/* Navigation flottante : hauteur constante, fond renforcé au défilement. */
body{padding-top:82px}
header{position:fixed;top:16px;left:50%;transform:translateX(-50%);width:calc(100% - 32px);max-width:1248px;z-index:20;background:rgba(7,26,49,.65);border:1px solid rgba(147,181,226,.1);border-radius:999px;box-shadow:none;backdrop-filter:blur(16px);transition:background-color .25s ease,box-shadow .25s ease,border-color .25s ease}
header.is-scrolled{background:rgba(7,26,49,.97);border-color:rgba(147,181,226,.18);box-shadow:0 10px 28px rgba(0,8,20,.3)}
header .wrap.nav{width:100%;min-height:64px;padding-left:25px;padding-right:25px}
@media(max-width:900px){body{padding-top:78px}header .wrap.nav{min-height:60px;padding-left:22px;padding-right:22px}.nav nav{top:calc(100% + 9px);left:0;right:0;border:1px solid #2d496c;border-radius:19px;padding:24px}}
@media(max-width:480px){body{padding-top:72px}header{top:12px;width:calc(100% - 20px)}header .wrap.nav{min-height:58px;padding-left:18px;padding-right:15px}.nav nav{top:calc(100% + 8px)}}
header .nav .brand{width:76px;height:37px}
@media(max-width:900px){header .nav .brand{width:72px;height:35px}}
@media(max-width:480px){header .nav .brand{width:68px;height:33px}}
@media(prefers-reduced-motion:reduce){header{transition:none}}