.flip-title {
  perspective: 1000px;
  margin-bottom: 25px;
  height: 40px;
}

.flip-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

.flip-title:hover .flip-inner {
  transform: rotateY(180deg);
}

.flip-front, .flip-back {
  position: absolute;
  width: 100%;
  backface-visibility: hidden;
  font-size: 26px;
  font-weight: bold;
  color: #0d47a1;
}

.flip-front {
  transform: rotateY(0deg);
}

.flip-back {
  transform: rotateY(180deg);
  color:  #0d47a1;
}

   body {
      background: linear-gradient(to right, #cfd9df, #e2ebf0);
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      margin: 0;
    }

    .converter-container {
      background-color: #ffffff;
      padding: 35px;
      border-radius: 20px;
      box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
      text-align: center;
      width: 420px;
      transition: transform 0.3s ease;
    }

    .converter-container:hover {
      transform: scale(1.02);
    }

    .converter-container h1 {
      color: #0d47a1;
      margin-bottom: 25px;
      font-size: 28px;
    }

    select, input[type="number"], button {
      width: 100%;
      padding: 12px;
      margin: 10px 0;
      border-radius: 10px;
      border: 1px solid #ccc;
      font-size: 16px;
      transition: all 0.3s ease;
    }

    select:hover, input[type="number"]:hover {
      border-color: #1565c0;
      box-shadow: 0 0 8px rgba(21, 101, 192, 0.3);
    }

    button {
      background-color: #1976d2;
      color: white;
      font-weight: bold;
      cursor: pointer;
      border: none;
    }

    button:hover {
      background-color: #0d47a1;
      box-shadow: 0 4px 12px rgba(13, 71, 161, 0.4);
    }

    .result {
      margin-top: 20px;
      font-size: 18px;
      font-weight: bold;
      color: #2e7d32;
    }