* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

body {
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 800px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

.header {
    background: #2c3e50;
    color: white;
    padding: 20px;
    text-align: center;
    position: relative;
}

.header h1 {
    font-size: 24px;
    margin-bottom: 5px;
}

.header p {
    font-size: 14px;
    opacity: 0.8;
}

.form-section {
    padding: 30px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #2c3e50;
}

input, select, textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
    transition: all 0.3s;
}

input:focus, select:focus, textarea:focus {
    border-color: #3498db;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
    outline: none;
}

.btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 14px 20px;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s;
    margin-bottom: 10px;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.btn-primary {
    background: #3498db;
}

.btn-primary:hover {
    background: #2980b9;
}

.btn-success {
    background: #27ae60;
}

.btn-success:hover {
    background: #219653;
}

.radio-group, .checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 10px;
}

.radio-group label, .checkbox-group label {
    display: flex;
    align-items: center;
    font-weight: normal;
    cursor: pointer;
    padding: 12px 15px;
    border-radius: 6px;
    transition: all 0.2s ease;
    border: 1px solid #eee;
    background: #f8f9fa;
}

.radio-group label:hover, .checkbox-group label:hover {
    background-color: #e8f4fd;
    border-color: #3498db;
}

input[type="radio"], input[type="checkbox"] {
    width: auto;
    margin-right: 10px;
    transform: scale(1.2);
}

textarea {
    resize: vertical;
    min-height: 120px;
}

.alert {
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 20px;
    text-align: center;
    font-weight: 600;
}

.alert-success {
    background: #e8f6ef;
    color: #27ae60;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #fdeaea;
    color: #e74c3c;
    border: 1px solid #f5c6cb;
}

.invitation-section {
    text-align: center;
    padding: 40px 20px;
}

.invitation-section h2 {
    margin-bottom: 30px;
    color: #2c3e50;
    border-bottom: none;
}

.main-form {
    margin-top: 20px;
}

.form-section-title {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
    color: #2c3e50;
    font-size: 18px;
    font-weight: 600;
}

.footer {
    text-align: center;
    padding: 15px;
    font-size: 12px;
    color: #7f8c8d;
    border-top: 1px solid #eee;
}

.question-section {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    border-left: 4px solid #3498db;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.loading {
    text-align: center;
    padding: 20px;
    display: none;
}

.spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto 15px;
    border: 4px solid rgba(52, 152, 219, 0.2);
    border-left: 4px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@media (max-width: 600px) {
    .form-section {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 20px;
    }
    
    .question-section {
        padding: 15px;
    }
}