/* ============================================================
   HEADER — Bhatti Chemicals Industry
   Sticky, transparent-to-solid on scroll, premium B2B nav
============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Sora:wght@600;700;800&family=Inter:wght@400;500;600&display=swap');

:root {
  --header-height: 84px;
  --header-height-scrolled: 68px;
  --brand-jade: #007b5e;
  --brand-jade-dark: #005a45;
  --brand-gold: #c8922a;
  --brand-bg-dark: #0d1f19;
  --header-border: rgba(255, 255, 255, 0.08);
}

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

html, body {
  max-width: 100%;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  scroll-padding-top: calc(var(--header-height-scrolled) + 10px);
}

body {
  font-family: 'Inter', system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  scroll-behavior: smooth;
}

/* ============================================================
   HEADER SHELL
============================================================ */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background: linear-gradient(to bottom, rgba(13,31,25,0.85) 0%, rgba(13,31,25,0.35) 70%, transparent 100%);
  backdrop-filter: blur(2px);
  transition: height 0.3s ease, background 0.3s ease, box-shadow 0.3s ease, backdrop-filter 0.3s ease;
  border-bottom: 1px solid transparent;
}

.site-header.scrolled {
  height: var(--header-height-scrolled);
  background: rgba(13, 31, 25, 0.92);
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.18);
  border-bottom: 1px solid var(--header-border);
}

/* When a page starts with a light section instead of a dark hero,
   this modifier can be added by the page to keep header readable */
.site-header.on-light:not(.scrolled) {
  background: linear-gradient(to bottom, rgba(13,31,25,0.65) 0%, rgba(13,31,25,0.15) 100%);
}

.header-inner {
  width: 100%;
  max-width: 1320px;
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

/* ============================================================
   LOGO
============================================================ */
.logo-link {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  gap: 10px;
  text-decoration: none;
}

.logo {
  height: 42px;
  width: auto;
  display: block;
  transition: height 0.3s ease;
}

.site-header.scrolled .logo { height: 36px; }

/* ============================================================
   PRIMARY NAV
============================================================ */
.main-nav {
  display: flex;
  align-items: center;
  flex: 1;
  justify-content: center;
}

.main-nav > ul {
  list-style: none;
  margin: 0; padding: 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav > ul > li {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  font-size: 0.94rem;
  color: rgba(255, 255, 255, 0.88);
  text-decoration: none;
  padding: 10px 16px;
  border-radius: 8px;
  transition: background 0.2s, color 0.2s;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  background: rgba(255, 255, 255, 0.1);
  color: #ffffff;
}

.nav-link.active {
  background: var(--brand-jade);
}

.nav-chevron {
  width: 10px; height: 10px;
  transition: transform 0.25s ease;
  flex-shrink: 0;
  opacity: 0.75;
}

.has-dropdown:hover .nav-chevron,
.has-dropdown:focus-within .nav-chevron {
  transform: rotate(180deg);
}

/* ============================================================
   DROPDOWNS
============================================================ */
.dropdown {
  position: absolute;
  top: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  background: #ffffff;
  border-radius: 14px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.18), 0 2px 8px rgba(0,0,0,0.08);
  border: 1px solid #e2e8e0;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
  z-index: 10;
}

/* Invisible bridge to prevent hover loss between nav item and dropdown */
.dropdown::before {
  content: '';
  position: absolute;
  top: -20px;
  left: 0;
  width: 100%;
  height: 20px;
  background: transparent;
}

.has-dropdown:hover .dropdown,
.has-dropdown:focus-within .dropdown {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

/* Products megamenu */
.products-dropdown {
  width: 560px;
  padding: 20px;
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 20px;
}

.dropdown-featured {
  background: var(--brand-bg-dark);
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  position: relative;
}

.dropdown-featured img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  display: block;
}

.dropdown-featured-body {
  padding: 12px 14px 14px;
}

.dropdown-tag {
  display: inline-block;
  background: rgba(200, 146, 42, 0.25);
  color: #f4c85a;
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 4px;
  margin-bottom: 6px;
}

.dropdown-featured strong {
  display: block;
  font-family: 'Sora', sans-serif;
  color: #ffffff;
  font-size: 0.95rem;
  margin-bottom: 3px;
}

.dropdown-featured span.dropdown-desc {
  display: block;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.78rem;
  line-height: 1.5;
}

.dropdown-list {
  list-style: none;
  margin: 0; padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
  align-content: start;
}

.dropdown-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: #1a1a1a;
  font-size: 0.87rem;
  font-weight: 600;
  transition: background 0.15s, color 0.15s;
}

.dropdown-list a::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--brand-jade);
  flex-shrink: 0;
}

.dropdown-list a:hover,
.dropdown-list a.active {
  background: #f0f2f0;
  color: var(--brand-jade);
}

.dropdown-viewall {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-top: 4px;
  padding: 11px;
  border-top: 1px solid #e2e8e0;
  color: var(--brand-jade);
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
  transition: background 0.15s;
  border-radius: 0 0 8px 8px;
}

.dropdown-viewall:hover { background: #f0f2f0; }

/* About dropdown (simple list) */
.about-dropdown {
  width: 220px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.about-dropdown a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 11px 14px;
  border-radius: 8px;
  text-decoration: none;
  color: #1a1a1a;
  font-size: 0.88rem;
  font-weight: 600;
  transition: background 0.15s, color 0.15s;
}

.about-dropdown a::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--brand-jade);
  flex-shrink: 0;
}

.about-dropdown a:hover,
.about-dropdown a.active {
  background: #f0f2f0;
  color: var(--brand-jade);
}

/* ============================================================
   HEADER ACTIONS (CTA + mobile toggle)
============================================================ */
.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

.btn-header-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--brand-jade);
  color: #ffffff;
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 0.87rem;
  padding: 11px 20px;
  border-radius: 7px;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s, transform 0.15s;
}

.btn-header-cta:hover {
  background: var(--brand-jade-dark);
  transform: translateY(-1px);
}

/* Hamburger */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 42px; height: 42px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  cursor: pointer;
  flex-shrink: 0;
  padding: 0;
}

.menu-toggle span {
  display: block;
  width: 18px; height: 2px;
  background: #ffffff;
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================
   MOBILE SIDEBAR
============================================================ */
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.sidebar-overlay.open {
  opacity: 1;
  visibility: visible;
}

.mobile-sidebar {
  position: fixed;
  top: 0; right: -320px;
  width: 300px;
  max-width: 84vw;
  height: 100%;
  background: #ffffff;
  z-index: 1002;
  transition: right 0.35s cubic-bezier(0.23, 1, 0.32, 1);
  overflow-y: auto;
  box-shadow: -8px 0 32px rgba(0, 0, 0, 0.15);
}

.mobile-sidebar.open { right: 0; }

.mobile-sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  border-bottom: 1px solid #e2e8e0;
}

.mobile-sidebar-header img { height: 34px; }

.mobile-sidebar-close {
  width: 34px; height: 34px;
  border-radius: 50%;
  border: none;
  background: #f0f2f0;
  color: #1a1a1a;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
}

.mobile-nav-list {
  list-style: none;
  margin: 0; padding: 12px;
}

.mobile-nav-list > li {
  border-bottom: 1px solid #f0f2f0;
}

.mobile-nav-list > li:last-child { border-bottom: none; }

.mobile-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 15px 10px;
  text-decoration: none;
  color: #1a1a1a;
  font-family: 'Sora', sans-serif;
  font-weight: 600;
  font-size: 0.98rem;
}

.mobile-nav-link.active { color: var(--brand-jade); }

.mobile-accordion-toggle {
  width: 26px; height: 26px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  background: #f0f2f0;
  transition: transform 0.25s ease, background 0.2s;
  flex-shrink: 0;
}

.mobile-accordion-toggle svg { width: 10px; height: 10px; transition: transform 0.25s; }

.mobile-nav-list li.accordion-open .mobile-accordion-toggle {
  background: var(--brand-jade);
}
.mobile-nav-list li.accordion-open .mobile-accordion-toggle svg {
  transform: rotate(180deg);
  filter: brightness(0) invert(1);
}

.mobile-submenu {
  list-style: none;
  margin: 0; padding: 0 0 10px 10px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

li.accordion-open .mobile-submenu {
  max-height: 400px;
}

.mobile-submenu a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  text-decoration: none;
  color: #4a5568;
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: 6px;
}

.mobile-submenu a::before {
  content: '';
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--brand-jade);
  flex-shrink: 0;
}

.mobile-submenu a:hover,
.mobile-submenu a.active { background: #f0f2f0; color: var(--brand-jade); }

.mobile-sidebar-cta {
  padding: 20px;
}

.btn-primary-mobile {
  display: block;
  text-align: center;
  background: var(--brand-jade);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.92rem;
  padding: 13px;
  border-radius: 8px;
  text-decoration: none;
}

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 1024px) {
  .main-nav { display: none; }
  .menu-toggle { display: flex; }
  .btn-header-cta.desktop-only { display: none; }
}

@media (max-width: 480px) {
  .header-inner { padding: 0 16px; }
  .mobile-sidebar { width: 100%; max-width: 100%; right: -100%; }
}

@media (prefers-reduced-motion: reduce) {
  .site-header, .dropdown, .mobile-sidebar, .sidebar-overlay, .menu-toggle span { transition: none; }
}