body {
    font-family: Arial, sans-serif;
    margin: 0;
    background: #f5f5f5;
}

header {
    background: #3f51b5;
    color: white;
    padding: 16px;
    text-align: center;
}

main {
    display: flex;
    gap: 20px;
    padding: 20px;
    flex-wrap: wrap;
}

/* Cards */
.registration-form,
.attendee-list {
    flex: 1;
    min-width: 300px;
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

form {
    display: flex;
    flex-direction: column;
}

label {
    margin-top: 10px;
    font-weight: bold;
}

input, select {
    padding: 10px;
    margin-top: 5px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

/* Button */
button {
    margin-top: 15px;
    padding: 10px;
    background: #3f51b5;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:disabled {
    background: #ccc;
}

/* Table */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

th {
    background: #3f51b5;
    color: white;
}

td, th {
    padding: 8px;
    border: 1px solid #ddd;
}

/* Actions */
.action-btn {
    margin-right: 5px;
    cursor: pointer;
    border: none;
    padding: 5px 8px;
    border-radius: 4px;
}

.edit {
    background: orange;
    color: white;
}

.delete {
    background: red;
    color: white;
}

/* Error */
.error {
    color: red;
    font-size: 12px;
    display: none;
}