如何使文本下方的图像变暗

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;700&display=swap');
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Open Sans', sans-serif;
  font-weight: 400;
  position: relative;
}

a {
  text-decoration: none;
  color: #fff;
}

ul {
  list-style: none;
}

img {
  display: block;
  max-width: 100%;
}

.container {
  max-width: 1170px;
  margin: 0 auto;
  display: block;
  width: 100%;
  padding: 0 15px;
}

.header {
  position: absolute;
  width: 100%;
  padding: 15px 0;
  top: 0;
  left: 0;
  z-index: 2;
}

.header__container {
  display: flex;
  align-items: center;
}

.menu {
  text-transform: uppercase;
  font-size: 16px;
  margin-left: auto;
}

.menu > ul {
  display: grid;
  grid-template-columns: repeat(4, auto);
  grid-gap: 10px;
}

.menu__link {
  position: relative;
  display: inline-block;
}

.menu__link::after {
  position: absolute;
  content: '';
  display: block;
  width: 100%;
  height: 1px;
  background-color: white;
  transform-origin: left top;
  transition: transform 0.2s ease-in-out;
}

.menu__link:hover::after {
  transform: scaleX(0);
}

.header__logo {
  width: 179px;
  min-width: 100px;
  margin-right: 20px;
}


/* Интро */

.intro {
  position: relative;
  background: url(https://netology-code.github.io/html-2-diploma/sources/images/banner-bg.jpg) no-repeat center;
  background-size: cover;
  min-height: 100vh;
  z-index: 1;
  display: flex;
  align-items: center;
}

.intro::before {
  position: absolute;
  display: block;
  content: '';
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background-color: rgba(0, 0, 0, 0.5);
}

.intro__title {
  color: #fff;
  text-align: center;
  font-size: 45px;
}

@media (max-width: 500px) {
  .intro__title {
    font-size: 8vw;
  }
  .menu {
    font-size: 13px;
  }
  
  .menu > ul {
    grid-template-columns: repeat(3, auto);
  }
}

@media (max-height: 200px) {
  .intro__title {
    font-size: 9vh;
  }
}

<header class="header">
  <div class="container">
    <div class="header__container">
      <div class="header__logo">
        <a href="#">
          <img src="https://netology-code.github.io/html-2-diploma/sources/images/noemi-logo.svg">
        </a>
      </div>
      <nav class="menu">
        <ul>
          <li class="menu__item">
            <a class="menu__link" href="#">Главная</a>
          </li>
          <li class="menu__item">
            <a class="menu__link" href="#">Посты</a>
          </li>
          <li class="menu__item">
            <a class="menu__link" href="#">Статьи</a>
          </li>
          <li class="menu__item">
            <a class="menu__link" href="#">Теги</a>
          </li>
          <li class="menu__item">
            <a class="menu__link" href="#">Темы</a>
          </li>
          <li class="menu__item">
            <a class="menu__link" href="#">Контакты</a>
          </li>
        </ul>
      </nav>
    </div>
  </div>
</header>

<div class="intro">
  <div class="container">
    <div class="intro__title">
      <h3>Блог о творчестве, спорте, и образе жизни</h3>
    </div>
  </div>
</div>

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;700&display=swap');

body {
  font-family: 'Open Sans', sans-serif;
  font-weight: 400;
  margin: 0px;
}

a {
    text-decoration: none;
    color: #fff;
}

ul {
    padding-left: 0px;
    display: flex;
}

li {
    list-style-type: none;
    padding-left: 35px;
}

h1 {
  margin: 0;
}

p {
  margin: 0;
}

.menu {
    text-transform: uppercase;
    margin-left: auto;
    margin-top: 28px;
  font-size: 13px;
}

.header {
    display: flex;
}

.container {
    
    width: 1170px;
    margin-right: auto;
    margin-left: auto;
}

.logo {
    width: 179px;
    height: 41px;
    margin-top: 28px
}

/* Интро */

.intro {
    display: block;
    padding-bottom: 120px;
    background-image: url(https://netology-code.github.io/html-2-diploma/sources/images/banner-bg.jpg);
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
    margin-bottom: 64px;
    /*Решение*/
    box-shadow: inset 0 0 0 200vw rgba(0,0,0,.5)
}

.title {
  color: #fff;
  text-align: center;
  font-size: 45px;
  padding-left: 200px;
  padding-right: 200px;
  
}

.date {
  opacity: 50%;
  display: inline-block;
  margin-right: 14px;
}

.author {
  font-weight: 700;
  display: inline-block;
  margin-bottom: ;
  
}

.img {
 display: block;
 width: 381px;
}

.tag {
  text-transform: uppercase;
  font-weight: 700;
  color: #b59f5b;
  font-size: 14px;
  margin-right: 19px;
}

.block {
  display: flex;
  margin-bottom: 59px;
  width: 790px;
  
}

.block-title {
  text-transform: uppercase;
  margin-top: 15px;
  margin-bottom: 37px;
}

.text {
    margin-left: 31px;
}

.text-d {
  margin-top: 54px;
}

<div class="intro">
    <div class="container">
        <!-- Хэдер -->
        <header>
            <div class="header">
                <div class="logo">
                    <a href="#">
                        <img src="https://netology-code.github.io/html-2-diploma/sources/images/noemi-logo.svg">
                    </a>
                </div>
                <nav class="menu">
                    <ul>
                        <li>
                            <a href="#">Главная</a>
                        </li>
                        <li>
                            <a href="#">Посты</a>
                        </li>
                        <li>
                            <a href="#">Статьи</a>
                        </li>
                        <li>
                            <a href="#">Теги</a>
                        </li>
                        <li>
                            <a href="#">Темы</a>
                        </li>
                        <li>
                            <a href="#">Контакты</a>
                        </li>
                    </ul>
                </nav>
            </div>
            <div class="title">
                <h3>Блог о творчестве, спорте, и образе жизни</h3>
            </div>  
        </header>
    </div>
</div>

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;700&display=swap');
body {
  font-family: 'Open Sans', sans-serif;
  font-weight: 400;
  margin: 0px;
}

a {
  text-decoration: none;
  color: #fff;
}

ul {
  padding-left: 0px;
  display: flex;
}

li {
  list-style-type: none;
  padding-left: 35px;
  text-shadow:  0 0 3px #000, 0 0 3px #000,  0 0 3px #000;
    background: #0004;
}

h1 {
  margin: 0;
  background: #0004;
}

p {
  margin: 0;
}

.menu {
  text-transform: uppercase;
  margin-left: auto;
  margin-top: 28px;
  font-size: 13px;
}

.header {
  display: flex;
}

.container {
  width: 1170px;
  margin-right: auto;
  margin-left: auto;
}

.logo {
  width: 179px;
  height: 41px;
  margin-top: 28px
}


/* Интро */

.intro {
  display: block;
  padding-bottom: 120px;
  background-image: url(https://netology-code.github.io/html-2-diploma/sources/images/banner-bg.jpg);
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  margin-bottom: 64px;
}

.title {
  color: #fff;
  text-align: center;
  font-size: 45px;
  padding-left: 200px;
  padding-right: 200px;
}

h3 {
  text-shadow: 0 0 3px #000,  0 0 3px #000,  0 0 3px #000;
    background: #0004;
  box-shadow: 0 0 4px #0004;

  }

<div class="intro">
  <div class="container">
    <!-- Хэдер -->
    <header>
      <div class="header">
        <div class="logo">
          <a href="#">
            <img src="https://netology-code.github.io/html-2-diploma/sources/images/noemi-logo.svg">
          </a>
        </div>
        <nav class="menu">
          <ul>
            <li>
              <a href="#">Главная</a>
            </li>
            <li>
              <a href="#">Посты</a>
            </li>
            <li>
              <a href="#">Статьи</a>
            </li>
            <li>
              <a href="#">Теги</a>
            </li>
            <li>
              <a href="#">Темы</a>
            </li>
            <li>
              <a href="#">Контакты</a>
            </li>
          </ul>
        </nav>
      </div>
      <div class="title">
        <h3>Блог о творчестве, спорте, и образе жизни</h3>
      </div>
    </header>
  </div>
</div>