/* ================================================================
   扫雷 Minesweeper - 主题系统
   CSS变量驱动，支持浅色/深色模式切换
   ================================================================ */

/* ========== CSS变量 - 浅色主题（默认） ========== */
:root,
[data-theme="light"] {
  --bg-page:            #e0e0e0;
  --bg-panel:           #c0c0c0;
  --bg-panel-active:    #b0b0b0;
  --bg-counter:         #000;
  --bg-kbd:             #eee;
  --bg-cell-hover:      #d0d0d0;
  --bg-wrong-flag:      #ffcccc;
  --bg-mine:            #ff0000;

  --border-light:       #ffffff;
  --border-dark:        #808080;
  --border-kbd:         #aaa;

  --color-counter:      #ff0000;
  --color-text:         #333;
  --color-hint:         #666;

  --shadow:             rgba(0, 0, 0, 0.3);
  --transition-speed:   0.25s;
}

/* ========== CSS变量 - 深色主题 ========== */
[data-theme="dark"] {
  --bg-page:            #1a1a2e;
  --bg-panel:           #2d2d3f;
  --bg-panel-active:    #252535;
  --bg-counter:         #0d0d1a;
  --bg-kbd:             #333344;
  --bg-cell-hover:      #3d3d4f;
  --bg-wrong-flag:      #4a2525;
  --bg-mine:            #cc3333;

  --border-light:       #4a4a5a;
  --border-dark:        #1a1a28;
  --border-kbd:         #555566;

  --color-counter:      #ff5555;
  --color-text:         #ccccdd;
  --color-hint:         #888899;

  --shadow:             rgba(0, 0, 0, 0.6);
  --transition-speed:   0.25s;
}

/* ========== 全局重置 ========== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-page);
  color: var(--color-text);
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
  user-select: none;
  -webkit-user-select: none;
  transition: background var(--transition-speed);
}

/* ========== 主题切换按钮 ========== */
.theme-toggle {
  position: fixed;
  top: 16px;
  right: 16px;
  width: 40px;
  height: 40px;
  font-size: 20px;
  border: 2px solid;
  border-color: var(--border-light) var(--border-dark) var(--border-dark) var(--border-light);
  background: var(--bg-panel);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  z-index: 100;
  transition: background var(--transition-speed), border-color var(--transition-speed), transform 0.15s;
}

.theme-toggle:hover {
  transform: scale(1.1);
}

.theme-toggle:active {
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
  transform: scale(0.95);
}

/* ========== 游戏容器 ========== */
.game-container {
  background: var(--bg-panel);
  border: 3px solid;
  border-color: var(--border-light) var(--border-dark) var(--border-dark) var(--border-light);
  padding: 10px;
  box-shadow: 2px 2px 8px var(--shadow);
  transition: background var(--transition-speed), border-color var(--transition-speed), box-shadow var(--transition-speed);
}

/* ========== 顶部状态栏 ========== */
.status-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  padding: 4px 6px;
  background: var(--bg-panel);
  border: 2px solid;
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
  transition: background var(--transition-speed), border-color var(--transition-speed);
}

.counter {
  background: var(--bg-counter);
  color: var(--color-counter);
  font-family: 'Consolas', 'Courier New', monospace;
  font-size: 24px;
  font-weight: bold;
  padding: 2px 6px;
  min-width: 54px;
  text-align: center;
  border: 2px solid;
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
  line-height: 1;
  transition: background var(--transition-speed), color var(--transition-speed), border-color var(--transition-speed);
}

#face {
  width: 42px;
  height: 42px;
  font-size: 24px;
  border: 2px solid;
  border-color: var(--border-light) var(--border-dark) var(--border-dark) var(--border-light);
  background: var(--bg-panel);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  outline: none;
  padding: 0;
  transition: background var(--transition-speed), border-color var(--transition-speed);
}

#face:active {
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
}

/* ========== 难度选择 ========== */
.difficulty-bar {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 10px;
}

.difficulty-bar button {
  padding: 4px 14px;
  font-size: 14px;
  font-family: inherit;
  color: var(--color-text);
  border: 2px solid;
  border-color: var(--border-light) var(--border-dark) var(--border-dark) var(--border-light);
  background: var(--bg-panel);
  cursor: pointer;
  outline: none;
  transition: background var(--transition-speed), border-color var(--transition-speed), color var(--transition-speed);
}

.difficulty-bar button:active,
.difficulty-bar button.active {
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
  background: var(--bg-panel-active);
}

/* ========== 棋盘 ========== */
.board-wrapper {
  border: 3px solid;
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
  display: inline-block;
  transition: border-color var(--transition-speed);
}

#board {
  display: grid;
  gap: 0;
  background: var(--bg-panel);
  line-height: 1;
  transition: background var(--transition-speed);
}

/* ========== 格子 ========== */
.cell {
  border: 2px solid;
  border-color: var(--border-light) var(--border-dark) var(--border-dark) var(--border-light);
  background: var(--bg-panel);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  cursor: pointer;
  position: relative;
  transition: background var(--transition-speed), border-color var(--transition-speed);
}

.cell:hover:not(.revealed):not(.flagged):not(.exploded):not(.mine) {
  background: var(--bg-cell-hover);
}

.cell:active:not(.revealed):not(.flagged):not(.exploded):not(.mine) {
  border-color: var(--border-dark) var(--border-light) var(--border-light) var(--border-dark);
}

/* 已揭开 */
.cell.revealed {
  border: 1px solid var(--border-dark);
  background: var(--bg-panel);
  cursor: default;
}

/* 地雷 */
.cell.mine {
  background: var(--bg-mine);
}

/* 爆炸的雷 - 踩中那颗 */
.cell.exploded {
  background: var(--bg-mine);
  animation: explode 0.35s ease-out;
}

@keyframes explode {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.5); }
  100% { transform: scale(1); }
}

/* 旗帜 */
.cell.flagged {
  cursor: default;
}

/* 错误标记 */
.cell.wrong-flag {
  background: var(--bg-wrong-flag);
}

/* ========== 标题 ========== */
.game-title {
  font-size: 22px;
  font-weight: bold;
  margin-bottom: 12px;
  color: var(--color-text);
  text-align: center;
  transition: color var(--transition-speed);
}

/* ========== 键盘提示 ========== */
.hint {
  margin-top: 12px;
  font-size: 13px;
  color: var(--color-hint);
  text-align: center;
  line-height: 1.8;
  transition: color var(--transition-speed);
}

.hint kbd {
  background: var(--bg-kbd);
  border: 1px solid var(--border-kbd);
  border-radius: 3px;
  padding: 1px 5px;
  font-family: inherit;
  font-size: 12px;
  transition: background var(--transition-speed), border-color var(--transition-speed);
}

/* ========== 响应式 ========== */
@media (max-width: 860px) {
  .game-container {
    padding: 6px;
  }

  .difficulty-bar button {
    padding: 3px 8px;
    font-size: 12px;
  }

  .counter {
    font-size: 18px;
    min-width: 44px;
    padding: 2px 4px;
  }

  #face {
    width: 36px;
    height: 36px;
    font-size: 20px;
  }
}

@media (max-width: 500px) {
  body {
    padding: 10px;
  }

  .game-title {
    font-size: 18px;
    margin-bottom: 8px;
  }

  .difficulty-bar {
    gap: 4px;
  }

  .difficulty-bar button {
    padding: 3px 6px;
    font-size: 11px;
  }

  .counter {
    font-size: 15px;
    min-width: 38px;
  }

  #face {
    width: 32px;
    height: 32px;
    font-size: 18px;
  }

  .theme-toggle {
    top: 10px;
    right: 10px;
    width: 34px;
    height: 34px;
    font-size: 17px;
  }
}