I got a problem in HTML and CSS in creating a reponsive website

body {
  background-color: #a7bcb9;
  color: #ffffff;
  font-family: Parkinsans, sans-serif;
  margin: 50px 50px 0px 50px;
  display: flex;
  flex-direction: column;
  min-height: 95vh;
}

.main {
  flex: 1;
}

h1 {
  font-size: 5rem;
  text-align: center;
}

footer {
  text-align: right;
  color: midnightblue;
}

.tile-image {
  float: left;
  width: 200px;
  margin-right: 5%;
}

.card {
  width: 45%
}

.left {
  float: left;
}

.right {
  float: right;
}

.life {
  font-style: italic;
  color: #49beb7;
}

@media (max-width: 680px) {
  h1 {
    font-size: 3.5rem;
    text-align: center;
  }
  .card {
    width: 100%;
    display: block;
    margin-bottom: 30px;
    text-align: justify;
  }
  .card img {
    width: 100%;
    height: auto;
    margin-bottom: 10px;
    display: block;
    object-fit: cover;
  }
}

<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Parkinsans:[email protected]&display=swap" rel="stylesheet">

<div class="main">
  <h1>philosophy of <br><span class="life">life</span></h1>
  <div class="left card"><img class="tile-image" src="https://placehold.co/600x400" alt="luffy's gear 5ᵗʰ">
    <h2 class="card-title">leason of Life</h2>
    <p>The things you do in this life is always worth nothing in the end.</p>
  </div>

  <div class="right card"><img class="tile-image" src="https://placehold.co/600x400" alt="luffy's gear 5ᵗʰ">

    <h2 class="card-title">leason of Life 2</h2>
    <p>Acumalating wealth is not your job but Acumalating knowlede is.</p>
  </div>
</div>

<footer>
  <p>Create. Develop. Design.</p>
</footer>