body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(180deg, #0f0f0f, #1a1a1a);
  color: #fff;
  overflow: hidden;
}

/* 🏠 tela inicial */
#home {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 20px;
}

.materia {
  padding: 20px 40px;
  font-size: 22px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  background: #3498db;
  color: white;
}

/* topo */
#topbar {
  position: fixed;
  top: 10px;
  left: 20px;
  font-size: 18px;
  opacity: 0.8;
  z-index: 10;
}

/* container */
#container {
  height: 100vh;
  width: 100vw;
  overflow-y: scroll;
  scroll-snap-type: y mandatory;
  scroll-behavior: smooth;
}

/* cards */
.card {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  text-align: center;
  font-size: 42px;
  line-height: 1.4;
  scroll-snap-align: start;
}

.card-inner {
  background: rgba(255,255,255,0.06);
  backdrop-filter: blur(12px);
  border-radius: 24px;
  padding: 40px;
  box-shadow: 0 15px 60px rgba(0,0,0,0.8);
  max-width: 800px;
}

/* setas */
#controls {
  position: fixed;
  right: 20px;
  bottom: 160px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#controls button {
  padding: 20px;
  font-size: 28px;
  border-radius: 16px;
  border: none;
  cursor: pointer;
  background: rgba(255,255,255,0.1);
  color: white;
}

/* botões principais */
#actions {
  position: fixed;
  bottom: 20px;
  width: 100%;

  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-end;

  padding: 0 20px;
  box-sizing: border-box;
  gap: 10px;
}

#leftActions {
  display: flex;
  gap: 15px;
  width: 100%;
}

#actions button {
  border: none;
  cursor: pointer;
  font-weight: bold;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  transition: transform 0.15s ease;
}

#actions button:active {
  transform: scale(0.92);
}

/* revisar */
#reviewBtn {
  background: #e67e22;
  color: white;
  padding: 18px 24px;
  font-size: 18px;
  border-radius: 16px;
}

/* reset */
#resetBtn {
  background: #3498db;
  color: white;
  padding: 18px 24px;
  font-size: 18px;
  border-radius: 16px;
}

/* botão gigante */
#knowBtn {
  background: #2ecc71;
  color: white;

  width: 100%;
  padding: 70px 40px;
  font-size: 56px;
  border-radius: 28px;

  box-shadow: 0 20px 50px rgba(0,0,0,0.8);
}

/* foguetes */
.foguete {
  position: fixed;
  bottom: 0;
  font-size: 28px;
  animation: subir 1.2s ease-out forwards;
}

.explosao {
  position: fixed;
  font-size: 42px;
  animation: explodir 0.8s ease-out forwards;
}

@keyframes subir {
  0% { transform: translateY(0); }
  100% { transform: translateY(-70vh); }
}

@keyframes explodir {
  0% { transform: scale(0.5); opacity: 1; }
  100% { transform: scale(2.5); opacity: 0; }
}