/* ============================================================
   Homepage — journey strip & on-this-day (uses tokens/base/components)
   ============================================================ */

/* hero */
.journey-hero {
  position: relative;
  min-height: 78vh;
  display: grid;
  align-content: center;
  max-width: var(--max-width);
  margin-inline: auto;
  padding: var(--space-8) var(--space-5) var(--space-6);
}

/* Carina Nebula backdrop — full-bleed behind the centered container,
   reaching up under the translucent sticky header */
.journey-hero::before {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  top: calc(-1 * var(--header-h));
  bottom: 0;
  background: url("/assets/images/carina-nebula.jpg") center 32% / cover no-repeat;
  z-index: -2;
}

/* dark scrim so text stays readable over the nebula, dissolving
   into the page background at the bottom edge */
.journey-hero::after {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  top: calc(-1 * var(--header-h));
  bottom: 0;
  background: linear-gradient(
    180deg,
    rgba(8, 9, 12, 0.62) 0%,
    rgba(8, 9, 12, 0.42) 42%,
    rgba(8, 9, 12, 0.72) 78%,
    var(--color-bg) 100%
  );
  z-index: -1;
}

.journey-hero > * {
  position: relative;
}

.journey-hero h1 {
  font-size: clamp(3rem, 8vw, 5.75rem);
  text-transform: uppercase;
  line-height: 0.98;
  margin-top: var(--space-4);
  color: #ffffff;
  text-shadow: 0 2px 28px rgba(4, 6, 10, 0.7);
}

.journey-hero .hero-kicker {
  color: var(--color-accent);
  text-shadow: 0 1px 14px rgba(4, 6, 10, 0.8);
}

.journey-hero .hook {
  color: #f5f7fa;
  font-size: clamp(1.08rem, 2vw, 1.4rem);
  max-width: 58ch;
  margin-top: var(--space-5);
  text-shadow: 0 1px 14px rgba(4, 6, 10, 0.75);
}

.hero-actions {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-top: var(--space-6);
}

/* breathing room between the CTAs and the telemetry strip */
.journey-hero .facts-strip {
  margin-top: var(--space-8);
}

/* image credit, tucked into the hero's bottom-right corner */
.hero-credit {
  position: absolute;
  right: var(--space-5);
  bottom: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: rgba(242, 242, 240, 0.55);
  text-shadow: 0 1px 8px rgba(4, 6, 10, 0.8);
}

.hero-credit:hover {
  color: rgba(242, 242, 240, 0.85);
}

/* on this day */
.otd {
  max-width: var(--max-width);
  margin-inline: auto;
  padding: var(--space-6) var(--space-5) 0;
}

.otd-empty {
  color: var(--color-muted);
}

.otd-note {
  color: var(--color-muted);
  font-size: var(--text-sm);
  margin-top: var(--space-2);
  margin-bottom: var(--space-5);
}

/* ============================================================
   The evolution — milestones as one lineage, 1957 to today.
   A central spine "grows" down the section as you scroll (JS
   sets --growth 0→1); each milestone branches off it, era-colored.
   ============================================================ */

.evo-strip {
  max-width: var(--max-width);
  margin-inline: auto;
  padding: var(--space-8) var(--space-5) var(--space-6);
  text-align: center;
}

.evo-lede {
  max-width: 62ch;
  margin: var(--space-4) auto 0;
  color: var(--color-muted);
  font-size: var(--text-lg);
  line-height: 1.65;
}

.evolution {
  --growth: 1;
  list-style: none;
  position: relative;
  max-width: 920px;
  margin: var(--space-7) auto var(--space-6);
  padding-block: var(--space-4);
  text-align: left;
}

/* the full lineage track (dim) */
.evolution::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(
    180deg,
    transparent,
    var(--color-border) 4%,
    var(--color-border) 96%,
    transparent
  );
}

/* the grown part of the lineage (bright, era-colored) — JS drives it */
.evolution::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  height: 100%;
  width: 3px;
  transform: translateX(-50%) scaleY(var(--growth));
  transform-origin: top;
  background: linear-gradient(
    180deg,
    var(--era-1),
    var(--era-2),
    var(--era-2),
    var(--era-3),
    var(--era-4),
    var(--era-5),
    var(--era-6)
  );
  box-shadow: 0 0 14px var(--accent-glow);
}

.evo-item {
  position: relative;
  width: 50%;
  padding: var(--space-4) var(--space-6) var(--space-6);
}

.evo-item:nth-child(odd) {
  left: 0;
  text-align: right;
}

.evo-item:nth-child(even) {
  left: 50%;
  text-align: left;
}

/* connector from the spine to the card */
.evo-item::before {
  content: "";
  position: absolute;
  top: 30px;
  height: 2px;
  width: var(--space-6);
  background: linear-gradient(
    90deg,
    transparent,
    var(--era-accent, var(--color-accent))
  );
}

.evo-item:nth-child(odd)::before {
  right: 0;
}

.evo-item:nth-child(even)::before {
  left: 0;
  transform: scaleX(-1);
}

/* node on the spine */
.evo-node {
  position: absolute;
  top: 22px;
  z-index: 1;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid var(--era-accent, var(--color-accent));
  box-shadow: 0 0 12px var(--accent-glow);
}

.evo-node::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--era-accent, var(--color-accent));
}

.evo-item:nth-child(odd) .evo-node {
  right: -8px;
}

.evo-item:nth-child(even) .evo-node {
  left: -8px;
}

.evo-item a {
  display: block;
  color: var(--color-text);
}

.evo-year {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.2em;
  color: var(--era-accent, var(--color-accent));
  margin-bottom: var(--space-2);
}

.evo-media {
  display: block;
  overflow: hidden;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-strong);
  margin-bottom: var(--space-3);
}

.evo-media img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: 50% 18%;
  filter: saturate(0.92);
  transition: transform var(--transition-med), filter var(--transition-med);
}

.evo-item a:hover .evo-media img {
  transform: scale(1.04);
  filter: saturate(1.05);
}

.evo-name {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
}

.evo-item a:hover .evo-name {
  color: var(--era-accent, var(--color-accent));
}

.evo-outcome {
  display: block;
  margin-top: var(--space-1);
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.6;
}

@media (max-width: 760px) {
  .evolution::before,
  .evolution::after {
    left: 9px;
    transform: none;
  }
  .evolution::after {
    transform-origin: top;
    transform: scaleY(var(--growth));
  }
  .evo-item,
  .evo-item:nth-child(odd),
  .evo-item:nth-child(even) {
    width: 100%;
    left: 0;
    text-align: left;
    padding: var(--space-3) 0 var(--space-5) var(--space-7);
  }
  .evo-item:nth-child(odd)::before,
  .evo-item:nth-child(even)::before {
    left: 17px;
    right: auto;
    width: var(--space-4);
    transform: none;
  }
  .evo-item:nth-child(odd) .evo-node,
  .evo-item:nth-child(even) .evo-node {
    left: 2px;
    right: auto;
  }
}

.center-cta { margin-top: var(--space-6); }