body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
  }
  
  .app {
    text-align: center;
    width: 80%;
    max-width: 600px;
    padding: 20px;
    background-color: #f0f0f0;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  }
  
  h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
  }
  
  .contents {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
  }
  
  .break, .session {
    flex-basis: 45%;
    text-align: center;
  }
  
  .break button, .session button {
    font-size: 1.5rem;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
  }
  
  .break button:hover, .session button:hover {
    background-color: #0056b3;
  }
  
  .break span, .session span {
    font-size: 1.5rem;
    margin: 0 10px;
  }
  
  .timer {
    margin-bottom: 20px;
  }
  
  .timer h2 {
    font-size: 2rem;
    margin-bottom: 10px;
  }
  
  .timer span {
    display: block;
    font-size: 3rem;
  }
  
  .controls {
    margin-top: 20px;
  }
  
  .controls button {
    font-size: 1.5rem;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 4px;
    padding: 10px 20px;
    margin: 0 10px;
    cursor: pointer;
  }
  
  .controls button:hover {
    background-color: #218838;
  }