    :root {
      --primary-color: #0f1523;
      --secondary-color: #0f1523;
      --accent-color: #e1cbbd;
      --error-color: #f14668;
      --text-color: #ffffff;
      --shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
      --radius: 20px;
      --transition: all 0.3s ease-in-out;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: 'Cairo', sans-serif;
    }

    body {
      background: #0f1523;
      color: var(--text-color);
      display: flex;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
      padding: 20px;
    }

    .calculator-container {
      background-color: rgba(29, 35, 57, 0.5);
      padding: 40px 30px;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      max-width: 450px;
      width: 100%;
      text-align: center;
      animation: fadeIn 0.8s ease-out;
    }

    h1 {
      font-size: 2.5rem;
      margin-bottom: 24px;
      color: #e1cbbd;
    }

    .form-group {
      margin-bottom: 24px;
      text-align: right;
    }

    label {
      display: block;
      font-size: 1rem;
      margin-bottom: 8px;
      color: var(--text-color);
    }

    input {
      width: 100%;
      padding: 12px;
      border: px solid var(--primary-color);
      border-radius: var(--radius);
      background: rgba(32, 33, 36, 0.5);
      color: var(--text-color);
      font-size: 1rem;
      text-align: right;
      transition: var(--transition);
    }

    input:focus {
      outline: none;
      border-color: var(--accent-color);
      box-shadow: 0 0 8px var(--accent-color);
    }

    .dimensions-group {
      display: flex;
      gap: 10px;
    }

    .dimensions-group input {
      flex: 1;
    }

    button {
      background-color: rgba(32, 33, 36, 0.5);
      color: #fff;
      padding: 14px 20px;
      border: none;
      border-radius: var(--radius);
      font-size: 1.1rem;
      font-weight: bold;
      cursor: pointer;
      transition: var(--transition);
      width: 100%;
      margin-top: 20px;
    }

    button:hover {
      background-color: #e1cbbd;
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    }

    .result,
    .error {
      margin-top: 20px;
      padding: 20px;
      border-radius: var(--radius);
      text-align: center;
      display: none;
    }

    .result {
      background-color: rgba(29, 35, 57, 0.5);
      border: px solid var(--accent-color);
      color: var(--accent-color);
      animation: slideIn 0.5s ease-out;
    }

    .result h3 {
    Color: #fff;
      margin-bottom: 10px;
    }

    .error {
      background-color: var(--error-color);
      border: 2px solid darkred;
      color: #fff;
      animation: shake 0.5s ease-out;
    }

    footer {
      margin-top: 20px;
      font-size: 0.8rem;
      text-align: center;
    }

    footer a {
      color: var(--accent-color);
      text-decoration: none;
    }

    footer a:hover {
      text-decoration: underline;
    }

    @keyframes fadeIn {
      from {
        opacity: 0;
        transform: translateY(20px);
      }

      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    @keyframes slideIn {
      from {
        opacity: 0;
        transform: translateY(10px);
      }

      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    @keyframes shake {
      0%, 100% {
        transform: translateX(0);
      }
      25% {
        transform: translateX(-5px);
      }
      50% {
        transform: translateX(5px);
      }
      75% {
        transform: translateX(-5px);
      }
    }