/* ============================================
   REEL LCI Database — Custom Styles
   Layer Stack + Clean Editorial theme
   ============================================ */

/* ---- CSS Variables (brand tokens) ---- */
:root {
  --carrier-navy: #1B2A41;
  --trace-cyan: #1A6B9C;
  --wafer-grey: #E5E7EB;
  --carbon: #111827;
  --muted-slate: #64748B;

  /* Extended palette for layer stack */
  --layer-substrate: #C4956A;
  --layer-oxide: #2563EB;
  --layer-metal: #D97706;
  --layer-dielectric: #1E3A5F;
  --layer-passivation: #059669;
  --layer-poly: #6B7280;
  --layer-nitride: #7C3AED;
  --layer-via: #92400E;
}

/* ---- Base ---- */
html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  color: var(--carbon);
  overflow-x: hidden;
}

/* ---- Hero section ---- */
.hero {
  background: linear-gradient(180deg, #0F1B2D 0%, #0F1B2D 40%, var(--carrier-navy) 70%, #1E3650 100%);
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* Wafer grid background pattern */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(26, 107, 156, 0.08) 1px, transparent 1px);
  background-size: 32px 32px;
  animation: grid-drift 60s linear infinite;
}

@keyframes grid-drift {
  from { transform: translate(0, 0); }
  to { transform: translate(32px, 32px); }
}

/* ---- Layer Stack illustration ---- */
.layer-stack {
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: 3px;
  margin-top: 3rem;
  position: relative;
}

.layer {
  border-radius: 4px;
  opacity: 0;
  transform: scaleX(0.3);
  animation: layer-build 0.7s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

.layer:nth-child(1)  { animation-delay: 0.3s; }
.layer:nth-child(2)  { animation-delay: 0.4s; }
.layer:nth-child(3)  { animation-delay: 0.5s; }
.layer:nth-child(4)  { animation-delay: 0.6s; }
.layer:nth-child(5)  { animation-delay: 0.7s; }
.layer:nth-child(6)  { animation-delay: 0.8s; }
.layer:nth-child(7)  { animation-delay: 0.9s; }
.layer:nth-child(8)  { animation-delay: 1.0s; }
.layer:nth-child(9)  { animation-delay: 1.1s; }
.layer:nth-child(10) { animation-delay: 1.2s; }
.layer:nth-child(11) { animation-delay: 1.3s; }

@keyframes layer-build {
  to {
    opacity: 1;
    transform: scaleX(1);
  }
}

/* Layer stack annotations */
.layer-label {
  position: absolute;
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.5);
  white-space: nowrap;
  opacity: 0;
  animation: label-fade 0.5s ease forwards;
}

.layer-label.left {
  right: calc(100% + 12px);
  text-align: right;
}

.layer-label.right {
  left: calc(100% + 12px);
  text-align: left;
}

.layer-label::before {
  content: '';
  position: absolute;
  top: 50%;
  width: 8px;
  height: 1px;
  background: rgba(255, 255, 255, 0.25);
}

.layer-label.left::before {
  left: calc(100% + 4px);
}

.layer-label.right::before {
  right: calc(100% + 4px);
}

@keyframes label-fade {
  to { opacity: 1; }
}

/* ---- Section layer dividers ---- */
.section-divider {
  height: 4px;
  display: flex;
  gap: 2px;
  overflow: hidden;
}

.section-divider span {
  flex: 1;
  border-radius: 1px;
}

/* ---- Navigation ---- */
.nav-glass {
  background: rgba(27, 42, 65, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(26, 107, 156, 0.2);
  transition: all 0.3s ease;
}

.nav-glass.scrolled {
  background: rgba(27, 42, 65, 0.95);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.nav-link {
  position: relative;
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.2s ease;
  font-size: 0.875rem;
  letter-spacing: 0.02em;
}

.nav-link:hover,
.nav-link.active {
  color: #fff;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--trace-cyan);
  transition: width 0.2s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* ---- Vertical side nav ---- */
.side-nav {
  position: fixed;
  left: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 40;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
}

.side-nav.visible {
  opacity: 1;
  pointer-events: auto;
}

.side-nav-item {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.375rem 0.25rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.side-nav-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--wafer-grey);
  border: 1.5px solid #d1d5db;
  flex-shrink: 0;
  transition: all 0.25s ease;
}

.side-nav-item:hover .side-nav-dot {
  background: var(--trace-cyan);
  border-color: var(--trace-cyan);
  transform: scale(1.3);
}

.side-nav-item.active .side-nav-dot {
  background: var(--trace-cyan);
  border-color: var(--trace-cyan);
  box-shadow: 0 0 0 3px rgba(26, 107, 156, 0.15);
  transform: scale(1.2);
}

.side-nav-label {
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--muted-slate);
  letter-spacing: 0.02em;
  white-space: nowrap;
  opacity: 0;
  transform: translateX(-4px);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.side-nav-item:hover .side-nav-label,
.side-nav-item.active .side-nav-label {
  opacity: 1;
  transform: translateX(0);
}

.side-nav-item.active .side-nav-label {
  color: var(--trace-cyan);
  font-weight: 600;
}

/* Hide side nav on small screens — not enough space */
@media (max-width: 1024px) {
  .side-nav {
    display: none;
  }
}

/* ---- Dataset availability notice ---- */
.dataset-notice {
  box-shadow: 0 4px 24px rgba(26, 107, 156, 0.06);
}

.dataset-notice img,
.dataset-notice video {
  display: block;
}



/* ---- Stat cards ---- */
.stat-card {
  background: white;
  border: 1px solid var(--wafer-grey);
  border-radius: 12px;
  padding: 2rem 1.5rem;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(27, 42, 65, 0.1);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(135deg, var(--carrier-navy), var(--trace-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---- Virtual Factory pipeline ---- */
.pipeline {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  gap: 0;
  align-items: center;
  position: relative;
}

.pipeline-arrow-gap {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--trace-cyan);
  font-size: 1.5rem;
  padding: 0 0.25rem;
}

@media (max-width: 768px) {
  .pipeline {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .pipeline-arrow-gap {
    transform: rotate(90deg);
    padding: 0.5rem 0;
  }
}

.pipeline-step {
  position: relative;
  padding: 2rem 1.5rem;
  text-align: center;
  border-radius: 12px;
  transition: transform 0.2s ease;
}

.pipeline-step:hover {
  transform: translateY(-2px);
}

/* pipeline-arrow removed — replaced by pipeline-arrow-gap */

/* ---- Category grid ---- */
.category-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  background: white;
  border: 1px solid var(--wafer-grey);
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--carrier-navy);
  transition: all 0.2s ease;
}

.category-chip:hover {
  border-color: var(--trace-cyan);
  background: rgba(26, 107, 156, 0.05);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(26, 107, 156, 0.1);
}

.category-chip .chip-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ---- FAQ accordion ---- */
.faq-item {
  border-bottom: 1px solid var(--wafer-grey);
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem 0;
  font-weight: 600;
  color: var(--carrier-navy);
  cursor: pointer;
  text-align: left;
  background: none;
  border: none;
  font-size: 1rem;
  font-family: inherit;
}

.faq-question:hover {
  color: var(--trace-cyan);
}

.faq-chevron {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  transition: transform 0.3s ease;
  color: var(--muted-slate);
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.22, 1, 0.36, 1),
              padding 0.35s ease;
  padding-bottom: 0;
}

.faq-item.open .faq-answer {
  max-height: 600px;
  padding-bottom: 1.25rem;
}

/* ---- Contact form ---- */
.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--wafer-grey);
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.9375rem;
  color: var(--carbon);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  background: white;
}

.form-input:focus {
  outline: none;
  border-color: var(--trace-cyan);
  box-shadow: 0 0 0 3px rgba(26, 107, 156, 0.12);
}

.form-input::placeholder {
  color: var(--muted-slate);
}

textarea.form-input {
  resize: vertical;
  min-height: 120px;
}

/* ---- Buttons ---- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  background: var(--trace-cyan);
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9375rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-primary:hover {
  background: #15587F;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(26, 107, 156, 0.3);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  background: transparent;
  color: white;
  border: 1.5px solid rgba(255, 255, 255, 0.35);
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9375rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-secondary:hover {
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.08);
}

.btn-dark {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  background: var(--carrier-navy);
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9375rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-dark:hover {
  background: #142232;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(27, 42, 65, 0.3);
}

/* ---- Scroll reveal ---- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---- Methodology report card ---- */
.report-card {
  background: linear-gradient(135deg, #f8fafc 0%, var(--wafer-grey) 100%);
  border: 1px solid #d1d5db;
  border-radius: 16px;
  overflow: hidden;
}

.report-toc-item {
  padding: 0.625rem 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  font-size: 0.9375rem;
  color: var(--carrier-navy);
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.report-toc-item:last-child {
  border-bottom: none;
}

.report-toc-num {
  font-weight: 700;
  color: var(--trace-cyan);
  font-size: 0.8125rem;
  min-width: 1.5rem;
}

/* ---- Mobile hamburger ---- */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  width: 22px;
  height: 2px;
  background: white;
  border-radius: 1px;
  transition: all 0.3s ease;
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(27, 42, 65, 0.98);
    padding: 1rem 1.5rem;
    flex-direction: column;
    gap: 0.75rem;
    border-bottom: 1px solid rgba(26, 107, 156, 0.2);
  }

  .nav-links.open {
    display: flex;
  }
}

/* ---- Footer ---- */
.footer {
  background: var(--carrier-navy);
  color: rgba(255, 255, 255, 0.6);
}

.footer a {
  color: rgba(255, 255, 255, 0.6);
  transition: color 0.2s ease;
}

.footer a:hover {
  color: white;
}

/* ---- Utilities ---- */
.text-gradient {
  background: linear-gradient(135deg, #fff 0%, rgba(255, 255, 255, 0.8) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.layer-divider {
  height: 3px;
  background: linear-gradient(90deg,
    var(--layer-substrate) 0%,
    var(--layer-oxide) 15%,
    var(--layer-metal) 30%,
    var(--layer-dielectric) 45%,
    var(--layer-passivation) 60%,
    var(--layer-nitride) 75%,
    var(--trace-cyan) 100%
  );
  border-radius: 2px;
  opacity: 0.6;
}