.containerw {
       border: 1px solid #ced4da;
      text-align: center;
      background: #fff;
      padding: 15px;
      border-radius: 15px;
      box-shadow: 0 2px 8px rgba(16, 185, 129, 0.1);
    }
   .display {
  font-size: 48px; /* pehle 24px ya chhota hoga, ab bada */
  font-weight: bold;
  text-align: center;
  margin-bottom: 20px;
  color: #222; /* aap chahein to color bhi change kar sakte hain */
}
    .buttons {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 15px;
    }
    button {
      padding: 10px 20px;
      font-size: 1rem;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      transition: 0.3s ease;
      background: #007bff;
      color: white;
    }
    button:disabled {
      background: #999;
      color: #eee;
      cursor: not-allowed;
    }