body {
    font-family: Arial, sans-serif;
    max-width: 850px;
    margin: 40px auto;
    background: #f4f6f8;
    color: #222;
}

h1 {
    text-align: center;
}

.card {
    background: white;
    padding: 25px;
    margin: 25px 0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.12);
}

label {
    font-weight: bold;
}

input {
    width: 100%;
    padding: 8px;
    margin-top: 6px;
    margin-bottom: 18px;
}

button {
    padding: 10px 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.result {
    background: #e9ffe9;
    padding: 15px;
    border-radius: 8px;
    margin-top: 15px;
}