.brain-library {
  --brain-ink:var(--color-charcoal,#3a322c);
  --brain-muted:#6e756d;
  --brain-olive:var(--color-olive,#7a8b5e);
  --brain-paper:var(--color-alabaster,#f7f5ef);
  --brain-line:rgba(58,50,44,.12);
  max-width:1500px;
  margin:0 auto 3rem;
  color:var(--brain-ink);
  background:rgba(255,255,255,.7);
  border:1px solid var(--brain-line);
  border-radius:1.4rem;
  overflow:hidden;
  box-shadow:0 20px 55px rgba(58,50,44,.08);
}

.brain-hero {
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(240px,.65fr);
  gap:2rem;
  padding:clamp(2rem,5vw,4rem);
  background:linear-gradient(135deg,#3a322c 0%,#545b45 55%,#7a8b5e 100%);
  color:#fff;
}

.brain-eyebrow {
  margin:0 0 .55rem;
  text-transform:uppercase;
  letter-spacing:.14em;
  font-size:.7rem;
  font-weight:600;
  opacity:.76;
}

.brain-hero h1 {
  font-family:Lora,serif;
  font-size:clamp(2.2rem,5vw,4.5rem);
  line-height:1;
  margin:0 0 1rem;
  font-weight:500;
}

.brain-intro {
  max-width:850px;
  margin:0;
  line-height:1.7;
  color:rgba(255,255,255,.84);
}

.brain-north-star {
  align-self:end;
  margin:0;
  padding:0 0 0 1.25rem;
  border-left:2px solid rgba(255,255,255,.55);
  font-family:Lora,serif;
  font-size:clamp(1rem,2vw,1.25rem);
  line-height:1.55;
  color:#fff;
}

.brain-toolbar {
  position:sticky;
  top:0;
  z-index:12;
  display:grid;
  grid-template-columns:minmax(280px,1fr) 220px 190px auto;
  gap:1rem;
  padding:1rem 1.25rem;
  background:rgba(247,245,239,.96);
  backdrop-filter:blur(15px);
  border-bottom:1px solid var(--brain-line);
}

.brain-search-wrap {
  display:flex;
  align-items:center;
  gap:.6rem;
  padding:0 .85rem;
  background:#fff;
  border:1px solid var(--brain-line);
  border-radius:.75rem;
}

.brain-search-wrap input {
  width:100%;
  min-height:44px;
  border:0;
  outline:0;
  background:transparent;
  font:inherit;
  color:inherit;
}

.brain-select-wrap {
  display:grid;
  gap:.2rem;
  min-width:0;
}

.brain-select-wrap span {
  font-size:.65rem;
  text-transform:uppercase;
  letter-spacing:.08em;
  color:var(--brain-muted);
}

.brain-select-wrap select {
  width:100%;
  min-height:44px;
  padding:.5rem .7rem;
  border:1px solid var(--brain-line);
  border-radius:.75rem;
  background:#fff;
  color:inherit;
  font:inherit;
}

.brain-tool-btn,.brain-primary-btn {
  border:0;
  border-radius:.75rem;
  padding:.7rem 1rem;
  font:inherit;
  cursor:pointer;
}

.brain-tool-btn {
  align-self:end;
  min-height:44px;
  background:#fff;
  border:1px solid var(--brain-line);
  color:inherit;
}

.brain-primary-btn {
  background:var(--brain-olive);
  color:#fff;
}

.brain-mobile-tools {
  display:none;
}

.brain-layout {
  display:grid;
  grid-template-columns:300px minmax(0,1fr);
  min-height:720px;
}

.brain-toc {
  padding:1.35rem;
  border-right:1px solid var(--brain-line);
  background:rgba(247,245,239,.75);
}

.brain-toc-heading {
  display:flex;
  justify-content:space-between;
  align-items:flex-start;
}

.brain-toc h2 {
  font-family:Lora,serif;
  font-size:1.4rem;
  margin:0 0 1rem;
}

.brain-toc-heading button {
  display:none;
}

.brain-toc nav {
  display:grid;
  gap:.38rem;
}

.brain-toc button[data-brain-file] {
  width:100%;
  padding:.75rem;
  border:0;
  border-radius:.7rem;
  background:transparent;
  color:inherit;
  text-align:left;
  cursor:pointer;
  font:inherit;
}

.brain-toc button[data-brain-file]:hover,.brain-toc button.active {
  background:rgba(122,139,94,.13);
}

.brain-toc button strong {
  display:block;
  font-size:.86rem;
  font-weight:500;
}

.brain-toc button small {
  display:block;
  margin-top:.18rem;
  color:var(--brain-muted);
  font-size:.68rem;
}

.brain-recent {
  margin-top:1.5rem;
  padding-top:1.2rem;
  border-top:1px solid var(--brain-line);
}

.brain-recent h3 {
  font-size:.78rem;
  text-transform:uppercase;
  letter-spacing:.08em;
}

.brain-recent button {
  display:block;
  width:100%;
  border:0;
  background:none;
  text-align:left;
  padding:.45rem 0;
  color:var(--brain-olive);
  cursor:pointer;
}

.brain-muted {
  color:var(--brain-muted);
  font-size:.8rem;
}

.brain-content {
  padding:clamp(1.25rem,3vw,2.2rem);
  min-width:0;
}

.brain-overview-head {
  display:flex;
  justify-content:space-between;
  gap:2rem;
  align-items:flex-end;
  margin-bottom:1.35rem;
}

.brain-overview-head h2,.brain-detail h2 {
  font-family:Lora,serif;
  font-size:clamp(1.8rem,3vw,2.7rem);
  font-weight:500;
  margin:.15rem 0 .5rem;
}

.brain-overview-head p {
  max-width:780px;
  margin:0;
  color:var(--brain-muted);
  line-height:1.6;
}

.brain-metrics {
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:.75rem;
  margin-bottom:1rem;
}

.brain-metrics article {
  padding:1rem;
  background:#fff;
  border:1px solid var(--brain-line);
  border-radius:.85rem;
}

.brain-metrics strong {
  display:block;
  font-family:Lora,serif;
  font-size:1.7rem;
}

.brain-metrics span {
  font-size:.75rem;
  color:var(--brain-muted);
}

.brain-principles {
  display:flex;
  flex-wrap:wrap;
  gap:.45rem;
  margin:1rem 0 1.5rem;
}

.brain-principles span,.brain-tag {
  padding:.42rem .65rem;
  border-radius:999px;
  background:rgba(122,139,94,.13);
  font-size:.72rem;
}

.brain-cards {
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:.85rem;
}

.brain-card {
  padding:1.15rem;
  border:1px solid var(--brain-line);
  border-radius:1rem;
  background:#fff;
  cursor:pointer;
  transition:transform .2s,box-shadow .2s;
}

.brain-card:hover {
  transform:translateY(-2px);
  box-shadow:0 12px 28px rgba(58,50,44,.08);
}

.brain-card h3 {
  font-family:Lora,serif;
  margin:.35rem 0;
  font-size:1.2rem;
}

.brain-card p {
  margin:.35rem 0 .8rem;
  color:var(--brain-muted);
  line-height:1.5;
  font-size:.85rem;
}

.brain-card-layer {
  font-size:.65rem;
  text-transform:uppercase;
  letter-spacing:.1em;
  color:var(--brain-olive);
}

.brain-detail-head {
  display:flex;
  justify-content:space-between;
  gap:1rem;
  align-items:flex-start;
}

.brain-back {
  border:1px solid var(--brain-line);
  background:#fff;
  border-radius:.7rem;
  padding:.6rem .8rem;
  cursor:pointer;
}

.brain-insights {
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:.8rem;
  margin:1.2rem 0;
}

.brain-insight {
  padding:1rem;
  border:1px solid var(--brain-line);
  border-radius:.85rem;
  background:#fff;
}

.brain-insight h3 {
  font-size:.8rem;
  text-transform:uppercase;
  letter-spacing:.07em;
  margin:0 0 .4rem;
}

.brain-insight p {
  margin:0;
  color:var(--brain-muted);
  line-height:1.55;
}

.brain-insight ul {
  margin:.25rem 0 0;
  padding-left:1.2rem;
  color:var(--brain-muted);
  line-height:1.6;
}

.brain-view-tabs {
  display:inline-flex;
  flex-wrap:wrap;
  gap:.4rem;
  padding:.35rem;
  margin:0 0 .6rem;
  border:1px solid var(--brain-line);
  border-radius:999px;
  background:rgba(255,255,255,.72);
}

.brain-view-tab {
  border:0;
  border-radius:999px;
  padding:.72rem 1rem;
  background:transparent;
  color:var(--brain-ink);
  font:500 .84rem/1 Inter,sans-serif;
  cursor:pointer;
}

.brain-view-tab.active {
  background:var(--brain-olive);
  color:#fff;
  box-shadow:0 5px 14px rgba(58,50,44,.14);
}

.brain-authority-note {
  margin:0 0 1.25rem;
  color:#6f675f;
  font-size:.8rem;
}

.brain-function-doc {
  max-width:850px;
  margin:0 auto;
  padding:clamp(1.25rem,3vw,3.5rem);
  border:1px solid var(--brain-line);
  border-radius:1.15rem;
  background:#fff;
  box-shadow:0 16px 42px rgba(58,50,44,.08);
  line-height:1.72;
}

.brain-function-doc h3 {
  margin:2rem 0 .7rem;
  padding-top:.25rem;
  border-top:1px solid rgba(58,50,44,.08);
  font-family:Lora,serif;
  font-size:1.35rem;
}

.brain-function-doc blockquote {
  margin:1.2rem 0;
  padding:1rem 1.15rem;
  border-left:4px solid var(--brain-olive);
  border-radius:0 .75rem .75rem 0;
  background:rgba(122,139,94,.08);
  font-family:Lora,serif;
}

.brain-function-doc li+li {
  margin-top:.42rem;
}

.brain-reader-tools,.brain-source-tools {
  display:flex;
  justify-content:flex-end;
  flex-wrap:wrap;
  gap:.45rem;
  margin:0 0 .75rem;
  padding:.55rem;
  border:1px solid var(--brain-line);
  border-radius:.9rem;
  background:rgba(248,246,241,.94);
}

.brain-reader-tools button,.brain-source-tools button {
  border:1px solid var(--brain-line);
  border-radius:.65rem;
  padding:.55rem .75rem;
  background:#fff;
  color:var(--brain-ink);
  font:500 .78rem/1 Inter,sans-serif;
  cursor:pointer;
}

.brain-source {
  white-space:pre-wrap;
  overflow:auto;
  max-height:600px;
  padding:1.2rem;
  border-radius:.9rem;
  background:#272d27;
  color:#eef2eb;
  font:12.5px/1.55 ui-monospace,SFMono-Regular,Menlo,monospace;
}

.brain-empty {
  text-align:center;
  padding:4rem 1rem;
}

.brain-footer {
  padding:1rem 1.35rem;
  border-top:1px solid var(--brain-line);
  color:var(--brain-muted);
  font-size:.78rem;
}

@media(max-width:1000px) {
  .brain-toolbar {
    grid-template-columns:minmax(0,1fr) minmax(0,1fr) auto;
  }
  .brain-search-wrap {
    grid-column:1/-1;
  }
  .brain-select-wrap select {
    width:100%;
  }
  .brain-layout {
    grid-template-columns:1fr;
  }
  .brain-mobile-tools {
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:.8rem 1rem;
    border-bottom:1px solid var(--brain-line);
  }
  .brain-mobile-tools button {
    border:0;
    background:var(--brain-olive);
    color:#fff;
    border-radius:.65rem;
    padding:.55rem .75rem;
  }
  .brain-toc {
    position:fixed;
    z-index:100;
    inset:0 auto 0 0;
    width:min(88vw,340px);
    transform:translateX(-105%);
    transition:transform .25s;
    box-shadow:20px 0 50px rgba(58,50,44,.18);
    overflow:auto;
  }
  .brain-toc.open {
    transform:translateX(0);
  }
  .brain-toc-heading button {
    display:block;
    border:0;
    background:none;
    font-size:1.8rem;
  }
  .brain-hero {
    grid-template-columns:1fr;
  }
  .brain-metrics {
    grid-template-columns:repeat(2,1fr);
  }
}

@media(max-width:680px) {
  .brain-library {
    margin:0;
    border-radius:0;
    border-left:0;
    border-right:0;
  }
  .brain-toolbar {
    position:static;
    grid-template-columns:1fr;
  }
  .brain-search-wrap,.brain-select-wrap,.brain-tool-btn {
    grid-column:1;
  }
  .brain-tool-btn {
    width:100%;
  }
  .brain-cards,.brain-insights {
    grid-template-columns:1fr;
  }
  .brain-overview-head {
    display:grid;
  }
  .brain-primary-btn {
    width:100%;
  }
  .brain-hero {
    padding:2rem 1.2rem;
  }
  .brain-content {
    padding:1rem;
  }
  .brain-metrics {
    grid-template-columns:repeat(2,1fr);
  }
  .brain-view-tabs {
    width:100%;
    display:grid;
    grid-template-columns:1fr;
    border-radius:1rem;
  }
  .brain-view-tab {
    width:100%;
  }
}

@media print {
  .brain-hero,.brain-toolbar,.brain-toc,.brain-detail-head,.brain-view-tabs,.brain-authority-note,.brain-reader-tools,.brain-source-tools,.brain-footer {
    display:none!important;
  }
  .brain-library {
    border:0;
    box-shadow:none;
  }
  .brain-content {
    padding:0;
  }
  .brain-function-doc {
    max-width:none;
    border:0;
    box-shadow:none;
  }
}