:root {
  --ink: #06111f;
  --navy: #0a1b31;
  --blue: #0e3d63;
  --teal: #21c4bd;
  --gold: #f5bd4e;
  --red: #e85d5d;
  --paper: #f7f2ea;
  --white: #ffffff;
  --text: #102033;
  --muted: #566778;
  --line: rgba(16, 32, 51, 0.16);
  --line-dark: rgba(247, 242, 234, 0.2);
  --shadow: 0 24px 70px rgba(6, 17, 31, 0.2);
  --radius: 8px;
  --max: 1160px;
  --heading: "Nunito Sans", "Avenir Next", Arial, sans-serif;
  --body: "Atkinson Hyperlegible", "Segoe UI", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--body);
  font-size: 18px;
  line-height: 1.58;
}

body::before {
  background:
    linear-gradient(90deg, rgba(14, 61, 99, 0.06) 1px, transparent 1px),
    linear-gradient(0deg, rgba(14, 61, 99, 0.05) 1px, transparent 1px);
  background-size: 42px 42px;
  content: "";
  inset: 0;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.52), transparent 46rem);
  pointer-events: none;
  position: fixed;
  z-index: -1;
}

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

a {
  color: inherit;
}

h1,
h2,
h3 {
  font-family: var(--heading);
  letter-spacing: 0;
  line-height: 1.04;
  margin: 0;
}

h1 {
  color: white;
  font-size: clamp(2.7rem, 6vw, 5.25rem);
  max-width: 13ch;
}

h2 {
  font-size: clamp(1.85rem, 3.8vw, 3.55rem);
  max-width: 18ch;
}

h3 {
  font-size: 1.18rem;
}

p {
  margin: 0;
}

.skip-link {
  background: var(--gold);
  color: var(--ink);
  font-weight: 900;
  left: 1rem;
  padding: 0.65rem 0.9rem;
  position: absolute;
  top: -5rem;
  z-index: 100;
}

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

.site-header {
  align-items: center;
  background: rgba(6, 17, 31, 0.92);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line-dark);
  display: flex;
  gap: 1rem;
  justify-content: space-between;
  padding: 0.85rem clamp(1rem, 4vw, 3rem);
  position: sticky;
  top: 0;
  z-index: 50;
}

.brand {
  align-items: center;
  color: white;
  display: inline-flex;
  gap: 0.75rem;
  min-width: 18rem;
  text-decoration: none;
}

.brand-mark {
  background: linear-gradient(135deg, var(--teal), var(--red));
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: var(--radius);
  color: white;
  display: grid;
  font-family: var(--heading);
  font-weight: 900;
  height: 3rem;
  place-items: center;
  width: 3.3rem;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: rgba(247, 242, 234, 0.75);
  font-size: 0.78rem;
}

.site-nav {
  align-items: center;
  color: rgba(247, 242, 234, 0.78);
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  justify-content: flex-end;
}

.site-nav a {
  border-radius: var(--radius);
  font-size: 0.92rem;
  font-weight: 800;
  padding: 0.55rem 0.68rem;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a[aria-current="page"] {
  background: rgba(33, 196, 189, 0.16);
  color: white;
}

.nav-toggle {
  background: transparent;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  color: white;
  display: none;
  font: inherit;
  font-weight: 900;
  padding: 0.55rem 0.7rem;
}

.hero {
  min-height: calc(88vh - 4.8rem);
  position: relative;
}

.hero-image,
.page-hero::before {
  inset: 0;
  position: absolute;
  z-index: -2;
}

.hero-image img,
.page-hero::before {
  height: 100%;
  object-fit: cover;
  object-position: center;
  width: 100%;
}

.hero-image::after,
.page-hero::after {
  background:
    linear-gradient(90deg, rgba(6, 17, 31, 0.98), rgba(6, 17, 31, 0.78) 42%, rgba(6, 17, 31, 0.2)),
    linear-gradient(0deg, rgba(6, 17, 31, 0.97), transparent 48%);
  content: "";
  inset: 0;
  position: absolute;
}

.hero-content,
.page-hero-inner {
  display: grid;
  gap: 1rem;
  margin: 0 auto;
  max-width: var(--max);
  min-height: calc(88vh - 4.8rem);
  padding: clamp(3.5rem, 7vw, 6rem) clamp(1rem, 4vw, 3rem) 3rem;
  place-content: center start;
}

.page-hero {
  background:
    linear-gradient(135deg, rgba(6, 17, 31, 0.98), rgba(14, 61, 99, 0.72)),
    url("assets/iss-flyaround-nasa.webp") center / cover no-repeat;
  color: white;
  min-height: 58vh;
  position: relative;
}

.page-hero-inner {
  min-height: 58vh;
  position: relative;
  z-index: 1;
}

.status-note,
.eyebrow {
  color: var(--gold);
  font-family: var(--heading);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.status-note {
  background: rgba(6, 17, 31, 0.64);
  border: 1px solid rgba(245, 189, 78, 0.5);
  border-radius: var(--radius);
  color: #ffe7ad;
  display: inline-flex;
  padding: 0.45rem 0.65rem;
  width: fit-content;
}

.hero-copy {
  color: rgba(247, 242, 234, 0.9);
  font-size: clamp(1.08rem, 2vw, 1.34rem);
  max-width: 46rem;
}

.hero-actions,
.builder-actions,
.trail-nav,
.site-footer nav {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.button {
  align-items: center;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  display: inline-flex;
  font: inherit;
  font-weight: 900;
  justify-content: center;
  min-height: 2.8rem;
  padding: 0.78rem 1rem;
  text-decoration: none;
}

.button-primary {
  background: linear-gradient(135deg, var(--red), #8b63ff);
  color: white;
  box-shadow: 0 18px 48px rgba(232, 93, 93, 0.26);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(247, 242, 234, 0.34);
  color: white;
}

.section {
  padding: clamp(4rem, 8vw, 7rem) clamp(1rem, 4vw, 3rem);
}

.section > * {
  margin-inline: auto;
  max-width: var(--max);
}

.section-heading {
  display: grid;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.intro-band,
.light-band,
.builder-section {
  background: var(--white);
}

.dark-band {
  background: linear-gradient(135deg, rgba(6, 17, 31, 0.98), rgba(14, 61, 99, 0.95));
  color: white;
}

.dark-band h2 {
  color: white;
}

.split {
  align-items: center;
  display: grid;
  gap: clamp(1.25rem, 4vw, 3rem);
  grid-template-columns: minmax(0, 1fr) minmax(18rem, 0.72fr);
}

.split p {
  color: var(--muted);
  font-size: clamp(1.02rem, 1.5vw, 1.16rem);
  margin-top: 0.9rem;
  max-width: 50rem;
}

.signal-panel {
  background:
    linear-gradient(145deg, rgba(6, 17, 31, 0.96), rgba(14, 61, 99, 0.88));
  border: 1px solid rgba(33, 196, 189, 0.24);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  color: white;
  display: grid;
  gap: 0.65rem;
  padding: 1.2rem;
}

.signal-panel span {
  color: var(--gold);
  font-family: var(--heading);
  font-size: 0.82rem;
  font-weight: 900;
  text-transform: uppercase;
}

.signal-panel strong {
  font-family: var(--heading);
  font-size: clamp(1.6rem, 3vw, 2.5rem);
  line-height: 1.05;
}

.signal-panel p {
  color: rgba(247, 242, 234, 0.78);
  margin: 0;
}

.card-grid,
.feature-grid,
.fact-grid,
.review-grid,
.source-grid {
  display: grid;
  gap: 1rem;
}

.card-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

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

.review-grid,
.source-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.path-card,
.feature-grid article,
.fact-grid article,
.review-grid article,
.source-grid article {
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  color: var(--text);
  display: grid;
  gap: 0.7rem;
  padding: 1.1rem;
}

.path-card {
  min-height: 17rem;
  text-decoration: none;
}

.path-card span,
.fact-grid span,
.review-grid span {
  color: var(--red);
  font-family: var(--heading);
  font-size: 0.86rem;
  font-weight: 900;
}

.path-card p,
.feature-grid p,
.fact-grid p,
.review-grid p,
.source-grid p {
  color: var(--muted);
}

.path-card:hover,
.path-card:focus-visible {
  border-color: rgba(232, 93, 93, 0.44);
  transform: translateY(-2px);
}

.dark-band .feature-grid article {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(247, 242, 234, 0.18);
  box-shadow: none;
  color: white;
}

.dark-band .feature-grid p {
  color: rgba(247, 242, 234, 0.76);
}

.narrative {
  background: var(--white);
}

.narrative p {
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.25rem);
  margin-bottom: 1rem;
  max-width: 60rem;
}

.source-note {
  color: var(--muted);
  margin-top: 1rem;
}

.source-note a,
.card-link {
  color: var(--blue);
  font-weight: 900;
  text-decoration-thickness: 0.12em;
  text-underline-offset: 0.18em;
}

.builder-layout {
  align-items: start;
  display: grid;
  gap: 1.2rem;
  grid-template-columns: minmax(0, 0.85fr) minmax(20rem, 1fr);
}

.support-form,
.markdown-panel {
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: grid;
  gap: 1rem;
  padding: 1.1rem;
}

label {
  color: var(--text);
  display: grid;
  font-weight: 800;
  gap: 0.45rem;
}

input,
select,
textarea {
  background: white;
  border: 1px solid rgba(16, 32, 51, 0.2);
  border-radius: var(--radius);
  color: var(--text);
  font: inherit;
  min-height: 2.75rem;
  padding: 0.72rem 0.8rem;
  width: 100%;
}

textarea {
  resize: vertical;
}

.markdown-panel textarea {
  background: #06111f;
  border-color: #06111f;
  color: #e9f7f6;
  font-family: "Cascadia Mono", Consolas, monospace;
  font-size: 0.88rem;
  line-height: 1.5;
}

.privacy-note {
  color: var(--muted);
  font-size: 0.92rem;
}

.trail-nav {
  background: var(--ink);
  gap: 0.9rem;
  justify-content: space-between;
  padding: 1.2rem clamp(1rem, 4vw, 3rem);
}

.trail-nav .button {
  min-width: min(100%, 14rem);
}

.site-footer {
  background: #030914;
  color: rgba(247, 242, 234, 0.72);
  display: grid;
  gap: 1rem;
  padding: 2rem clamp(1rem, 4vw, 3rem);
}

.site-footer p,
.site-footer nav {
  margin-inline: auto;
  max-width: var(--max);
  width: 100%;
}

.site-footer a {
  color: white;
  font-weight: 800;
  text-decoration: none;
}

.back-to-top {
  background: var(--gold);
  border: 1px solid rgba(6, 17, 31, 0.12);
  border-radius: var(--radius);
  bottom: 1.15rem;
  box-shadow: var(--shadow);
  color: var(--ink);
  cursor: pointer;
  display: inline-flex;
  font: inherit;
  font-weight: 900;
  justify-content: center;
  min-height: 3.2rem;
  min-width: 3.2rem;
  opacity: 0;
  padding: 0.65rem 0.75rem;
  pointer-events: none;
  position: fixed;
  right: 1.15rem;
  transform: translateY(0.5rem);
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 80;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

@media (max-width: 1100px) {
  .card-grid,
  .review-grid,
  .source-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 760px) {
  body {
    font-size: 16px;
  }

  .site-header {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .brand {
    min-width: 0;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    display: none;
    flex-basis: 100%;
    justify-content: flex-start;
  }

  .site-nav.is-open {
    display: flex;
  }

  .hero,
  .hero-content,
  .page-hero,
  .page-hero-inner {
    min-height: 64vh;
  }

  .split,
  .card-grid,
  .feature-grid,
  .fact-grid,
  .review-grid,
  .source-grid,
  .builder-layout {
    grid-template-columns: 1fr;
  }

  .trail-nav {
    justify-content: flex-start;
  }

  .trail-nav .button {
    flex: 1 1 100%;
  }
}