/* Introduction — a quiet, abstract Nile data stream rather than a map. */
.intro-screen {
  min-height: min(46.5rem, 100vh);
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(23rem, 0.8fr);
  align-items: center;
  gap: clamp(var(--s-6), 5vw, var(--s-9));
  padding-block: clamp(var(--s-6), 6vh, var(--s-8));
}
.intro-copy {
  max-width: var(--reading-max);
}
.intro-title {
  position: relative;
  margin-block-end: var(--s-3);
  color: var(--ink);
  font-size: var(--fs-h1);
  font-weight: var(--fw-bold);
  letter-spacing: -0.035em;
}
.intro-title::after {
  content: "";
  display: block;
  width: clamp(4rem, 12vw, 6.5rem);
  height: 3px;
  margin-block-start: var(--s-3);
  border-radius: var(--r-pill);
  background: var(--cyan-400);
}
.intro-subtitle {
  margin-block: 0 var(--s-4);
  color: var(--teal-700);
  font-size: var(--fs-h2);
  font-weight: var(--fw-medium);
  line-height: var(--lh-head);
}
.intro-descriptor {
  color: var(--ink-2);
  font-size: var(--fs-body);
  max-width: var(--reading-max);
  margin-block-end: 0;
}
.intro-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s-3);
  margin-block: var(--s-6);
}
.intro-actions .btn {
  transition:
    transform var(--dur-fast) var(--ease-out),
    box-shadow var(--dur-fast) var(--ease-out),
    background var(--dur-fast) var(--ease-out);
}
.intro-actions .btn:hover:not(:disabled),
.intro-actions .btn:focus-visible {
  transform: translateY(-1px);
  box-shadow: var(--shadow-2);
}
.intro-quick {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.quick-hint {
  font-size: var(--fs-small);
  font-weight: var(--fw-regular);
  color: var(--ink-3);
}
.intro-disclaimer {
  display: flex;
  align-items: flex-start;
  gap: var(--s-2);
  margin-block-end: 0;
}
.intro-disclaimer svg {
  width: 1.2em;
  height: 1.2em;
  margin-block-start: 0.3em;
  color: var(--teal-700);
  flex: none;
}
.hero-art {
  align-self: stretch;
  min-height: 0;
  max-height: 35rem;
  display: grid;
  place-items: center;
  overflow: hidden;
}
.intro-nile-svg {
  width: min(100%, 30rem);
  height: min(100%, 35rem);
  min-height: 29rem;
  overflow: visible;
  --dur-flag-rise: 600ms;
  --dur-flag-wave: 3000ms;
}
.nile-wash {
  pointer-events: none;
}
.nile-dot-grid {
  fill: var(--border);
  opacity: 0.9;
}
.nile-underlay,
.nile-main,
.nile-pulse,
.nile-node-tick,
.nile-connector {
  stroke-linecap: round;
  stroke-linejoin: round;
}
.nile-underlay {
  stroke: var(--cyan-200);
  stroke-width: 14;
  opacity: 0.5;
}
.nile-main {
  stroke: var(--cyan-400);
  stroke-width: 4;
}
.nile-underlay.nile-branch {
  stroke-width: 10;
}
.nile-main.nile-branch {
  stroke-width: 2.5;
}
.nile-pulse {
  stroke: var(--gold-400);
  stroke-width: 5;
  opacity: 0;
}
.nile-network {
  opacity: 1;
}
.nile-connector {
  stroke: var(--cyan-200);
  stroke-width: 1;
  stroke-dasharray: 2 6;
  fill: none;
  opacity: 0;
}
.nile-node {
  opacity: 0;
}
.nile-node-tick {
  stroke: var(--cyan-400);
  stroke-width: 1.25;
  fill: none;
}
.nile-node-ring {
  fill: none;
  stroke: var(--teal-700);
  stroke-width: 2;
  opacity: 0.35;
  transform-box: fill-box;
  transform-origin: center;
}
.nile-node-circle {
  fill: var(--surface);
  stroke: var(--teal-700);
  stroke-width: 1.5;
}
.nile-node-icon {
  color: var(--teal-700);
}
.nile-label text {
  fill: var(--ink-2);
  font-family: var(--font);
  font-size: 16px;
  font-weight: var(--fw-medium);
}
.nile-label rect {
  fill: var(--surface);
  stroke: var(--border);
  stroke-width: 1;
}
.nile-label {
  opacity: 0;
}
.nile-packet-guide {
  fill: none;
  stroke: none;
}
.nile-data-packet {
  fill: var(--surface);
  stroke: var(--teal-700);
  stroke-width: 1;
  transform-box: fill-box;
  transform-origin: center;
}
.intro-nile-svg.is-live .nile-node-ring {
  animation: nile-node-breathe 2400ms var(--ease-in-out) infinite;
}
.intro-nile-svg.is-live .nile-node-1 .nile-node-ring {
  animation-delay: 300ms;
}
.intro-nile-svg.is-live .nile-node-2 .nile-node-ring {
  animation-delay: 600ms;
}
.intro-nile-svg.is-live .nile-node-3 .nile-node-ring {
  animation-delay: 900ms;
}
.intro-nile-svg.is-live .nile-node-4 .nile-node-ring {
  animation-delay: 1200ms;
}
.intro-nile-svg.is-live .nile-node-5 .nile-node-ring {
  animation-delay: 1500ms;
}
.intro-nile-svg.is-live-paused .nile-node-ring {
  animation-play-state: paused;
}
@keyframes nile-node-breathe {
  50% {
    opacity: 0;
    transform: scale(1.5);
  }
}
.nile-flag-pole {
  stroke: var(--ink-2);
  stroke-width: 1.5;
}
.nile-flag-finial {
  fill: var(--gold-400);
}
.nile-flag-entrance {
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
}
/* Pole grows from its foot; the cloth unfurls from the pole (SVG user units). */
.nile-flag-poleg {
  transform-box: view-box;
  transform-origin: 342px 78px;
}
.nile-flag-wave {
  transform-box: view-box;
  transform-origin: 342px 47px;
}
.nile-flag-slice {
  transform-box: fill-box;
  transform-origin: center;
}
.nile-flag-shade {
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
}
html.motion-off .intro-nile-svg {
  --dur-flag-rise: 0ms;
  --dur-flag-wave: 0ms;
}
@media (prefers-reduced-motion: reduce) {
  .intro-nile-svg {
    --dur-flag-rise: 0ms;
    --dur-flag-wave: 0ms;
  }
}
html.motion-off .nile-underlay,
html.motion-off .nile-main {
  stroke-dasharray: none !important;
  stroke-dashoffset: 0 !important;
}
html.motion-off .nile-node-ring,
html.motion-off .nile-data-packet {
  animation: none !important;
}
@media (prefers-reduced-motion: reduce) {
  .nile-node-ring,
  .nile-data-packet {
    animation: none !important;
  }
}
@media (max-width: 1023px) {
  .intro-screen {
    grid-template-columns: 1fr;
    align-items: start;
    gap: var(--s-5);
  }
  .hero-art {
    height: min(20rem, 58vw);
    max-height: 20rem;
    justify-self: center;
    width: min(100%, 29rem);
  }
  .intro-nile-svg {
    min-height: 0;
    height: 100%;
  }
  .nile-label text {
    font-size: 13px;
  }
}
@media (max-width: 600px) {
  .intro-screen {
    min-height: 0;
    padding-block: var(--s-6);
  }
  .intro-actions {
    align-items: stretch;
    flex-direction: column;
    margin-block: var(--s-5);
  }
  .intro-actions .btn {
    width: 100%;
  }
  .intro-subtitle {
    margin-block-end: var(--s-3);
  }
  .hero-art {
    width: 100%;
    height: min(22rem, 90vw);
  }
  .intro-nile-svg {
    width: min(100%, 26rem);
  }
  .nile-label text {
    font-size: 21px;
  }
}