:root {
  --gs-bg: #FFFFFF;
  --gs-bg-subtle: #F4F6F5;
  --gs-text: #374151;
  --gs-text-muted: #6B7280;
  --gs-emerald: #059669;
  --gs-emerald-glow: rgba(5, 150, 105, 0.12);
  --gs-emerald-dark: #047857;
  --gs-border: #E5E7EB;
}

.gas-sentinel-page {
  background: var(--gs-bg);
  color: var(--gs-text);
  font-family: Georgia, 'Times New Roman', 'Palatino Linotype', serif;
  line-height: 1.65;
}

.gas-sentinel-page a {
  color: var(--gs-emerald);
}

.gs-back-link {
  position: fixed;
  top: 1.5rem;
  left: 1.5rem;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.8rem;
  border: 1px solid var(--gs-border);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  color: var(--gs-text);
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 0.75rem 2rem rgba(55, 65, 81, 0.06);
}

.gs-back-link:hover {
  color: var(--gs-emerald-dark);
  opacity: 1;
}

.gs-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 12vh 2rem;
  position: relative;
}

.gs-section:nth-child(even) {
  background: var(--gs-bg-subtle);
}

.gs-container {
  width: min(100%, 1080px);
  margin: 0 auto;
}

.gs-eyebrow {
  color: var(--gs-emerald);
  font-size: 0.9rem;
  letter-spacing: 0.16em;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
}

.gs-hero {
  text-align: center;
  overflow: hidden;
}

.gs-hero::before {
  content: '';
  position: absolute;
  inset: 12% auto auto 50%;
  width: min(44rem, 82vw);
  aspect-ratio: 1;
  transform: translateX(-50%);
  border-radius: 999px;
  background: radial-gradient(circle, var(--gs-emerald-glow) 0%, rgba(5, 150, 105, 0) 68%);
  pointer-events: none;
}

.gs-hero__content {
  position: relative;
}

.gs-hero__title {
  color: var(--gs-text);
  font-size: clamp(4.25rem, 13vw, 10rem);
  font-weight: 400;
  letter-spacing: -0.08em;
  line-height: 0.9;
  margin-bottom: 2rem;
}

.gs-wordmark {
  max-width: 480px;
  width: 80vw;
  margin: 0 auto 2rem;
  display: block;
}

.gs-hero__subheadline,
.gs-section__subtitle {
  color: var(--gs-text);
  font-size: clamp(1.35rem, 3vw, 2.3rem);
  font-weight: 400;
  line-height: 1.25;
  margin: 0 auto 1.25rem;
  max-width: 820px;
}

.gs-hero__body,
.gs-section__body {
  color: var(--gs-text-muted);
  font-size: clamp(1.05rem, 2vw, 1.28rem);
  margin: 0 auto;
  max-width: 720px;
}

.gs-pull-quote {
  border: 0;
  color: var(--gs-emerald-dark);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  font-style: italic;
  margin: 4rem auto 0;
  max-width: 760px;
  padding-top: 1.5rem;
  position: relative;
  text-align: center;
}

.gs-pull-quote::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: 5rem;
  height: 2px;
  transform: translateX(-50%);
  background: var(--gs-emerald);
}

.gs-section__title {
  color: var(--gs-text);
  font-size: clamp(2.25rem, 6vw, 5rem);
  font-weight: 400;
  letter-spacing: -0.045em;
  line-height: 1.02;
  margin: 0 auto 2rem;
  max-width: 980px;
  text-align: center;
}

.gs-system-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
  margin: 4rem 0 2.5rem;
  position: relative;
}

.gs-system-grid::before {
  content: '';
  position: absolute;
  left: 8%;
  right: 8%;
  top: 50%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gs-border), transparent);
  transform: translateY(-50%);
  z-index: 0;
}

.gs-system-node {
  position: relative;
  z-index: 1;
  min-height: 9rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.15rem;
  padding: 1.5rem;
  border: 1px solid var(--gs-border);
  border-radius: 1.25rem;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 1rem 3rem rgba(55, 65, 81, 0.05);
  color: var(--gs-text);
  font-size: 1.12rem;
  text-align: center;
}

.gs-warning-badge {
  display: inline-grid;
  place-items: center;
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 999px;
  background: rgba(5, 150, 105, 0.14);
  color: var(--gs-emerald-dark);
  font-family: Arial, sans-serif;
  font-size: 0.95rem;
  font-weight: 700;
}

.gs-pain-list {
  display: grid;
  gap: 0.75rem;
  max-width: 760px;
  margin: 0 auto;
  color: var(--gs-text-muted);
  font-size: clamp(1rem, 2vw, 1.15rem);
  list-style: none;
  text-align: center;
}

.gs-pain-list li::before {
  content: '•';
  color: var(--gs-emerald);
  margin-right: 0.5rem;
}

.gs-solution,
.gs-features,
.gs-impact,
.gs-cta {
  text-align: center;
}

.gs-pillars-grid,
.gs-feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 3.5rem auto 0;
  max-width: 880px;
  text-align: left;
}

.gs-pillar-card,
.gs-feature-card {
  border: 1px solid var(--gs-border);
  border-radius: 1.25rem;
  background: var(--gs-bg);
  box-shadow: 0 1rem 3rem rgba(55, 65, 81, 0.04);
}

.gs-pillar-card {
  border-left: 4px solid var(--gs-emerald);
  padding: 1.5rem;
}

.gs-pillar-card h3,
.gs-feature-card h3 {
  color: var(--gs-text);
  font-size: 1.35rem;
  font-weight: 400;
  line-height: 1.25;
  margin-bottom: 0.6rem;
}

.gs-pillar-card p,
.gs-feature-card p {
  color: var(--gs-text-muted);
  font-size: 1rem;
  line-height: 1.6;
}

.gs-badge {
  display: inline-flex;
  align-items: center;
  margin-top: 2.5rem;
  padding: 0.7rem 1.1rem;
  border: 1px solid rgba(5, 150, 105, 0.22);
  border-radius: 999px;
  background: var(--gs-emerald-glow);
  color: var(--gs-emerald-dark);
  font-size: 1rem;
}

.gs-feature-card {
  padding: 1.75rem;
  position: relative;
  overflow: hidden;
}

.gs-feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gs-emerald);
}

.gs-footer-line {
  color: var(--gs-emerald-dark);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  margin-top: 3rem;
}

.gs-impact__subhead {
  color: var(--gs-text-muted);
  max-width: 760px;
}

.gs-loss-chart {
  position: relative;
  width: min(100%, 900px);
  height: clamp(20rem, 45vw, 31rem);
  margin: 4rem auto 0;
  border-left: 1px solid var(--gs-border);
  border-bottom: 1px solid var(--gs-border);
  border-radius: 1.5rem;
  background: linear-gradient(180deg, #FFFFFF 0%, var(--gs-bg-subtle) 100%);
  box-shadow: 0 1.5rem 4rem rgba(55, 65, 81, 0.07);
  overflow: hidden;
}

.gs-loss-chart__grid {
  position: absolute;
  inset: 1rem 1.25rem 3.5rem 4rem;
  background-image:
    linear-gradient(var(--gs-border) 1px, transparent 1px),
    linear-gradient(90deg, var(--gs-border) 1px, transparent 1px);
  background-size: 100% 25%, 20% 100%;
  opacity: 0.55;
}

.gs-loss-chart__curve {
  position: absolute;
  inset: 18% 7% 14% 12%;
  background: linear-gradient(135deg, rgba(5, 150, 105, 0.14) 0%, rgba(5, 150, 105, 0.46) 45%, rgba(5, 150, 105, 0.58) 100%);
  clip-path: polygon(0 89%, 11% 87%, 22% 82%, 34% 74%, 46% 62%, 58% 48%, 70% 32%, 82% 16%, 100% 0, 100% 100%, 0 100%);
}

.gs-loss-chart__curve::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0 48%, var(--gs-emerald-dark) 49%, var(--gs-emerald-dark) 51%, transparent 52% 100%);
  clip-path: polygon(0 89%, 11% 87%, 22% 82%, 34% 74%, 46% 62%, 58% 48%, 70% 32%, 82% 16%, 100% 0, 100% 7%, 82% 23%, 70% 39%, 58% 55%, 46% 69%, 34% 81%, 22% 89%, 11% 94%, 0 96%);
  opacity: 0.75;
}

.gs-loss-chart__overlay {
  position: absolute;
  left: 50%;
  top: 48%;
  transform: translate(-50%, -50%);
  color: rgba(26, 26, 26, 0.68);
  font-family: Arial, sans-serif;
  font-size: clamp(1.65rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: 0.08em;
  line-height: 1;
  text-align: center;
  width: 90%;
}

.gs-axis-label {
  position: absolute;
  color: var(--gs-text-muted);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.gs-axis-label--y {
  left: 1rem;
  top: 50%;
  transform: rotate(-90deg) translateX(-50%);
  transform-origin: left top;
}

.gs-loss-chart__x-axis {
  position: absolute;
  left: 4rem;
  right: 1.25rem;
  bottom: 1.15rem;
  display: flex;
  justify-content: space-between;
  color: var(--gs-text-muted);
  font-size: 0.95rem;
}

.gs-cta {
  min-height: 82vh;
}

.gs-cta__content {
  max-width: 820px;
}

.gs-cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 1rem;
  min-width: 13rem;
  padding: 0.95rem 1.6rem;
  border-radius: 999px;
  background: var(--gs-emerald);
  color: #FFFFFF !important;
  font-size: 1.05rem;
  box-shadow: 0 1rem 2.5rem rgba(5, 150, 105, 0.2);
}

.gs-cta-button:hover {
  background: var(--gs-emerald-dark);
  opacity: 1;
}

.gs-cta__note {
  color: var(--gs-text-muted);
  font-size: 1rem;
  margin-top: 1.25rem;
}

@media (max-width: 840px) {
  .gs-section {
    padding: 10vh 1.25rem;
  }

  .gs-back-link {
    top: 1rem;
    left: 1rem;
  }

  .gs-system-grid,
  .gs-pillars-grid,
  .gs-feature-grid {
    grid-template-columns: 1fr;
  }

  .gs-system-grid::before {
    left: 50%;
    right: auto;
    top: 6%;
    bottom: 6%;
    width: 1px;
    height: auto;
    background: linear-gradient(180deg, transparent, var(--gs-border), transparent);
  }

  .gs-system-node {
    min-height: 7rem;
  }

  .gs-loss-chart {
    height: 22rem;
    border-radius: 1rem;
  }

  .gs-axis-label--y {
    left: 0.75rem;
  }

  .gs-loss-chart__grid,
  .gs-loss-chart__x-axis {
    left: 3rem;
  }
}

@media (max-width: 520px) {
  .gs-hero__title {
    font-size: clamp(3.45rem, 18vw, 5rem);
  }

  .gs-section__title {
    letter-spacing: -0.035em;
  }

  .gs-loss-chart__overlay {
    font-size: 1.45rem;
    letter-spacing: 0.05em;
  }
}

.gs-screenshot {
  padding: 0 0 6vh;
}
.gs-screenshot__figure {
  margin: 0;
}
.gs-screenshot__img {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  display: block;
  border-radius: 6px;
  border: 1px solid var(--gs-border);
  box-shadow: 0 8px 40px rgba(5, 150, 105, 0.10);
}