/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

/* 页面容器 */
body {
    background-color: #000;
    min-height: 100vh;
}

.page-container {
    max-width: 720px;
    width: 100%;
    margin: 0 auto;
    background-color: #fff;
    min-height: 100vh;
    position: relative;
    padding-bottom: 60px;
}

/* 内容区域 */
.content {
    padding: 20px;
}

.placeholder {
    height: 1000px;
}

/* 底部导航 */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: #000;
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    justify-content: space-around;
    padding: 10px 0;
    z-index: 100;
}

.nav-item {
    color: #fff;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-size: 12px;
    padding: 8px 12px;
    border-radius: 8px;
    transition: background 0.3s;
}

.nav-item i {
    font-size: 18px;
    margin-bottom: 4px;
}

.nav-item:hover {
    background: rgba(255,255,255,0.1);
}

/* 响应式调整 */
@media (max-width: 480px) {
    .nav-item {
        font-size: 10px;
        padding: 6px 8px;
    }
    .nav-item i {
        font-size: 16px;
    }
}