:root{
  --primary:#0f2a5c;
  --primary-light:#1e4ba0;
  --accent:#f59e0b;
  --accent-dark:#d97706;
  --bg:#f8fafc;
  --surface:#ffffff;
  --text:#1e293b;
  --muted:#64748b;
  --border:#e2e8f0;
  --danger:#dc2626;
  --success:#16a34a;
  --warning:#ea580c;
  --info:#0891b2;
  --red:#fef2f2;
  --green:#f0fdf4;
  --yellow:#fefce8;
  --blue:#eff6ff;
  --purple:#faf5ff;
}
*{box-sizing:border-box;margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
  background:var(--bg);color:var(--text);line-height:1.6;
  display:grid;grid-template-columns:280px 1fr;min-height:100vh;
}

/* SIDEBAR */
aside.sidebar{
  background:linear-gradient(180deg,var(--primary) 0%,var(--primary-light) 100%);
  color:#fff;padding:1.5rem 1rem;position:sticky;top:0;height:100vh;overflow-y:auto;
}
aside h1{font-size:1.15rem;margin-bottom:.25rem;letter-spacing:.5px}
aside .subtitle{font-size:.75rem;opacity:.8;margin-bottom:1.5rem;font-style:italic}
aside nav ul{list-style:none}
aside nav > ul > li{margin-bottom:.3rem}
aside nav a{
  color:#fff;text-decoration:none;display:block;padding:.55rem .75rem;
  border-radius:6px;font-size:.88rem;transition:all .2s;
  border-left:3px solid transparent;
}
aside nav a:hover{background:rgba(255,255,255,.12);border-left-color:var(--accent)}
aside nav a.active{background:rgba(255,255,255,.2);border-left-color:var(--accent);font-weight:600}
aside nav .sub{margin-left:.5rem;margin-top:.2rem;list-style:none}
aside nav .sub a{font-size:.78rem;padding:.3rem .75rem;opacity:.85}

/* MOBILE TOP BAR */
.mobile-topbar{
  display:none;position:sticky;top:0;z-index:100;
  background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);
  color:#fff;padding:.75rem 1rem;
  align-items:center;justify-content:space-between;
  box-shadow:0 2px 10px rgba(0,0,0,.15);
}
.mobile-topbar .title{font-size:1rem;font-weight:600;display:flex;flex-direction:column}
.mobile-topbar .title small{font-size:.7rem;opacity:.85;font-weight:400}
.hamburger{
  background:rgba(255,255,255,.15);border:none;color:#fff;
  width:42px;height:42px;border-radius:8px;cursor:pointer;
  font-size:1.3rem;
}
.overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:50}
.overlay.active{display:block}

/* MAIN */
main{padding:2rem 2.5rem;max-width:1200px;margin:0 auto;width:100%}

/* HEADERS */
h2.unit-title{
  font-size:2rem;color:var(--primary);border-bottom:4px solid var(--accent);
  padding-bottom:.5rem;margin-bottom:1.5rem;
}
h3.section-title{
  font-size:1.4rem;color:var(--primary);margin:2rem 0 .8rem;
  padding-left:.75rem;border-left:4px solid var(--accent);
}
h4{font-size:1.1rem;color:var(--primary-light);margin:1.2rem 0 .5rem}
h5{font-size:.95rem;color:var(--muted);text-transform:uppercase;letter-spacing:.5px;margin:.8rem 0 .4rem}

p{margin-bottom:.8rem}
ul,ol{margin-left:1.5rem;margin-bottom:.8rem}
li{margin-bottom:.25rem}

/* CARDS */
.card{
  background:var(--surface);border-radius:10px;padding:1.25rem;
  box-shadow:0 1px 3px rgba(0,0,0,.05);border:1px solid var(--border);
  margin-bottom:1rem;
}
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem;margin:1rem 0}

.callout{padding:1rem 1.25rem;border-radius:8px;margin:1rem 0;border-left:4px solid}
.callout.danger{background:var(--red);border-color:var(--danger);color:#991b1b}
.callout.warning{background:var(--yellow);border-color:var(--warning);color:#92400e}
.callout.success{background:var(--green);border-color:var(--success);color:#166534}
.callout.info{background:var(--blue);border-color:var(--info);color:#155e75}
.callout.key{background:var(--purple);border-color:#9333ea;color:#6b21a8}
.callout strong{display:block;margin-bottom:.3rem;font-size:.85rem;text-transform:uppercase;letter-spacing:.5px}

/* TABLES */
.table-wrap{overflow-x:auto;margin:1rem 0;border-radius:8px;border:1px solid var(--border);-webkit-overflow-scrolling:touch}
table{width:100%;border-collapse:collapse;background:#fff;font-size:.88rem}
thead{background:var(--primary);color:#fff}
th{padding:.75rem;text-align:left;font-weight:600;font-size:.85rem}
td{padding:.65rem .75rem;border-top:1px solid var(--border);vertical-align:top}
tbody tr:nth-child(even){background:#f8fafc}
tbody tr:hover{background:#eef2ff}
table.compact td,table.compact th{padding:.4rem .6rem;font-size:.82rem}

/* TABS */
.tabs{margin:1rem 0}
.tab-buttons{display:flex;flex-wrap:wrap;gap:.25rem;border-bottom:2px solid var(--border);margin-bottom:1rem}
.tab-btn{
  padding:.6rem 1rem;background:transparent;border:none;cursor:pointer;
  font-size:.9rem;font-weight:500;color:var(--muted);
  border-bottom:3px solid transparent;margin-bottom:-2px;
}
.tab-btn:hover{color:var(--primary)}
.tab-btn.active{color:var(--primary);border-bottom-color:var(--accent)}
.tab-content{display:none}
.tab-content.active{display:block}

/* ACCORDION */
details{
  background:var(--surface);border:1px solid var(--border);border-radius:8px;
  margin-bottom:.5rem;overflow:hidden;
}
details[open]{box-shadow:0 2px 6px rgba(0,0,0,.08)}
summary{
  padding:.85rem 1rem;cursor:pointer;font-weight:500;list-style:none;
  display:flex;justify-content:space-between;align-items:center;
}
summary::-webkit-details-marker{display:none}
summary:hover{background:#f1f5f9}
summary::after{content:'▼';font-size:.7rem;color:var(--muted);transition:transform .2s}
details[open] summary::after{transform:rotate(180deg)}
details > *:not(summary){padding:0 1rem 1rem}

/* BADGES */
.badge{display:inline-block;padding:.15rem .55rem;border-radius:12px;font-size:.72rem;font-weight:600;text-transform:uppercase}

/* PRODUCT CARD */
.product-card{
  background:var(--surface);border-radius:12px;padding:1.25rem;
  border-left:5px solid var(--primary);box-shadow:0 1px 4px rgba(0,0,0,.06);
  margin-bottom:1rem;
}
.product-card.ce{border-color:#dc2626}
.product-card.plaq{border-color:#eab308}
.product-card.pfc{border-color:#f59e0b}
.product-card.crio{border-color:#0891b2}
.product-card.afer{border-color:#9333ea}
.product-card.hemo{border-color:#16a34a}
.product-card h4{margin-top:0}

.key-facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:.5rem;margin:.75rem 0}
.key-facts .kf{background:#f1f5f9;padding:.5rem .75rem;border-radius:6px;font-size:.82rem}
.key-facts .kf b{display:block;color:var(--primary);font-size:.72rem;text-transform:uppercase}

/* FLASHCARDS */
.flashcards{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:.75rem;margin:1rem 0}
.flashcard{
  background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);
  color:#fff;padding:1rem;border-radius:10px;cursor:pointer;
  min-height:120px;display:flex;flex-direction:column;justify-content:center;
}
.flashcard:hover{transform:translateY(-3px);box-shadow:0 6px 20px rgba(15,42,92,.3)}
.flashcard .back{display:none;font-size:.88rem}
.flashcard.flipped{background:linear-gradient(135deg,var(--accent) 0%,var(--accent-dark) 100%)}
.flashcard.flipped .front{display:none}
.flashcard.flipped .back{display:block}
.flashcard .q{font-weight:600;font-size:.95rem}
.flashcard .hint{font-size:.7rem;opacity:.7;margin-top:.5rem;text-transform:uppercase}

/* QUIZ */
.quiz{background:var(--surface);border-radius:10px;padding:1.25rem;border:1px solid var(--border);margin:1rem 0}
.quiz-q{font-weight:500;margin-bottom:.75rem}
.quiz-options{display:grid;gap:.4rem}
.quiz-opt{
  background:#f8fafc;padding:.6rem .9rem;border-radius:6px;cursor:pointer;
  border:2px solid transparent;font-size:.9rem;
}
.quiz-opt:hover{background:#e0e7ff}
.quiz-opt.correct{background:#dcfce7;border-color:#16a34a}
.quiz-opt.wrong{background:#fee2e2;border-color:#dc2626}

/* HERO */
.hero{
  background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);
  color:#fff;padding:2.5rem 2rem;border-radius:14px;margin-bottom:2rem;
}
.hero h1{font-size:2rem;margin-bottom:.5rem}
.hero p{opacity:.9;max-width:700px}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:1rem;margin-top:1.5rem}
.stat{background:rgba(255,255,255,.15);padding:.85rem;border-radius:8px;text-align:center}
.stat b{display:block;font-size:1.6rem;color:var(--accent)}
.stat span{font-size:.78rem;opacity:.85}

/* GLOSSARY */
.glossary{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:.5rem}
.glossary .term{background:#fff;padding:.6rem .85rem;border-radius:6px;border:1px solid var(--border);font-size:.85rem}
.glossary .term b{color:var(--primary);font-weight:700}

.value{font-family:'SF Mono',Monaco,monospace;background:#f1f5f9;padding:.1rem .4rem;border-radius:4px;font-size:.88em;color:var(--primary)}

/* UNIT ACTIONS - PDF button */
.unit-actions{
  display:flex;gap:.5rem;margin-bottom:1.5rem;flex-wrap:wrap;
  background:linear-gradient(135deg,#fef3c7 0%,#fde68a 100%);
  padding:.85rem 1rem;border-radius:10px;border:1px solid #fbbf24;
  align-items:center;justify-content:space-between;
}
.unit-actions .label{font-size:.88rem;color:#92400e;font-weight:500}
.btn-pdf{
  background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);
  color:#fff;border:none;padding:.65rem 1.2rem;border-radius:8px;
  cursor:pointer;font-size:.88rem;font-weight:600;
  box-shadow:0 2px 6px rgba(15,42,92,.2);
}
.btn-pdf:hover{transform:translateY(-1px)}

footer{margin-top:3rem;padding-top:1.5rem;border-top:1px solid var(--border);text-align:center;color:var(--muted);font-size:.8rem}

/* MOBILE */
@media(max-width:900px){
  body{grid-template-columns:1fr;display:block}
  aside.sidebar{
    position:fixed;top:0;left:0;
    width:min(85vw,320px);height:100vh;z-index:200;
    transform:translateX(-100%);transition:transform .3s ease;
  }
  aside.sidebar.open{transform:translateX(0);box-shadow:4px 0 20px rgba(0,0,0,.3)}
  .mobile-topbar{display:flex}
  main{padding:1rem;max-width:100%}
  .hero{padding:1.5rem 1.25rem}
  .hero h1{font-size:1.5rem}
  .hero p{font-size:.9rem}
  .stats{grid-template-columns:repeat(2,1fr);gap:.6rem}
  .stat b{font-size:1.3rem}
  h2.unit-title{font-size:1.4rem}
  h3.section-title{font-size:1.15rem;margin:1.5rem 0 .6rem}
  h4{font-size:1rem}
  p,li{font-size:.92rem}
  .card-grid{grid-template-columns:1fr;gap:.75rem}
  .product-card{padding:1rem}
  .key-facts{grid-template-columns:repeat(2,1fr)}
  .table-wrap{margin:.75rem -.5rem;border-radius:0;border-left:none;border-right:none}
  table{font-size:.82rem}
  th,td{padding:.5rem .55rem}
  table.compact td,table.compact th{font-size:.75rem;padding:.35rem .45rem}
  .tab-buttons{flex-wrap:nowrap;overflow-x:auto}
  .tab-btn{white-space:nowrap;font-size:.82rem}
  .unit-actions{flex-direction:column;align-items:stretch;gap:.6rem;text-align:center}
  .btn-pdf{width:100%;padding:.8rem;font-size:.95rem}
  .flashcards{grid-template-columns:1fr}
  .glossary{grid-template-columns:1fr}
  .quiz-opt{padding:.75rem;font-size:.88rem}
  aside nav a{padding:.7rem .9rem;font-size:.92rem}
}

@media(max-width:480px){
  main{padding:.85rem}
  .hero{padding:1.25rem 1rem}
  .hero h1{font-size:1.3rem}
  .stats{grid-template-columns:1fr 1fr}
  h2.unit-title{font-size:1.25rem}
  .key-facts{grid-template-columns:1fr}
  table{font-size:.78rem}
  th,td{padding:.4rem .45rem}
}