/* Reset default browser styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: black;
  font-family: Arial, sans-serif;
}

.game-container {
  position: relative;
  width: 100%;
  height: 100%;
}

.flashcard {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: transparent;
  text-align: center;
  z-index: 2;
}

.word {
  font-size: calc(10vw + 10vh);
  color: white;
  text-transform: lowercase;
  white-space: nowrap;
}

.category {
  font-size: 2em;
  color: white;
  margin-bottom: 20px;
}

.score {
  position: absolute;
  top: 10px;
  left: 10px;
  font-size: 1.5em;
  color: white;
}

#nextButton {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  padding: 15px 30px;
  font-size: 1em;
}

.first-letter {
  color: yellow;
  text-decoration: underline red;
}

.warning-text {
  display: none;
  position: absolute;
  top: 20%;
  width: 100%;
  text-align: center;
  font-size: 5em;
  color: red;
  animation: warning-flash 0.5s infinite;
  z-index: 3;
}

@keyframes warning-flash {
  0% { opacity: 1; }
  50% { opacity: 0; }
  100% { opacity: 1; }
}

/* Explosion Effects */
.explosion-overlay,
.explosion-center,
.shockwave {
  display: none;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.explosion-overlay {
  background-color: red;
  z-index: 4;
}

.explosion-center {
  background: radial-gradient(circle, rgba(255,0,0,1) 0%, rgba(0,0,0,0) 70%);
  z-index: 5;
}

.shockwave {
  border: 5px solid red;
  border-radius: 50%;
  animation: shockwave-animation 2s forwards;
  z-index: 6;
}

@keyframes shockwave-animation {
  0% {
    transform: translate(-50%, -50%) scale(0);
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) scale(5);
    opacity: 0;
  }
}

/* Screen Shake */
@keyframes screen-shake {
  0% { transform: translate(0, 0); }
  25% { transform: translate(-5px, 5px); }
  50% { transform: translate(5px, -5px); }
  75% { transform: translate(-5px, -5px); }
  100% { transform: translate(0, 0); }
}

.screen-shake {
  animation: screen-shake 0.1s infinite;
}