body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f9f9f9;
}

.survey-container {
    background: white;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    padding: 20px;
    max-width: 500px;
    width: 100%;
    text-align: center;
}

.logo {
    width: 100px;
    margin-bottom: 20px;
}

.welcome-section {
    margin-bottom: 20px;
}

.progress-bar {
    width: 100%;
    background-color: #e0e0e0;
    border-radius: 8px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-bar-inner {
    height: 10px;
    background-color: #4CAF50;
    width: 0;
    transition: width 0.3s;
}

.question {
    display: none;
}

.question.active {
    display: block;
}

.button {
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.error {
    color: red;
    font-size: 12px;
}