/* ─────────────────────────────────────────────────────────────────────────
   Tokens (dark only)
───────────────────────────────────────────────────────────────────────── */
:root {
  --bg: #09090b;
  --bg-elev: #111114;
  --fg: #f4f4f5;
  --fg-muted: #a1a1aa;
  --fg-faint: #71717a;
  --accent: #8ab4ff;
  --accent-soft: rgba(138, 180, 255, 0.12);
  --line: rgba(255, 255, 255, 0.07);
  --line-strong: rgba(255, 255, 255, 0.12);
  --glass: rgba(17, 17, 20, 0.62);
  --glass-soft: rgba(255, 255, 255, 0.03);
  --glass-hover: rgba(255, 255, 255, 0.055);
  --glass-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.05);
  --shadow: 0 24px 60px -28px rgba(0, 0, 0, 0.7);
  --blur: blur(24px) saturate(150%);
  --radius: 16px;
  --radius-sm: 10px;
  --font-sans: 'Geist', 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-display: var(--font-sans);
  --font-mono: 'Geist Mono', ui-monospace, 'SFMono-Regular', monospace;
  --maxw: 1120px;
  color-scheme: dark;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "cv11";
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
h1, h2, h3, h4, p { margin: 0; }
h1, h2, h3 { letter-spacing: -0.02em; }
ul, ol { margin: 0; padding: 0; list-style: none; }

::selection { background: var(--accent); color: var(--bg); }

/* Lucide icon font: one consistent outline style for every icon */
[class^="icon-"], [class*=" icon-"] { display: inline-block; line-height: 1; vertical-align: -0.125em; speak: never; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

/* Fixed, heavily blurred copy of the header image (set once it has loaded) + a soft accent glow */
.backdrop {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  pointer-events: none;
}
/* The blurred image bleeds past the edges (to hide blur fringes) inside a clipped box,
   so it can never make the page scroll sideways on mobile */
.backdrop::before {
  content: "";
  position: absolute;
  inset: -10%;
  background: var(--bg) var(--backdrop-image, none) center / cover no-repeat;
  opacity: .18;
  filter: blur(48px) saturate(80%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(60% 40% at 50% 0%, rgba(138, 180, 255, .06), transparent 70%);
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image: radial-gradient(rgba(255, 255, 255, .5) 1px, transparent 1px);
  background-size: 3px 3px;
  opacity: .025;
}

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ─────────────────────────────────────────────────────────────────────────
   Glass primitive
───────────────────────────────────────────────────────────────────────── */
.glass {
  background: var(--glass);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--glass-highlight), var(--shadow);
}

/* ─────────────────────────────────────────────────────────────────────────
   Navigation
───────────────────────────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 5px;
  border-radius: 14px;
  width: max-content;
  max-width: calc(100% - 32px);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 12px 0 0;
  margin-right: 4px;
  border-right: 1px solid var(--line);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.nav-brand img { width: 32px; height: 32px; border-radius: 9px; object-fit: cover; border: 1px solid var(--line-strong); }

.nav-links { display: flex; gap: 2px; }

.nav-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  color: var(--fg-muted);
  transition: color .2s, background-color .2s;
}
.nav-links a i { font-size: 15px; }
.nav-links a:hover { color: var(--fg); background: var(--glass-hover); }
.nav-links a[aria-current="page"] { color: var(--fg); background: var(--glass-hover); box-shadow: inset 0 0 0 1px var(--line); }

/* ─────────────────────────────────────────────────────────────────────────
   Photo hero band
───────────────────────────────────────────────────────────────────────── */
.photo-hero {
  position: relative;
  height: clamp(300px, 46vh, 460px);
  overflow: hidden;
  background:
    radial-gradient(80% 120% at 50% 0%, rgba(138, 180, 255, .10), transparent 60%),
    radial-gradient(40% 60% at 80% 30%, rgba(170, 140, 255, .06), transparent 70%),
    var(--bg);
  -webkit-mask-image: linear-gradient(180deg, #000 50%, transparent 100%);
  mask-image: linear-gradient(180deg, #000 50%, transparent 100%);
}
.photo-hero img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 38%;
  filter: brightness(1.1) saturate(105%);
}
/* Nothing is shown until NASA's picture has fully loaded */
.photo-hero img { opacity: 0; }
.photo-hero:not(.is-apod) img { visibility: hidden; }
.photo-hero.is-apod img { opacity: 1; animation: hero-in .7s ease both; }
@keyframes hero-in { from { opacity: 0; transform: scale(1.02); } }

/* Loader: a planet orbiting on a faint ring over a slowly drifting star field */
.hero-loader {
  position: absolute;
  inset: 0 0 18% 0;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  transition: opacity .5s ease;
}
.photo-hero:not(.is-loading) .hero-loader { opacity: 0; pointer-events: none; }

/* Only appears if the picture takes a while: fast (or cached) loads never show it */
.photo-hero.is-loading .hero-loader { animation: loader-in .5s ease .6s both; }
@keyframes loader-in { from { opacity: 0; } }

.photo-hero.is-loading::before {
  content: "";
  position: absolute;
  inset: -50%;
  background-image:
    radial-gradient(1px 1px at 20px 30px, rgba(255, 255, 255, .55), transparent),
    radial-gradient(1px 1px at 90px 120px, rgba(255, 255, 255, .35), transparent),
    radial-gradient(1.5px 1.5px at 160px 60px, rgba(255, 255, 255, .5), transparent),
    radial-gradient(1px 1px at 230px 170px, rgba(255, 255, 255, .3), transparent),
    radial-gradient(1px 1px at 300px 90px, rgba(255, 255, 255, .45), transparent);
  background-size: 320px 220px;
  animation: loader-in .5s ease .6s both, drift 40s linear .6s infinite;
  opacity: .7;
}
@keyframes drift { to { transform: translate(160px, 60px); } }

.orbit {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, .12);
  animation: spin 1.6s linear infinite;
}
.orbit::before {
  content: "";
  position: absolute;
  inset: 16px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, rgba(138, 180, 255, .9), rgba(138, 180, 255, .25) 70%);
  box-shadow: 0 0 24px rgba(138, 180, 255, .45);
}
.orbit .planet {
  position: absolute;
  top: -4px;
  left: 50%;
  width: 8px;
  height: 8px;
  margin-left: -4px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 0 12px rgba(255, 255, 255, .9);
}
@keyframes spin { to { transform: rotate(360deg); } }

.hero-loader-text {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--fg-faint);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 50% { opacity: .45; } }

.photo-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(9, 9, 11, .35) 0%, rgba(9, 9, 11, .5) 100%);
}

/* Label for NASA's picture of the day */
.photo-caption {
  position: absolute;
  z-index: 1;
  top: 76px;
  right: 20px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 500;
  color: rgba(244, 244, 245, .85);
  background: rgba(9, 9, 11, .45);
  border: 1px solid rgba(255, 255, 255, .1);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  white-space: nowrap;
  transition: color .2s, background-color .2s;
}
.photo-caption:hover { color: #fff; background: rgba(9, 9, 11, .7); }

/* ─────────────────────────────────────────────────────────────────────────
   Typography helpers
───────────────────────────────────────────────────────────────────────── */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.eyebrow.accent { color: var(--accent); }
.eyebrow.accent::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 10px var(--accent); }

.display {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.05;
}

.section { margin-top: 80px; }
.section-head { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 6px 16px; margin-bottom: 24px; }
.section-head h2 { font-size: clamp(24px, 3vw, 30px); font-weight: 600; line-height: 1.15; }
.section-head .eyebrow { white-space: nowrap; }

.muted { color: var(--fg-muted); }

/* ─────────────────────────────────────────────────────────────────────────
   Buttons & chips
───────────────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 0 16px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  border: 1px solid var(--line-strong);
  background: var(--glass-soft);
  color: var(--fg);
  cursor: pointer;
  transition: background-color .2s, border-color .2s, color .2s;
  font-family: inherit;
}
.btn:hover { background: var(--glass-hover); border-color: rgba(255, 255, 255, .2); }
.btn-primary { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.btn-primary:hover { background: #fff; border-color: #fff; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border-radius: 7px;
  font-size: 12.5px;
  color: var(--fg-muted);
  background: var(--glass-soft);
  border: 1px solid var(--line);
  white-space: nowrap;
}
a.chip { transition: color .2s, border-color .2s; }
a.chip:hover { color: var(--fg); border-color: var(--line-strong); }

.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--fg-faint); flex-shrink: 0; }

/* ─────────────────────────────────────────────────────────────────────────
   Footer
───────────────────────────────────────────────────────────────────────── */
.footer {
  margin-top: 96px;
  border-top: 1px solid var(--line);
  padding: 28px 0 36px;
  font-size: 13.5px;
  color: var(--fg-faint);
}
.footer .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; }
.footer-links { display: flex; gap: 4px; }
.footer-links a { display: inline-flex; align-items: center; gap: 8px; padding: 7px 12px; border-radius: 10px; color: var(--fg-muted); transition: color .2s, background-color .2s; }
.footer-links a:hover { color: var(--fg); background: var(--glass-hover); }

/* ─────────────────────────────────────────────────────────────────────────
   Reveal on scroll
───────────────────────────────────────────────────────────────────────── */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .7s ease, transform .7s cubic-bezier(.2, .7, .2, 1); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { transition-duration: 0s !important; animation-duration: 0s !important; }
}

/* Browsers without backdrop-filter: make glass opaque enough to read */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass { background: var(--bg-elev); }
}

@media (max-width: 640px) {
  body { font-size: 15px; }
  .container { padding: 0 16px; }
  .section { margin-top: 56px; }
}

/* Phones and small tablets: the nav becomes a floating bar at the bottom of the screen,
   like a toast, with an icon above each label so every page fits on the narrowest screens */
@media (max-width: 820px) {
  body { padding-bottom: calc(84px + env(safe-area-inset-bottom)); }

  .nav {
    top: auto;
    bottom: calc(12px + env(safe-area-inset-bottom));
    width: calc(100% - 24px);
    max-width: 420px;
    padding: 6px;
    border-radius: 18px;
    animation: nav-toast-in .45s cubic-bezier(.2, .8, .2, 1) .15s both;
  }
  .nav-brand { display: none; }
  .nav-links { flex: 1; display: grid; grid-auto-flow: column; grid-auto-columns: minmax(0, 1fr); gap: 4px; }
  .nav-links a {
    flex-direction: column;
    gap: 3px;
    padding: 8px 4px 7px;
    border-radius: 12px;
    font-size: 11.5px;
    line-height: 1.2;
    text-align: center;
  }
  .nav-links a i { font-size: 19px; }
  .nav-links a[aria-current="page"] { color: var(--fg); background: rgba(255, 255, 255, .08); }
  .nav-links a[aria-current="page"] i { color: var(--accent); }

  .photo-caption { top: 12px; right: 12px; }
}

@keyframes nav-toast-in {
  from { opacity: 0; transform: translate(-50%, 24px) scale(.96); }
  to { opacity: 1; transform: translate(-50%, 0); }
}