body {
    font-family: system-ui, sans-serif;
    margin: 0;
    padding: 0;
}

main {
    max-width: 800px;
    margin: 0 auto;
    padding: 24px;
}

#messages {
    border: 1px solid #ddd;
    padding: 12px;
    min-height: 200px;
    border-radius: 8px;
}

.msg {
    padding: 8px 0;
}

.msg .role {
    font-weight: 600;
    margin-right: 8px;
}

form {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

input {
    flex: 1;
    padding: 10px;
    border-radius: 6px;
    border: 1px solid #ccc;
}

button {
    padding: 10px 16px;
    border: 1px solid #333;
    background: #fff;
    border-radius: 6px;
    cursor: pointer;
}