/*
 * Starfield — Reveal.js Theme
 * A deep-space observatory aesthetic for astronomy presentations
 * by Tyler Malone / BAS
 *
 * Standalone theme — replaces black.css entirely.
 * Overrides Reveal's --r-* variables so structural rules work correctly,
 * then layers custom styling on top.
 */

/* ============================================
   FONTS
   ============================================ */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,700;1,400&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

/* ============================================
   REVEAL.JS VARIABLE OVERRIDES
   These feed into reveal.css's own selectors
   ============================================ */
:root {
  /* Starfield palette */
  --sf-bg-primary: #0a0e1a;
  --sf-bg-secondary: #111827;
  --sf-bg-card: rgba(255, 255, 255, 0.035);
  --sf-text-primary: #e8eaf0;
  --sf-text-secondary: #9ca3b4;
  --sf-text-muted: #6b7280;
  --sf-accent-gold: #d4a843;
  --sf-accent-gold-light: #f0d078;
  --sf-accent-blue: #60a5fa;
  --sf-accent-blue-dark: #3b82f6;
  --sf-accent-teal: #5eead4;
  --sf-border: rgba(255, 255, 255, 0.08);
  --sf-shadow: rgba(0, 0, 0, 0.4);

  /* Reveal core overrides */
  --r-background-color: var(--sf-bg-primary);
  --r-main-font: 'Source Sans 3', 'Source Sans Pro', -apple-system, BlinkMacSystemFont, sans-serif;
  --r-main-font-size: 22px;
  --r-main-color: var(--sf-text-primary);
  --r-block-margin: 16px;
  --r-heading-margin: 0 0 0.6em 0;
  --r-heading-font: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --r-heading-color: var(--sf-text-primary);
  --r-heading-line-height: 1.2;
  --r-heading-letter-spacing: -0.01em;
  --r-heading-text-transform: none;
  --r-heading-text-shadow: none;
  --r-heading-font-weight: 700;
  --r-heading1-text-shadow: none;
  --r-heading1-size: 2.4em;
  --r-heading2-size: 1.8em;
  --r-heading3-size: 1.3em;
  --r-heading4-size: 1.1em;
  --r-code-font: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  --r-link-color: var(--sf-accent-blue);
  --r-link-color-dark: var(--sf-accent-blue-dark);
  --r-link-color-hover: var(--sf-accent-blue);
  --r-selection-background-color: rgba(212, 168, 67, 0.35);
  --r-selection-color: #fff;
}

/* ============================================
   BACKGROUND — ANIMATED STARFIELD
   ============================================ */
.reveal-viewport {
  background: var(--sf-bg-primary);
  background-image:
    /* Subtle nebula washes */
    radial-gradient(ellipse at 18% 45%, rgba(59, 130, 246, 0.07) 0%, transparent 55%),
    radial-gradient(ellipse at 82% 20%, rgba(212, 168, 67, 0.045) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 85%, rgba(94, 234, 212, 0.03) 0%, transparent 45%);
}

/* Animated star layers — on .reveal-viewport so they render above its background */
.reveal-viewport::before,
.reveal-viewport::after {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
}

/* Layer 1: dense small-medium stars — fast twinkle */
.reveal-viewport::before {
  background-image:
    radial-gradient(1.5px 1.5px at 7% 12%, rgba(255,255,255,0.3), transparent),
    radial-gradient(1.5px 1.5px at 15% 68%, rgba(255,255,255,0.22), transparent),
    radial-gradient(1.5px 1.5px at 23% 34%, rgba(255,255,255,0.28), transparent),
    radial-gradient(1.5px 1.5px at 31% 82%, rgba(255,255,255,0.2), transparent),
    radial-gradient(1.5px 1.5px at 38% 8%, rgba(255,255,255,0.26), transparent),
    radial-gradient(1.5px 1.5px at 44% 55%, rgba(255,255,255,0.18), transparent),
    radial-gradient(1.5px 1.5px at 52% 27%, rgba(255,255,255,0.3), transparent),
    radial-gradient(1.5px 1.5px at 59% 91%, rgba(255,255,255,0.2), transparent),
    radial-gradient(1.5px 1.5px at 67% 45%, rgba(255,255,255,0.25), transparent),
    radial-gradient(1.5px 1.5px at 74% 73%, rgba(255,255,255,0.16), transparent),
    radial-gradient(1.5px 1.5px at 81% 18%, rgba(255,255,255,0.3), transparent),
    radial-gradient(1.5px 1.5px at 88% 60%, rgba(255,255,255,0.18), transparent),
    radial-gradient(1.5px 1.5px at 94% 38%, rgba(255,255,255,0.25), transparent),
    radial-gradient(1.5px 1.5px at 3% 50%, rgba(255,255,255,0.14), transparent),
    radial-gradient(1.5px 1.5px at 48% 4%, rgba(255,255,255,0.22), transparent),
    radial-gradient(1.5px 1.5px at 71% 88%, rgba(255,255,255,0.18), transparent),
    radial-gradient(1.5px 1.5px at 19% 95%, rgba(255,255,255,0.2), transparent),
    radial-gradient(1.5px 1.5px at 56% 42%, rgba(255,255,255,0.12), transparent),
    radial-gradient(1.5px 1.5px at 83% 3%, rgba(255,255,255,0.24), transparent),
    radial-gradient(1.5px 1.5px at 36% 67%, rgba(255,255,255,0.18), transparent);
  animation: starTwinkle1 3.5s ease-in-out infinite alternate;
}

/* Layer 2: sparse bright accent stars — offset fast twinkle */
.reveal-viewport::after {
  background-image:
    radial-gradient(2.5px 2.5px at 12% 22%, rgba(240,208,120,0.35), transparent),
    radial-gradient(2px 2px at 28% 78%, rgba(96,165,250,0.3), transparent),
    radial-gradient(2.5px 2.5px at 45% 15%, rgba(255,255,255,0.35), transparent),
    radial-gradient(2px 2px at 62% 65%, rgba(240,208,120,0.28), transparent),
    radial-gradient(2.5px 2.5px at 78% 35%, rgba(96,165,250,0.35), transparent),
    radial-gradient(2px 2px at 91% 80%, rgba(255,255,255,0.25), transparent),
    radial-gradient(2.5px 2.5px at 8% 88%, rgba(255,255,255,0.3), transparent),
    radial-gradient(2px 2px at 55% 50%, rgba(240,208,120,0.25), transparent),
    radial-gradient(2.5px 2.5px at 70% 10%, rgba(255,255,255,0.32), transparent),
    radial-gradient(2px 2px at 35% 42%, rgba(96,165,250,0.22), transparent);
  animation: starTwinkle2 5s ease-in-out infinite alternate;
}

@keyframes starTwinkle1 {
  0%   { opacity: 0.55; }
  100% { opacity: 1; }
}

@keyframes starTwinkle2 {
  0%   { opacity: 1; }
  100% { opacity: 0.45; }
}

/* ============================================
   SLIDE LAYOUT
   ============================================ */
.reveal .slides {
  text-align: left;
}

.reveal {
  font-size: var(--r-main-font-size) !important;
}

.reveal .slides section,
.reveal .slides section > section {
  font-family: var(--r-main-font);
  color: var(--sf-text-primary);
  font-weight: 400;
  line-height: 1.6;
  padding: 30px 50px;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4,
.reveal h5,
.reveal h6 {
  font-family: var(--r-heading-font);
  color: var(--r-heading-color);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin: var(--r-heading-margin);
  text-transform: none;
  text-shadow: none;
  word-wrap: break-word;
}

.reveal h1 { font-size: var(--r-heading1-size); }
.reveal h2 { font-size: var(--r-heading2-size); }

.reveal h3 {
  font-size: var(--r-heading3-size);
  font-family: var(--r-main-font);
  font-weight: 600;
  color: var(--sf-accent-gold);
}

.reveal h4 {
  font-size: var(--r-heading4-size);
  font-family: var(--r-main-font);
  font-weight: 500;
  color: var(--sf-accent-blue);
}

.reveal p {
  font-size: 0.95em;
  line-height: 1.7;
  color: var(--sf-text-secondary);
  margin: 0 0 0.8em 0;
}

.reveal .slides section > p:first-of-type {
  color: var(--sf-text-primary);
}

/* ============================================
   LISTS
   ============================================ */
.reveal ul,
.reveal ol {
  display: block;
  text-align: left;
  margin-left: 0.6em;
  font-size: 0.95em;
  color: var(--sf-text-secondary);
}

.reveal ol {
  list-style-type: decimal;
}

.reveal ul {
  list-style-type: disc;
}

.reveal li {
  margin-bottom: 0.6em;
  line-height: 1.5;
}

.reveal li::marker {
  color: var(--sf-accent-gold);
}

.reveal ul ul,
.reveal ul ol,
.reveal ol ul,
.reveal ol ol {
  display: block;
  margin-top: 0.3em;
  margin-left: 1.4em;
  font-size: 0.92em;
}

.reveal ul ul li::marker {
  color: var(--sf-accent-blue);
}

.reveal ul ul {
  list-style-type: square;
}

.reveal ul ul ul {
  list-style-type: circle;
}

/* ============================================
   STRONG, EM, LINKS
   ============================================ */
.reveal strong,
.reveal b {
  color: var(--sf-text-primary);
  font-weight: 600;
}

.reveal em {
  color: var(--sf-accent-gold-light);
  font-style: italic;
}

.reveal a {
  color: var(--sf-accent-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(96, 165, 250, 0.3);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.reveal a:hover {
  color: var(--sf-accent-blue);
  border-bottom-color: var(--sf-accent-blue);
  text-shadow: none;
  border-top: none;
  border-left: none;
  border-right: none;
}

/* ============================================
   BLOCKQUOTES
   ============================================ */
.reveal blockquote {
  display: block;
  position: relative;
  width: auto;
  margin: 0.8em 0;
  padding: 0.8em 1.2em;
  background: var(--sf-bg-card);
  border-left: 3px solid var(--sf-accent-gold);
  border-radius: 0 6px 6px 0;
  font-style: italic;
  color: var(--sf-accent-gold-light);
  font-size: 0.85em;
  box-shadow: none;
}

.reveal blockquote p,
.reveal blockquote p:first-child,
.reveal blockquote p:last-child {
  display: block;
  color: var(--sf-accent-gold-light);
  font-style: italic;
}

/* ============================================
   TABLES
   ============================================ */
.reveal table {
  margin: 0.8em 0;
  border-collapse: collapse;
  border-spacing: 0;
  width: 100%;
  font-size: 0.82em;
}

.reveal table th {
  background: rgba(212, 168, 67, 0.12);
  color: var(--sf-accent-gold);
  font-weight: 600;
  text-align: left;
  padding: 0.6em 0.8em;
  border-bottom: 2px solid var(--sf-accent-gold);
}

.reveal table td {
  padding: 0.5em 0.8em;
  border-bottom: 1px solid var(--sf-border);
  color: var(--sf-text-secondary);
  vertical-align: top;
}

.reveal table tr:last-child td,
.reveal table tbody tr:last-child td {
  border-bottom: none;
}

.reveal table tbody tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

/* ============================================
   IMAGES
   ============================================ */
.reveal img,
.reveal video,
.reveal iframe {
  max-width: 95%;
  max-height: 95%;
}

.reveal img {
  margin: 0;
}

.reveal section img {
  border: none;
  box-shadow: 0 4px 24px var(--sf-shadow);
  border-radius: 6px;
  max-height: 55vh;
}

.reveal section img.no-shadow {
  box-shadow: none;
  border-radius: 0;
}

.reveal section img.badge {
  box-shadow: none;
  border-radius: 0;
  max-height: 120px;
  vertical-align: middle;
}

.reveal section img.portrait {
  border-radius: 50%;
  max-height: 140px;
  box-shadow: 0 2px 12px var(--sf-shadow);
}

/* ============================================
   TITLE SLIDE
   ============================================ */
.reveal .title-slide {
  text-align: center;
  display: flex !important;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 0 !important;
}

.reveal .title-slide h1 {
  font-size: 2.6em;
  margin-bottom: 0.15em;
  background: linear-gradient(
    135deg,
    var(--sf-text-primary) 0%,
    var(--sf-accent-gold-light) 50%,
    var(--sf-text-primary) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.reveal .title-slide .subtitle {
  font-family: var(--r-main-font);
  font-size: 0.85em;
  color: var(--sf-text-secondary);
  font-weight: 300;
  margin-bottom: 1.5em;
  letter-spacing: 0.02em;
}

.reveal .title-slide .byline {
  font-family: var(--r-main-font);
  font-size: 0.62em;
  color: var(--sf-text-muted);
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-top: 1.5em;
  border-top: 1px solid var(--sf-border);
}

/* Decorative divider above byline */
.reveal .title-slide .subtitle::after {
  content: '';
  display: block;
  width: 80px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--sf-accent-gold), transparent);
  margin: 1.5em auto 0;
}

/* ============================================
   SECTION HEADER SLIDES
   ============================================ */
.reveal .section-header {
  text-align: center;
  display: flex !important;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 0 !important;
}

.reveal .section-header h2 {
  font-size: 2.4em;
  margin-bottom: 0.2em;
  background: linear-gradient(135deg, var(--sf-accent-gold-light), var(--sf-accent-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 30px rgba(212, 168, 67, 0.15));
}

.reveal .section-header p {
  font-size: 0.9em;
  color: var(--sf-text-muted);
  letter-spacing: 0.04em;
}

/* Decorative line beneath section headers */
.reveal .section-header h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 2px;
  background: linear-gradient(90deg, var(--sf-accent-gold), var(--sf-accent-blue));
  margin: 0.5em auto 0;
  border-radius: 1px;
  /* Reset background-clip so the line is visible */
  -webkit-background-clip: unset;
  -webkit-text-fill-color: unset;
  background-clip: unset;
}

/* ============================================
   STAT / NUMBER CALLOUTS
   ============================================ */
.reveal .stat {
  font-family: 'Playfair Display', serif;
  font-size: 2.8em;
  font-weight: 700;
  color: var(--sf-accent-gold);
  line-height: 1.1;
  display: block;
  margin: 0.3em 0 0.1em;
  text-shadow: 0 0 40px rgba(212, 168, 67, 0.2);
}

.reveal .stat-label {
  font-family: var(--r-main-font);
  font-size: 0.65em;
  color: var(--sf-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  display: block;
  line-height: 1.4;
}

/* Stat card glass effect */
.reveal .columns .col:has(.stat) {
  background: var(--sf-bg-card);
  border: 1px solid var(--sf-border);
  border-radius: 10px;
  padding: 1.2em 0.8em;
  transition: border-color 0.3s ease;
}

.reveal .columns .col:has(.stat):hover {
  border-color: rgba(212, 168, 67, 0.2);
}

/* ============================================
   CLOSING / QUOTE SLIDE
   ============================================ */
.reveal .closing-slide {
  text-align: center;
  display: flex !important;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 0 !important;
}

.reveal .closing-slide blockquote {
  border-left: none;
  text-align: center;
  font-size: 1.15em;
  background: none;
  padding: 0;
  font-family: 'Playfair Display', serif;
}

.reveal .closing-slide blockquote p {
  text-align: center;
}

.reveal .closing-slide .attribution {
  font-family: var(--r-main-font);
  font-size: 0.6em;
  color: var(--sf-text-muted);
  font-style: normal;
  margin-top: 0.5em;
  letter-spacing: 0.04em;
}

/* ============================================
   TWO-COLUMN LAYOUT
   ============================================ */
.reveal .columns {
  display: flex;
  gap: 2em;
  align-items: flex-start;
}

.reveal .columns .col {
  flex: 1;
}

.reveal .columns .col-narrow {
  flex: 0.6;
}

.reveal .columns .col-wide {
  flex: 1.4;
}

/* ============================================
   PORTRAIT GRID
   ============================================ */
.reveal .portrait-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4em;
  justify-content: center;
  margin: 1em 0;
}

/* 2-over-3 row layout */
.reveal .portrait-grid.portrait-grid-2over3 {
  flex-direction: column;
  align-items: center;
  gap: 1.8em;
}

.reveal .portrait-grid .portrait-row {
  display: flex;
  gap: 2.5em;
  justify-content: center;
}

.reveal .portrait-grid .portrait-item {
  text-align: center;
  width: 180px;
  transition: transform 0.3s ease;
}

.reveal .portrait-grid .portrait-item:hover {
  transform: translateY(-3px);
}

.reveal .portrait-grid .portrait-item img {
  border-radius: 50%;
  width: 140px;
  height: 140px;
  object-fit: cover;
  object-position: center 20%;
  box-shadow:
    0 2px 12px var(--sf-shadow),
    0 0 0 2px rgba(212, 168, 67, 0.15);
  transition: box-shadow 0.3s ease;
}

.reveal .portrait-grid .portrait-item:hover img {
  box-shadow:
    0 4px 20px var(--sf-shadow),
    0 0 0 2px rgba(212, 168, 67, 0.35);
}

.reveal .portrait-grid .portrait-item .name {
  font-size: 0.75em;
  color: var(--sf-text-primary);
  margin-top: 0.5em;
  font-weight: 600;
  display: block;
  letter-spacing: 0.02em;
}

.reveal .portrait-grid .portrait-item .role {
  font-size: 0.65em;
  color: var(--sf-text-muted);
  display: block;
  line-height: 1.5;
  margin-top: 0.15em;
}

/* ============================================
   SOURCE CITATION
   ============================================ */
.reveal .source {
  font-size: 0.48em;
  color: var(--sf-text-muted);
  font-style: italic;
  margin-top: 1.5em;
  border-top: 1px solid var(--sf-border);
  padding-top: 0.5em;
  opacity: 0.7;
}

/* ============================================
   PROGRESS BAR & CONTROLS
   ============================================ */
.reveal .progress {
  height: 3px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--sf-accent-gold);
}

.reveal .controls {
  color: var(--sf-accent-gold);
}

.reveal .controls button {
  opacity: 0.4;
  transition: opacity 0.3s ease;
}

.reveal .controls button:hover {
  opacity: 1;
}

/* Slide number */
.reveal .slide-number {
  font-family: var(--r-main-font);
  font-size: 0.5em;
  color: var(--sf-text-muted);
  background: transparent;
}

/* ============================================
   FRAGMENT ANIMATIONS
   ============================================ */
.reveal .slides section .fragment {
  transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.reveal .slides section .fragment.visible {
  opacity: 1;
}

/* ============================================
   TITLE SLIDE LOGOS
   ============================================ */
.reveal .title-slide .title-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2.5em;
  margin-bottom: 1.5em;
}

.reveal .title-slide .title-logos .title-logo {
  box-shadow: none;
  border-radius: 0;
  max-height: 120px;
  width: auto;
}

/* ============================================
   PERSISTENT CORNER LOGOS
   ============================================ */
.corner-logo {
  position: fixed;
  bottom: 16px;
  z-index: 30;
  pointer-events: none;
}

.corner-logo-left {
  left: 20px;
}

.corner-logo-right {
  right: 20px;
}

.corner-logo img {
  height: 44px;
  width: auto;
  opacity: 0.5;
  transition: opacity 0.3s ease;
}

.corner-logo img:hover {
  opacity: 0.8;
}

/* ============================================
   MISC ELEMENT RESETS
   ============================================ */
.reveal sup { vertical-align: super; font-size: smaller; }
.reveal sub { vertical-align: sub; font-size: smaller; }
.reveal small { display: inline-block; font-size: 0.6em; line-height: 1.2em; }

/* ============================================
   PRINT / PDF
   ============================================ */
@media print {
  .reveal-viewport {
    background: var(--sf-bg-primary) !important;
  }
  .reveal-viewport::before,
  .reveal-viewport::after {
    display: none;
  }
  .backgrounds {
    background-color: var(--sf-bg-primary);
  }
}