* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;

    font-family: Arial, sans-serif;

    background: #f2f4f7;
    color: #333;
}

.container {
    width: 90%;
    max-width: 700px;

    margin: 50px auto;
    padding: 30px;

    background: white;

    border-radius: 12px;

    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;

    margin-bottom: 15px;

    color: #2c3e50;
}

.description {
    text-align: center;

    color: #666;

    margin-bottom: 30px;
}

label {
    display: block;

    margin-top: 15px;
    margin-bottom: 6px;

    font-weight: bold;
}

input,
select {
    width: 100%;

    padding: 12px;

    font-size: 16px;

    border: 1px solid #ccc;
    border-radius: 6px;

    background: white;
}

input:focus,
select:focus {
    outline: none;

    border-color: #3498db;
}

button {
    width: 100%;

    margin-top: 25px;

    padding: 14px;

    border: none;
    border-radius: 6px;

    background: #27ae60;
    color: white;

    font-size: 17px;
    font-weight: bold;

    cursor: pointer;
}

button:hover {
    background: #219150;
}

.result {
    margin-top: 25px;

    padding: 20px;

    background: #eafaf1;

    border-left: 5px solid #27ae60;

    border-radius: 6px;
}

.result h2 {
    margin-top: 0;

    color: #219150;
}

.result p {
    line-height: 1.6;
}

.error {
    margin-top: 20px;

    padding: 15px;

    background: #fdecea;

    color: #c0392b;

    border-left: 5px solid #c0392b;

    border-radius: 6px;
}

@media (max-width: 600px) {

    .container {
        width: 95%;

        margin: 20px auto;

        padding: 20px;
    }

    h1 {
        font-size: 24px;
    }
}