/* 公用星空背景 v2 */
.starfield{position:fixed;inset:0;z-index:0;pointer-events:none;opacity:0;transition:opacity 1.6s ease}
.starfield.auto{z-index:-1}
.starfield.star-on{opacity:1}
.starfield .st-a,.starfield .st-b{position:absolute;inset:0;display:block;filter:none;border-radius:0;background-image:url(/assets/starfield.svg?v=2);background-size:cover;background-position:center;background-repeat:no-repeat}
.starfield .st-a{opacity:.9;animation:stTwA 14s ease-in-out infinite alternate}
.starfield .st-b{background-size:134% 134%;background-position:32% 18%;opacity:.45;animation:stTwB 9s ease-in-out infinite alternate}
@keyframes stTwA{0%{opacity:.78}100%{opacity:1}}
@keyframes stTwB{0%{opacity:.28}100%{opacity:.6}}
@media (prefers-reduced-motion:reduce){.starfield .st-a,.starfield .st-b{animation:none}}