:root{
  --bg:#0b1220;
  --card:#111a2e;
  --text:#e9eefc;
  --muted:#aab6df;
  --accent:#6aa6ff;
  --ok:#1db954;
  --bad:#e53935;
  --border:rgba(255,255,255,.12);
  --shadow:0 10px 30px rgba(0,0,0,.35);
}

*{ box-sizing:border-box; }
body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: linear-gradient(180deg, #071024, var(--bg));
  color:var(--text);
}

a{ color:var(--accent); text-decoration:none; }
a:hover{ text-decoration:underline; }

.container{
  max-width: 980px;
  margin: 28px auto;
  padding: 0 16px;
}

.header{
  display:flex;
  gap:16px;
  justify-content:space-between;
  align-items:flex-start;
  margin-bottom: 18px;
}

.brand h1{
  margin:0;
  font-size: 1.35rem;
}
.brand p{
  margin:6px 0 0 0;
  color:var(--muted);
}

.card{
  background: rgba(17,26,46,.92);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.grid{
  display:grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

@media (min-width: 860px){
  .grid{
    grid-template-columns: 1fr 1fr;
  }
}

.section-title{
  margin: 0 0 10px 0;
  font-size: 1.05rem;
}

.tense{
  border:1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  background: rgba(0,0,0,.15);
}

.tensename{
  font-weight: 700;
  margin: 0 0 8px 0;
}

.example{
  color: var(--muted);
  margin: 8px 0 0 0;
  line-height:1.5;
}

.button-row{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin-top: 10px;
}

.btn{
  display:inline-block;
  padding: 10px 14px;
  border-radius: 12px;
  background: rgba(106,166,255,.15);
  border: 1px solid rgba(106,166,255,.35);
  color: var(--text);
  font-weight: 600;
}

.btn:hover{ background: rgba(106,166,255,.22); }

hr{
  border:0;
  border-top:1px solid var(--border);
  margin: 18px 0;
}

.quiz{
  max-width: 820px;
  margin: 0 auto;
}

.q{
  border:1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  background: rgba(0,0,0,.12);
  margin-bottom: 14px;
}

.q h3{
  margin:0 0 10px 0;
  font-size: 1rem;
}

.answers{
  display:grid;
  gap:10px;
}

.answer{
  display:flex;
  align-items:flex-start;
  gap:10px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,.10);
  background: rgba(255,255,255,.03);
}

.answer input{ margin-top: 3px; }

.answer.correct{
  border-color: rgba(29,185,84,.8);
  background: rgba(29,185,84,.12);
}
.answer.wrong{
  border-color: rgba(229,57,53,.8);
  background: rgba(229,57,53,.12);
}

.controls{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  justify-content:space-between;
  align-items:center;
  margin: 12px 0 18px 0;
}

.btn-primary{
  cursor:pointer;
  padding: 11px 14px;
  border-radius: 12px;
  border: 1px solid rgba(106,166,255,.4);
  background: rgba(106,166,255,.18);
  color: var(--text);
  font-weight: 700;
}
.btn-primary:hover{ background: rgba(106,166,255,.24); }

.small{
  color:var(--muted);
  font-size:.95rem;
}

.result{
  font-weight: 800;
  margin-top: 10px;
}

.footer-note{
  color: var(--muted);
  font-size:.95rem;
  margin-top: 14px;
  line-height:1.45;
}