:root{
  --menu-panel: var(--card-background, #ffffff);
  --menu-border: var(--border-color, rgba(0,0,0,0.12));
  --menu-text: var(--text-color, #0f172a);
  --menu-muted: var(--subtext-color, rgba(15, 23, 42, 0.72));
  --menu-soft: rgba(15, 23, 42, 0.05);

  --menu-radius: 16px;
  --menu-radius-sm: 12px;

  --menu-shadow: var(--box-shadow, 0 10px 30px rgba(0,0,0,0.08));
  --menu-shadow-sm: 0 4px 12px rgba(0,0,0,0.08);
}

body.dark-mode{
  --menu-panel: rgba(16, 24, 42, 0.94);
  --menu-border: rgba(255,255,255,0.12);
  --menu-text: rgba(255,255,255,0.92);
  --menu-muted: rgba(255,255,255,0.72);
  --menu-soft: rgba(255,255,255,0.08);
  --menu-shadow: 0 10px 30px rgba(0,0,0,0.35);
  --menu-shadow-sm: 0 6px 18px rgba(0,0,0,0.28);
}

.sr-only{
  position:absolute!important;
  width:1px!important;
  height:1px!important;
  padding:0!important;
  margin:-1px!important;
  overflow:hidden!important;
  clip:rect(0,0,0,0)!important;
  white-space:nowrap!important;
  border:0!important;
}

/* --- Container --- */
.demo-library{
  max-width: 1220px;
  margin: 0 auto;
  padding: 18px 16px 42px;
  color: var(--menu-text);
}

/* --- Hero --- */
.library-hero{
  display: flex;
  gap: 16px;
  align-items: flex-start;
  justify-content: space-between;
  padding: 16px 16px;
  border: 1px solid var(--menu-border);
  border-radius: var(--menu-radius);
  background: linear-gradient(180deg, var(--menu-panel), rgba(255,255,255,0.94));
  box-shadow: var(--menu-shadow-sm);
}
body.dark-mode .library-hero{
  background: linear-gradient(180deg, var(--menu-panel), rgba(10, 15, 28, 0.92));
}

.library-eyebrow{
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.8);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--menu-muted);
}
body.dark-mode .library-eyebrow{ background: rgba(255,255,255,0.08); }

.library-hero h1{
  margin: 10px 0 8px;
  font-size: 26px;
  line-height: 1.15;
}

.library-hero p{
  margin: 0;
  max-width: 72ch;
  color: var(--menu-muted);
  line-height: 1.6;
}

.library-hero__meta{
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
  margin-top: 2px;
}

.meta-pill{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.8);
  color: var(--menu-muted);
  font-size: 12px;
  font-weight: 700;
}
body.dark-mode .meta-pill{ background: rgba(255,255,255,0.08); }

.meta-pill kbd{
  padding: 2px 7px;
  border-radius: 8px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
  color: var(--menu-text);
  font-weight: 900;
  font-size: 12px;
}
body.dark-mode .meta-pill kbd{ background: rgba(255,255,255,0.14); }

/* --- Top controls --- */
.library-controls{
  position: sticky;
  top: 0;
  z-index: 20;

  margin-top: 12px;
  border: 1px solid var(--menu-border);
  border-radius: var(--menu-radius);
  background: var(--menu-panel);
  box-shadow: var(--menu-shadow-sm);
}

.controls-row{
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
}

.controls-row--primary{
  border-bottom: 1px solid var(--menu-border);
}

@media (max-width: 900px){
  .controls-row--primary{
    flex-wrap: wrap;
    justify-content: flex-start;
  }
  .results{ margin-left: auto; }
}

/* --- Smaller search --- */
.searchbox{
  flex: 1 1 420px;
  max-width: 560px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
}
body.dark-mode .searchbox{ background: rgba(255,255,255,0.08); }

.searchbox i{ color: var(--menu-muted); font-size: 14px; }

.searchbox input{
  width: 100%;
  border: none;
  outline: none;
  background: transparent;
  color: var(--menu-text);
  font-size: 14px;
}
.searchbox input::placeholder{ color: rgba(0,0,0,0.45); }
body.dark-mode .searchbox input::placeholder{ color: rgba(255,255,255,0.45); }

.icon-btn{
  border: none;
  background: transparent;
  padding: 5px 7px;
  border-radius: 10px;
  cursor: pointer;
  color: var(--menu-muted);
}
.icon-btn:hover{
  background: var(--menu-soft);
  color: var(--menu-text);
}

/* Results label */
.results{
  display: flex;
  gap: 8px;
  align-items: baseline;
  justify-content: flex-end;
  white-space: nowrap;
  color: var(--menu-muted);
  flex: 0 0 auto;
}
.results-strong{
  color: var(--menu-text);
  font-weight: 900;
}
.results-count{
  padding-left: 8px;
  border-left: 1px solid var(--menu-border);
}

.controls-row--secondary{
  padding-top: 9px;
}

.lecture-pills{
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.lecture-pill{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
  color: var(--menu-text);
  font-family: 'Poppins', 'Roboto', sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.25;
  cursor: pointer;
  flex: 0 0 auto;
}
body.dark-mode .lecture-pill{ background: rgba(255,255,255,0.08); }

.lecture-pill:hover{ background: var(--menu-soft); }

.lecture-pill.is-active{
  border-color: rgba(0,0,0,0.22);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.12);
}
body.dark-mode .lecture-pill.is-active{
  border-color: rgba(255,255,255,0.22);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.18);
}

.pill-dot{
  width: 9px;
  height: 9px;
  border-radius: 999px;
  background: var(--pill-accent, rgba(0,0,0,0.25));
  box-shadow: 0 0 0 3px var(--pill-accent-soft, rgba(0,0,0,0.08));
}

.pill-count{
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
  color: var(--menu-muted);
  font-family: 'Poppins', 'Roboto', sans-serif;
  font-size: 12px;
  font-weight: 600;
}
body.dark-mode .pill-count{ background: rgba(255,255,255,0.14); }

/* --- Empty state --- */
.empty-state{
  display: none;
  margin: 12px 0 0;
  padding: 12px 14px;
  border: 1px dashed var(--menu-border);
  border-radius: var(--menu-radius-sm);
  color: var(--menu-muted);
  background: rgba(255,255,255,0.85);
}
body.dark-mode .empty-state{ background: rgba(255,255,255,0.08); }
.empty-state.is-visible{ display: flex; gap: 10px; align-items: center; }

/* --- Main list --- */
.library-main{
  margin-top: 14px;
}

/* Lecture sections */
.lecture-group{
  margin-top: 18px;
  padding: 14px 14px 4px;
  border-radius: var(--menu-radius);
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.92);
}
body.dark-mode .lecture-group{ background: rgba(255,255,255,0.06); }

.lecture-group.is-hidden{ display: none; }

.lecture-head{
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 2px 2px 10px;
  border-bottom: 1px solid var(--menu-border);
}

.lecture-head h2{
  margin: 0;
  font-size: 18px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.lecture-accent{
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: var(--lecture-accent, rgba(0,0,0,0.25));
  box-shadow: 0 0 0 4px var(--lecture-accent-soft, rgba(0,0,0,0.08));
}

.lecture-count{
  color: var(--menu-muted);
  font-weight: 800;
  font-size: 13px;
}

/* Section blocks */
.section-block{
  margin-top: 10px;
  padding-top: 10px;
}
.section-block.is-hidden{ display: none; }

.section-head{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}
.section-head h3{
  margin: 0;
  font-size: 15px;
  color: var(--menu-text);
}
.section-count{
  color: var(--menu-muted);
  font-weight: 900;
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
}
body.dark-mode .section-count{ background: rgba(255,255,255,0.14); }

/* Always grid layout */
.demo-grid{
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}
@media (max-width: 1100px){
  .demo-grid{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 720px){
  .demo-grid{ grid-template-columns: 1fr; }
}

/* Cards with lecture color accent */
.demo-card{
  border-radius: var(--menu-radius);
  border: 1px solid var(--menu-border);
  border-left: 5px solid var(--lecture-accent, rgba(0,0,0,0.22));
  background: rgba(255,255,255,0.98);
  box-shadow: var(--menu-shadow-sm);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 150px;
}
body.dark-mode .demo-card{ background: rgba(255,255,255,0.08); }

.demo-card:hover{
  transform: translateY(-1px);
  box-shadow: var(--menu-shadow);
}

.demo-card.is-hidden{ display: none; }

.demo-main{
  display: flex;
  gap: 12px;
  padding: 14px 14px 10px;
}

.demo-icon{
  width: 44px;
  height: 44px;
  border-radius: 14px;
  border: 1px solid var(--menu-border);
  background: var(--lecture-accent-softer, rgba(0,0,0,0.06));
  display: grid;
  place-items: center;
  color: var(--lecture-accent, #0B5ED7);
  flex: 0 0 auto;
}

.demo-text{ min-width: 0; }
.demo-title{
  margin: 8px 0 6px;
  font-size: 15px;
  line-height: 1.25;
}
.demo-desc{
  margin: 0;
  color: var(--menu-muted);
  font-size: 13px;
  line-height: 1.45;
}

.demo-tags{
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.tag{
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid var(--menu-border);
  background: rgba(255,255,255,0.85);
  color: var(--menu-muted);
  font-size: 12px;
  font-weight: 800;
}
body.dark-mode .tag{ background: rgba(255,255,255,0.14); }

/* Launch row */
.demo-launch{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 14px 12px;
  border-top: 1px solid var(--menu-border);
  color: var(--menu-text);
  text-decoration: none;
  font-weight: 900;
  font-size: 13px;
}
.demo-launch i{ color: var(--menu-muted); }
.demo-launch:hover{
  background: var(--menu-soft);
}

.lecture-group{ scroll-margin-top: 120px; }