@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap");

:root {
  --bg-color: #f9fafd;
  --primary-accent: #6a67ea;
  --secondary-accent: #509bfd;
  --board-bg: #eef2f8;
  --cell-bg: rgba(255, 255, 255, 0.96);
  --cell-border: #e6ecf2;
  --text-dark: #333a45;
  --text-light: #8a8f98;
  --button-bg: linear-gradient(
    75deg,
    var(--primary-accent),
    var(--secondary-accent)
  );
  --button-hover-bg: linear-gradient(75deg, #5c5ae7, #408eec);

  --shadow-soft: 0 3px 6px rgba(60, 64, 67, 0.08);
  --shadow-medium-soft: 0 6px 12px rgba(60, 64, 67, 0.12),
    0 1px 3px rgba(60, 64, 67, 0.06);
  --shadow-deep-soft: 0 10px 25px rgba(60, 64, 67, 0.15),
    0 3px 8px rgba(60, 64, 67, 0.08);
  --shadow-inset-light: inset 0 1px 2px rgba(0, 0, 0, 0.04);

  --grid-width: 6;
  --grid-height: 8;
  --cell-size: 55px;
  --cell-gap: 4px;
  --board-padding: 12px;

  --base-font-size: 16px;
  --main-border-radius: 14px;
  --cell-border-radius-factor: 0.18;

  --board-width: calc(
    (var(--cell-size) * var(--grid-width)) +
      (var(--cell-gap) * (var(--grid-width) - 1)) + (var(--board-padding) * 2)
  );
  --board-height: calc(
    (var(--cell-size) * var(--grid-height)) +
      (var(--cell-gap) * (var(--grid-height) - 1)) + (var(--board-padding) * 2)
  );
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  font-family: "Poppins", sans-serif;
  background-color: var(--bg-color);
  padding: 25px 15px;
  color: var(--text-dark);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  font-size: var(--base-font-size);
  box-sizing: border-box;
}

.container {
  width: 100%;
  max-width: var(--board-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

h1 {
  font-weight: 600;
  font-size: clamp(1.8em, 5vw, 2.5em);
  color: var(--primary-accent);
  margin-bottom: 20px;
  letter-spacing: -0.6px;
  text-align: center;
}

.hud {
  display: flex;
  justify-content: space-around;
  align-items: center;
  width: 100%;
  max-width: calc(var(--board-width) - 20px);
  margin-bottom: 25px;
  gap: 15px;
  flex-wrap: wrap;
}

.score-container,
.level-container {
  font-size: clamp(1.1em, 3.5vw, 1.4em);
  font-weight: 500;
  color: var(--text-dark);
  background-color: #ffffff;
  padding: 8px 18px;
  border-radius: var(--main-border-radius);
  box-shadow: var(--shadow-medium-soft);
  transition: transform 0.25s ease-out, box-shadow 0.25s ease-out;
  white-space: nowrap;
  flex-shrink: 0;
}

.level-container {
  transition: transform 0.2s ease-out, box-shadow 0.25s ease-out;
}

#game-board {
  display: grid;
  grid-template-columns: repeat(var(--grid-width), var(--cell-size));
  grid-template-rows: repeat(var(--grid-height), var(--cell-size));
  background-color: var(--board-bg);
  border-radius: var(--main-border-radius);
  padding: var(--board-padding);
  box-shadow: var(--shadow-deep-soft), var(--shadow-inset-light);
  position: relative;
  gap: var(--cell-gap);
  width: var(--board-width);
  height: var(--board-height);
  max-width: 100%;
  box-sizing: border-box;
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: calc(var(--cell-size) * 0.6);
  cursor: grab;
  user-select: none;
  background-color: var(--cell-bg);
  border: 1px solid var(--cell-border);
  border-radius: calc(var(--cell-size) * var(--cell-border-radius-factor));
  box-sizing: border-box;
  transition: background-color 0.2s ease-out, box-shadow 0.25s ease-out,
    border-color 0.2s ease-out, opacity 0.15s ease-out,
    transform 0.2s cubic-bezier(0.25, 0.8, 0.25, 1);
  box-shadow: var(--shadow-soft), var(--shadow-inset-light);
  will-change: transform, opacity, box-shadow;
}

.cell:not(.dragging):not(.matched):hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: var(--shadow-medium-soft), var(--shadow-inset-light);
  background-color: #ffffff;
  border-color: #dfe6ee;
}

@keyframes disappear {
  0% {
    transform: scale(1);
    opacity: 1;
  }
  40% {
    transform: scale(1.08) rotate(2deg);
    opacity: 0.8;
  }
  100% {
    transform: scale(0.1) rotate(-8deg);
    opacity: 0;
  }
}

.cell.matched {
  animation: disappear 0.3s forwards cubic-bezier(0.6, -0.28, 0.735, 0.045);
  pointer-events: none;
}

.cell.dragging {
  cursor: grabbing;
  box-shadow: var(--shadow-deep-soft);
  opacity: 0.9;
}

.cell.drag-over {
  outline: 2px solid var(--primary-accent);
  outline-offset: -3px;
  background-color: rgba(106, 103, 234, 0.1);
}

#reset-button {
  margin-top: 30px;
  padding: 14px 30px;
  font-size: clamp(1em, 3.6vw, 1.15em);
  font-weight: 500;
  cursor: pointer;
  background: var(--button-bg);
  color: white;
  border: none;
  border-radius: var(--main-border-radius);
  box-shadow: var(--shadow-medium-soft), inset 0 -2px 3px rgba(0, 0, 0, 0.1);
  transition: background 0.25s ease,
    transform 0.15s cubic-bezier(0.25, 0.8, 0.25, 1), box-shadow 0.25s ease;
  letter-spacing: 0.4px;
}

#reset-button:hover {
  background: var(--button-hover-bg);
  box-shadow: var(--shadow-deep-soft), inset 0 -1px 2px rgba(0, 0, 0, 0.05);
  transform: translateY(-3px);
}

#reset-button:active {
  transform: translateY(-1px) scale(0.98);
  box-shadow: var(--shadow-soft), inset 0 1px 2px rgba(0, 0, 0, 0.1);
}