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

    body {
      background: linear-gradient(135deg, #6e8efb, #a777e3);
      height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .container {
      background: #fff;
      max-width: 400px;
      padding: 25px;
      margin: 10px;
      border-radius: 15px;
      box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
      text-align: center;
      transition: 0.3s ease-in-out;
    }

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

    /* ====== Title ====== */
    h1 {
      margin-bottom: 20px;
      color: #4b4b4b;
      font-size: 28px;
    }

    /* ====== Input Fields ====== */
    input {
      width: 90%;
      padding: 12px;
      margin: 10px 0;
      font-size: 16px;
      border: 2px solid #ddd;
      border-radius: 8px;
      outline: none;
      transition: 0.3s;
    }

    input:focus {
      border-color: #6e8efb;
      box-shadow: 0 0 5px #6e8efb;
    }

    button {
      width: 95%;
      padding: 12px;
      margin-top: 15px;
      font-size: 18px;
      font-weight: bold;
      background-color: #6e8efb;
      color: white;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      transition: 0.3s;
    }

    button:hover {
      background-color: #5a78e0;
    }

    /* ====== Result Box ====== */
    #result {
      margin-top: 20px;
      padding: 15px;
      font-size: 18px;
      color: #333;
      background: #f7f7f7;
      border-radius: 10px;
      border: 2px solid #ddd;
      box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    }

    /* ====== Grade Colors ====== */
    .grade-a-plus { color: #27ae60; font-weight: bold; }
    .grade-a { color: #2ecc71; font-weight: bold; }
    .grade-b { color: #f39c12; font-weight: bold; }
    .grade-c { color: #e67e22; font-weight: bold; }
    .grade-fail { color: #e74c3c; font-weight: bold; }