.product-tabs{--tab-b:#e5e7eb;--bg:#fff;--muted:#f9fafb;--text:#111827;--radius:12px; margin:1rem 0}
.product-tabs .tabset{position:relative}
.product-tabs .tabset input[type=radio]{position:absolute; inset:0; opacity:0; pointer-events:none}
.product-tabs .tab-nav{display:flex; flex-wrap:wrap; gap:.25rem; border-bottom:1px solid var(--tab-b)}
.product-tabs .tab-nav label{
  padding:.65rem 1rem; font-weight:600; cursor:pointer; user-select:none;
  background:var(--muted); border:1px solid var(--tab-b); border-bottom:none;
  border-top-left-radius:var(--radius); border-top-right-radius:var(--radius);
}
.product-tabs .tab-nav label:focus-visible{outline:2px solid #3b82f6; outline-offset:2px}

.product-tabs .tab-panels{border:1px solid var(--tab-b); border-top:none; background:var(--bg); border-bottom-left-radius:var(--radius); border-bottom-right-radius:var(--radius)}
.product-tabs .tab-panel{display:none; padding:1rem}
.product-tabs .tab-panel > :first-child{margin-top:0}

#tab-desc:checked ~ .tab-nav label[for=tab-desc],
#tab-lab:checked  ~ .tab-nav label[for=tab-lab],
#tab-profile:checked  ~ .tab-nav label[for=tab-profile],
#tab-faq:checked  ~ .tab-nav label[for=tab-faq]{background:var(--bg); color:var(--text); border-bottom:1px solid var(--bg)}

#tab-desc:checked ~ .tab-panels #panel-desc{display:block}
#tab-lab:checked  ~ .tab-panels #panel-lab{display:block}
#tab-profile:checked  ~ .tab-panels #panel-profile{display:block}
#tab-faq:checked  ~ .tab-panels #panel-faq{display:block}

.product-tabs:has(#panel-lab:empty) label[for=tab-lab]{display:none}
.product-tabs #panel-lab:empty{display:none !important}

@media (max-width:640px){
  .product-tabs .tab-nav{gap:.35rem}
  .product-tabs .tab-nav label{font-size:.95rem; padding:.55rem .8rem}
}

@media print{
  .product-tabs .tab-nav{display:none}
  .product-tabs .tab-panel{display:block}
}

@media (max-width:640px){
  .product-tabs{ margin:.5rem 0 }
  .product-tabs .tab-nav{
    position:sticky; top:0; z-index:2; background:var(--bg);
    overflow-x:auto; -webkit-overflow-scrolling:touch; white-space:nowrap;
    gap:.5rem; padding:.5rem .25rem; scrollbar-width:thin;
  }
  .product-tabs .tab-nav label{
    flex:0 0 auto; padding:.75rem 1rem; border-radius:999px; /* comfy tap targets */
    font-size:1rem;
  }
  .product-tabs .tab-panel{ padding:.9rem .75rem }
}