.materials-nav { position:relative; }
.materials-nav-trigger { display:inline-flex; align-items:center; gap:6px; border:0; padding:0; background:transparent; color:inherit; font:inherit; font-weight:inherit; cursor:pointer; min-height:38px; }
.materials-nav-trigger>img { filter:invert(1); transition:transform .15s; }
.site-header.scrolled .materials-nav-trigger>img,.materials-page .materials-nav-trigger>img { filter:none; }
.materials-nav-trigger[aria-expanded=true]>img { transform:rotate(180deg); }
.materials-nav-panel { position:fixed; top:100px; left:50%; transform:translateX(-50%); width:min(1040px,calc(100vw - 48px)); max-height:calc(100svh - 125px); overflow:auto; color:var(--ink); background:white; border:1px solid #dfe6e1; border-radius:10px; box-shadow:0 20px 60px #11182726; padding:26px; font-weight:400; }
.materials-nav-panel[hidden] { display:none; }
.materials-nav-heading { display:flex; justify-content:space-between; align-items:center; gap:20px; border-bottom:1px solid #e4ebe6; padding-bottom:20px; margin-bottom:22px; }
.materials-nav-heading strong { display:block; font-size:20px; letter-spacing:-.02em; }
.materials-nav-heading p { font-size:13px; color:var(--muted); margin:7px 0 0; line-height:1.6; }
.materials-nav-heading>a { font-size:12px; color:var(--green); text-decoration:underline; white-space:nowrap; }
.materials-nav-columns { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:26px; }
.materials-nav-label { font-size:11px; text-transform:uppercase; letter-spacing:.08em; font-weight:700; color:var(--muted); margin:0 0 12px; }
.materials-nav-family { border-bottom:1px solid #e4ebe6; }
.materials-nav-family>summary { display:flex; gap:10px; align-items:center; padding:14px 0; list-style:none; font-size:15px; font-weight:750; cursor:pointer; }
.materials-nav-family>summary::-webkit-details-marker { display:none; }
.materials-nav-family>summary>img { width:14px; height:14px; }
.materials-nav-family[open]>summary>img { transform:rotate(180deg); }
.materials-nav-count { margin-left:auto; font-size:11px; font-weight:400; color:var(--muted); }
.materials-nav-grades { display:grid; gap:3px; padding:0 0 13px; }
.materials-nav-grades>a { display:flex; justify-content:space-between; align-items:center; gap:12px; border-radius:4px; font-size:12px; padding:9px 10px; line-height:1.45; }
.materials-nav-grades>a:hover { background:#edf3ef; color:var(--green); }
.materials-nav-grades small { font-size:10px; color:var(--muted); flex:none; }
.materials-nav-grades .materials-nav-series { color:var(--green); background:#edf3ef; font-weight:750; }
.materials-nav-trigger:focus-visible,.materials-nav-panel a:focus-visible,.materials-nav-family>summary:focus-visible { outline:2px solid var(--green); outline-offset:4px; }
@media(max-width:920px){
  .materials-nav-trigger { width:100%; padding:12px 14px; min-height:44px; justify-content:space-between; text-align:left; border-radius:6px; background:#ffffff0f; }
  .materials-page .materials-nav-trigger>img,.site-header.scrolled .materials-nav-trigger>img { filter:invert(1); }
  .materials-nav-panel { position:static; transform:none; width:100%; max-height:none; box-shadow:none; padding:16px; margin-top:8px; border-radius:6px; }
  .materials-nav-columns { grid-template-columns:1fr; gap:18px; }
  .materials-nav-heading { display:block; padding-bottom:14px; margin-bottom:18px; }
  .materials-nav-heading strong { font-size:16px; }
  .materials-nav-heading p { font-size:12px; }
  .materials-nav-panel .materials-nav-heading>a { display:block; padding:10px 0 0; color:var(--green); background:transparent; }
  .nav .materials-nav-grades>a { padding:9px 7px; color:var(--ink); background:transparent; }
  .nav .materials-nav-grades>a:hover,.nav .materials-nav-grades .materials-nav-series { background:#edf3ef; color:var(--green); }
  .nav.open { overflow-y:auto; overscroll-behavior:contain; }
}
@media(prefers-reduced-motion:reduce){.materials-nav-trigger>img{transition:none;}}