/* ═══════════════════════════════════════════════════════════
   OHRA HYDRO POLYMERS — Design System
   The Hold Beneath Growth
   ═══════════════════════════════════════════════════════════ */

/* --- Reset & Base --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: 'Montserrat', -apple-system, BlinkMacSystemFont, sans-serif;
  background: #E3E7E2;
  color: #2D3436;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
::selection { background: #4A5E46; color: #fff; }

/* --- Design Tokens --- */
:root {
  --forest: #4A5E46;
  --forest-dark: #3A4E38;
  --sage: #7A8E7A;
  --mist: #D0D6CF;
  --clay: #C7CDC8;
  --stone: #E3E7E2;
  --stone-light: #EBEFEB;
  --charcoal: #2D3436;
  --charcoal-light: #3D4446;
  --white: #ffffff;
  --green-accent: #2E7D32;
  --grow-accent: #4A5E46;
  --cal-accent: #1a1a2e;
  --section-padding: clamp(80px, 10vw, 160px);
  --container: 1280px;
  --gutter: clamp(24px, 4vw, 64px);
}

/* --- Typography --- */
.display-xl {
  font-size: clamp(3.5rem, 8vw, 7rem);
  font-weight: 800;
  line-height: 0.92;
  letter-spacing: -0.04em;
}
.display-lg {
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
}
.display-md {
  font-size: clamp(2rem, 3.5vw, 3rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.heading-lg {
  font-size: clamp(1.5rem, 2.5vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.heading-md {
  font-size: clamp(1.25rem, 1.5vw, 1.5rem);
  font-weight: 600;
  line-height: 1.3;
}
.body-lg {
  font-size: clamp(1.05rem, 1.2vw, 1.25rem);
  font-weight: 300;
  line-height: 1.7;
}
.body-md {
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
}
.label {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.container-wide {
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--gutter); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gutter); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: calc(var(--gutter) * 0.5); }

@media (max-width: 1024px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}
@media (min-width: 768px) and (max-width: 1024px) {
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .grid-4 { grid-template-columns: 1fr 1fr; }
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1.5rem 0;
  transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}
.nav.scrolled {
  padding: 0.75rem 0;
  background: rgba(227, 231, 226, 0.92);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid rgba(199, 205, 200, 0.4);
}
.nav__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.nav__logo {
  display: flex;
  align-items: center;
  gap: 12px;
}
.nav__logo img { height: 40px; width: auto; }
.nav__logo-text {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--forest);
}
.nav__links {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
}
.nav__link {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--charcoal-light);
  transition: color 0.3s;
  position: relative;
}
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--forest);
  transition: width 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}
.nav__link:hover { color: var(--forest); }
.nav__link:hover::after { width: 100%; }
.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: 0.625rem 1.5rem;
  background: var(--forest);
  color: var(--stone);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  transition: all 0.3s;
}
.nav__cta:hover { background: var(--forest-dark); transform: translateY(-1px); }
.nav__mobile-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }

.nav__mobile {
  display: none;
  flex-direction: column;
  padding: 1.5rem var(--gutter);
  background: rgba(227, 231, 226, 0.98);
  backdrop-filter: blur(20px);
  border-top: 1px solid rgba(199, 205, 200, 0.4);
}
.nav__mobile.active { display: flex; }
.nav__mobile .nav__link { padding: 0.75rem 0; display: block; }

@media (max-width: 768px) {
  .nav__links { display: none; }
  .nav__cta { display: none; }
  .nav__mobile-toggle { display: flex; flex-direction: column; gap: 5px; }
  .nav__mobile-toggle span { display: block; width: 24px; height: 2px; background: var(--charcoal); transition: all 0.3s; }
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 1rem 2.25rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
  position: relative;
  overflow: hidden;
}
.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.1), transparent);
  opacity: 0;
  transition: opacity 0.4s;
}
.btn:hover::before { opacity: 1; }
.btn-primary {
  background: var(--forest);
  color: var(--stone);
}
.btn-primary:hover { background: var(--forest-dark); transform: translateY(-2px); box-shadow: 0 8px 32px rgba(74, 94, 70, 0.3); }
.btn-outline {
  background: transparent;
  color: #fff;
  border: 1.5px solid rgba(255,255,255,0.4);
}
.btn-outline:hover { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.7); }
.btn-dark {
  background: var(--charcoal);
  color: var(--stone);
}
.btn-dark:hover { background: var(--forest); transform: translateY(-2px); }

/* --- Section Styles --- */
.section { padding: var(--section-padding) 0; }
.section-dark { background: var(--charcoal); color: #fff; }
.section-stone { background: var(--stone); }
.section-light { background: var(--stone-light); }
.section-white { background: var(--white); }
.section-forest { background: var(--forest); color: #fff; }

.section__tag {
  color: var(--sage);
  margin-bottom: 1rem;
  display: block;
}
.section-dark .section__tag { color: var(--mist); }
.section__header {
  max-width: 700px;
  margin-bottom: clamp(48px, 5vw, 80px);
}
.section__divider {
  width: 60px;
  height: 3px;
  background: var(--forest);
  margin-top: 1.5rem;
}
.section-dark .section__divider { background: var(--mist); }

/* --- Footer --- */
.footer {
  background: var(--charcoal);
  color: rgba(255,255,255,0.6);
  padding: 4rem 0 2rem;
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}
.footer__logo {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 1rem;
}
.footer__logo img { height: 32px; filter: brightness(0) invert(1) opacity(0.5); }
.footer__logo-text { font-size: 1.125rem; font-weight: 700; color: #fff; }
.footer__desc {
  font-size: 0.875rem;
  line-height: 1.7;
  max-width: 360px;
}
.footer__heading {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 1rem;
}
.footer__links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.footer__links a {
  font-size: 0.875rem;
  transition: color 0.3s;
}
.footer__links a:hover { color: #fff; }
.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer__copy {
  font-size: 0.6875rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
}
.footer__legal {
  display: flex;
  gap: 1.5rem;
}
.footer__legal a {
  font-size: 0.6875rem;
  transition: color 0.3s;
}
.footer__legal a:hover { color: #fff; }

@media (max-width: 768px) {
  .footer__grid { grid-template-columns: 1fr; }
  .footer__bottom { flex-direction: column; gap: 1rem; text-align: center; }
}

/* --- Animations --- */
@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(1); }
  50% { opacity: 1; transform: scaleY(1.2); }
}

.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 100ms; }
.reveal-delay-2 { transition-delay: 200ms; }
.reveal-delay-3 { transition-delay: 300ms; }
.reveal-delay-4 { transition-delay: 400ms; }
.reveal-delay-5 { transition-delay: 500ms; }

.parallax {
  will-change: transform;
}

/* --- Image Treatments --- */
.img-reveal {
  position: relative;
  overflow: hidden;
}
.img-reveal::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--forest);
  transform-origin: right;
  transition: transform 1s cubic-bezier(0.22, 1, 0.36, 1);
  transform: scaleX(1);
}
.img-reveal.visible::after {
  transform: scaleX(0);
}

/* --- Divider --- */
.divider {
  width: 100%;
  height: 1px;
  background: rgba(199, 205, 200, 0.3);
}
.divider-dark {
  background: rgba(255, 255, 255, 0.08);
}

/* --- Challenge List (Dark Section) --- */
.challenge-list {
  display: flex;
  flex-direction: column;
}
.challenge-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  transition: all 0.3s;
  cursor: pointer;
}
.challenge-item:hover {
  padding-left: 1rem;
  background: rgba(255,255,255,0.02);
}
.challenge-item__text {
  font-size: 1.125rem;
  font-weight: 500;
}
.challenge-item__arrow {
  color: var(--mist);
  transition: transform 0.3s;
}
.challenge-item:hover .challenge-item__arrow {
  transform: translateX(6px);
}

/* --- Insight Cards (Dark Section) --- */
.insight-card {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.08);
  padding: 3rem;
  transition: border-color 0.4s;
}
.insight-card:hover { border-color: rgba(220, 224, 219, 0.4); }
.insight-card__number {
  font-size: 3.5rem;
  font-weight: 800;
  color: rgba(220, 224, 219, 0.35);
  margin-bottom: 1.5rem;
  line-height: 1;
}
.insight-card__title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}
.insight-card__desc {
  color: rgba(220, 224, 219, 0.85);
  line-height: 1.7;
}

/* --- Breadcrumb --- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--sage);
  margin-bottom: 2rem;
}
.breadcrumb a { color: var(--sage); transition: color 0.3s; }
.breadcrumb a:hover { color: var(--forest); }
.breadcrumb span { color: var(--clay); }

/* --- Tags --- */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.tag {
  display: inline-block;
  padding: 0.375rem 1rem;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--forest);
  background: rgba(74, 94, 70, 0.05);
  border: 1px solid rgba(74, 94, 70, 0.2);
}

/* --- Performance Bars --- */
.perf-card {
  background: var(--stone);
  padding: 3rem;
}
.perf-card__heading {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--charcoal-light);
  margin-bottom: 2rem;
}
.perf-bar {
  margin-bottom: 1.25rem;
}
.perf-bar:last-child { margin-bottom: 0; }
.perf-bar__label {
  display: flex;
  justify-content: space-between;
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
}
.perf-bar__label span:first-child { color: var(--charcoal-light); }
.perf-bar__value {
  font-weight: 600;
  font-size: 0.8125rem;
}
.perf-bar__track {
  width: 100%;
  height: 6px;
  background: rgba(199, 205, 200, 0.5);
  overflow: hidden;
}
.perf-bar__fill {
  height: 100%;
  transition: width 1.2s cubic-bezier(0.22, 1, 0.36, 1);
}

/* --- Topic List (Knowledge Center) --- */
.topic-list {
  display: flex;
  flex-direction: column;
}
.topic-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--clay);
  transition: all 0.3s;
  cursor: pointer;
}
.topic-item:last-child { border-bottom: none; }
.topic-item:hover { padding-left: 1rem; }
.topic-item__tag {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--forest);
  margin-bottom: 0.5rem;
  display: block;
}
.topic-item__title {
  font-size: 1.125rem;
  font-weight: 600;
  transition: color 0.3s;
}
.topic-item:hover .topic-item__title { color: var(--forest); }
.topic-item__desc {
  font-size: 0.875rem;
  color: var(--charcoal-light);
  margin-top: 0.25rem;
}
.topic-item__arrow {
  color: var(--sage);
  font-size: 1.25rem;
  transition: all 0.3s;
  flex-shrink: 0;
  margin-top: 0.25rem;
}
.topic-item:hover .topic-item__arrow { color: var(--forest); transform: translateX(4px); }

/* --- Glossary Card --- */
.glossary-card {
  background: #fff;
  border: 1px solid rgba(199, 205, 200, 0.3);
  padding: 2rem;
}
.glossary-card__term {
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.glossary-card__def {
  font-size: 0.875rem;
  color: var(--charcoal-light);
  line-height: 1.6;
}

/* --- Utility --- */
.text-forest { color: var(--forest); }
.text-sage { color: var(--sage); }
.text-mist { color: var(--mist); }
.text-charcoal { color: var(--charcoal); }
.text-white { color: #fff; }
.bg-stone { background: var(--stone); }
.bg-forest { background: var(--forest); }
.bg-charcoal { background: var(--charcoal); }
.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-4 { margin-bottom: 4rem; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-1 { gap: 1rem; }
.gap-2 { gap: 2rem; }