/* ==========================================================================
   Vibe Design Reference — Shared Chrome (navbar, prompt-card, pager, footer)
   ========================================================================== */

/* ---------------------- Navbar ---------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: transparent;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease), backdrop-filter 0.3s var(--ease);
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(14, 14, 18, 0.72);
  backdrop-filter: saturate(150%) blur(14px);
  -webkit-backdrop-filter: saturate(150%) blur(14px);
  border-bottom-color: var(--border);
}
[data-theme="light"] .nav.scrolled {
  background: rgba(246, 242, 233, 0.78);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 16px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  position: relative;
}
.nav-logo {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text);
}
.nav-logo .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  display: inline-block;
  box-shadow: 0 0 12px var(--accent);
}
.nav-logo small {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 400;
}

.nav-trail {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  /* center in the bar regardless of logo/actions widths */
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  white-space: nowrap;
}
.nav-trail a { transition: color 0.2s; }
.nav-trail a:hover { color: var(--text); }
.nav-trail span.sep { color: var(--text-dim); }
.nav-trail .here { color: var(--accent); }

.nav-actions { display: flex; align-items: center; gap: 8px; }

/* GitHub / YouTube icon buttons */
.nav-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.2s;
}
.nav-icon-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
  transform: translateY(-2px);
}
.nav-icon-btn svg { width: 17px; height: 17px; }

/* YouTube red tint on hover */
.nav-icon-btn.yt:hover { color: #FF4444; border-color: rgba(255,68,68,0.45); }

/* divider pip between icon group and theme toggle */
.nav-actions .nav-divider {
  width: 1px;
  height: 22px;
  background: var(--border);
  margin: 0 2px;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  color: var(--text);
  transition: transform 0.2s, border-color 0.2s, background 0.2s;
}
.theme-toggle:hover { border-color: var(--border-strong); transform: rotate(-12deg); }
.theme-toggle svg { width: 16px; height: 16px; }
.theme-toggle .sun { display: none; }
.theme-toggle .moon { display: block; }
[data-theme="light"] .theme-toggle .sun { display: block; }
[data-theme="light"] .theme-toggle .moon { display: none; }

@media (max-width: 900px) {
  .nav-trail { display: none; }
}
@media (max-width: 560px) {
  .nav-icon-btn { display: none; }
  .nav-actions .nav-divider { display: none; }
}

/* ---------------------- Prompt card ---------------------- */
.prompt-card {
  background: #0A0A0E;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
}
[data-theme="light"] .prompt-card {
  background: #FAFAF7;
}
.prompt-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}
.prompt-head .lang {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-soft);
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.copy-btn:hover { color: var(--text); border-color: var(--border-strong); }
.copy-btn.copied { color: var(--accent); border-color: var(--accent); }
.copy-btn svg { width: 14px; height: 14px; }
.prompt-body {
  margin: 0;
  padding: 22px 26px;
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--text-soft);
  white-space: pre-wrap;
  word-break: break-word;
  overflow-x: auto;
  max-height: 380px;
  scrollbar-width: thin;
}
.prompt-body code { font-family: inherit; }

/* ---------------------- Pager ---------------------- */
.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  padding-top: 48px;
  border-top: 1px solid var(--border);
}
.pager a {
  display: block;
  padding: 22px 26px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.2s, transform 0.2s, background 0.2s;
}
.pager a:hover { border-color: var(--accent); transform: translateY(-2px); }
.pager .label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
}
.pager .title {
  font-family: var(--font-display);
  font-size: 20px;
  color: var(--text);
  letter-spacing: -0.01em;
}
.pager .next { text-align: right; }
@media (max-width: 600px) {
  .pager { grid-template-columns: 1fr; }
  .pager .next { text-align: left; }
}

/* ---------------------- Footer ---------------------- */
.foot {
  padding: 64px 0 48px;
  border-top: 1px solid var(--border);
  margin-top: 80px;
}
.foot-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.foot-inner a { color: var(--text-soft); border-bottom: 1px solid transparent; }
.foot-inner a:hover { color: var(--accent); border-color: var(--accent); }

/* ---------------------- Toast ---------------------- */
.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--accent);
  color: #1A1300;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 14px 22px;
  border-radius: 999px;
  box-shadow: var(--shadow-strong);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s var(--ease), transform 0.3s var(--ease-out-back);
  z-index: 1000;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------------------- Demo Fullscreen Toggle ---------------------- */
/* A floating "Fullscreen" button injected into every .demo by global.js */
.demo-fs {
  position: absolute;
  top: 16px;
  left: 16px;
  z-index: 100;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  background: rgba(0, 0, 0, 0.6);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  cursor: pointer;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease), transform 0.15s var(--ease);
}
.demo-fs:hover {
  background: var(--accent);
  color: #1A1300;
  border-color: var(--accent);
  transform: translateY(-1px);
}
.demo-fs:active { transform: translateY(0); }
.demo-fs svg { width: 13px; height: 13px; flex-shrink: 0; }
.demo-fs .text { line-height: 1; }

/* Fullscreen state — the .demo element is moved to body and takes over the viewport */
.demo.is-fullscreen {
  position: fixed !important;
  top: 0 !important;
  left: 0 !important;
  right: 0 !important;
  bottom: 0 !important;
  inset: 0 !important;
  z-index: 9999 !important;
  width: 100vw !important;
  height: 100vh !important;
  max-width: 100vw !important;
  min-height: 100vh !important;
  margin: 0 !important;
  border: 0 !important;
  border-radius: 0 !important;
  box-shadow: 0 0 0 9999px rgba(0,0,0,0.5);
  animation: demo-fs-in 0.28s var(--ease-out-back);
}
@keyframes demo-fs-in {
  from { transform: scale(0.96); opacity: 0.7; }
  to { transform: scale(1); opacity: 1; }
}
.demo.is-fullscreen .demo-fs {
  top: 24px;
  left: 24px;
  background: var(--accent);
  color: #1A1300;
  border-color: var(--accent);
  box-shadow: 0 4px 14px rgba(0,0,0,0.3);
}
.demo.is-fullscreen .demo-fs:hover {
  background: var(--accent-soft);
}
.demo.is-fullscreen .demo-badge {
  top: 24px !important;
  right: 24px !important;
}
/* When a demo is fullscreen, lock the underlying body scroll */
body.demo-fullscreen-open {
  overflow: hidden;
}
/* Hide the grain overlay and other fixed chrome behind the fullscreen demo */
body.demo-fullscreen-open .grain,
body.demo-fullscreen-open .nav,
body.demo-fullscreen-open .toast {
  z-index: 1;
}

/* Placeholder left in the original DOM position while the demo is fullscreen */
.demo-placeholder {
  width: 100%;
  min-height: 380px;
  border: 2px dashed var(--border-strong);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  display: grid;
  place-items: center;
  text-align: center;
  padding: 32px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  line-height: 1.8;
}
.demo-placeholder .ic {
  display: block;
  font-size: 28px;
  color: var(--accent);
  margin-bottom: 14px;
}
.demo-placeholder b { color: var(--text); font-weight: 600; }
.demo-placeholder kbd {
  display: inline-block;
  padding: 2px 7px;
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text);
  margin: 0 2px;
}
.demo-placeholder .return-btn {
  margin-top: 18px;
  padding: 10px 18px;
  background: var(--accent);
  color: #1A1300;
  border: 0;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s var(--ease);
}
.demo-placeholder .return-btn:hover { background: var(--accent-soft); }

/* Subtle floating Esc-hint pill at the bottom of fullscreen */
.demo-fs-hint {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10000;
  display: none;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  border-radius: 999px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.1);
  pointer-events: none;
  animation: demo-fs-hint-fade 4s ease-out forwards;
}
body.demo-fullscreen-open .demo-fs-hint { display: inline-flex; }
.demo-fs-hint kbd {
  padding: 2px 8px;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 4px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
}
@keyframes demo-fs-hint-fade {
  0%, 70% { opacity: 1; transform: translateX(-50%) translateY(0); }
  100% { opacity: 0; transform: translateX(-50%) translateY(10px); }
}

/* ---------------------- Demo-page section blocks ---------------------- */
.entry-hero {
  padding: 80px 0 40px;
}
.entry-hero .num-badge { margin-bottom: 24px; }
.entry-hero .title {
  font-family: var(--font-display);
  font-size: clamp(44px, 7vw, 88px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 0.98;
  color: var(--text);
  margin-bottom: 16px;
}
.entry-hero .title em { font-style: italic; font-weight: 300; color: var(--accent); }
.entry-hero .tagline {
  font-size: 19px;
  color: var(--text-soft);
  max-width: 60ch;
  line-height: 1.55;
}

.entry-section { padding: 48px 0; }
.entry-section h2 {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
  display: flex;
  align-items: baseline;
  gap: 14px;
}
.entry-section h2::before {
  content: "";
  display: inline-block;
  width: 28px;
  height: 1px;
  background: var(--accent);
}
.entry-section .body p {
  font-size: 17px;
  line-height: 1.7;
  color: var(--text-soft);
  margin-bottom: 14px;
}
.entry-section .body code {
  font-family: var(--font-mono);
  font-size: 13.5px;
  background: var(--bg-elev);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--accent-soft);
}

/* Demo full-bleed shell */
.demo-shell {
  margin: 16px 0 0;
}
.demo-shell .demo {
  min-height: 480px;
  display: block;
}

/* Section number labels on category index */
.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 40px;
}
.cat-grid .card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 28px;
  position: relative;
  overflow: hidden;
}
.cat-grid .card:hover { transform: translateY(-3px); }
.cat-grid .card .num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
}
.cat-grid .card .name {
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text);
  line-height: 1.1;
}
.cat-grid .card .tease {
  color: var(--text-muted);
  font-size: 14.5px;
  line-height: 1.55;
  flex-grow: 1;
}
.cat-grid .card .view {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-soft);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
  transition: color 0.2s;
}
.cat-grid .card:hover .view { color: var(--accent); }
.cat-grid .card .view::after {
  content: "→";
  transition: transform 0.2s;
}
.cat-grid .card:hover .view::after { transform: translateX(3px); }

/* Category hero (chapter intro pages) */
.cat-hero {
  padding: 80px 0 28px;
}
.cat-hero .ch-num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 22px;
}
.cat-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(52px, 8vw, 96px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 0.98;
}
.cat-hero h1 em { font-style: italic; font-weight: 300; color: var(--accent); }
.cat-hero .intro {
  font-size: 19px;
  line-height: 1.6;
  color: var(--text-soft);
  max-width: 65ch;
  margin-top: 22px;
}