/* Keep the header in normal flow so revealing it never shifts page content. */
.nav-shell.scroll-nav{position:sticky;top:0;z-index:60;isolation:isolate;transition:transform .26s ease}
.nav-shell::before{content:"";position:absolute;inset:0;z-index:-1;pointer-events:none;background:rgba(250,250,253,.94);border-bottom:1px solid rgba(221,215,232,.75);box-shadow:0 8px 28px rgba(43,32,61,.07);opacity:0;transition:opacity .22s ease}
.nav-shell.is-scrolled::before{opacity:1}
.nav-shell.scroll-nav.is-hidden{transform:translateY(calc(-100% - 28px));pointer-events:none}
.nav-shell.scroll-nav:focus-within{transform:translateY(0);pointer-events:auto}
@supports(backdrop-filter:blur(16px)){.nav-shell.is-scrolled::before{background:rgba(250,250,253,.86);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px)}}
@media(prefers-reduced-motion:reduce){.nav-shell.scroll-nav,.nav-shell::before{transition:none}}