:root {
  --primary-color: #eeae00;
  --secondary-color: #e92929;
  --accent-color: #5a4bda;
  --background-overlay: rgba(0, 0, 0, 0.85);
  --text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  --transition-fast: 0.2s ease-in-out;
  --transition-medium: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --card-perspective: 1500px;
  --card-ratio: 1.4;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  height: 100%;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)),
    url("../img/stage.gif") center/cover fixed;
  font-family: "Press Start 2P", system-ui, sans-serif;
  line-height: 1.6;
  color: var(--primary-color);
  overflow-x: hidden;
}

.container {
  position: relative;
  width: 100%;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.start-container {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  display: flex;
  justify-content: center;
  width: 100%;
}

.game-container {
  flex: 1;
  display: grid;
  place-items: center;
  padding: 2rem;
  position: relative;
  width: 100%;
  min-height: calc(100vh - 4rem);
  height: 100%;
}

.game-board {
  --card-width: min(18vw, 150px);
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1rem;
  margin: auto;
  perspective: var(--card-perspective);
  transition: opacity var(--transition-medium);
  width: fit-content;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1;
}

.card {
  position: relative;
  width: var(--card-width);
  height: calc(var(--card-width) * var(--card-ratio));
  transform-style: preserve-3d;
  transition: transform var(--transition-medium);
  cursor: pointer;
}

.card-face,
.card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  background: #1a1a1a;
  overflow: hidden;
}

.card-back {
  background: url("../img/cardback.png") center/cover;
}

.card-face {
  transform: rotateY(180deg);
  background: linear-gradient(45deg, #2c2c2c 0%, #1a1a1a 100%);
}

.card.flip {
  transform: rotateY(180deg);
}

.button {
  --button-padding: 1rem 2rem;
  margin-top: 1.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--button-padding);
  border: 3px solid var(--secondary-color);
  border-radius: 8px;
  background: linear-gradient(145deg, #d4af37, #ffd700);
  color: var(--secondary-color);
  font: inherit;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-shadow: 2px 2px 0 var(--accent-color);
}

.button:hover {
  background: linear-gradient(145deg, #c21e1e, #e92929);
  color: #ffd700;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(233, 41, 41, 0.4);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: var(--background-overlay);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-medium);
  z-index: 1000;
}

.modal-overlay.active {
  padding: 3rem;
  opacity: 1;
  visibility: visible;
}

.modal {
  background: linear-gradient(145deg, #1a1a1aff, #2c2c2c);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  text-shadow: 2px 2px 0 var(--accent-color);
  font-size: 2.5rem;
  text-align: center;
  max-width: min(90vw, 900px);
}

.heading-xl {
  font-size: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: 1.5rem;
  text-shadow: 3px 3px 0 var(--accent-color);
}

.text-lg {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  color: #fff;
  margin-bottom: 2rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 1200px) {
  .game-board {
    grid-template-columns: repeat(auto-fit, minmax(var(--card-width), 1fr));
    justify-content: center;
  }
}

@media (max-width: 768px) {
  .game-board {
    grid-template-columns: repeat(4, 1fr);
    --card-width: min(22vw, 120px);
  }
}

@media (max-width: 480px) {
  .game-board {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
  }

  .modal {
    padding: 1.5rem;
  }

  .button {
    padding: 0.75rem 1.5rem;
  }
}