/* =========================================================================
   Persistent site header and session navigation for lecture decks.
   Sits above reveal.js and matches jameswil.com.
   ========================================================================= */

:root {
  --jw-bar-h: 38px;
  --jw-bg: #0a0a0a;
  --jw-fg: #f2f2f2;
  --jw-muted: #8e8e8e;
  --jw-line: #262626;
}

/* Reserve the bar's height so slide content never sits underneath it. */
html body .reveal-viewport {
  padding-top: var(--jw-bar-h);
  box-sizing: border-box;
}

.jw-bar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--jw-bar-h);
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-inline: 0.75rem;
  background: var(--jw-bg);
  color: var(--jw-fg);
  border-bottom: 1px solid var(--jw-line);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Inter, Roboto,
    'Helvetica Neue', Arial, sans-serif;
  font-size: 12px;
  line-height: 1;
  user-select: none;
}

.jw-bar a { text-decoration: none; color: inherit; }

.jw-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  flex: none;
  transition: opacity 160ms ease;
}
.jw-brand:hover { opacity: 0.75; }
.jw-mark {
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  background: var(--jw-fg);
  color: var(--jw-bg);
  font-size: 8px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.jw-brand-name { font-weight: 500; letter-spacing: -0.01em; }

.jw-context {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-width: 0;
  margin-right: auto;
  color: var(--jw-muted);
  font-family: ui-monospace, 'SF Mono', 'Cascadia Mono', Menlo, Consolas, monospace;
  font-size: 11px;
}
.jw-course { color: var(--jw-fg); }
.jw-course:hover { text-decoration: underline; text-underline-offset: 3px; }
.jw-sep { opacity: 0.4; }
.jw-session {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.jw-count {
  flex: none;
  padding: 2px 6px;
  border: 1px solid var(--jw-line);
  color: var(--jw-muted);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.jw-nav { display: flex; gap: 0.4rem; flex: none; }
.jw-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 5px 10px;
  border: 1px solid var(--jw-line);
  color: var(--jw-muted);
  font-size: 11px;
  letter-spacing: 0.04em;
  transition: color 160ms ease, border-color 160ms ease;
}
.jw-nav-btn:hover { color: var(--jw-fg); border-color: var(--jw-fg); }
.jw-nav-btn.is-off { opacity: 0.3; }

/* Reveal draws its own controls bottom right; nothing to avoid up here, but
   the progress bar sits at the top in some themes. Keep it below the bar. */
.reveal .progress { z-index: 99; }

/* Presenting should be uninterrupted: the bar hides in fullscreen and can be
   toggled with the H key. */
.jw-bar.is-hidden { display: none; }
html.jw-bare .reveal-viewport { padding-top: 0; }

@media (max-width: 40rem) {
  .jw-brand-name,
  .jw-count { display: none; }
  .jw-context { font-size: 10px; }
  .jw-nav-btn { padding: 5px 8px; }
}

@media print {
  .jw-bar { display: none; }
  html body .reveal-viewport { padding-top: 0; }
}