<!DOCTYPE html>
<html lang="ru">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
    <div class="wrapper">
      <div class="container">
        <div class="bg-wrapper"></div>
        <h1 class="title-head">Заголовок</h1>
      </div>
  </div>
</body>
</html>
* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  position: relative;
  margin: 0;
  border: 20px solid #fff;
}

h1 {
  margin: 0;
}

.wrapper {
  background: #a8ff78;
  background: -webkit-linear-gradient(to right, #78ffd6, #a8ff78); 
  background: linear-gradient(to right, #78ffd6, #a8ff78);
  height: 100%;
  
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
}

.bg-wrapper {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100%;
  height: 100%;
  opacity: 0.8;
  background: #0F2027;
  background: -webkit-linear-gradient(to right, #2C5364, #203A43, #0F2027);  
  background: linear-gradient(to right, #2C5364, #203A43, #0F2027);
  filter: blur(150px);
}

.title-head {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #fff;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.