nav {
    position: fixed;          /* 固定在视口 */
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: flex-start;  /* 靠左对齐 */
    gap: clamp(15px, 8vw, 80px);
    padding: clamp(20px, 8vw, 30px) clamp(12px, 8vw, 220px);          /* 左右留一些边距，不贴边 */
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(8px);
    z-index: 1000;
}

nav a {
    color: #f0f0f0;
    text-decoration: none;
    font-size: clamp(16px, 1.5vw, 24px);
    font-weight: 500;
    transition: 0.2s;
    letter-spacing: 3px;
}

nav a:hover {
    color: #aaa;
}

@media screen and (max-width: 768px) {
    nav {
        width: 100%;
    }
}