body {
    background-color: #f4f4f9;
    margin: 0;
    padding: 0;
}
.container {
    max-width: 800px;
    margin: 50px auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
h1 {
    text-align: center;
    color: #333;
}
.currency-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px;
    border-bottom: 1px solid #eaeaea;
}
.currency-row:last-child {
    border-bottom: none;
}
.currency-row label {
    flex: 1;
    font-size: 1.1em;
    color: #555;
}
.currency-row input {
    flex: 1;
    padding: 10px;
    font-size: 1em;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin-right: 10px;
}
.currency-row button {
    padding: 10px 15px;
    background-color: #007bff;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}
.currency-row button:hover {
    background-color: #0056b3;
}
.message {
    text-align: center;
    padding: 10px;
    display: none;
    margin-top: 10px;
    border-radius: 4px;
}
.message.success {
    background-color: #d4edda;
    color: #155724;
}
.message.error {
    background-color: #f8d7da;
    color: #721c24;
}