/* ─── AetherSDR landing page ──────────────────────────────────────────────
   Scroll-coupled parallax modeled on https://squidfunk.github.io/mkdocs-material/

   The hero is 100vh, in document flow, with overflow:hidden. Inside it,
   two absolutely-positioned layers (background + alien audience) are
   translated by JavaScript at different speeds as the user scrolls.
   The whole hero scrolls away with the page once you're past it; the
   tile grid below appears underneath, exactly like Material's homepage.
*/

:root {
  --aether-bg-deep:    #050818;
  --aether-bg-mid:     #0a0e27;
  --aether-violet:     #5b21b6;
  --aether-violet-2:   #7c3aed;
  --aether-cyan:       #06b6d4;
  --aether-cyan-2:     #67e8f9;
  --aether-text:       #f0f4f8;
  --aether-text-dim:   #cbd5e1;
}

/* ── Hero shell ───────────────────────────────────────────────────────
   In document flow, exactly one viewport tall, clips its parallax
   children. Scrolls away naturally with the page. */

.aether-hero {
  position: relative;
  height: 100vh;
  min-height: 560px;
  overflow: hidden;            /* contain bg + UI to the hero */
  isolation: isolate;
  background-color: var(--aether-bg-deep);
}

/* ── Layer 1: AetherSDR UI screenshot, slowest drift ────────────────── */

/* Static gradient + starfield backdrop. No parallax — it's the deep
   void. The UI image is its own positioned element below this. */
.aether-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-color: var(--aether-bg-deep);
  background-image:
    /* Vignette so text in the lower-left stays legible */
    linear-gradient(180deg, transparent 0%, rgba(5, 8, 24, 0.55) 80%, rgba(5, 8, 24, 0.85) 100%),
    linear-gradient(90deg, rgba(5, 8, 24, 0.7) 0%, transparent 50%),
    /* Atmospheric tint */
    radial-gradient(ellipse 60% 50% at 50% 30%, rgba(124, 58, 237, 0.30), transparent 70%),
    radial-gradient(ellipse 80% 60% at 50% 110%, rgba(6, 182, 212, 0.20), transparent 70%),
    /* Starfield fallback */
    url('../assets/hero-stars.svg');
  background-size: cover, cover, cover, cover, cover;
  background-position: center, center, center, center, center;
  background-repeat: no-repeat, no-repeat, no-repeat, no-repeat, no-repeat;
}

/* AetherSDR UI screenshot as its own positioned <img>. Sized so it
   sits BELOW the Material header and inside the visible viewport,
   never extending behind the header band. Parallax-fast so it rises
   away as the user scrolls. */
.aether-ui {
  position: absolute;
  /* 4vh below the top to clear the Material header */
  top: 4vh;
  left: 50%;
  /* Width-driven sizing: the image renders at its natural aspect
     ratio at this width. No max-height constraint, so the image is
     never letterboxed inside an oversized box. */
  width: min(90vw, 1500px);
  height: auto;
  z-index: 1;
  filter: drop-shadow(0 12px 40px rgba(6, 182, 212, 0.35));
  pointer-events: none;
  will-change: transform;
  transform: translateX(-50%) translateY(var(--parallax-y, 0));
}

/* ── Layer 2: alien audience, fastest drift (closest to camera) ─────── */

/* ── Hero content — bottom-left, in front of all parallax layers.
   Uses parallax-speed > 1 (data-parallax-speed="1.30" in the HTML),
   so it "rises" faster than the UI screen behind it — classic
   foreground behavior. */

.aether-hero__content {
  position: absolute;
  z-index: 3;
  bottom: 6vh;
  left: 4vw;
  text-align: left;
  max-width: min(580px, 90vw);
  color: var(--aether-text);
  will-change: transform;
  transform: translateY(var(--parallax-y, 0));
}

.aether-hero__title {
  font-size: clamp(2.5rem, 5.5vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1;
  margin: 0 0 0.5rem;
  background: linear-gradient(135deg, #c4b5fd 0%, var(--aether-cyan-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 4px 30px rgba(124, 58, 237, 0.4);
}

.aether-hero__subtitle {
  font-size: clamp(1rem, 1.8vw, 1.35rem);
  font-weight: 500;
  margin: 0 0 1.25rem;
  color: #a5b4fc;
  letter-spacing: 0.01em;
}

.aether-hero__lede {
  font-size: clamp(0.9rem, 1.15vw, 1.05rem);
  line-height: 1.6;
  margin: 0 0 0.75rem;
  color: var(--aether-text-dim);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.7);
}

.aether-hero__radios {
  font-size: clamp(0.72rem, 0.85vw, 0.82rem);
  font-weight: 500;
  letter-spacing: 0.02em;
  line-height: 1.5;
  margin: 0 0 2rem;
  color: rgba(165, 180, 252, 0.85);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.7);
}

.aether-hero__cta {
  display: flex;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.aether-hero .md-button {
  border-radius: 999px;
  padding: 0.55rem 1.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 200ms ease, box-shadow 200ms ease;
  backdrop-filter: blur(6px);
  background-color: rgba(15, 23, 42, 0.55);
}

.aether-hero .md-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(124, 58, 237, 0.35);
}

.aether-hero .md-button--primary {
  background: linear-gradient(135deg,
    var(--aether-violet-2) 0%, var(--aether-cyan) 100%);
  border: none;
  color: white;
  backdrop-filter: none;
}

/* ── Scroll hint at the very bottom ──────────────────────────────── */

.aether-hero__scroll-hint {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: 22px;
  height: 36px;
  border: 2px solid rgba(255, 255, 255, 0.45);
  border-radius: 14px;
  z-index: 2;
}

.aether-hero__scroll-hint span {
  display: block;
  width: 3px;
  height: 7px;
  background: rgba(255, 255, 255, 0.85);
  border-radius: 2px;
  margin: 5px auto 0;
  animation: aether-scroll-hint 2s infinite;
}

@keyframes aether-scroll-hint {
  0%   { transform: translateY(0); opacity: 0.7; }
  60%  { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0.7; }
}

/* ── Tile grid below the hero (in normal flow, appears as user scrolls) */

.aether-home-below {
  position: relative;
  z-index: 1;
  padding: 5rem 1.5rem 6rem;
  background: var(--md-default-bg-color);
}

.aether-tiles {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
}

.aether-tile {
  display: block;
  padding: 1.5rem 1.5rem 1.65rem;
  border-radius: 14px;
  background: var(--md-code-bg-color, rgba(255, 255, 255, 0.03));
  border: 1px solid var(--md-default-fg-color--lightest, rgba(255, 255, 255, 0.08));
  color: inherit !important;
  text-decoration: none;
  transition: transform 200ms ease, border-color 200ms ease, box-shadow 200ms ease;
}

.aether-tile:hover {
  transform: translateY(-3px);
  border-color: var(--aether-cyan);
  box-shadow: 0 12px 28px rgba(6, 182, 212, 0.2);
}

.aether-tile h3 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
  font-weight: 700;
  background: linear-gradient(135deg, #c4b5fd, var(--aether-cyan-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.aether-tile p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--md-default-fg-color--light);
}

/* ── Reduced motion ───────────────────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  /* Keep the centering transform for .aether-ui, kill the parallax */
  .aether-ui { transform: translateX(-50%) !important; }
  .aether-hero__content { transform: none !important; }
  .aether-hero__scroll-hint span { animation: none; }
}

/* ── Polish for doc pages ─────────────────────────────────────────────── */

.md-typeset code { border-radius: 4px; }
.md-typeset table:not([class]) th { font-weight: 600; }

/* ── Docs-as-of version badge in the navigation tabs row ───────────────
   Sits at the right end of the tabs row (next to Troubleshooting),
   reusing existing horizontal space so the header doesn't grow taller.
   Single source of truth for the docs version — bump the `content`
   value when regenerating against a new AetherSDR release. The future
   _generator/update.py script edits this same string. */

.md-tabs__list {
  align-items: center;
}


/* ── Accessibility: improve tab link contrast (WCAG AA) ─────────────────── */
.md-tabs__link {
  color: #ffffff !important;
  opacity: 1 !important;
}
.md-tabs__link:hover,
.md-tabs__link:focus {
  color: #ffffff !important;
  opacity: 0.85 !important;
}

/* ── Sidebar: collapsible section styling ──────────────────────────────────
   With navigation.sections removed, top-level folders become collapsible
   groups. Color the section labels with the accent so they pop, and give
   the active page a clear left-border indicator like PyMdown's site. */

/* Section title (collapsible group label) */
.md-nav--primary .md-nav__item--nested > .md-nav__link {
  color: var(--aether-cyan-2);
  font-weight: 600;
  letter-spacing: 0.02em;
}
.md-nav--primary .md-nav__item--nested > .md-nav__link:hover {
  color: var(--aether-violet-2);
}

/* Currently-open section label */
.md-nav--primary .md-nav__item--nested > .md-nav__link[aria-expanded="true"],
.md-nav--primary .md-nav__item--active > .md-nav__link {
  color: var(--aether-violet-2);
}

/* Active page: left-border accent */
.md-nav__link--active {
  border-left: 2px solid var(--aether-cyan);
  padding-left: 0.5rem !important;
  color: var(--aether-text) !important;
}

/* Smooth chevron rotation on expand/collapse */
.md-nav__icon {
  transition: transform 200ms ease;
}

/* ── Section icons in sidebar ──────────────────────────────────────────── */
.md-nav__section-icon {
  display: inline-flex;
  align-items: center;
  width: 1em;
  height: 1em;
  margin-right: 0.5em;
  vertical-align: -0.125em;
  color: var(--aether-cyan);
}
.md-nav__section-icon svg {
  width: 100%;
  height: 100%;
  fill: currentColor;
}