Text on an image with vignette effect CSS

I am trying to create a page banner which is an image with text over it. There are two things I am facing trouble with two things.

1. I need a smooth vignette effect on these images so that the text is clearly visible. I have tried the following but am not happy with the end result. I would like to get something as shown in the following image which shows a kind of smooth transition.

2. The text hides below the vignette effect. I tried using z-index but it does not work.

body {
  margin: 0px;
}

#page-banner img {
  width: 100%;
  object-fit: cover;
  height: 48vh;
}

#page-banner .vignette:after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 100%;
  -webkit-box-shadow: inset 20em 5em 15em black;
  -moz-box-shadow: inset 20em 5em 15em black;
  box-shadow: inset 20em 5em 15em black;
  z-index: 0;
}

#page-banner .text {
  width: 50%;
  right: 50%;
  z-index: 1;
}

#page-banner .text-over-image {
  position: relative;
}

#page-banner .text-over-image p {
  font-size: 60px;
  color: white;
  margin: 0;
  position: absolute;
  top: 50%;
  left: 15%;
  right: 45%;
  transform: translate(-10%, -50%);
}

<section id="page-banner">
  <div class="text-over-image vignette">
    <img src="https://wallpaperaccess.com/full/5117570.jpg">
    <div class="text">
      <p>I am trying to learn adding vignette to images</p>
    </div>
  </div>
</section>