/* ==========================================================================
   APOD VIEWER — orient-luxury design system
   Near-black base, gold accent stack, grain overlay, parchment light mode.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Cinzel:wght@500;600;700&family=Cormorant+Garamond:ital,wght@0,400;0,500;0,600;1,400&family=Syne:wght@500;600;700&family=IBM+Plex+Mono:wght@400;500&display=swap');

/* ---------- Design tokens ---------- */
:root {
  /* type */
  --ol-font-display: 'Cinzel', serif;
  --ol-font-body: 'Cormorant Garamond', serif;
  --ol-font-ui: 'Syne', sans-serif;
  --ol-font-mono: 'IBM Plex Mono', monospace;

  /* layout */
  --ol-radius: 2px;
  --ol-border-w: 1px;
  --ol-max-width: 1180px;
  --ol-space-1: 0.4rem;
  --ol-space-2: 0.8rem;
  --ol-space-3: 1.6rem;
  --ol-space-4: 2.4rem;
  --ol-space-5: 4rem;

  /* motion */
  --ol-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --ol-dur: 420ms;
}

/* Dark theme (default) */
:root,
html[data-theme="dark"] {
  --ol-bg: #09080b;
  --ol-bg-elevated: #121016;
  --ol-bg-card: #15131a;
  --ol-hairline: rgba(201, 168, 76, 0.18);

  --ol-gold-100: #c9a84c;
  --ol-gold-80: rgba(201, 168, 76, 0.8);
  --ol-gold-60: rgba(201, 168, 76, 0.6);
  --ol-gold-40: rgba(201, 168, 76, 0.4);
  --ol-gold-20: rgba(201, 168, 76, 0.16);
  --ol-gold-dark: #8a6820;

  --ol-text: #ede7da;
  --ol-text-dim: rgba(237, 231, 218, 0.66);
  --ol-text-faint: rgba(237, 231, 218, 0.4);

  --ol-shadow: 0 24px 60px -20px rgba(0, 0, 0, 0.7);
  --ol-grain-opacity: 0.05;
}

/* Light theme — warm parchment */
html[data-theme="light"] {
  --ol-bg: #f0ebe0;
  --ol-bg-elevated: #f2ede8;
  --ol-bg-card: #fbf8f2;
  --ol-hairline: rgba(138, 104, 32, 0.28);

  --ol-gold-100: #8a6820;
  --ol-gold-80: rgba(138, 104, 32, 0.85);
  --ol-gold-60: rgba(138, 104, 32, 0.6);
  --ol-gold-40: rgba(138, 104, 32, 0.35);
  --ol-gold-20: rgba(138, 104, 32, 0.14);
  --ol-gold-dark: #6b4f18;

  --ol-text: #211c14;
  --ol-text-dim: rgba(33, 28, 20, 0.68);
  --ol-text-faint: rgba(33, 28, 20, 0.46);

  --ol-shadow: 0 24px 60px -24px rgba(90, 70, 30, 0.28);
  --ol-grain-opacity: 0.035;
}

/* ---------- Reset ---------- */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--ol-bg);
  color: var(--ol-text);
  font-family: var(--ol-font-body);
  font-size: 18px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--ol-dur) var(--ol-ease), color var(--ol-dur) var(--ol-ease);
  min-height: 100vh;
  position: relative;
}
img { max-width: 100%; display: block; }
a { color: var(--ol-gold-100); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3 { font-family: var(--ol-font-display); font-weight: 600; margin: 0; letter-spacing: 0.02em; }

/* ---------- Grain overlay ---------- */
.grain-overlay {
  position: fixed;
  inset: 0;
  z-index: 999;
  pointer-events: none;
  mix-blend-mode: soft-light;
  opacity: var(--ol-grain-opacity);
}

/* ---------- Layout shell ---------- */
.shell {
  max-width: var(--ol-max-width);
  margin: 0 auto;
  padding: 0 var(--ol-space-3);
}

/* ---------- Header ---------- */
.site-header {
  border-bottom: var(--ol-border-w) solid var(--ol-hairline);
  background: linear-gradient(180deg, var(--ol-bg-elevated), transparent);
}
.site-header .shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--ol-space-3);
  padding-bottom: var(--ol-space-3);
  gap: var(--ol-space-2);
}
.wordmark {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.wordmark .mark {
  font-family: var(--ol-font-display);
  font-size: 1.5rem;
  letter-spacing: 0.14em;
  color: var(--ol-text);
}
.wordmark .tagline {
  font-family: var(--ol-font-ui);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ol-gold-100);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--ol-space-2);
}
.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: var(--ol-border-w) solid var(--ol-hairline);
  background: var(--ol-bg-card);
  color: var(--ol-gold-100);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 200ms var(--ol-ease), transform 200ms var(--ol-ease);
}
.icon-btn:hover { border-color: var(--ol-gold-60); transform: translateY(-1px); }
.icon-btn svg { width: 18px; height: 18px; }
.icon-btn .icon-moon { display: block; }
.icon-btn .icon-sun { display: none; }
html[data-theme="light"] .icon-btn .icon-moon { display: none; }
html[data-theme="light"] .icon-btn .icon-sun { display: block; }

/* ---------- Hero / media frame ---------- */
.hero {
  padding: var(--ol-space-4) 0 var(--ol-space-2);
}
.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--ol-bg-card);
  border: var(--ol-border-w) solid var(--ol-hairline);
  border-radius: var(--ol-radius);
  overflow: hidden;
  box-shadow: var(--ol-shadow);
}
.media-frame img,
.media-frame iframe {
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #000;
  border: 0;
}
.media-frame .skeleton {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--ol-font-ui);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ol-text-faint);
  background:
    linear-gradient(110deg, var(--ol-bg-card) 8%, var(--ol-bg-elevated) 18%, var(--ol-bg-card) 33%);
  background-size: 200% 100%;
  animation: shimmer 1.6s linear infinite;
}
@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
.caption-bar {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: var(--ol-space-3);
  background: linear-gradient(0deg, rgba(0,0,0,0.72), transparent);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--ol-space-2);
  pointer-events: none;
}
.caption-bar .cap-title {
  font-family: var(--ol-font-display);
  color: #f4efe2;
  font-size: clamp(1.1rem, 2.4vw, 1.6rem);
  text-shadow: 0 2px 12px rgba(0,0,0,0.6);
}
.caption-bar .cap-date {
  font-family: var(--ol-font-mono);
  font-size: 0.78rem;
  color: rgba(244, 239, 226, 0.85);
  white-space: nowrap;
}

/* ---------- Date navigator ---------- */
.date-nav {
  display: flex;
  align-items: center;
  gap: var(--ol-space-2);
  padding: var(--ol-space-3) 0;
  flex-wrap: wrap;
}
.nav-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: var(--ol-border-w) solid var(--ol-hairline);
  background: var(--ol-bg-card);
  color: var(--ol-text);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 200ms var(--ol-ease), opacity 200ms var(--ol-ease);
}
.nav-btn:hover:not(:disabled) { border-color: var(--ol-gold-60); }
.nav-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.date-input {
  font-family: var(--ol-font-mono);
  font-size: 0.9rem;
  background: var(--ol-bg-card);
  color: var(--ol-text);
  border: var(--ol-border-w) solid var(--ol-hairline);
  border-radius: var(--ol-radius);
  padding: 0.5rem 0.7rem;
}
.pill-btn {
  font-family: var(--ol-font-ui);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  background: transparent;
  border: var(--ol-border-w) solid var(--ol-gold-40);
  color: var(--ol-gold-100);
  border-radius: 999px;
  padding: 0.55rem 1.1rem;
  transition: background 200ms var(--ol-ease), border-color 200ms var(--ol-ease);
}
.pill-btn:hover { background: var(--ol-gold-20); border-color: var(--ol-gold-80); }
.pill-btn.is-loading { opacity: 0.6; pointer-events: none; }

/* ---------- Content grid ---------- */
.content-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr;
  gap: var(--ol-space-4);
  padding: var(--ol-space-3) 0 var(--ol-space-5);
  align-items: start;
}
@media (max-width: 820px) {
  .content-grid { grid-template-columns: 1fr; }
}

/* Explanation article */
.explanation h2 {
  font-size: 1.3rem;
  color: var(--ol-gold-100);
  margin-bottom: var(--ol-space-2);
}
.explanation .lede::first-letter {
  font-family: var(--ol-font-display);
  font-size: 3.4rem;
  float: left;
  line-height: 0.8;
  padding: 0.1rem 0.5rem 0 0;
  color: var(--ol-gold-100);
}
.explanation p {
  font-size: 1.18rem;
  color: var(--ol-text);
  font-weight: 400;
}
.explanation .credit {
  margin-top: var(--ol-space-3);
  font-family: var(--ol-font-ui);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ol-text-faint);
}

/* Observation log card (signature element) */
.log-card {
  border: var(--ol-border-w) solid var(--ol-hairline);
  background: var(--ol-bg-card);
  border-radius: var(--ol-radius);
  padding: var(--ol-space-3);
  position: sticky;
  top: var(--ol-space-3);
}
.log-card .log-title {
  font-family: var(--ol-font-ui);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ol-gold-100);
  border-bottom: var(--ol-border-w) solid var(--ol-hairline);
  padding-bottom: var(--ol-space-2);
  margin-bottom: var(--ol-space-2);
}
.log-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.55rem 0;
  border-bottom: var(--ol-border-w) dashed var(--ol-hairline);
  gap: var(--ol-space-2);
}
.log-row:last-child { border-bottom: none; }
.log-row .log-label {
  font-family: var(--ol-font-ui);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ol-text-faint);
  white-space: nowrap;
}
.log-row .log-value {
  font-family: var(--ol-font-mono);
  font-size: 0.85rem;
  color: var(--ol-text);
  text-align: right;
}
.log-row .log-value a { font-family: var(--ol-font-mono); }
.log-badge {
  display: inline-block;
  font-family: var(--ol-font-ui);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  border: var(--ol-border-w) solid var(--ol-gold-40);
  color: var(--ol-gold-100);
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: var(--ol-border-w) solid var(--ol-hairline);
  padding: var(--ol-space-3) 0 var(--ol-space-5);
}
.site-footer .shell {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--ol-space-2);
  font-family: var(--ol-font-ui);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ol-text-faint);
}

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: var(--ol-space-3);
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  z-index: 1000;
  background: var(--ol-bg-card);
  border: var(--ol-border-w) solid var(--ol-gold-40);
  color: var(--ol-text);
  font-family: var(--ol-font-ui);
  font-size: 0.82rem;
  padding: 0.8rem 1.4rem;
  border-radius: var(--ol-radius);
  box-shadow: var(--ol-shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 260ms var(--ol-ease), transform 260ms var(--ol-ease);
  max-width: 90vw;
}
.toast.is-visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- Focus states ---------- */
a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--ol-gold-100);
  outline-offset: 2px;
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* ---------- Small screens ---------- */
@media (max-width: 520px) {
  body { font-size: 16.5px; }
  .wordmark .mark { font-size: 1.25rem; }
  .caption-bar .cap-title { font-size: 1rem; }
  .log-card { position: static; }
}