* {
                        box-sizing: border-box;
                        font-family: "Cairo", Arial, sans-serif;
                    }

                    body {
                        background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
                        margin: 0;
                        padding: 20px;
                        display: flex;
                        justify-content: center;
                        align-items: center;
                        min-height: 100vh;
                    }

                    .calculator {
                        background: #1e1e2f;
                        padding: 40px;
                        border-radius: 20px;
                        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
                        width: 100%;
                        max-width: 600px;
                        color: white;
                    }

                    h2 {
                        text-align: center;
                        margin-bottom: 30px;
                        color: #00d4ff;
                        font-size: 26px;
                    }

                    .form-group {
                        margin-bottom: 20px;
                    }

                    label {
                        font-weight: bold;
                        display: block;
                        margin-bottom: 8px;
                        font-size: 16px;
                    }

                    input {
                        width: 100%;
                        padding: 14px;
                        border-radius: 10px;
                        border: none;
                        background: #2c2c3e;
                        color: white;
                        font-size: 16px;
                    }

                    input:focus {
                        outline: 2px solid #00d4ff;
                    }

                    button {
                        width: 100%;
                        padding: 16px;
                        margin-top: 15px;
                        background: #00d4ff;
                        color: black;
                        border: none;
                        border-radius: 10px;
                        font-size: 18px;
                        font-weight: bold;
                        cursor: pointer;
                        transition: 0.3s;
                    }

                    button:hover {
                        background: #00aacc;
                    }

                    .result {
                        margin-top: 30px;
                        background: #2c2c3e;
                        padding: 20px;
                        border-radius: 12px;
                        font-size: 18px;
                    }

                    .result p {
                        margin: 12px 0;
                    }

                    @media (max-width: 480px) {
                        .calculator {
                            padding: 25px;
                        }

                        h2 {
                            font-size: 20px;
                        }

                        input,
                        button {
                            font-size: 14px;
                        }

                        .result {
                            font-size: 16px;
                        }
                    }