/* ==========================================================================
   Slide Viewer Theme -- 16:9 HTML Pages
   Core overlay, frame, controls
   ========================================================================== */

#slide-viewer-overlay {
  --slide-bg-deep: var(--color-bg-body, #0a0e17);
  --slide-bg-elevated: #1e293b;
  --slide-text-primary: #f1f5f9;
  --slide-text-secondary: #94a3b8;
  --slide-text-tertiary: #64748b;
  --slide-accent-blue: #60a5fa;
  --slide-accent-violet: #a78bfa;
  --slide-accent-green: #34d399;
  --slide-accent-amber: #fbbf24;
  --slide-glass-bg: rgba(17, 24, 39, 0.74);
  --slide-glass-border: rgba(148, 163, 184, 0.14);
  --slide-border-subtle: rgba(148, 163, 184, 0.08);
  --slide-border-medium: rgba(148, 163, 184, 0.18);
  --slide-font-heading: var(--kesson-font-serif-display);
  --slide-font-body: "Inter", "Noto Sans JP", system-ui, sans-serif;
  --slide-font-mono: var(--kesson-font-mono-ui);
  --slide-radius: 16px;
  --slide-radius-sm: 8px;

  position: fixed;
  inset: 0;
  z-index: 1500;
  display: none;
  background:
    radial-gradient(circle at 20% 20%, rgba(96, 165, 250, 0.08), transparent 28%),
    radial-gradient(circle at 80% 10%, rgba(167, 139, 250, 0.08), transparent 24%),
    rgba(5, 10, 19, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

#slide-viewer-overlay.visible {
  display: block;
}

#slide-viewer-overlay .slide-viewer-shell {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem 1.25rem 1.5rem;
}

#slide-viewer-overlay .slide-viewer-frame {
  position: relative;
  width: min(92vw, calc(84vh * 16 / 9));
  aspect-ratio: 16 / 9;
  border-radius: var(--slide-radius);
  border: 1px solid var(--slide-glass-border);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.03), rgba(255, 255, 255, 0.01)),
    rgba(9, 14, 25, 0.96);
  box-shadow: 0 24px 72px rgba(0, 0, 0, 0.42);
  overflow: hidden;
}

#slide-viewer-overlay .slide-viewer-stage {
  position: relative;
  width: 100%;
  height: 100%;
}

#slide-viewer-overlay .slide-viewer-page {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  color: var(--slide-text-primary);
  font-family: var(--slide-font-body);
  text-align: left;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(96, 165, 250, 0.06), transparent 45%),
    radial-gradient(ellipse at 78% 18%, rgba(167, 139, 250, 0.05), transparent 34%),
    var(--slide-bg-deep);
  transition: opacity 220ms ease, visibility 220ms ease;
}

#slide-viewer-overlay .slide-viewer-page.is-active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

#slide-viewer-overlay .slide-content {
  box-sizing: border-box;
  width: 100%;
  height: 100%;
  padding: 2rem 2.5rem;
  overflow: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(148, 163, 184, 0.45) transparent;
}

#slide-viewer-overlay .slide-content::-webkit-scrollbar {
  width: 10px;
}

#slide-viewer-overlay .slide-content::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.35);
  border-radius: 999px;
}

/* -- Close button -- */

.slide-viewer-close {
  position: fixed;
  top: 16px;
  right: 24px;
  z-index: 1510;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--slide-glass-border);
  border-radius: 999px;
  background: var(--slide-glass-bg);
  color: var(--slide-text-secondary);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: all 0.25s ease;
}

.slide-viewer-close:hover {
  color: var(--slide-text-primary);
  background: rgba(96, 165, 250, 0.12);
  border-color: rgba(96, 165, 250, 0.25);
}

/* -- Fullscreen button -- */

.slide-viewer-fullscreen {
  position: fixed;
  right: 24px;
  bottom: 16px;
  z-index: 1510;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow:
    0 10px 24px rgba(0, 0, 0, 0.18),
    0 0 20px rgba(120, 155, 220, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.95);
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.slide-viewer-fullscreen:hover,
.slide-viewer-fullscreen:focus-visible {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.28);
  box-shadow:
    0 14px 34px rgba(0, 0, 0, 0.22),
    0 0 26px rgba(132, 168, 232, 0.18),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.slide-viewer-close:focus-visible,
.slide-viewer-fullscreen:focus-visible {
  outline: 2px solid var(--kesson-focus-ring, rgba(100, 150, 255, 0.86));
  outline-offset: 2px;
}

/* -- Fullscreen API overrides -- */

#slide-viewer-overlay:fullscreen .slide-viewer-shell,
#slide-viewer-overlay:-webkit-full-screen .slide-viewer-shell {
  padding: 0.75rem;
}

#slide-viewer-overlay:fullscreen .slide-viewer-frame,
#slide-viewer-overlay:-webkit-full-screen .slide-viewer-frame {
  width: min(100vw, calc(100vh * 16 / 9));
  height: min(100vh, calc(100vw * 9 / 16));
  max-width: 100vw;
  max-height: 100vh;
  border-radius: 0;
}

#slide-viewer-overlay:fullscreen .slide-viewer-toolbar,
#slide-viewer-overlay:-webkit-full-screen .slide-viewer-toolbar {
  width: min(100vw, calc(100vh * 16 / 9));
}

/* -- Toolbar -- */

#slide-viewer-overlay .slide-viewer-toolbar {
  width: min(92vw, calc(84vh * 16 / 9));
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.75rem;
}

#slide-viewer-overlay .slide-viewer-nav {
  min-width: 72px;
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--slide-glass-border);
  border-radius: 999px;
  background: var(--slide-glass-bg);
  color: var(--slide-text-primary);
  font-family: var(--slide-font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.25s ease;
}

#slide-viewer-overlay .slide-viewer-nav:hover:not(:disabled) {
  background: rgba(96, 165, 250, 0.12);
  border-color: rgba(96, 165, 250, 0.28);
}

#slide-viewer-overlay .slide-viewer-nav:disabled {
  opacity: 0.45;
  cursor: default;
}

#slide-viewer-overlay .slide-viewer-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 1rem;
  border: 1px solid var(--slide-glass-border);
  border-radius: 999px;
  background: var(--slide-glass-bg);
  color: var(--slide-text-secondary);
}

#slide-viewer-overlay .slide-viewer-title {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-family: var(--slide-font-heading);
  font-size: 0.92rem;
  color: var(--slide-text-primary);
  letter-spacing: 0.03em;
}

#slide-viewer-overlay .slide-viewer-count {
  flex: 0 0 auto;
  font-family: var(--slide-font-mono);
  font-size: 0.76rem;
  color: var(--slide-text-tertiary);
}

/* ==========================================================================
   Rich Slide Viewer (iframe mode)
   ========================================================================== */

/* When toolbar is hidden in rich mode, expand frame to fill the space */
#slide-viewer-overlay .slide-viewer-stage > iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: none;
  border-radius: inherit;
  background: var(--slide-bg-deep);
}