*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  :root {
    --orange: #E85D26;
    --orange-hover: #C94D1E;
    --orange-pale: #FFF3EC;
    --orange-mid: #F47A45;
    --dark: #181818;
    --gray-dk: #3D3D3D;
    --gray-md: #6B6B6B;
    --gray-lt: #A8A8A8;
    --gray-bg: #F5F4F1;
    --white: #FFFFFF;
    --border: #E6E4DF;
    --green: #2A9D59;
    --sale-bg: #FFF0E0;
    --sale-text: #B85000;
    --radius: 14px;
    --radius-sm: 8px;
    --shadow-soft: 0 2px 16px rgba(0,0,0,0.07);
    --shadow-product: 0 20px 60px rgba(0,0,0,0.12);
    --t: 0.22s cubic-bezier(0.4,0,0.2,1);
  }

  body {
    font-family: 'DM Sans', sans-serif;
    background: var(--gray-bg);
    color: var(--dark);
    min-height: 100vh;
  }

  /* ── BREADCRUMB ── */
  .breadcrumb {
    padding: 18px 40px;
    font-size: 13px;
    color: var(--gray-md);
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .breadcrumb a { color: var(--gray-md); text-decoration: none; transition: color var(--t); }
  .breadcrumb a:hover { color: var(--orange); }
  .breadcrumb .sep { color: var(--gray-lt); font-size: 11px; }
  .breadcrumb .current { color: var(--dark); font-weight: 500; }

  /* ══════════════════════════════
     PRODUCT LAYOUT
  ══════════════════════════════ */
  .product-page {
    max-width: 1180px;
    margin: 0 auto;
    padding: 36px 24px 80px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 52px;
    align-items: start;
  }

  /* ═══════════ LEFT – Gallery ═══════════ */
  .gallery-col {
    display: flex;
    gap: 14px;
    position: sticky;
    top: 24px;
  }

  .gallery-thumbs {
    display: flex;
    flex-direction: column;
    gap: 10px;
    flex-shrink: 0;
  }

  .thumb {
    width: 72px;
    height: 72px;
    border-radius: 10px;
    border: 2px solid transparent;
    background: var(--white);
    cursor: pointer;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color var(--t), box-shadow var(--t);
    padding: 8px;
  }

  .thumb:hover { border-color: var(--orange-mid); }
  .thumb.active { border-color: var(--orange); box-shadow: 0 0 0 3px var(--orange-pale); }

  .thumb svg { width: 48px; height: 48px; }

  /* Main image */
  .gallery-main {
    flex: 1;
    background: var(--white);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 420px;
    padding: 32px;
    position: relative;
    overflow: hidden;
  }

  .gallery-main::before {
    content: '';
    position: absolute;
    bottom: -40px;
    left: 50%;
    transform: translateX(-50%);
    width: 260px;
    height: 80px;
    background: radial-gradient(ellipse, rgba(232,93,38,0.12) 0%, transparent 70%);
    pointer-events: none;
  }

  .gallery-main .main-vial {
    width: 210px;
    filter: drop-shadow(var(--shadow-product));
    animation: float 4s ease-in-out infinite;
  }

  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
  }

  .gallery-zoom-hint {
    position: absolute;
    bottom: 14px;
    right: 14px;
    font-size: 11px;
    color: var(--gray-lt);
    display: flex;
    align-items: center;
    gap: 4px;
  }

  /* ═══════════ RIGHT – Info ═══════════ */
  .info-col {}

  /* Stars & reviews */
  .review-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
  }

  .stars {
    display: flex;
    gap: 2px;
  }

  .star-full { color: #F5A623; font-size: 18px; }
  .star-half { color: #F5A623; font-size: 18px; opacity: 0.6; }

  .review-count {
    font-size: 13px;
    color: var(--orange);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
    cursor: pointer;
  }

  /* Product title */
  .product-title {
    font-family: 'Playfair Display', serif;
    font-size: 42px;
    font-weight: 700;
    color: var(--dark);
    line-height: 1.1;
    letter-spacing: -0.5px;
    margin-bottom: 16px;
  }

  /* Pricing */
  .price-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 22px;
    flex-wrap: wrap;
  }

  .price-original {
    font-size: 18px;
    color: var(--gray-lt);
    text-decoration: line-through;
    font-weight: 400;
  }

  .price-current {
    font-size: 22px;
    font-weight: 700;
    color: var(--dark);
  }

  .price-current span { color: var(--gray-md); font-weight: 400; font-size: 16px; }

  .sale-badge {
    background: var(--sale-bg);
    color: var(--sale-text);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.8px;
    text-transform: uppercase;
    padding: 5px 10px;
    border-radius: 20px;
    border: 1px solid #F5C89A;
  }

  /* Divider */
  .divider {
    height: 1px;
    background: var(--border);
    margin: 20px 0;
  }

  /* Section label */
  .section-label {
    font-size: 13px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 12px;
    letter-spacing: 0.2px;
  }

  /* Size selector */
  .size-options {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 20px;
  }

  .size-btn {
    padding: 8px 18px;
    border-radius: 50px;
    border: 1.5px solid var(--border);
    background: var(--white);
    font-family: 'DM Sans', sans-serif;
    font-size: 13px;
    font-weight: 500;
    color: var(--gray-dk);
    cursor: pointer;
    transition: all var(--t);
  }

  .size-btn:hover { border-color: var(--orange-mid); color: var(--orange); }

  .size-btn.active {
    border-color: var(--orange);
    background: var(--orange-pale);
    color: var(--orange);
    font-weight: 700;
  }

  /* Quantity */
  .qty-row {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 20px;
  }

  .qty-control {
    display: flex;
    align-items: center;
    background: var(--white);
    border: 1.5px solid var(--border);
    border-radius: 50px;
    overflow: hidden;
  }

  .qty-btn {
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    font-size: 18px;
    color: var(--gray-dk);
    cursor: pointer;
    transition: background var(--t), color var(--t);
  }

  .qty-btn:hover { background: var(--orange-pale); color: var(--orange); }

  .qty-input {
    width: 44px;
    text-align: center;
    border: none;
    font-family: 'DM Sans', sans-serif;
    font-size: 15px;
    font-weight: 700;
    color: var(--dark);
    background: transparent;
    outline: none;
  }

  .bulk-badge {
    background: #FFF8E1;
    color: #8B6000;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.5px;
    padding: 5px 10px;
    border-radius: 20px;
    border: 1px solid #F5DC8A;
  }

  /* BAC Water Add-on */
  .addon-box {
    background: var(--white);
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
  }

  .addon-label-bar {
    padding: 10px 16px;
    font-size: 12px;
    color: var(--gray-md);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .addon-label-bar strong { color: var(--dark); font-weight: 600; }
  .addon-required {
    font-size: 11px;
    color: var(--gray-lt);
    font-style: italic;
  }

  .addon-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    cursor: pointer;
    transition: background var(--t);
  }

  .addon-option:hover { background: var(--gray-bg); }

  .addon-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--orange);
    flex-shrink: 0;
  }

  .addon-name {
    flex: 1;
    font-size: 14px;
    font-weight: 500;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 6px;
  }

  .addon-info {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 1.5px solid var(--gray-lt);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    font-weight: 700;
    color: var(--gray-lt);
    cursor: help;
    flex-shrink: 0;
  }

  .addon-price {
    font-size: 14px;
    font-weight: 700;
    color: var(--green);
  }

  /* CTA buttons */
  .cta-row {
    display: flex;
    gap: 10px;
    margin-bottom: 16px;
  }

  .btn-add-cart {
    flex: 1;
    background: var(--orange);
    color: var(--white);
    border: none;
    border-radius: 50px;
    padding: 16px 28px;
    font-family: 'DM Sans', sans-serif;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: background var(--t), box-shadow var(--t), transform var(--t);
  }

  .btn-add-cart:hover {
    background: var(--orange-hover);
    box-shadow: 0 8px 24px rgba(232,93,38,0.35);
    transform: translateY(-1px);
  }

  .btn-add-cart:active { transform: translateY(0); }

  .btn-share {
    background: var(--white);
    color: var(--dark);
    border: 1.5px solid var(--border);
    border-radius: 50px;
    padding: 16px 22px;
    font-family: 'DM Sans', sans-serif;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 7px;
    white-space: nowrap;
    transition: border-color var(--t), color var(--t);
  }

  .btn-share:hover { border-color: var(--orange); color: var(--orange); }

  /* Free shipping note */
  .shipping-note {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--gray-md);
    justify-content: center;
    padding: 10px;
    background: #F0FFF6;
    border-radius: var(--radius-sm);
    border: 1px solid #C3EDD5;
    margin-bottom: 20px;
  }

  .shipping-note svg { color: var(--green); flex-shrink: 0; }
  .shipping-note strong { color: var(--dark); }

  /* Research Calculator toggle */
  .calc-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--white);
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 14px 18px;
    cursor: pointer;
    transition: border-color var(--t);
    font-size: 14px;
    font-weight: 600;
    color: var(--dark);
    user-select: none;
  }

  .calc-toggle:hover { border-color: var(--orange); }

  .calc-chevron {
    transition: transform var(--t);
    color: var(--gray-md);
  }

  .calc-toggle.open .calc-chevron { transform: rotate(180deg); }

  .calc-body {
    display: none;
    background: var(--white);
    border: 1.5px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    padding: 18px;
  }

  .calc-body.open { display: block; }

  .calc-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 14px;
  }

  .calc-field label {
    display: block;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.8px;
    text-transform: uppercase;
    color: var(--gray-lt);
    margin-bottom: 5px;
  }

  .calc-field input, .calc-field select {
    width: 100%;
    padding: 9px 12px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: 'DM Sans', sans-serif;
    font-size: 14px;
    color: var(--dark);
    background: var(--gray-bg);
    outline: none;
    transition: border-color var(--t);
  }

  .calc-field input:focus, .calc-field select:focus { border-color: var(--orange); }

  .calc-result {
    background: var(--orange-pale);
    border: 1px solid #F5C09A;
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    font-size: 13px;
    color: var(--gray-dk);
  }

  .calc-result strong { color: var(--orange); font-size: 16px; }

  /* ══════════════════════════════
     TABS SECTION
  ══════════════════════════════ */
  .tabs-section {
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 24px 80px;
  }

  .tabs-nav {
    display: flex;
    border-bottom: 2px solid var(--border);
    gap: 0;
    overflow-x: auto;
  }

  .tab-btn {
    padding: 14px 24px;
    font-family: 'DM Sans', sans-serif;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-md);
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    cursor: pointer;
    white-space: nowrap;
    transition: color var(--t), border-color var(--t);
  }

  .tab-btn:hover { color: var(--dark); }
  .tab-btn.active { color: var(--orange); border-bottom-color: var(--orange); font-weight: 700; }

  .tab-content {
    background: var(--white);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius) var(--radius);
    padding: 36px;
  }

  .tab-pane { display: none; }
  .tab-pane.active { display: block; }

  .tab-pane .desc-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .tab-pane p {
    font-size: 14px;
    line-height: 1.8;
    color: var(--gray-dk);
  }

  .tab-pane .disclaimer {
    font-size: 12px;
    line-height: 1.8;
    color: var(--gray-md);
    border-left: 3px solid var(--orange);
    padding-left: 14px;
    margin-top: 16px;
  }

  /* COA pane */
  .coa-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }

  .coa-card {
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 18px;
    text-align: center;
  }

  .coa-card .coa-lot { font-size: 11px; color: var(--gray-lt); margin-bottom: 4px; letter-spacing: 0.8px; text-transform: uppercase; }
  .coa-card .coa-name { font-size: 14px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
  .coa-card .coa-purity { font-size: 22px; font-weight: 700; color: var(--green); }
  .coa-card .coa-label { font-size: 11px; color: var(--gray-lt); margin-top: 2px; }

  /* Potency pane – progress bars */
  .potency-bars { display: flex; flex-direction: column; gap: 14px; }

  .bar-row {}
  .bar-header { display: flex; justify-content: space-between; font-size: 13px; margin-bottom: 6px; }
  .bar-header span:first-child { font-weight: 600; color: var(--dark); }
  .bar-header span:last-child { font-weight: 700; color: var(--orange); }

  .bar-track {
    height: 8px;
    background: var(--border);
    border-radius: 4px;
    overflow: hidden;
  }

  .bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--orange), var(--orange-mid));
    border-radius: 4px;
    transition: width 1s ease;
  }

  /* References pane */
  .ref-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .ref-item {
    font-size: 13px;
    color: var(--gray-md);
    line-height: 1.6;
    padding-left: 20px;
    position: relative;
  }
  .ref-item::before {
    content: counter(ref);
    counter-increment: ref;
    position: absolute;
    left: 0;
    color: var(--orange);
    font-weight: 700;
    font-size: 11px;
  }
  .ref-list { counter-reset: ref; }
  .ref-item a { color: var(--orange); text-decoration: none; }

  /* Responsive */
  @media (max-width: 900px) {
    .product-page { grid-template-columns: 1fr; gap: 28px; }
    .gallery-col { position: static; }
    .tab-pane .desc-grid { grid-template-columns: 1fr; }
    .coa-grid { grid-template-columns: 1fr 1fr; }
  }

  @media (max-width: 600px) {
    .product-page { padding: 20px 16px 40px; }
    .tabs-section { padding: 0 16px 40px; }
    .breadcrumb { padding: 14px 16px; }
    .product-title { font-size: 32px; }
    .cta-row { flex-direction: column; }
    .coa-grid { grid-template-columns: 1fr; }
    .calc-grid { grid-template-columns: 1fr; }
  }