:root {
  --paper: #f4efe4;
  --paper-strong: #fcf8f0;
  --ink: #1b2530;
  --ink-soft: #425262;
  --line: rgba(27, 37, 48, 0.14);
  --line-strong: rgba(27, 37, 48, 0.28);
  --rust: #b85c38;
  --rust-deep: #8f3f24;
  --atlas-blue: #2d5576;
  --atlas-blue-soft: #8aa8bf;
  --card: rgba(252, 248, 240, 0.9);
  --shadow: 0 26px 60px rgba(25, 34, 44, 0.09);
  --radius-lg: 28px;
  --radius-md: 18px;
  --max-width: 1180px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  font-family: "IBM Plex Sans", sans-serif;
  background:
    radial-gradient(circle at 12% 18%, rgba(138, 168, 191, 0.16), transparent 22%),
    radial-gradient(circle at 80% 16%, rgba(184, 92, 56, 0.12), transparent 18%),
    linear-gradient(180deg, #f8f2e6 0%, #f4efe4 54%, #efe7d6 100%);
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(27, 37, 48, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27, 37, 48, 0.02) 1px, transparent 1px);
  background-size: 36px 36px;
  opacity: 0.45;
  pointer-events: none;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  padding: 0.75rem 1rem;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  z-index: 20;
}

.skip-link:focus {
  top: 1rem;
}

.page-shell {
  position: relative;
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
  padding-bottom: 4rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1rem 0;
  backdrop-filter: blur(18px);
  background: rgba(244, 239, 228, 0.86);
  border-bottom: 1px solid rgba(27, 37, 48, 0.08);
}

.brand-lockup {
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.4rem;
}

.site-nav a {
  padding: 0.7rem 0.95rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 0.95rem;
  transition: background-color 180ms ease, color 180ms ease;
}

.site-nav a[aria-current="page"],
.site-nav a:hover,
.site-nav a:focus-visible {
  background: rgba(45, 85, 118, 0.11);
  color: var(--ink);
}

main {
  padding-top: 1.25rem;
}

section[id] {
  scroll-margin-top: 6.25rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.95fr);
  gap: 1.5rem;
  align-items: stretch;
  padding: 3.2rem 0 2rem;
}

.hero-copy,
.hero-panel,
.content-card,
.info-card,
.science-step,
.source-card,
.closing-panel,
.accent-card {
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.hero-copy {
  padding: 2.1rem;
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}

.hero-copy::after {
  content: "";
  position: absolute;
  inset: auto -6rem -5rem auto;
  width: 18rem;
  height: 18rem;
  border-radius: 50%;
  border: 1px solid rgba(184, 92, 56, 0.2);
  opacity: 0.6;
}

.eyebrow,
.card-kicker,
.panel-label {
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.78rem;
  color: var(--atlas-blue);
  margin: 0 0 0.95rem;
}

h1,
h2,
h3 {
  font-family: "Fraunces", serif;
  margin: 0;
  font-weight: 600;
  line-height: 0.96;
}

h1 {
  font-size: clamp(3rem, 7vw, 5.8rem);
  max-width: 10ch;
}

h2 {
  font-size: clamp(2rem, 4.2vw, 3.35rem);
  max-width: 12ch;
}

h3 {
  font-size: 1.55rem;
  line-height: 1.05;
}

p,
li,
dd,
dt,
summary {
  line-height: 1.7;
}

.hero-intro,
.content-card p,
.info-card p,
.science-step p,
.source-card p,
.closing-panel p,
.faq-list p {
  color: var(--ink-soft);
  font-size: 1.04rem;
}

.hero-intro {
  max-width: 60ch;
  margin: 1.2rem 0 0;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin-top: 2rem;
}

.primary-button,
.secondary-link,
.source-card a,
.footer-links a {
  text-decoration: none;
}

.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3.25rem;
  padding: 0.9rem 1.35rem;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--rust) 0%, var(--rust-deep) 100%);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 12px 26px rgba(143, 63, 36, 0.22);
}

.primary-button:hover,
.primary-button:focus-visible {
  transform: translateY(-1px);
}

.secondary-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--atlas-blue);
  font-weight: 600;
}

.secondary-link::after,
.source-card a::after,
.footer-links a::after {
  content: "↗";
  font-size: 0.85em;
}

.fact-ribbon {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.9rem;
  margin: 2.1rem 0 0;
  padding: 0;
}

.fact-ribbon div {
  padding: 1rem 0.9rem;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.48);
  border: 1px solid rgba(27, 37, 48, 0.07);
}

.fact-ribbon dt {
  margin: 0;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--atlas-blue);
}

.fact-ribbon dd {
  margin: 0.4rem 0 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.hero-panel {
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: grid;
  grid-template-rows: 250px auto;
  gap: 1rem;
}

.orbit-diagram {
  position: relative;
  border-radius: 24px;
  background:
    radial-gradient(circle at center, rgba(252, 248, 240, 0.96), rgba(245, 238, 225, 0.9)),
    linear-gradient(180deg, rgba(138, 168, 191, 0.08), rgba(184, 92, 56, 0.06));
  border: 1px solid rgba(27, 37, 48, 0.08);
  overflow: hidden;
}

.orbit,
.trajectory {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(45, 85, 118, 0.2);
}

.orbit-a {
  inset: 1rem 2.2rem 2rem 1.5rem;
}

.orbit-b {
  inset: 2.8rem 0.8rem 1.1rem 4.4rem;
}

.trajectory {
  width: 125%;
  height: 160%;
  left: -10%;
  top: -18%;
  border-color: rgba(184, 92, 56, 0.4);
  border-left-color: transparent;
  border-bottom-color: transparent;
  transform: rotate(-24deg);
}

.orbital-node {
  position: absolute;
  width: 0.95rem;
  height: 0.95rem;
  border-radius: 50%;
}

.node-sun {
  background: var(--rust);
  left: 51%;
  top: 48%;
  box-shadow: 0 0 0 12px rgba(184, 92, 56, 0.11);
}

.node-comet {
  background: var(--atlas-blue);
  left: 76%;
  top: 28%;
  box-shadow:
    -32px 8px 0 0 rgba(45, 85, 118, 0.14),
    -64px 18px 0 0 rgba(45, 85, 118, 0.08);
}

.panel-copy h2 {
  font-size: 2.15rem;
  margin-bottom: 1rem;
  max-width: 11ch;
}

.signal-list {
  padding: 0;
  margin: 0 0 1rem;
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

.signal-list li {
  padding-left: 1rem;
  position: relative;
  color: var(--ink-soft);
}

.signal-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.9rem;
  width: 0.35rem;
  height: 0.35rem;
  border-radius: 50%;
  background: var(--rust);
}

.panel-note {
  margin: 0;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.section {
  margin-top: 1.65rem;
  padding: 1rem 0;
}

.section-heading {
  display: grid;
  gap: 0.4rem;
  margin-bottom: 1.4rem;
}

.split-section .split-grid,
.card-grid,
.science-grid,
.source-grid {
  display: grid;
  gap: 1rem;
}

.split-grid {
  grid-template-columns: 1.2fr 0.8fr;
}

.content-card,
.accent-card,
.info-card,
.science-step,
.source-card {
  border-radius: 24px;
  padding: 1.4rem;
}

.accent-card {
  background: linear-gradient(180deg, rgba(45, 85, 118, 0.08), rgba(252, 248, 240, 0.92));
}

.card-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.info-card h3 {
  margin-top: 0.75rem;
}

.science-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.science-step {
  position: relative;
  padding-top: 3.3rem;
}

.step-index {
  position: absolute;
  left: 1.4rem;
  top: 1.25rem;
  color: var(--atlas-blue-soft);
  font-size: 0.95rem;
  letter-spacing: 0.18em;
}

.timeline-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1rem;
}

.timeline-list li {
  display: grid;
  grid-template-columns: minmax(150px, 180px) 1fr;
  gap: 1rem;
  align-items: start;
  padding: 1.3rem;
  border-radius: 24px;
  background: rgba(252, 248, 240, 0.82);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.timeline-date {
  display: inline-block;
  color: var(--atlas-blue);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.timeline-list h3 {
  margin-bottom: 0.6rem;
}

.timeline-list p {
  margin: 0;
  color: var(--ink-soft);
}

.faq-list {
  display: grid;
  gap: 0.8rem;
}

.faq-list details {
  border-radius: 20px;
  border: 1px solid var(--line);
  background: rgba(252, 248, 240, 0.9);
  box-shadow: var(--shadow);
  padding: 1rem 1.1rem;
}

.faq-list summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  padding-right: 1.8rem;
  position: relative;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 0;
  color: var(--atlas-blue);
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list p {
  margin: 0.8rem 0 0;
}

.source-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.source-card a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  color: var(--rust-deep);
}

.closing-panel {
  border-radius: 28px;
  padding: 1.7rem;
  margin-top: 2rem;
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  align-items: end;
}

.closing-panel h2 {
  margin-bottom: 0.75rem;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: 1.2rem 0 0;
  margin-top: 2rem;
  border-top: 1px solid rgba(27, 37, 48, 0.12);
  color: var(--ink-soft);
}

.site-footer p {
  margin: 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.js .is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1080px) {
  .hero,
  .split-grid,
  .card-grid,
  .science-grid,
  .source-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 2rem;
  }

  .hero-panel {
    grid-template-rows: 220px auto;
  }

  .fact-ribbon {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .closing-panel,
  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(calc(100% - 1.1rem), var(--max-width));
  }

  .site-header {
    align-items: flex-start;
    flex-direction: column;
    padding-bottom: 0.85rem;
  }

  .hero-copy,
  .hero-panel,
  .content-card,
  .accent-card,
  .info-card,
  .science-step,
  .source-card,
  .closing-panel,
  .timeline-list li {
    border-radius: 20px;
  }

  .hero-copy,
  .hero-panel {
    padding: 1.25rem;
  }

  .timeline-list li {
    grid-template-columns: 1fr;
  }

  .fact-ribbon {
    grid-template-columns: 1fr;
  }

  h1 {
    max-width: 9ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  [data-reveal] {
    transition: none;
    opacity: 1;
    transform: none;
  }

  .primary-button {
    transform: none;
  }
}