1 {
      font-size: 112px;
    }
}