:root {
  --bg-color: #f0f0f0;
  --board-bg: #bdbdbd;
  --cell-bg: #c0c0c0;
  --cell-border-light: #ffffff;
  --cell-border-dark: #7b7b7b;
  --cell-revealed: #dcdcdc;
  --text-color: #333;
  --accent-color: #0095ff;
}

* {
  box-sizing: border-box;
  user-select: none;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-color);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
}

.container {
  background-color: var(--board-bg);
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  border: 4px solid #fff;
}

.header {
  background-color: #4a4a4a;
  color: red;
  font-family: 'Courier New', Courier, monospace;
  font-weight: bold;
  font-size: 24px;
  padding: 10px;
  margin-bottom: 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 3px inset #7b7b7b;
  border-radius: 4px;
}

.counter-box {
  background-color: #000;
  padding: 4px 8px;
  border-radius: 2px;
  min-width: 60px;
  text-align: center;
  display: flex;
  flex-direction: column;
}

.counter-box .label {
  color: #888;
  font-size: 10px;
  font-family: sans-serif;
  margin-top: 2px;
}

.emoji-btn {
  font-size: 24px;
  background-color: var(--cell-bg);
  border: 3px outset #fff;
  cursor: pointer;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
}

.emoji-btn:active {
  border: 3px inset #7b7b7b;
}

.board {
  display: grid;
  gap: 1px;
  background-color: #7b7b7b;
  border: 4px inset #7b7b7b;
  margin-bottom: 15px;
}

.cell {
  width: 30px;
  height: 30px;
  background-color: var(--cell-bg);
  border-top: 3px solid var(--cell-border-light);
  border-left: 3px solid var(--cell-border-light);
  border-right: 3px solid var(--cell-border-dark);
  border-bottom: 3px solid var(--cell-border-dark);
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  cursor: pointer;
  font-size: 18px;
}

.cell.revealed {
  background-color: var(--cell-revealed);
  border: 1px solid #999;
  width: 30px;
  height: 30px;
}

.cell.mine {
  background-color: #ff4d4d;
}

.cell.flagged {
  color: red;
}

.controls {
  text-align: center;
}

.difficulty-selector button {
  padding: 8px 16px;
  margin: 0 4px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  background-color: #e0e0e0;
  font-weight: bold;
  transition: all 0.2s;
}

.difficulty-selector button:hover {
  background-color: #d0d0d0;
}

.difficulty-selector button.active {
  background-color: var(--accent-color);
  color: white;
}

/* Number colors */
.c-1 { color: blue; }
.c-2 { color: green; }
.c-3 { color: red; }
.c-4 { color: darkblue; }
.c-5 { color: brown; }
.c-6 { color: teal; }
.c-7 { color: black; }
.c-8 { color: gray; }

/* Explosion Effect */
.explosion-particle {
  position: fixed;
  border-radius: 50%;
  pointer-events: none;
  z-index: 9999;
  animation: explode 0.6s ease-out forwards;
}

@keyframes explode {
  0% {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
  }
  100% {
    transform: translate(calc(-50% + var(--tx)), calc(-50% + var(--ty))) scale(0);
    opacity: 0;
  }
}