/* 公共样式文件 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
header {
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 1.5rem;
    font-weight: bold;
    color: #2c3e50;
}

.logo::before {
    content: '';
    width: 32px;
    height: 32px;
    flex: 0 0 auto;
    background: url('../images/logo.png') no-repeat center / contain;
}

.logo a {
    text-decoration: none;
    color: inherit;
}

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

.nav-menu a {
    text-decoration: none;
    color: #333;
    transition: color 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #3498db;
}

/* 页脚样式 */
footer {
    background-color: #2c3e50;
    color: #fff;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: #667eea;
    color: #fff;
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #5568d3;
}

/* 响应式设计 */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
}