*, *::before, *::after { box-sizing: border-box; }
:root {
  --coal: #0f0e0c;
  --graphite: #1e1e1e;
  --slate: #4a4843;
  --sand: #d4c9b5;
  --cream: #f7f4ed;
  --bone: #efeae0;
  --white: #ffffff;
  --line: rgba(30, 30, 30, 0.14);
  --serif: Georgia, "Times New Roman", serif;
  --font: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--graphite);
  background: var(--bone);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.stack-page {
  width: min(1180px, calc(100vw - 48px));
  margin: 0 auto;
}
.stack-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 72px;
  border-bottom: 1px solid var(--line);
  font-size: 13px;
  font-weight: 700;
}
.stack-nav a { text-decoration: none; }
.stack-nav .back { color: var(--slate); }
.stack-brand {
  width: 118px;
  height: 45px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.stack-brand img {
  width: 118px;
  height: 45px;
  display: block;
}
.stack-hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(340px, 0.68fr);
  gap: clamp(36px, 6vw, 84px);
  align-items: end;
  padding: clamp(64px, 9vw, 124px) 0 clamp(52px, 7vw, 90px);
}
.eyebrow {
  margin: 0 0 18px;
  color: var(--slate);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}
h1, h2, h3, p { margin-top: 0; }
h1 {
  margin-bottom: 26px;
  color: var(--coal);
  font-family: var(--serif);
  font-size: clamp(44px, 7vw, 82px);
  font-weight: 500;
  line-height: 0.98;
  letter-spacing: -0.04em;
  text-wrap: balance;
}
.lead {
  max-width: 690px;
  color: var(--slate);
  font-size: clamp(17px, 2vw, 22px);
  line-height: 1.5;
  text-wrap: pretty;
}
.hero-image {
  position: relative;
  min-height: 440px;
  overflow: hidden;
  background: var(--coal);
  box-shadow: 0 24px 80px rgba(15, 14, 12, 0.16);
}
.hero-image img {
  width: 100%;
  height: 100%;
  min-height: inherit;
  display: block;
  object-fit: cover;
  opacity: 0.86;
}
.hero-image span {
  position: absolute;
  top: 22px;
  left: 24px;
  right: 24px;
  color: var(--white);
  font-weight: 700;
  text-align: center;
  text-shadow: 0 1px 20px rgba(0, 0, 0, 0.55);
}
.comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.compare-card {
  min-height: 360px;
  padding: clamp(28px, 4vw, 52px);
}
.compare-card + .compare-card { border-left: 1px solid var(--line); }
.compare-card h2 {
  margin-bottom: 28px;
  font-family: var(--serif);
  font-size: clamp(30px, 4vw, 52px);
  font-weight: 500;
  letter-spacing: -0.04em;
}
.compare-card p {
  color: var(--slate);
  font-size: 16px;
  line-height: 1.62;
}
.new-card {
  color: var(--white);
  background: var(--coal);
}
.new-card h2 { color: var(--white); }
.new-card p { color: rgba(255, 255, 255, 0.72); }
.section {
  padding: clamp(56px, 8vw, 104px) 0;
  border-bottom: 1px solid var(--line);
}
.section-head {
  max-width: 720px;
  margin-bottom: 34px;
}
.section h2 {
  margin-bottom: 18px;
  color: var(--coal);
  font-family: var(--serif);
  font-size: clamp(34px, 4vw, 56px);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.04em;
}
.section-head p,
.section > p {
  color: var(--slate);
  font-size: 16px;
  line-height: 1.62;
}
.system-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.system-grid span {
  min-height: 78px;
  display: flex;
  align-items: center;
  padding: 18px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--graphite);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.02em;
}
.system-grid .system-logo {
  min-height: 126px;
  justify-content: center;
  flex-direction: column;
  gap: 14px;
  text-align: center;
}
.system-logo img {
  display: block;
  width: min(150px, 78%);
  max-height: 38px;
  object-fit: contain;
}
.system-logo img.logo-mark {
  width: 42px;
  max-height: 42px;
}
.system-logo em {
  color: var(--slate);
  font-size: 11px;
  font-style: normal;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.path-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.path-step {
  min-height: 210px;
  padding: 24px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.path-step strong {
  display: block;
  margin-bottom: 18px;
  color: var(--coal);
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.path-step p {
  color: var(--slate);
  font-size: 14px;
  line-height: 1.55;
}
.cta {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  align-items: center;
  padding: clamp(48px, 8vw, 88px) 0;
}
.cta h2 {
  max-width: 680px;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.04em;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid rgba(30, 30, 30, 0.22);
  border-radius: 8px;
  color: var(--graphite);
  background: var(--bone);
  font-size: 13px;
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
}
.button:hover { background: var(--cream); }
@media (max-width: 840px) {
  .stack-page { width: calc(100vw - 32px); }
  .stack-nav { min-height: 64px; }
  .stack-hero,
  .comparison,
  .cta { grid-template-columns: 1fr; display: grid; }
  .hero-image { min-height: 340px; }
  .compare-card + .compare-card { border-left: 0; border-top: 1px solid var(--line); }
  .system-grid,
  .path-grid { grid-template-columns: 1fr 1fr; }
  .cta { align-items: start; }
}
@media (max-width: 520px) {
  .stack-nav { font-size: 12px; }
  .stack-nav .back { display: none; }
  .system-grid,
  .path-grid { grid-template-columns: 1fr; }
  .hero-image { min-height: 280px; }
}