body {
    font-family: 'Segoe UI', sans-serif;
    background: #f5f7fa;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: auto;
    background: #ffffff;
    padding: 30px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 16px;
}

th, td {
    padding: 12px 15px;
    border: 1px solid #ddd;
    text-align: left;
}

thead {
    background-color: #007BFF;
    color: #ffffff;
}

tr:nth-child(even) {
    background-color: #f2f2f2;
}

.error {
    color: red;
    font-weight: bold;
    text-align: center;
}