/* Site header navigation. Shared by every page; see nav.js.
   Page stylesheets set the width and padding of .site-nav-inner. */

header.site-nav{
  position:sticky;
  top:0;
  z-index:30;
  background:var(--bg);
  border-bottom:1px solid var(--border);
}
.site-nav-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px 20px;
  flex-wrap:wrap;
}
.site-brand{white-space:nowrap;}

.site-nav-links{display:flex;align-items:center;gap:4px;}
.site-nav-links > a,
.nav-group-btn{
  font-family:"IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  font-size:14px;
  font-weight:500;
  color:var(--text-muted);
  text-decoration:none;
  white-space:nowrap;
  padding:8px 10px;
  border-radius:8px;
}
.site-nav-links > a:hover,
.nav-group-btn:hover{color:var(--text);background:var(--surface-2);}
.site-nav-links a[aria-current],
.nav-group-btn.is-current{color:var(--accent);}
.site-nav a:focus-visible,
.site-nav button:focus-visible{outline:2px solid var(--focus);outline-offset:2px;}

.site-nav-links > a.nav-cta{
  background:var(--accent);
  color:var(--on-accent);
  font-weight:600;
  margin-left:6px;
  order:10;
}
.site-nav-links > a.nav-cta:hover{background:var(--accent);color:var(--on-accent);opacity:.92;}
.site-nav-links > a.nav-cta[aria-current]{color:var(--on-accent);}

/* Health topics dropdown */
.nav-group{position:relative;}
.nav-group-btn{
  display:inline-flex;
  align-items:center;
  gap:5px;
  border:0;
  background:none;
  cursor:pointer;
}
.nav-group-btn svg{width:12px;height:12px;transition:transform .15s ease;}
.nav-group-btn[aria-expanded="true"] svg{transform:rotate(180deg);}
.nav-group-label{display:none;}
.nav-group-menu{
  display:none;
  position:absolute;
  top:calc(100% + 6px);
  left:0;
  min-width:230px;
  padding:6px;
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:12px;
  box-shadow:var(--shadow);
}
.nav-group-menu a{
  display:block;
  padding:9px 12px;
  border-radius:8px;
  font-size:14px;
  color:var(--text);
  text-decoration:none;
}
.nav-group-menu a:hover{background:var(--surface-2);}
.nav-group-menu a[aria-current]{color:var(--accent);font-weight:600;}
/* Without JavaScript the dropdown opens on hover and keyboard focus. */
header.site-nav:not(.js-nav) .nav-group:hover .nav-group-menu,
header.site-nav:not(.js-nav) .nav-group:focus-within .nav-group-menu,
.nav-group-btn[aria-expanded="true"] ~ .nav-group-menu{display:block;}

/* Menu button (phones and small tablets only) */
.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  font:inherit;
  font-size:14px;
  font-weight:600;
  color:var(--text);
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:10px;
  padding:8px 12px;
  cursor:pointer;
}
.nav-toggle svg{width:18px;height:18px;}
.nav-toggle .icon-close{display:none;}
.nav-toggle[aria-expanded="true"] .icon-open{display:none;}
.nav-toggle[aria-expanded="true"] .icon-close{display:block;}

@media (max-width:860px){
  .js-nav .nav-toggle{display:inline-flex;}
  .js-nav .site-nav-links{display:none;}
  .js-nav.is-open .site-nav-links{display:flex;}

  .site-nav-links{
    width:100%;
    flex-direction:column;
    align-items:stretch;
    gap:2px;
    padding:4px 0 14px;
    max-height:calc(100vh - 70px);
    overflow-y:auto;
  }
  .site-nav-links > a{font-size:15px;padding:11px 12px;}
  .site-nav-links > a.nav-cta{order:-1;margin:0 0 6px;text-align:center;padding:12px;}

  .nav-group-btn{display:none;}
  .nav-group-label{
    display:block;
    font-family:"IBM Plex Mono", monospace;
    font-size:11px;
    letter-spacing:.08em;
    text-transform:uppercase;
    color:var(--text-muted);
    padding:12px 12px 4px;
  }
  .nav-group-menu,
  header.site-nav:not(.js-nav) .nav-group:hover .nav-group-menu{
    display:grid;
    grid-template-columns:1fr 1fr;
    position:static;
    min-width:0;
    padding:0 0 6px;
    background:none;
    border:0;
    box-shadow:none;
    border-bottom:1px solid var(--border);
    border-radius:0;
    margin-bottom:6px;
  }
  .nav-group-menu a{font-size:15px;padding:10px 12px;}
}
@media (max-width:380px){
  .nav-group-menu,
  header.site-nav:not(.js-nav) .nav-group:hover .nav-group-menu{grid-template-columns:1fr;}
}
@media (prefers-reduced-motion:reduce){
  .nav-group-btn svg{transition:none;}
}