SOURCE

<div class="container">
  <h2>Contact Us</h2>
  <div class="row">
    <div class="col">
      <div class="form-group">
        <label>First Name</label>
        <input type="text" required="required">
      </div>
    </div>

    <div class="col">
      <div class="form-group">
        <label>Surname</label>
        <input type="text" required="required">
      </div>
    </div>

    <div class="col">
      <div class="form-group">
        <label>Email</label>
        <input type="text" required="required">
      </div>
    </div>

    <div class="col">
      <div class="form-group">
        <label>Phone</label>
        <input type="text" required="required">
      </div>
    </div>

    <div class="col">
      <div class="form-group">
        <label>Message</label>
        <textarea required="required"></textarea>
      </div>
    </div>

    <div class="col">
      <input type="submit" value="Submit">
    </div>
  </div>
</div>

* {
  margin: 0;
  padding: 0;
  border-size: border-box;
}

html, body {
  height: 100vh;
  background: #666666;
  font-family: 'Balsamiq Sans', sans-serif;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  width: 70%;
  padding: 30px 90px 90px 90px;
  border: 6px solid rgba(0, 0, 0, 0.3);
  box-shadow: 20px 20px 0 rgba(0, 0, 0, 0.3);
  border-radius: 50px;
  position: relative;
}

.container h2 {
  color: rgba(0, 0, 0, 0.3);
  font-size: 60px;
  text-transform: uppercase;
}

.container .row {
  position: relative;
  width: 100%;
  display: grid;
  grid: auto / auto auto;
  grid-template-columns: repeat(auto-fit,minmax(40%, 1fr));
  grid-gap: 30px;
}

.container .row .col {
  position: relative;
  width: 100%;
  margin: 30px 20px 40px 0;
  transition: 0.5s;
}

.container .row .form-group {
  position: relative;
  width: 100%;
  height: 40px;
  color: #ffffff;
}

.container .row .form-group input,
.container .row .form-group textarea {
  position: absolute;
  width: 90%;
  height: 100%;
  background: transparent;
  outline: none;
  font-size: 24px;
  padding: 10px 0 10px 20px;
  border: 5px solid rgba(0, 0, 0, 0.3);
  box-shadow: 10px 10px 0 rgba(0, 0, 0, 0.3);
  color: #ffffff;
  border-radius: 50px;
}

.container .row .form-group label {
  line-height: 40px;
  color: #ffffff;
  font-size: 24px;
  margin: 0 0 0 30px;
  display: block;
  pointer-events: none;
}

.row .col:nth-child(6) {
  margin-top: 64px;
}

.container .row .form-group input:focus,
.container .row .form-group textarea:focus {
  border: 5px solid #ffffff;
  transition: all 0.5s;
}

.container .row input[type="submit"] {
  border: 5px solid rgba(0, 0, 0, 0.3);
  box-shadow: 10px 10px 0 rgba(0, 0, 0, 0.3);
  padding: 10px;
  height: 100%;
  width: 50%;
  cursor: pointer;
  outline: none;
  background: transparent;
  text-transform: uppercase;
  color: #ffffff;
  line-height: 40px;
  font-size: 24px;
  font-weight: 700;
  border-radius: 45px;
  transition: all 0.4s;
}

.container .row input[type="submit"]:hover {
  border: 5px solid rgba(255, 255, 255, 1);
  color: #ffffff;
  transition: all 0.4s;
}

@media screen and (max-width: 900px) {
  .container .row {
    grid-template-columns: repeat(auto-fit,minmax(70%, 1fr));
  }
  
    .container {
    padding: 20px;
  }
  
  .container h2 {
    font-size: 34px;
  }
  
  .container .row input[type="submit"] {
    width: 100%;
  }
}