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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    background: white;
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    width: 100%;
    max-width: 500px;
    margin: 1rem;
}

.header {
    text-align: center;
    margin-bottom: 2rem;
}

.header h1 {
    color: #333;
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.header p {
    color: #666;
    font-size: 1rem;
}

.auth-container {
    margin-top: 2rem;
}

.auth-tabs {
    display: flex;
    margin-bottom: 1.5rem;
    border-radius: 10px;
    overflow: hidden;
    background: #f8f9fa;
}

.tab-btn {
    flex: 1;
    padding: 1rem;
    border: none;
    background: #f8f9fa;
    color: #666;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    font-weight: 500;
}

.tab-btn:hover {
    background: #e9ecef;
}

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

.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
}

.chat-form {
    display: none;
}

.chat-form.active {
    display: block;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 1rem;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

button[type="submit"] {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease;
}

button[type="submit"]:hover {
    transform: translateY(-2px);
}

.message {
    margin-top: 1rem;
    padding: 0.75rem;
    border-radius: 5px;
    text-align: center;
    display: none;
}

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

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

.main-content {
    margin-top: 1rem;
}

.user-info {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.user-info button {
    padding: 0.5rem 1rem;
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.user-info button:hover {
    background: #c82333;
}

.chat-options {
    margin-top: 1rem;
}

.option-tabs {
    display: flex;
    margin-bottom: 1.5rem;
    border-radius: 10px;
    overflow: hidden;
    background: #f8f9fa;
}

.chat-options h3 {
    color: #333;
    margin-bottom: 1rem;
    text-align: center;
}

@media (max-width: 600px) {
    .container {
        margin: 0.5rem;
        padding: 1.5rem;
    }
    
    .header h1 {
        font-size: 2rem;
    }
}