.product-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.2rem 1.5rem;
  max-width: 1280px;
  margin: 0 auto;
  border-bottom: 1px solid rgba(148, 163, 184, 0.15);
}
.product-nav-brand { display: flex; align-items: center; gap: 0.65rem; text-decoration: none; }
.product-nav-logo { width: 34px; height: 34px; border-radius: 999px; object-fit: cover; border: 1px solid rgba(148, 163, 184, 0.5); }
.product-nav-name { font-size: 0.82rem; font-weight: 700; letter-spacing: 0.26em; text-transform: uppercase; color: #f9fafb; }
.product-nav-name span { color: #38bdf8; }
.product-back { font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase; color: #9ca3af; text-decoration: none; transition: color 0.15s; }
.product-back:hover { color: #e5e7eb; }

.product-main { max-width: 1000px; margin: 0 auto; padding: 4rem 2rem 5rem; }

.product-badge {
  display: inline-block;
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 700;
  color: #38bdf8;
  border: 1px solid rgba(56, 189, 248, 0.35);
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 1.2rem;
}

.product-title { font-size: clamp(2rem, 5vw, 3rem); font-weight: 700; letter-spacing: 0.03em; margin-bottom: 0.4rem; }
.product-title span { color: #38bdf8; }

.product-subtitle { color: #6b7280; margin-bottom: 2rem; letter-spacing: 0.06em; text-transform: uppercase; font-size: 0.78rem; }

.product-intro { display: flex; gap: 2.5rem; align-items: flex-start; margin-bottom: 2.5rem; }
.product-vial { width: 380px; flex-shrink: 0; border-radius: 0.75rem; }
.product-desc { flex: 1; font-size: 0.97rem; color: #9ca3af; line-height: 1.75; margin-bottom: 0; }

.product-details { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin-bottom: 2.5rem; }

.product-detail-card { background: rgba(15, 23, 42, 0.9); border: 1px solid rgba(148, 163, 184, 0.2); border-radius: 1rem; padding: 1.1rem 1.2rem; }
.product-detail-label { font-size: 0.65rem; letter-spacing: 0.16em; text-transform: uppercase; color: #6b7280; margin-bottom: 0.3rem; }
.product-detail-value { font-size: 0.92rem; font-weight: 600; color: #e5e7eb; margin-bottom: 0.4rem; }
.product-detail-desc { font-size: 0.72rem; color: #6b7280; line-height: 1.55; margin-top: 0.5rem; }

.product-detail-expand { margin-top: 0.5rem; }
.product-detail-expand summary { font-size: 0.65rem; letter-spacing: 0.1em; text-transform: uppercase; color: #38bdf8; cursor: pointer; list-style: none; display: inline-flex; align-items: center; gap: 0.3rem; user-select: none; }
.product-detail-expand summary::-webkit-details-marker { display: none; }
.product-detail-expand summary::after { content: "▾"; font-size: 0.7rem; transition: transform 0.15s ease; }
.product-detail-expand[open] summary::after { transform: rotate(180deg); }

.product-cta {
  background: linear-gradient(135deg, #0284c7, #38bdf8);
  color: #f9fafb;
  border: 1px solid rgba(186, 230, 253, 0.3);
  border-radius: 999px;
  padding: 0.8rem 2rem;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  display: inline-block;
  box-shadow: 0 14px 45px rgba(2, 132, 199, 0.3);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.product-cta:hover { transform: translateY(-1px); box-shadow: 0 18px 55px rgba(2, 132, 199, 0.45); }

.product-page-back { display: block; margin-bottom: 2rem; font-size: 0.78rem; color: #6b7280; text-decoration: none; letter-spacing: 0.04em; transition: color 0.15s; }
.product-page-back:hover { color: #f9fafb; }

.product-disclaimer { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid rgba(31, 41, 55, 0.9); font-size: 0.7rem; color: #374151; line-height: 1.7; }

.labs-footer { border-top: 1px solid rgba(31, 41, 55, 0.9); padding: 2rem 1.5rem; text-align: center; }
.labs-footer-link { font-size: 0.8rem; color: #e5e7eb; text-decoration: none; letter-spacing: 0.06em; transition: color 0.15s; }
.labs-footer-link:hover { color: #ffffff; }
.labs-footer-disclaimer { font-size: 0.7rem; color: #4b5563; line-height: 1.7; max-width: 560px; margin: 0 auto 1rem; }
.labs-footer-copy { font-size: 0.72rem; color: #374151; }

@media (max-width: 600px) {
  .product-intro { flex-direction: column; align-items: center; }
  .product-vial { width: 100%; max-width: 260px; }
  .product-details { grid-template-columns: 1fr; }
}