body {
    margin: 0;
    font-family: Noto Sans SC;
    position: relative;
    color: white;
    padding-top: 60px; /* 与导航栏高度相同 */
}


/** 导航栏 **/
nav {
    background: rgba(0, 0, 0, 0.5);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    z-index: 1000;
    /* 导航栏位于页面其他内容上，请确认页面内容高度与导航栏同步！padding-top=60px */
}

nav img {
    width: 120px;
    height: 50px;
    margin-left: 10px;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    position: absolute;
    left: 50px;
    margin-left: 120px;
}

nav ul li {
    margin-right: 20px;
}

nav ul li a {
    text-decoration: none;
    color: #fff;
    font-size: 16px;
    position: relative;
    z-index: 1;
}

nav div {
    display: flex;
    align-items: center;
}

nav div a {
    text-decoration: none;
    color: #fff;
    margin-left: 20px;
    font-size: 16px;
    position: relative;
    z-index: 1;
}

.menu-toggle {
    display: none;
    font-size: 24px;
    color: #fff;
    cursor: pointer;
    margin-right: 10px;
}

nav ul li a:hover {
    color: skyblue;
}

h1,
h2 {
    font-family: 'Noto Sans SC', sans-serif;
    font-weight: 500;
    text-align: center;
}

.warninfo {
    color: red;
    font-size: 24px;
}


.virus-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 20px;
}

.virus-item {
    background: rgba(0, 0, 0, 0.7);
    margin: 10px;
    padding: 20px;
    border-radius: 10px;
    width: 250px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

.virus-item p {
    margin: 10px 0;
    font-size: 18px;
}

.virus-item a {
    display: block;
    margin: 5px 0;
    color: #00bfff;
    text-decoration: none;
}

.virus-item a:hover {
    color: #ff8c00;
}

.virus-item:nth-last-of-type(6) a:nth-of-type(2) {
    text-decoration: line-through;
    text-decoration-thickness: 2px;
}

.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

.popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: 20px;
    border-radius: 10px;
    width: 700px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
    background: linear-gradient(45deg, #71c9ce, #7799CC);
}

.popup > p {
    padding-top: 3px;
}

.msg {
    font-size: 18px;
}

.note {
    font-size: 22px;
    color: yellow;
    text-align: center;
}

.OK {
    width: 144px;
    height: 50px;
    display: flex;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 16px;
    border: 3px, solid, #54acb0;
    border-radius: 5px;
    background: #208e94;
    border: 0;
    color: white;
    font-size: large;
}
/**footer**/
.footer {
    /* 移除 position: fixed 以及相关定位属性 */
    width: 100%;
    background-color: #333; /* 灰色背景 */
    color: white; /* 白色文字 */
    padding: 20px 0;
    /* 移除或者降低 z - index 值 */
    z-index: auto;
}

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

.footer-logo img {
    max-height: 50px; /* 调整logo大小 */
}

.footer-info {
    display: flex;
    flex-direction: column;
}

.footer-links a {
    color: white;
    text-decoration: none;
    margin-right: 15px;
}

.footer-links a:hover {
    text-decoration: underline;
}

.footer-contact {
    margin: 10px 0;
}

.footer-contact span {
    margin-right: 15px;
}

.footer-copyright {
    font-size: 0.9em;
}