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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: #f8f9fa;
    color: #333;
}

/* 导航栏 */
.navbar {
    background: #ffffff;
    border-bottom: 1px solid #e9ecef;
    padding: 1rem 2rem;
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: #333;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i {
    color: #007bff;
}

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

.nav-links a {
    color: #6c757d;
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: #007bff;
}

/* 主内容区 */
.main-content {
    flex: 1;
    padding: 3rem 2rem;
}

.content-wrapper {
    max-width: 1200px;
    margin: 0 auto;
}

.hero-section {
    text-align: center;
    margin-bottom: 3rem;
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #212529;
    font-weight: 600;
}

.hero-section p {
    font-size: 1.1rem;
    color: #6c757d;
    line-height: 1.6;
}

/* 登录方式卡片 */
.login-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
}

.method-card {
    background: #ffffff;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 2rem;
    transition: box-shadow 0.2s, transform 0.2s;
    cursor: pointer;
}

.method-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.method-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #007bff;
}

.method-card h3 {
    color: #212529;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
}

.method-card p {
    color: #6c757d;
    line-height: 1.6;
    font-size: 0.9rem;
    text-align: center;
}

/* 底部栏 */
.footer {
    background: #ffffff;
    border-top: 1px solid #e9ecef;
    padding: 2rem;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: #6c757d;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #007bff;
}

.copyright {
    color: #adb5bd;
    font-size: 0.85rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 1.75rem;
    }

    .hero-section p {
        font-size: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .navbar {
        padding: 1rem;
    }

    .login-methods {
        grid-template-columns: 1fr;
    }
}