/* =============================================================
   HZL Microsite — Header / Navigation (Concept A: Frosted Navy Bar)
   ============================================================= */

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--z-header);
  transform: translateY(0);
  transition: transform var(--dur-base) var(--ease-out);
  will-change: transform;
}
/* Auto-hide on scroll-down, reveal on scroll-up */
.site-header.is-hidden { transform: translateY(-100%); }

/* ---- Utility strip ---------------------------------------- */
.utility-bar {
  height: var(--utility-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(4, 14, 26, 0.55);
  transition: opacity var(--dur-base) var(--ease-out),
              height var(--dur-base) var(--ease-out);
  overflow: hidden;
}
.utility-bar__inner { display: flex; justify-content: flex-end; }
.utility-links { display: flex; gap: clamp(1rem, 2vw, 2.25rem); }
.utility-links a {
  font-size: var(--fs-utility);
  letter-spacing: 0.04em;
  color: var(--on-dark-dim);
  transition: color var(--dur-fast) var(--ease-out);
}
.utility-links a:hover { color: var(--teal-300); }

/* Collapse the utility strip once scrolled */
.site-header.is-scrolled .utility-bar {
  height: 0;
  opacity: 0;
  border-color: transparent;
}

/* ---- Main bar --------------------------------------------- */
.nav-bar {
  height: var(--bar-h);
  background: transparent;
  transition: height var(--dur-base) var(--ease-out),
              background-color var(--dur-base) var(--ease-out),
              box-shadow var(--dur-base) var(--ease-out),
              backdrop-filter var(--dur-base) var(--ease-out);
}
.nav-bar__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

/* Frosted state */
.site-header.is-scrolled .nav-bar {
  height: var(--bar-h-scrolled);
  background: var(--navy-glass);
  -webkit-backdrop-filter: blur(16px) saturate(120%);
  backdrop-filter: blur(16px) saturate(120%);
  box-shadow: 0 10px 30px -18px rgba(0, 0, 0, 0.7);
}

/* ---- Brand: Vedanta | Hindustan Zinc co-branded lockup ---- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: clamp(0.7rem, 1.4vw, 1.25rem);
  flex: none;
}
.brand__logo {
  display: block;
  width: auto;
  transition: height var(--dur-base) var(--ease-out);
}
.brand__logo--vedanta { height: 26px; }
.brand__logo--hzl { height: 40px; }
.brand__divider {
  width: 1px;
  height: 36px;
  background: rgba(255, 255, 255, 0.28);
  flex: none;
}
/* Shrink slightly with the frosted bar */
.site-header.is-scrolled .brand__logo--vedanta { height: 22px; }
.site-header.is-scrolled .brand__logo--hzl { height: 34px; }
.site-header.is-scrolled .brand__divider { height: 30px; }

/* Drawer head logo */
.mobile-drawer__head .brand__logo--hzl { height: 36px; }

/* ---- Primary nav ------------------------------------------ */
.primary-nav { height: 100%; }
.nav-list {
  display: flex;
  align-items: stretch;
  height: 100%;
  gap: clamp(0.25rem, 1vw, 1.25rem);
}
.nav-item { display: flex; }
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.45ch;
  padding: 0 0.5rem;
  height: 100%;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-nav);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--on-dark);
  white-space: nowrap;
}
.nav-link__caret {
  width: 8px; height: 8px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: translateY(-2px) rotate(45deg);
  opacity: 0.6;
  transition: transform var(--dur-fast) var(--ease-out), opacity var(--dur-fast);
}
/* Teal ink underline */
.nav-link::after {
  content: '';
  position: absolute;
  left: 0.5rem; right: 0.5rem; bottom: 18px;
  height: 2px;
  background: var(--teal-400);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur-fast) var(--ease-out);
}
.nav-item.is-active .nav-link::after,
.nav-link:hover::after { transform: scaleX(1); }
.nav-item.is-active .nav-link__caret { transform: translateY(1px) rotate(225deg); opacity: 1; }

/* ---- Actions (search · CTA · burger) ---------------------- */
.nav-actions { display: flex; align-items: center; gap: clamp(0.5rem, 1.4vw, 1.1rem); }

.icon-btn {
  display: grid;
  place-items: center;
  width: 42px; height: 42px;
  border-radius: 50%;
  color: var(--on-dark);
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast);
}
.icon-btn:hover { background: rgba(255, 255, 255, 0.08); color: var(--teal-300); }
.icon-btn svg { width: 20px; height: 20px; }

.cta-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5ch;
  padding: 0.6rem 1.15rem;
  border-radius: 999px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.86rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #ffffff;
  background: #74bf43;
  box-shadow: 0 8px 22px -10px rgba(116, 191, 67, 0.7);
  transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast), background-color var(--dur-fast);
}
.cta-download:hover { transform: translateY(-2px); background: #82d44c; box-shadow: 0 12px 26px -10px rgba(116, 191, 67, 0.85); }
.cta-download svg { width: 16px; height: 16px; }

/* ---- Burger (always visible — primary nav lives in drawer) */
.menu-toggle { display: flex; align-items: center; justify-content: center; width: 44px; height: 44px; position: relative; }
.menu-toggle span {
  position: absolute;
  left: 11px; right: 11px;
  height: 2px;
  background: var(--on-dark);
  transition: transform var(--dur-fast) var(--ease-out), opacity var(--dur-fast);
}
.menu-toggle span:nth-child(1) { top: 15px; }
.menu-toggle span:nth-child(2) { top: 21px; }
.menu-toggle span:nth-child(3) { top: 27px; }
body.drawer-open .menu-toggle span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
body.drawer-open .menu-toggle span:nth-child(2) { opacity: 0; }
body.drawer-open .menu-toggle span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* =============================================================
   MEGA-PANELS (desktop dropdowns, injected by header.js)
   ============================================================= */
.mega-root {
  position: absolute;
  left: 0; right: 0;
  top: 100%;
  z-index: var(--z-mega);
  pointer-events: none;
}
.mega-panel {
  position: absolute;
  left: 0; right: 0; top: 0;
  background: var(--navy-glass);
  -webkit-backdrop-filter: blur(20px) saturate(130%);
  backdrop-filter: blur(20px) saturate(130%);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: var(--shadow-panel);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-out),
              visibility 0s linear var(--dur-fast);
}
.mega-panel.is-open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
  transition: opacity var(--dur-base) var(--ease-out),
              transform var(--dur-base) var(--ease-out),
              visibility 0s;
}
.mega-panel__inner {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: clamp(2rem, 4vw, 4.5rem);
  padding-block: 2.5rem 3rem;
}
.mega-panel__intro { border-right: 1px solid rgba(255, 255, 255, 0.08); padding-right: 2rem; }
.mega-panel__no {
  font-family: var(--font-display);
  font-size: 2.6rem;
  font-weight: 700;
  color: rgba(79, 224, 207, 0.28);
  line-height: 1;
}
.mega-panel__title {
  margin-top: 0.6rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--paper);
}
.mega-panel__blurb {
  margin-top: 0.85rem;
  font-size: 0.9rem;
  line-height: 1.55;
  color: var(--on-dark-dim);
  max-width: 30ch;
}
.mega-panel__links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.2rem 2.5rem;
  align-content: start;
}
.mega-panel__links a {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.6ch;
  padding: 0.7rem 0;
  font-size: var(--fs-mega-child);
  color: var(--on-dark);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: color var(--dur-fast) var(--ease-out), padding-left var(--dur-fast) var(--ease-out);
}
.mega-panel__links a::before {
  content: '';
  position: absolute; left: 0;
  width: 0; height: 1px;
  background: var(--teal-400);
  transition: width var(--dur-fast) var(--ease-out);
}
.mega-panel__links a:hover { color: var(--teal-300); padding-left: 1.4rem; }
.mega-panel__links a:hover::before { width: 1rem; }
.mega-panel__links .pdf-tag {
  margin-left: auto;
  font-family: var(--font-body);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--gold-400);
  border: 1px solid rgba(201, 162, 75, 0.4);
  border-radius: 3px;
  padding: 0.1rem 0.4rem;
}

/* Page dimmer behind any open panel */
.nav-scrim {
  position: fixed;
  inset: 0;
  background: rgba(2, 8, 16, 0.5);
  opacity: 0;
  visibility: hidden;
  z-index: calc(var(--z-header) - 5);
  transition: opacity var(--dur-base) var(--ease-out), visibility 0s linear var(--dur-base);
}
.nav-scrim.is-visible { opacity: 1; visibility: visible; transition: opacity var(--dur-base) var(--ease-out); }

/* =============================================================
   SEARCH OVERLAY
   ============================================================= */
.search-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-search);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 14vh;
  background: var(--navy-glass);
  -webkit-backdrop-filter: blur(22px);
  backdrop-filter: blur(22px);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-base) var(--ease-out), visibility 0s linear var(--dur-base);
}
.search-overlay.is-open { opacity: 1; visibility: visible; transition: opacity var(--dur-base) var(--ease-out); }
.search-overlay__close { position: absolute; top: 2rem; right: var(--gutter); }
.search-box {
  width: min(720px, 90vw);
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 2px solid rgba(255, 255, 255, 0.25);
  padding-bottom: 1rem;
}
.search-box svg { width: 26px; height: 26px; color: var(--teal-300); flex: none; }
.search-box input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(1.5rem, 4vw, 2.4rem);
  letter-spacing: 0.02em;
}
.search-box input::placeholder { color: rgba(238, 242, 246, 0.35); }
.search-results {
  width: min(720px, 90vw);
  margin-top: 1.5rem;
  max-height: 52vh;
  overflow-y: auto;
}
.search-results li a {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  color: var(--on-dark);
  transition: color var(--dur-fast), padding-left var(--dur-fast);
}
.search-results li a:hover { color: var(--teal-300); padding-left: 0.6rem; }
.search-results .res-group { font-size: 0.72rem; letter-spacing: 0.08em; color: var(--on-dark-dim); text-transform: uppercase; }
.search-results .res-empty { padding: 1rem 0.25rem; color: var(--on-dark-dim); }

/* =============================================================
   MOBILE DRAWER
   ============================================================= */
.mobile-drawer {
  position: fixed;
  inset: 0 0 0 auto;
  width: min(440px, 100vw);
  z-index: var(--z-drawer);
  background: var(--grad-navy-teal);
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform var(--dur-base) var(--ease-inout);
  overflow-y: auto;
}
body.drawer-open .mobile-drawer { transform: translateX(0); }
.mobile-drawer__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem var(--gutter);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.mobile-drawer__body { padding: 0.5rem var(--gutter) 2rem; flex: 1; }
.m-accordion { border-bottom: 1px solid rgba(255, 255, 255, 0.1); }
.m-accordion__head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.05rem 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--on-dark);
  text-align: left;
}
.m-accordion__head > span:first-child {
  flex: 1;
  text-align: left;
}
.m-accordion__head .plus { position: relative; width: 16px; height: 16px; flex: none; }
.m-accordion__head .plus::before,
.m-accordion__head .plus::after {
  content: ''; position: absolute; inset: 0; margin: auto;
  background: var(--teal-300);
  transition: transform var(--dur-fast) var(--ease-out);
}
.m-accordion__head .plus::before { width: 100%; height: 2px; }
.m-accordion__head .plus::after { width: 2px; height: 100%; }
.m-accordion.is-open .plus::after { transform: scaleY(0); }
.m-accordion__panel { overflow: hidden; height: 0; transition: height var(--dur-fast) var(--ease-out); }
.m-accordion__panel ul { padding-bottom: 0.5rem; }
.m-accordion__panel a {
  display: flex; justify-content: space-between; gap: 0.75rem;
  padding: 0.6rem 0 0.6rem 1rem;
  font-size: 0.92rem;
  color: var(--on-dark-dim);
}
.m-accordion__panel a:hover { color: var(--teal-300); }
.mobile-drawer__utility { margin-top: 1.5rem; display: grid; gap: 0.4rem; padding: 0 var(--gutter); }
.mobile-drawer__utility a { font-size: 0.82rem; color: var(--on-dark-dim); padding: 0.35rem 0; }
.mobile-drawer__cta { margin: 1.5rem var(--gutter) 2rem; }
.mobile-drawer__cta .cta-download { width: 100%; justify-content: center; }

.drawer-scrim {
  position: fixed; inset: 0;
  background: rgba(2, 8, 16, 0.6);
  z-index: calc(var(--z-drawer) - 1);
  opacity: 0; visibility: hidden;
  transition: opacity var(--dur-base) var(--ease-out), visibility 0s linear var(--dur-base);
}
body.drawer-open .drawer-scrim { opacity: 1; visibility: visible; transition: opacity var(--dur-base) var(--ease-out); }

/* =============================================================
   ENERGY SAVER TOGGLE
   ============================================================= */
.saver-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0 1rem;
  height: 36px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  font-family: var(--font-display);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--on-dark-dim);
  white-space: nowrap;
  flex: none;
  transition: border-color var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out),
              background-color var(--dur-fast) var(--ease-out);
}

/* Toggle SVG images — show/hide based on state */
.saver-toggle__img { flex: none; display: block; }
.saver-toggle__img--on  { display: none; }
.saver-toggle[aria-pressed="true"] .saver-toggle__img--off { display: none; }
.saver-toggle[aria-pressed="true"] .saver-toggle__img--on  { display: block; }

.saver-toggle:hover {
  border-color: rgba(79, 224, 207, 0.4);
  color: var(--teal-300);
  background: rgba(31, 194, 176, 0.07);
}
/* Active / on state */
.saver-toggle[aria-pressed="true"] {
  border-color: var(--teal-400);
  color: var(--teal-300);
  background: rgba(31, 194, 176, 0.12);
}

/* =============================================================
   SCREENSHOT BUTTON — busy spinner state
   ============================================================= */
.screenshot-btn.is-busy { opacity: 0.5; pointer-events: none; }
.screenshot-btn.is-busy svg { animation: spin 0.9s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* =============================================================
   ENERGY SAVER MODE — body class kills all motion overhead
   Uses CSS custom-property override so every component respects it
   ============================================================= */
body.is-saver {
  --dur-fast: 0.01ms;
  --dur-base: 0.01ms;
  --ease-out: linear;
  --ease-inout: linear;
}
body.is-saver .hero__chevron   { animation: none !important; }
body.is-saver .kpi__dot        { transition: none !important; }

/* =============================================================
   RESPONSIVE
   ============================================================= */

/* Primary nav always lives in the drawer — inline links hidden */
.primary-nav { display: none; }
.mega-root   { display: none; }

/* Simplify the header bar on tablets / phones */
@media (max-width: 900px) {
  .nav-actions .saver-toggle { display: none; }
  .nav-actions .tts-toggle   { display: none; }
}
@media (max-width: 768px) {
  .utility-bar                   { display: none; }
  .nav-actions .cta-download     { display: none; }
  .nav-actions .search-toggle    { display: none; }
}

/* Drop Vedanta mark on very small phones */
@media (max-width: 560px) {
  .nav-bar__inner .brand__logo--vedanta,
  .nav-bar__inner .brand__divider { display: none; }
}