body {
    font-family: Arial, sans-serif;
    margin: 0;
    background: #f0f2f5;
}

.container {
    max-width: 700px;
    margin: 30px auto;
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

h1, h2 {
    text-align: center;
    margin-bottom: 30px;
}

form label {
    display: block;
    margin-top: 15px;
    font-weight: bold;
}

input[type=text], input[type=password], button {
    width: 100%;
    padding: 12px;
    border-radius: 5px;
    border: 1px solid #ccc;
    box-sizing: border-box;
    margin-top: 5px;
}

button {
    background: #4CAF50;
    color: white;
    font-weight: bold;
    border: none;
    margin-top: 20px;
    cursor: pointer;
}

button.delete {
    background: #e74c3c;
}

.success {
    background: #d4edda;
    padding: 15px;
    border: 1px solid #c3e6cb;
    border-radius: 8px;
    margin-bottom: 20px;
}

table {
    border-collapse: collapse;
    width: 100%;
    margin-top: 30px;
}

th, td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: left;
}

th {
    background: #f8f8f8;
}

@media (max-width: 600px) {
    .container {
        margin: 10px;
    }

    table, thead, tbody, th, td, tr {
        display: block;
    }

    thead {
        display: none;
    }

    tr {
        margin-bottom: 15px;
        background: #fff;
        padding: 10px;
        border-radius: 8px;
        box-shadow: 0 0 5px rgba(0,0,0,0.1);
    }

    td {
        padding: 5px 0;
    }

    td:before {
        content: attr(data-label);
        font-weight: bold;
        display: block;
        margin-bottom: 5px;
    }
}