.hdr .ic { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.hdr { --h-bg: var(--navy-950); --h-fg: #ffffff; --h-fg-2: rgba(255,255,255,.78); --h-line: rgba(255,255,255,.28); --h-hover: rgba(255,255,255,.10); --h-active: rgba(255,255,255,.15); --h-focus: #9ea4ff;
  position: sticky; top: 0; z-index: 30; height: var(--hdr); background: var(--h-bg); border-bottom: 1px solid rgba(255,255,255,.12); }
.hdr :focus-visible { outline-color: var(--h-focus); }
.hdr { line-height: 1.5; }
.hdr .btn { background: transparent; color: var(--h-fg); border-color: var(--h-line); }
.hdr .btn:hover { background: var(--h-hover); border-color: var(--h-fg); }
.hdr .link { color: var(--h-fg-2); }
.hdr .link:hover { color: var(--h-fg); }
.hdr .wrap { max-width: 1280px; margin: 0 auto; padding: 0 20px; }
.hdr .wrap { height: 100%; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 12px; padding: 0 16px; }
.hdr .brand { justify-self: start; }
.hdr .brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); border-radius: 8px; }
.hdr .logo { display: block; width: auto; height: 44px; }
.hdr .logo-darktheme { display: none; }
.hdr .mainnav { display: flex; align-items: center; gap: 6px; font-size: 15px; font-weight: 600; }
@media (min-width: 1024px) { .hdr .mainnav { gap: 12px; font-size: 16px; } }
.hdr .nl { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border: 0; border-radius: 6px; background: transparent; color: var(--h-fg-2); font: inherit; text-decoration: none; white-space: nowrap; transition: background-color .15s, color .15s; }
.hdr .nl:hover, .hdr .nl[aria-expanded="true"] { background: var(--h-hover); color: var(--h-fg); }
.hdr .nl[aria-current="page"] { background: var(--h-active); color: var(--h-fg); font-weight: 600; }
.hdr .nl .ic { width: 16px; height: 16px; transition: rotate .2s; }
.hdr .nl[aria-expanded="true"] .ic { rotate: 180deg; }
.hdr .dd { position: relative; }
.hdr .dd-menu { position: absolute; left: 0; top: calc(100% + 8px); min-width: 180px; padding: 6px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; box-shadow: var(--shadow); }
.hdr .dd-menu a { display: block; padding: 9px 12px; border-radius: 8px; color: var(--text); font-size: 14px; font-weight: 600; text-decoration: none; }
.hdr .dd-menu a:hover { background: var(--row-hover); color: var(--ink); }
.hdr .htools { display: flex; align-items: center; justify-content: flex-end; gap: 8px; }
.hdr .btn.mbtn { display: none; }
.hdr .mnav { display: none; }
.hdr .btn { display: inline-flex; align-items: center; gap: 8px; min-height: 40px; padding: 0 14px; border-radius: 8px; border: 1px solid var(--border-strong); background: var(--surface); color: var(--text); font-size: 14px; font-weight: 600; text-decoration: none; transition: background-color .15s, border-color .15s; }
.hdr .btn:hover { background: var(--row-hover); border-color: var(--ink); }
.hdr .btn.icon { width: 40px; padding: 0; justify-content: center; }
.hdr .btn.primary { background: var(--accent-bg); color: var(--accent-fg); border-color: var(--accent-line); }
.hdr .btn.primary:hover { background: var(--navy-900); }
@media (pointer: coarse), (max-width: 767px) {
  .hdr .btn.icon { width: 44px; min-height: 44px; }
  .hdr .btn.back { min-height: 44px; }
  .hdr .brand { min-height: 44px; }
}
@media (max-width: 767px) {
  :root { --hdr: 60px; }
  .hdr { border-bottom-width: 0; }
  .hdr .wrap { grid-template-columns: 1fr auto 1fr; padding: 0 8px; }
  .hdr .mainnav { display: none; }
  .hdr .btn.mbtn { display: inline-flex; grid-column: 1; grid-row: 1; justify-self: start; width: 44px; min-height: 44px; border-color: transparent; border-radius: 999px; }
  .hdr .btn.mbtn:hover { border-color: transparent; }
  .hdr .brand { grid-column: 2; grid-row: 1; justify-self: center; }
  .hdr .htools { grid-column: 3; grid-row: 1; }
  .hdr .logo { height: 32px; }
  .hdr .mnav:not([hidden]) { display: flex; flex-direction: column; padding: 8px 16px 12px; background: var(--h-bg); border-bottom: 1px solid var(--h-line); position: absolute; left: 0; right: 0; top: 100%; }
  .hdr .mnav a { padding: 12px 8px; border-radius: 8px; color: var(--h-fg-2); font-size: 15px; font-weight: 600; text-decoration: none; }
  .hdr .mnav a:hover { background: var(--h-hover); color: var(--h-fg); }
  .hdr .mnav a[aria-current="page"] { background: var(--h-active); color: var(--h-fg); }
}
@media (max-width: 640px) {
  .hdr .wrap { padding: 0 16px; }
}
@media (prefers-reduced-motion: reduce) {
  .hdr .nl .ic { transition: none; }
}
.hdr .mnav summary { min-height: 44px; padding: 12px 8px; color: var(--h-fg); font-weight: 600; cursor: pointer; }
.hdr .mnav details a { display: block; margin-left: 12px; }
/* Shared navigation: Thi đấu mega menu */
.hdr .dd-mega:not([hidden]) { display: grid; grid-template-columns: repeat(2, minmax(200px, 1fr)); gap: 0 8px; min-width: 440px; }
.hdr .dd-group-label { margin: 0; padding: 8px 12px 4px; font-size: 12px; font-weight: 600; color: var(--muted, #6b7280); }
.hdr .mnav .dd-group { display: block; }
.hdr .mnav .dd-group-label { display: block; margin-left: 12px; padding: 8px 8px 2px; color: var(--h-fg-2); opacity: 0.85; }