:root{
  --cat-yellow:#F9C300;
  --cat-border:#2f2f2f;
  --text:#f2f2f2;
  --muted:#b9b9b9;
  --good:#2ecc71;
  --danger:#ff4d4d;
  --shadow:0 10px 28px rgba(0,0,0,.35);
}

*{box-sizing:border-box}
body{
  margin:0;
  background:#0e0e0e;
  color:var(--text);
  font-family:system-ui,Segoe UI,Roboto,Arial;
}

.topbar{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:14px 16px;
  border-bottom:1px solid var(--cat-border);
  background:#111;
}

.brand{display:flex;gap:12px;align-items:center}
.cat-mark{
  background:var(--cat-yellow);
  color:#111;
  font-weight:900;
  padding:8px 14px;
  border-radius:10px;
}
.brand-title{font-weight:800}
.brand-subtitle{font-size:12px;color:var(--muted)}

.layout{
  display:grid;
  grid-template-columns:340px 1fr;
  min-height:calc(100vh - 64px);
}

.sidebar{
  padding:14px;
  border-right:1px solid var(--cat-border);
}

.section-title{
  font-size:12px;
  text-transform:uppercase;
  color:var(--muted);
  margin-bottom:8px;
}

.tabs{display:flex;gap:8px}
.tab{
  flex:1;
  padding:10px;
  border:1px solid var(--cat-border);
  background:#0c0c0c;
  color:#fff;
  font-weight:800;
  border-radius:10px;
  cursor:pointer;
}
.tab.active{
  background:rgba(249,195,0,.15);
  color:var(--cat-yellow);
}

.input{
  width:100%;
  padding:10px;
  border-radius:10px;
  border:1px solid var(--cat-border);
  background:#0c0c0c;
  color:#fff;
}

.lesson{
  border:1px solid var(--cat-border);
  border-radius:12px;
  padding:10px;
  background:#0c0c0c;
  cursor:pointer;
}
.lesson.active{
  border-color:var(--cat-yellow);
}

.lesson-title{font-weight:800;font-size:13px}
.lesson-sub{font-size:12px;color:var(--muted)}

.content{padding:16px}

.player-card{
  border:1px solid var(--cat-border);
  border-radius:18px;
  background:#111;
  box-shadow:var(--shadow);
}

.video-shell{padding:10px}
.player{
  width:100%;
  max-height:70vh;
  background:black;
  border-radius:12px;
}

.player-header,.player-meta{
  display:flex;
  justify-content:space-between;
  padding:12px;
}

.pill{
  padding:6px 10px;
  border-radius:999px;
  background:rgba(249,195,0,.15);
  color:var(--cat-yellow);
  font-size:12px;
  font-weight:800;
}

.pill.subtle{
  background:#0c0c0c;
  color:var(--muted);
}

.btn{
  padding:8px 12px;
  border-radius:10px;
  border:1px solid var(--cat-border);
  background:#0c0c0c;
  color:#fff;
  cursor:pointer;
}
.btn.good{background:rgba(46,204,113,.15)}
.btn.danger{background:rgba(255,77,77,.15)}
.btn.ghost{background:none}

.info-grid{margin-top:16px}
.info-grid.single{display:grid;grid-template-columns:1fr}

.info-card{
  border:1px solid var(--cat-border);
  border-radius:18px;
  padding:16px;
  background:#0c0c0c;
}

.info-title{font-weight:900;margin-bottom:6px}
.info-text{color:var(--muted);line-height:1.6}

@media(max-width:980px){
  .layout{grid-template-columns:1fr}
}