/* Header: rangka, tinggi, dan bayangan saat scroll. */
header{position:sticky;top:0;z-index:20;background:var(--bg);border-bottom:1px solid var(--line)}
.bar{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:60px}
@media (max-width:760px){.bar{flex-wrap:nowrap;padding-top:8px;padding-bottom:8px}}
header{transition:box-shadow .3s}
header.sc{box-shadow:0 6px 20px rgba(8,17,31,.18)}
.bar{transition:min-height .3s}
header.sc .bar{min-height:50px}