:root {
  --primary: #0F172A; 
  --secondary: #1E293B; 
  --accent: #14B8A6; 
  --accent-hover: #0D9488; 
  --danger: #EF4444; 
  --bg-light: #F8FAFC; 
  --text-main: #334155; 
  --text-light: #94A3B8; 
  --card-bg: #FFFFFF;
  --border: #E2E8F0;
  --radius: 8px;
}

body {
  font-family: 'Inter', sans-serif;
  margin: 0;
  background-color: white; /* default to white for index, bg-light class for others */
  color: var(--text-main);
  line-height: 1.6;
}

.bg-light { background-color: var(--bg-light); }
h1, h2, h3, h4 { margin: 0; color: var(--primary); }
a { text-decoration: none; color: inherit; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 5%;
}

.text-center { text-align: center; }

/* Disclaimer */
.top-disclaimer {
  background-color: var(--danger);
  color: white;
  text-align: center;
  padding: 10px;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
}

/* Nav */
nav {
  background-color: white;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 15px 0;
}
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo { display: flex; align-items: center; gap: 10px; }
.aeternus-icon { width: 40px; height: auto; object-fit: contain; }
.logo-text { display: flex; flex-direction: column; }
.logo .brand { font-size: 1.5rem; font-weight: 700; color: var(--primary); line-height: 1.1; }
.logo .sub-brand { font-size: 0.75rem; color: var(--text-light); letter-spacing: 1px; }

.nav-links { display: flex; gap: 20px; }
.nav-links a { font-weight: 600; color: var(--text-main); transition: color 0.2s; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); }

.cart-trigger {
  cursor: pointer;
  background-color: var(--accent);
  color: white;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-weight: 600;
}

/* Hero */
.hero-image {
  background-image: linear-gradient(rgba(15, 23, 42, 0.75), rgba(30, 41, 59, 0.85)), url('images/hero.png');
  background-size: cover;
  background-position: center;
  color: white;
  padding: 100px 0;
  text-align: center;
}
.hero h1 { color: white; font-size: 3.5rem; margin-bottom: 20px; font-weight: 700; text-shadow: 0 2px 4px rgba(0,0,0,0.5); }
.hero h2 { color: var(--accent); font-size: 1.3rem; font-weight: 400; margin-bottom: 30px; text-shadow: 0 1px 2px rgba(0,0,0,0.5); }
.hero-warning { background-color: rgba(239, 68, 68, 0.2); border: 1px solid rgba(239, 68, 68, 0.6); color: #FECACA; padding: 15px; border-radius: var(--radius); max-width: 800px; margin: 0 auto 40px auto; font-size: 0.95rem; }

.btn { display: inline-block; padding: 12px 24px; border: none; border-radius: var(--radius); font-weight: 600; cursor: pointer; transition: 0.2s; }
.primary-btn { background-color: var(--accent); color: white; }
.primary-btn:hover { background-color: var(--accent-hover); transform: translateY(-2px); }
.btn-large { padding: 15px 35px; font-size: 1.1rem; }

/* Edu Section */
.educational-section { padding: 80px 5%; }
.edu-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.edu-text h3 { font-size: 2.2rem; margin-bottom: 20px; }
.edu-text p { font-size: 1.1rem; margin-bottom: 15px; color: var(--text-main); }
.edu-image img { width: 100%; border-radius: var(--radius); box-shadow: 0 15px 30px rgba(0,0,0,0.1); }

/* Trust Features */
.trust-section { padding: 70px 5%; border-top: 1px solid var(--border); }
.trust-section h3 { font-size: 2rem; margin-bottom: 40px; }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.feature-card { background: white; padding: 30px; border-radius: var(--radius); box-shadow: 0 4px 6px rgba(0,0,0,0.02); }
.feature-icon { font-size: 3rem; margin-bottom: 15px; }

/* Page Content Common */
.page-content { padding: 50px 5%; min-height: 60vh; }
.catalog-header { text-align: center; margin-bottom: 40px; }
.catalog-header h1 { font-size: 2.5rem; margin-bottom: 10px; }

/* Product Grid */
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 30px; }
.product-card { background-color: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 25px 20px; display: flex; flex-direction: column; align-items: center; text-align: center; transition: box-shadow 0.2s; cursor: pointer; }
.product-card:hover { box-shadow: 0 10px 20px rgba(0,0,0,0.08); transform: translateY(-2px); }
.product-vial-img { width: 120px; height: auto; margin-bottom: 20px; }
.product-card h4 { font-size: 1.25rem; margin-bottom: 5px; }
.ruo-badge { background-color: #FEF2F2; color: var(--danger); font-size: 0.7rem; padding: 4px 8px; border-radius: 4px; margin-bottom: 15px; font-weight: 700; border: 1px solid #FECACA; }
.product-card .price { font-size: 1.3rem; font-weight: 700; color: var(--primary); margin-bottom: 15px; }

/* Product Detail Page */
.back-link { display: inline-block; margin-bottom: 30px; color: var(--accent); font-weight: 600; }
.product-detail-layout { display: grid; grid-template-columns: 1fr 1.5fr; gap: 50px; background: white; padding: 40px; border-radius: var(--radius); box-shadow: 0 4px 15px rgba(0,0,0,0.03); }
.pd-img-box { background: var(--bg-light); border-radius: var(--radius); padding: 40px; display: flex; justify-content: center; align-items: center; border: 1px solid var(--border); }
.pd-img-box img { max-width: 100%; height: auto; mix-blend-mode: multiply; }
.pd-info h1 { font-size: 2.5rem; margin-bottom: 10px; }
.pd-info .price { font-size: 1.8rem; font-weight: 700; color: var(--accent); margin: 20px 0; }
.pd-info h3 { margin-top: 30px; margin-bottom: 10px; font-size: 1.2rem; border-bottom: 1px solid var(--border); padding-bottom: 5px; }
.pd-info p { color: var(--text-main); margin-bottom: 15px; }
.science-warning { background: var(--bg-light); border-left: 4px solid var(--accent); padding: 15px; font-size: 0.9rem; margin-bottom: 30px; font-style: italic; }

.add-block { display: flex; gap: 15px; margin-top: 30px; }
.add-block .qty { width: 80px; padding: 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 1rem; text-align: center; }
.add-block .btn { flex-grow: 1; }

/* Modals & Forms */
.modal { display: none; position: fixed; z-index: 1000; left: 0; top: 0; width: 100%; height: 100%; background-color: rgba(15, 23, 42, 0.6); backdrop-filter: blur(3px); }
.modal-content { background-color: white; margin: 5% auto; padding: 30px 40px; border-radius: var(--radius); width: 90%; max-width: 600px; position: relative; max-height: 85vh; overflow-y: auto; }
.close { color: var(--text-light); position: absolute; top: 15px; right: 20px; font-size: 28px; font-weight: bold; cursor: pointer; }
.cart-header { border-bottom: 1px solid var(--border); padding-bottom: 15px; margin-bottom: 20px; }
.cart-item { display: flex; justify-content: space-between; align-items: center; padding: 10px 0; border-bottom: 1px dashed var(--border); }
.cart-item-remove { color: var(--danger); cursor: pointer; font-size: 0.85rem; }
.cart-total { text-align: right; font-size: 1.4rem; margin: 20px 0; color: var(--primary); }
.checkout-form { background-color: var(--bg-light); padding: 20px; border-radius: var(--radius); border: 1px solid var(--border); }
.form-group { margin-bottom: 15px; }
.form-group label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 5px; }
.form-group input { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 4px; box-sizing: border-box; }
.legal-acknowledgment h4 { color: var(--danger); text-transform: uppercase; font-size: 0.85rem; margin-bottom: 10px; }
.checkbox-container { display: block; position: relative; padding-left: 30px; margin-bottom: 12px; cursor: pointer; font-size: 0.85rem; user-select: none; }
.checkbox-container input { position: absolute; opacity: 0; cursor: pointer; height: 0; width: 0; }
.checkmark { position: absolute; top: 0; left: 0; height: 20px; width: 20px; background-color: white; border: 1px solid #ccc; border-radius: 4px; }
.checkbox-container input:checked ~ .checkmark { background-color: var(--accent); border-color: var(--accent); }
.checkmark:after { content: ""; position: absolute; display: none; }
.checkbox-container input:checked ~ .checkmark:after { display: block; left: 6px; top: 2px; width: 5px; height: 10px; border: solid white; border-width: 0 2px 2px 0; transform: rotate(45deg); }
.checkout-btn { width: 100%; background-color: var(--primary); color: white; margin-top: 20px; }

/* Footers */
footer { background-color: var(--primary); color: var(--bg-light); }
.main-footer { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; padding: 60px 0; }
.footer-bottom { text-align: center; padding: 20px; background-color: #0b1120; font-size: 0.8rem; color: var(--text-light); }

@media (max-width: 768px) {
  .edu-grid, .features-grid, .product-detail-layout { grid-template-columns: 1fr; }
  .hero h1 { font-size: 2.2rem; }
  .main-footer { grid-template-columns: 1fr; text-align: center; }
}