* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.language-selector {
    text-align: center;
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.lang-btn {
    padding: 8px 15px;
    background: rgba(255,255,255,0.2);
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 25px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-2px);
}

.lang-btn.active {
    background: white;
    color: #667eea;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

.contact-form {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

.contact-form h1 {
    margin-bottom: 30px;
    color: #333;
    text-align: center;
    font-size: clamp(1.5rem, 5vw, 2.5rem);
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
    font-size: clamp(0.9rem, 4vw, 1rem);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.form-group input.error,
.form-group textarea.error {
    border-color: #ff4444;
}

.error-message {
    color: #ff4444;
    font-size: 14px;
    margin-top: 5px;
    display: none;
}

.challenge-group {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
}

#challenge-question {
    font-weight: bold;
    color: #667eea;
}

button[type="submit"] {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

button[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

button[type="submit"]:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    display: none;
}

.form-message.success {
    display: block;
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.form-message.error {
    display: block;
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

/* Responsividade */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .contact-form {
        padding: 30px 20px;
    }
    
    .language-selector {
        gap: 8px;
    }
    
    .lang-btn {
        padding: 6px 12px;
        font-size: 12px;
    }
}

@media (max-width: 480px) {
    .contact-form {
        padding: 20px 15px;
    }
    
    .language-selector {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .lang-btn {
        flex: 1 1 auto;
        min-width: 80px;
        font-size: 11px;
        padding: 5px 8px;
    }
    
    .challenge-group {
        padding: 15px;
    }
}

/* Melhorias para tablets */
@media (min-width: 768px) and (max-width: 1024px) {
    .container {
        max-width: 700px;
    }
    
    .form-group input,
    .form-group textarea {
        padding: 15px;
        font-size: 18px;
    }
    
    button[type="submit"] {
        padding: 18px;
        font-size: 20px;
    }
}