style.css

* {
    margin: 0;
    padding: 0;
  }
  body {
    width: 100%;
    height: 100vh;
    background-image: url(images/2345540.png);
    background-position: center;
    background-size: cover;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    justify-content: center;
    align-items: center;
    display: flex;
  }

  .heading_container {
    padding: 1rem;
    max-width: 300px;
    flex-direction:inherit;
    position: relative;
    border-radius: 10px;
    background-color: rgba(0, 0, 0, 0.6);
  }

  .stopwatch_container {
    padding: 1rem;
    max-width: 300px;
    text-align: center;
    position: relative;
    border-radius: 10px;
    background-color: rgba(0, 0, 0, 0.6);
  }

  .time {
    text-align: center;
    padding: 1rem 0;
    font-size: 2rem;
  }

  h1,
  p {
    color: #f8f8f8;
  }

  button {
    padding: 0.4rem 1rem;
    margin: 0 0.2rem;
    border-radius: 10px;
    border: 1px solid #f8f8f8;
  }

  button:hover {
    background-color: rgba(0, 0, 0, 0.4);
    color: #f8f8f8;
  }