:root{
  --bg:#071227;
  --card:#071a2d;
  --accent:#0ea5a4;
  --muted:#94a3b8;
  color-scheme: dark;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: linear-gradient(180deg,#04121b,#071227);
  color:#e6eef6;
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:18px;
}
.app{
  width:980px; max-width:96%;
  background: linear-gradient(180deg, rgba(5,12,24,0.9), rgba(7,18,32,0.9));
  border-radius:12px; padding:18px; box-shadow:0 10px 30px rgba(2,6,23,0.6);
}
.header h1{margin:0;font-size:20px}
.subtitle{color:var(--muted);font-size:13px;margin-top:6px}
.controls{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:14px}
.btn{background:rgba(255,255,255,0.03);border:1px solid rgba(255,255,255,0.04);padding:8px 10px;border-radius:8px;cursor:pointer}
.small{font-size:13px;color:var(--muted)}
.status{margin-top:12px}
.progress{height:10px;background:rgba(255,255,255,0.03);border-radius:8px;overflow:hidden;margin-top:6px}
.progress > div{height:100%;background:var(--accent);width:0%}
.main{display:flex;gap:12px;margin-top:12px}
.left{flex:1;max-height:420px;overflow:auto;padding-right:8px}
.right{width:320px;background:rgba(255,255,255,0.02);padding:12px;border-radius:10px}
.sentences{display:block}
.sentence{padding:8px;border-radius:6px;margin-bottom:6px;background:transparent}
.sentence.active{background:linear-gradient(90deg, rgba(14,165,164,0.08), rgba(14,165,164,0.02));border-left:3px solid var(--accent)}
.definitions{margin-top:8px;color:var(--muted);font-size:14px}
.footer{margin-top:12px;text-align:center}