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

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.header {
    background: rgba(255, 255, 255, 0.95);
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: #667eea;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #667eea;
}

.auth-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.7rem 1.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    display: inline-block;
}

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

.btn-primary:hover {
    background: #5a6fd8;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.hero {
    text-align: center;
    color: white;
    margin-bottom: 4rem;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.95);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.feature-card p {
    line-height: 1.6;
    color: #666;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 3rem 0;
}

.stat-card {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    color: white;
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.stat-label {
    opacity: 0.9;
}

.footer {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

.user-info {
    display: none;
    align-items: center;
    gap: 1rem;
    color: #333;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #667eea;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
}

.dropdown {
    position: relative;
}

.dropdown-content {
    display: none;
    position: absolute;
    right: 0;
    top: 100%;
    background: white;
    min-width: 200px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border-radius: 5px;
    z-index: 1000;
}

.dropdown-content a {
    display: block;
    padding: 0.7rem 1rem;
    color: #333;
    text-decoration: none;
    border-bottom: 1px solid #eee;
}

.dropdown-content a:hover {
    background: #f5f5f5;
}

.dropdown-content a:last-child {
    border-bottom: none;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        flex-direction: column;
        text-align: center;
    }
    
    .auth-buttons {
        flex-direction: column;
        width: 100%;
    }
}