<div class="card">
  <div class="gradient-border">
    <div class="content-wrapper">Hey, nice border!</div>
  </div>
</div>

.card {
  margin: 2rem auto;
  width: 350px;
}

.gradient-border {
  background-image: linear-gradient(#ff8a00 50%, transparent 50%);
  border: 1px solid #dadada;
  border-radius: 16px;
  padding: 35px;
}

.content-wrapper {
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.25);
  padding: 35px;
  text-align: center;
}