<div class="card">
  <img src="https://hsto.org/webt/5f/05/be/5f05beec7f6a9551235894.jpeg" alt="">
  <form action="#">
    <h3>Title form</h3>
    <input type="text">
    <button>Send</button>
  </form>
</div>

.card {
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  display: flex;
  img {
    width: 100%;
    height: auto;
  }
}

form {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  margin: auto;
  background: rgba(255,255,255, .9);
  max-width: 400px;
  max-height: 200px;
  
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  border-radius: 8px;
  border: 1px solid #c2c2c2;
  box-shadow: 0 0 25px 0px rgba(207,202,202,0.9);
  h3 {
    color: #35373A;
    margin: 0 0 15px 0;
  }
  input {
    width: 80%;
    padding: 0 5px;
    margin-bottom: 15px;
  }
  button {
    color: #35373A;
  }
}