body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f6;
    margin: 0;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
}
.container {
    background: #ffffff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    width: 100%;
    max-width: 500px;
}
h1 {
    font-size: 24px;
    color: #333;
    margin-bottom: 20px;
    text-align: center;
}
input[type="text"], input[type="number"] {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}
button {
    width: 100%;
    padding: 12px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
}
button:disabled {
    background-color: #cccccc;
}
.hidden {
    display: none;
}
.field-block {
    margin-bottom: 15px;
}
.field-block label {
    font-weight: 600;
    font-size: 14px;
    color: #555;
}
.controls {
    margin-top: 20px;
    border-top: 1px solid #eee;
    padding-top: 20px;
}
#status {
    margin-top: 15px;
    text-align: center;
    font-weight: bold;
    color: #28a745;
}