/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --green: #16a34a;
  --green-light: #f0fdf4;
  --slate: #334155;
  --slate-light: #f8fafc;
  --amber: #f59e0b;
  --indigo: #6366f1;
  --red-soft: #fef2f2;
  --green-soft: #f0fdf4;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--slate);
  line-height: 1.7;
  font-size: 17px;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 { line-height: 1.3; }

/* ── Hero ── */
.hero {
  background: linear-gradient(135deg, #064e3b 0%, #065f46 50%, #047857 100%);
  color: #fff;
  padding: 100px 24px 80px;
  text-align: center;
}

.hero .brand {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.7;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  margin-bottom: 16px;
}

.hero .subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  opacity: 0.85;
  max-width: 600px;
  margin: 0 auto;
}

/* ── Sections ── */
.section {
  padding: 72px 24px;
}

.section h2 {
  font-size: 1.8rem;
  margin-bottom: 16px;
  color: #0f172a;
}

.section p {
  margin-bottom: 16px;
}

.section--problem {
  background: #fff;
}

.section--solution {
  background: var(--green-light);
}

.section--approach {
  background: #fff;
}

.section--validation {
  background: var(--slate-light);
}

.section--beyond {
  background: #fff;
}

/* ── Spectrum Diagram ── */
.spectrum-diagram {
  display: flex;
  border-radius: 8px;
  overflow: hidden;
  margin: 28px 0 8px;
  height: 72px;
}

.spectrum-bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 600;
  gap: 2px;
}

.spectrum-bar.uv {
  background: #7c3aed;
}

.spectrum-bar.par {
  background: #16a34a;
}

.spectrum-bar.nir {
  background: #dc2626;
}

.spectrum-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  opacity: 0.9;
}

.spectrum-pct {
  font-size: 1.3rem;
}

.spectrum-caption {
  text-align: center;
  font-size: 0.85rem;
  color: #64748b;
  margin-bottom: 24px;
}

/* ── Film Diagram ── */
.film-diagram {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin: 36px 0;
  padding: 32px 16px;
  background: #fff;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
}

.film-diagram__sun {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  color: #92400e;
  font-weight: 600;
}

.film-diagram__arrows {
  display: flex;
  gap: 48px;
  margin: 4px 0;
}

.film-diagram__arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.arrow-down {
  display: block;
  width: 3px;
  height: 32px;
  background: var(--green);
  position: relative;
}
.arrow-down::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 7px solid transparent;
  border-right: 7px solid transparent;
  border-top: 8px solid var(--green);
}

.arrow-up {
  display: block;
  width: 3px;
  height: 32px;
  background: #dc2626;
  position: relative;
}
.arrow-up::after {
  content: "";
  position: absolute;
  top: -6px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 7px solid transparent;
  border-right: 7px solid transparent;
  border-bottom: 8px solid #dc2626;
}

.arrow-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--slate);
}

.film-diagram__film {
  width: 100%;
  max-width: 400px;
  text-align: center;
  padding: 10px 0;
  background: linear-gradient(90deg, #a7f3d0, #6ee7b7, #a7f3d0);
  border-radius: 4px;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.03em;
  color: #064e3b;
}

.film-diagram__greenhouse {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  color: var(--green);
  font-weight: 600;
}

/* ── Check List ── */
.check-list {
  list-style: none;
  margin: 20px 0 0;
}

.check-list li {
  padding: 6px 0 6px 28px;
  position: relative;
}

.check-list li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--green);
  font-weight: 700;
  font-size: 1.1rem;
}

/* ── Pipeline ── */
.pipeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 36px 0;
}

.pipeline__step {
  background: var(--slate-light);
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 24px 28px;
}

.pipeline__step h3 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.pipeline__step p {
  margin-bottom: 0;
  font-size: 0.95rem;
  color: #475569;
}

.pipeline__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--green);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.pipeline__connector {
  width: 3px;
  height: 20px;
  background: #cbd5e1;
  margin: 0 auto;
}

/* ── Comparison ── */
.comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: center;
  margin: 32px 0 0;
}

.comparison__card {
  padding: 24px;
  border-radius: 10px;
}

.comparison__card h3 {
  margin-bottom: 8px;
  font-size: 1rem;
}

.comparison__card p {
  margin-bottom: 0;
  font-size: 0.93rem;
}

.comparison__card--old {
  background: var(--red-soft);
  border: 1px solid #fecaca;
}

.comparison__card--new {
  background: var(--green-soft);
  border: 1px solid #bbf7d0;
}

.comparison__vs {
  font-weight: 700;
  font-size: 0.85rem;
  color: #94a3b8;
  text-transform: uppercase;
}

@media (max-width: 640px) {
  .comparison {
    grid-template-columns: 1fr;
  }
  .comparison__vs {
    text-align: center;
  }
}

/* ── Tunnels ── */
.tunnels {
  display: flex;
  gap: 24px;
  justify-content: center;
  flex-wrap: wrap;
  margin: 32px 0 12px;
}

.tunnel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  min-width: 140px;
}

.tunnel strong { font-size: 0.95rem; }
.tunnel span { font-size: 0.82rem; color: #64748b; text-align: center; }

.tunnels-caption {
  text-align: center;
  font-size: 0.85rem;
  color: #64748b;
  margin-top: 8px;
}

/* ── Applications ── */
.applications {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin: 28px 0;
}

.app-card {
  background: var(--slate-light);
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 24px;
  text-align: center;
}

.app-icon {
  margin-bottom: 12px;
}

.app-card h3 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.app-card p {
  font-size: 0.9rem;
  color: #475569;
  margin-bottom: 0;
}

.beyond-note {
  text-align: center;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--green);
  margin-top: 8px;
}

/* ── Footer ── */
.footer {
  background: #0f172a;
  color: #94a3b8;
  text-align: center;
  padding: 32px 24px;
  font-size: 0.85rem;
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .hero { padding: 64px 16px 56px; }
  .section { padding: 48px 16px; }
  .film-diagram__arrows { gap: 24px; }
}