body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.calculator-container {
    background-color: #ffffff;
    padding: 30px 40px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    max-width: 400px;
    width: 90%;
    text-align: center;
}

h1 {
    color: #333;
    margin-bottom: 25px;
    font-size: 1.8em;
}

.input-group {
    margin-bottom: 20px;
    text-align: left;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #555;
}

input[type="date"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #ced4da;
    border-radius: 6px;
    box-sizing: border-box;
    font-size: 16px;
    transition: border-color 0.3s;
}

input[type="date"]:focus {
    border-color: #007bff;
    outline: none;
}

button {
    background-color: #007bff;
    color: white;
    padding: 12px 25px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    transition: background-color 0.3s, transform 0.1s;
    width: 100%;
    margin-top: 10px;
}

button:hover {
    background-color: #0056b3;
}

button:active {
    transform: scale(0.98);
}

.result {
    margin-top: 30px;
    padding: 15px;
    background-color: #f8f9fa;
    border: 1px dashed #adb5bd;
    border-radius: 6px;
    color: #333;
    font-size: 1.1em;
    font-weight: 500;
    min-height: 20px; /* Ensures space even when empty */
    text-align: center;
}