html, body {
    height: 100%;
    width: 100%;
}

.container{
    max-width: 1200px;
    width: 60%;
    margin: 0 auto;
    padding: 15px;
    text-align: center;
    margin-top: 30px;

    border: solid 2px #ccc;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
    background-color: #f9f9f9;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 20px;
}

.container .header {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 20px;
}

.container .header h1 {
    color: #333;
    font-size: 2.5rem;
}

.container .header p {
    color: #666;
    font-size: 1.2rem;
}

.input-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.input {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 10px;
}

.input label {
    font-size: 1.2rem;
    color: #333;
}

.input input {
    padding: 10px;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 5px;
    width: 100%;
    max-width: 300px;
}

#calculate-btn {
    margin-top: 20px;
    padding: 10px 20px;
    font-size: 1.2rem;
    color: #fff;
    background-color: #28a745;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

#calculate-btn:hover {
    background-color: #218838;
}

#calculate-btn:active {
    background-color: #1e7e34;
}

.result-container {
    margin-top: 15px;
    padding: 15px;
    border: 1px solid #ccc;
    border-radius: 5px;
    background-color: #e9ecef;
}

.result-container h2 {
    font-size: 1.5rem;
    color: #333;
}

.error-msg {
    display: none;
    color: red;
    font-size: 1rem;
    margin-top: 10px;
}

.footer {
    margin-top: 15px;
    border: solid 1px #ccc;
    padding: 20px;
    width: 80%;
    
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer p {
    color: #666;
    font-size: 1rem;
}

.footer h2 {
    color: #333;
    font-size: 1.5rem;
}

@media (max-width: 600px) {
    .container {
        width: 90%;
    }

    .input input {
        width: 100%;
    }

    .footer {
        padding: 10px;
    }
}