body {
    font-family: Arial, sans-serif;
    margin: 0;
    background: #f4f6f8;
    color: #333;
}

#login-screen, #app-screen {
    max-width: 800px;
    margin: auto;
    padding: 20px;
}

input, select, button {
    margin: 5px 0;
    padding: 8px;
    width: 100%;
    box-sizing: border-box;
}

button {
    background: #ff9800;
    color: white;
    border: none;
    cursor: pointer;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

canvas {
    background: white;
    margin: 20px 0;
    padding: 10px;
    border-radius: 8px;
}