/* 基础样式设置 */
html, body {
    overscroll-behavior-x: none; /* 禁止浏览器默认的水平滑动行为（如手势导航） */
    width: 100%;
    overflow-x: hidden; /* 防止水平滚动 */
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f5f7;
    color: #333;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased; /* 字体抗锯齿优化 */
}

.container {
    max-width: 100%;
    margin: 0 auto;
    overflow: visible; /* 确保 sticky 定位生效 */
}

/* 回到顶部按钮样式 */
.back-to-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #0071e3;
    color: white;
    border: none;
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.3);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    z-index: 1000;
    transform: translateY(20px);
}

.back-to-top-btn.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top-btn:hover {
    background-color: #005bbd;
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 113, 227, 0.4);
}

@media (max-width: 768px) {
    .back-to-top-btn {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 1.1rem;
    }
}