/* ============ 动态宇宙星空背景 ============ */
#cosmic-stars {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    display: block;
}

/* 星云光晕层 */
#cosmic-nebula {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    background:
        radial-gradient(ellipse 60% 40% at 20% 20%, rgba(90, 40, 160, 0.18), transparent 60%),
        radial-gradient(ellipse 50% 50% at 80% 30%, rgba(0, 100, 180, 0.15), transparent 60%),
        radial-gradient(ellipse 55% 45% at 70% 80%, rgba(180, 30, 120, 0.10), transparent 60%),
        radial-gradient(ellipse 45% 35% at 30% 70%, rgba(0, 160, 160, 0.10), transparent 60%);
}

/* 页面内容在星空之上 */
body > .main,
body > .site-header,
body > .site-footer,
.main {
    position: relative;
    z-index: 1;
}

/* 让侧边栏也高于星空 */
.site-sidebar {
    position: relative;
    z-index: 1;
}

/* 确保页面内容可正常滚动 */
body {
    position: relative;
}