/* slides2.css — StellarSlides engine styles
   Replaces reveal.css + theme/black.css (~54KB → ~120 lines)
   Only engine-level concerns: visibility, transforms, backgrounds, fragments */

/* ===== Heading sizes (from reveal.js theme/black.css) ===== */
.reveal h1 { font-size: 2.5em; }
.reveal h2 { font-size: 1.6em; }
.reveal h3 { font-size: 1.3em; }
.reveal h4 { font-size: 1.0em; }
.reveal p, .reveal li { line-height: 1.3; }

/* ===== Slides container: positioned center, scaled by JS ===== */
.reveal .slides {
  position: absolute;
  top: 50%;
  left: 50%;
  /* width, height, transform set by StellarSlides.layout() */
  overflow: visible;
}

/* ===== Individual slides: stacked, only .present is visible ===== */
.reveal .slides > section {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  display: none;
  box-sizing: border-box;
}
.reveal .slides > section.present {
  display: block;
  z-index: 1;
}

/* ===== Backgrounds layer ===== */
.sd-backgrounds {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
  overflow: hidden;
}
.sd-bg {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  display: none;
  background-color: var(--r-background-color, #0a0a0a);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.sd-bg.present {
  display: block;
}
/* Filtered background: dark overlay via pseudo-element */
.sd-bg[data-filtered]::after {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.5);
}

/* ===== Background videos ===== */
.sd-bg video {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  min-width: 100%; min-height: 100%;
  object-fit: cover;
}

/* ===== Fragments: hidden by default, shown when .visible ===== */
.reveal .slides section .fragment {
  opacity: 0;
  transition: opacity 0.15s ease;
}
.reveal .slides section .fragment.visible {
  opacity: 1;
}

/* ===== Slide number ===== */
.sd-slide-number {
  position: absolute;
  bottom: 8px; right: 12px;
  font-size: 12px;
  font-family: var(--r-main-font, Inter, sans-serif);
  color: rgba(255, 255, 255, 0.4);
  z-index: 10;
}

/* ===== Progress bar ===== */
.sd-progress {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  z-index: 10;
}
.sd-progress span {
  display: block;
  height: 100%;
  background: var(--accent, #0ea5e9);
  transition: width 0.3s ease;
  width: 0;
}

/* ===== Controls (embed mode) ===== */
.sd-controls {
  position: absolute;
  bottom: 24px;
  right: 16px;
  z-index: 20;
  display: flex;
  gap: 8px;
}
.sd-controls button {
  width: 32px; height: 32px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.6);
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}
.sd-controls button:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* ===== Reveal container base (replaces reveal.css + theme/black.css) ===== */
/* CSS variable DEFAULTS are in themes.css :root — NOT here.
   This only applies the variables to the .reveal element. */
.reveal {
  position: relative;
  overflow: hidden;
  font-family: var(--r-main-font, Inter, sans-serif);
  font-size: var(--r-main-font-size, 28px);
  color: var(--r-main-color, #e2e8f0);
  background-color: var(--r-background-color, #0a0a0a);
}