body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont;
  background: #f4f6f8;
  margin: 0;
  color: #1f2937;
}

.topo {
  text-align: center;
  padding: 25px 15px;
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
}

main {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

/* GRID HOME */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card {
  background: white;
  border-radius: 14px;
  padding: 25px;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.06);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.12);
}

.container {
  background: white;
  padding: 25px;
  border-radius: 14px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.lesson-card {
  background: #f8fafc;
  padding: 15px;
  border-radius: 10px;
  margin-bottom: 15px;
}

/* BOTÕES */
button {
  margin-top: 15px;
  padding: 10px 16px;
  border-radius: 8px;
  border: none;
  background: #2563eb;
  color: white;
  cursor: pointer;
  font-size: 15px;
}

button:hover {
  background: #1d4ed8;
}

.voltar {
  background: #6b7280;
}

.voltar:hover {
  background: #4b5563;
}

/* QUIZ */
.opcao {
  display: block;
  width: 100%;
  background: #f1f5f9;
  color: #111827;
  margin: 8px 0;
  padding: 12px;
  border-radius: 10px;
  text-align: left;
}

.opcao:hover {
  background: #e0e7ff;
}

.hidden {
  display: none;
}
.opcao {
  display: block;
  width: 100%;
  margin: 8px 0;
  padding: 12px;
  font-size: 16px;
  cursor: pointer;
}

.correta {
  background-color: #4caf50;
  color: #fff;
  animation: piscar 0.8s ease-in-out 2;
}

.errada {
  background-color: #e53935;
  color: #fff;
}

@keyframes piscar {
  0% { opacity: 1; }
  50% { opacity: 0.3; }
  100% { opacity: 1; }
}



/* OVERLAY */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.7);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 999;
}

.overlay-content {
  background: #fff;
  width: 90%;
  max-width: 700px;
  height: 85%;
  border-radius: 12px;
  position: relative;
  overflow: hidden;
}

.overlay-content iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.close {
  position: absolute;
  top: 10px;
  right: 12px;
  background: #ef4444;
  color: white;
  border: none;
  padding: 6px 10px;
  border-radius: 50%;
  cursor: pointer;
}

.hidden {
  display: none;
}
.lesson-card {
  background: #f8fafc;
  padding: 15px;
  margin: 10px 0;
  border-radius: 10px;
  cursor: pointer;
  font-weight: bold;
}

.lesson-card.locked {
  background: #e5e7eb;
  color: #9ca3af;
  cursor: not-allowed;
}






.lang-switch {
  position: absolute;
  top: 15px;
  right: 20px;

  text-decoration: none;
  font-weight: 600;
  font-size: 14px;

  background: #e5e7eb;
  color: #1f2937;
  padding: 6px 10px;
  border-radius: 8px;
}

.lang-switch:hover {
  background: #c7d2fe;
}