/* ============================================================
 * 2048 —— 样式表
 * 深色主题 + 网格纹理背景，全部样式原生实现。
 * ============================================================ */
:root {
  --bg: #0c1014;
  --panel: #151c22;
  --panel-2: #1c242c;
  --cell-bg: #1b232b;
  --line: rgba(255, 255, 255, 0.08);
  --ink: #f2f6f8;
  --muted: #8a97a2;
  --gap: 12px;
}

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

html,
body {
  height: 100%;
}

/* 页面布局：居中容器、字体与渐变背景 */
body {
  min-height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 16px 30px;
  color: var(--ink);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  background:
    linear-gradient(180deg, #12181e 0%, #0b0f13 100%);
  overflow-x: hidden;
}

/* 背景网格纹理（不拦截点击） */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.7), transparent 92%);
}

/* 整体外壳：宽度限制，小屏下自适应 */
.shell {
  width: min(92vw, 520px);
  position: relative;
  display: flex;
  flex-direction: column;
}

/* 顶栏：标题 + 计分板 + 操作按钮 */
.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

/* 品牌区：Logo 与标题 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Logo：由 2/4/8/16 四个小色块拼成 */
.logo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3px;
  width: 34px;
  height: 34px;
  padding: 4px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 9px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.24);
}

.logo i {
  border-radius: 3px;
}

/* Logo 色块配色 */
.l2 { background: #d9e3eb; }
.l4 { background: #bfe6d7; }
.l8 { background: #ffb26b; }
.l16 { background: #ff6f8f; }

h1 {
  font-size: 46px;
  font-weight: 800;
  line-height: 1;
  color: #f7fafb;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.35);
  letter-spacing: 0;
}

/* 右侧控制区 */
.controls {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
}

.score-row {
  display: flex;
  gap: 10px;
}

/* 计分板卡片 */
.score-box {
  min-width: 108px;
  padding: 9px 14px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 10px 24px rgba(0, 0, 0, 0.2);
}

.score-label {
  font-size: 10px;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: 0;
}

.score-value {
  font-size: 22px;
  font-weight: 800;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0;
  transition: transform 160ms ease;
}

/* 加分时的缩放动画类（由 JS 添加） */
.score-value.bump {
  transform: scale(1.08);
}

.score-value.long {
  font-size: 17px;
}

.icon-row {
  display: flex;
  gap: 8px;
}

/* 图标按钮（新游戏/撤销/排行榜/音效） */
.icon-btn {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  color: #c6d0d8;
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, transform 100ms ease, border-color 150ms ease;
}

.icon-btn:hover {
  background: #202a33;
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.16);
}

.icon-btn:active {
  transform: scale(0.94);
}

.icon-btn:focus-visible {
  outline: 2px solid #62d9a5;
  outline-offset: 2px;
}

.icon-btn svg {
  width: 20px;
  height: 20px;
}

.icon-btn:disabled {
  opacity: 0.38;
  cursor: default;
  transform: none;
}

/* 棋盘容器（相对定位，供弹窗叠加） */
.board-wrap {
  position: relative;
}

/* 棋盘：正方形、圆角、禁止长按/滚动 */
.board {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  padding: var(--gap);
  background: #11171d;
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow:
    0 26px 70px rgba(0, 0, 0, 0.42),
    inset 0 1px 0 rgba(255, 255, 255, 0.045);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

/* 背景格层：4×4 网格 */
.cells {
  position: absolute;
  inset: var(--gap);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
}

.cell {
  border-radius: 12px;
  background: var(--cell-bg);
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* 方块层：绝对定位，方块用 transform 移动 */
.tiles {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

/* 单个方块：位移动画由 transform 完成 */
.tile {
  position: absolute;
  top: 0;
  left: 0;
  width: var(--cell);
  height: var(--cell);
  transition: transform 140ms cubic-bezier(0.25, 0.8, 0.3, 1);
  will-change: transform;
}

/* 方块数字面：缩放/透明度动画载体 */
.tile-face {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--tile-bg);
  color: var(--tile-color);
  font-weight: 800;
  line-height: 1;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.22),
    inset 0 -8px 16px rgba(0, 0, 0, 0.1),
    0 4px 14px rgba(0, 0, 0, 0.24);
  transition: opacity 110ms ease, transform 110ms ease;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0;
}

.tile-face.len-1,
.tile-face.len-2 {
  font-size: 42px;
}

.tile-face.len-3 {
  font-size: 32px;
}

.tile-face.len-4 {
  font-size: 24px;
}

.tile-face.len-5 {
  font-size: 19px;
}

.tile-face.len-6 {
  font-size: 15px;
}

.tile.spawn .tile-face {
  animation: spawn 180ms ease-out;
}

.tile.merge .tile-face {
  animation: merge 220ms ease;
  z-index: 2;
}

.tile.dying .tile-face {
  opacity: 0;
  transform: scale(0.5);
}

/* 方块数值配色（2 ~ 2048 专属色，超出用 .t-super） */
.t-2 { --tile-bg: #d9e3eb; --tile-color: #19232c; }
.t-4 { --tile-bg: #bfe6d7; --tile-color: #0f392d; }
.t-8 { --tile-bg: #ffb26b; --tile-color: #3b210b; }
.t-16 { --tile-bg: #ff8d63; --tile-color: #3a1706; }
.t-32 { --tile-bg: #ff6f8f; --tile-color: #3b0719; }
.t-64 { --tile-bg: #e85d6f; --tile-color: #ffffff; }
.t-128 { --tile-bg: #b995ff; --tile-color: #241244; }
.t-256 { --tile-bg: #62d7ff; --tile-color: #062d3d; }
.t-512 { --tile-bg: #4ce3a3; --tile-color: #073522; }
.t-1024 { --tile-bg: #ffd166; --tile-color: #3a2800; }
.t-2048 { --tile-bg: #ff5d8f; --tile-color: #ffffff; }

.t-super {
  --tile-bg: #2b3640;
  --tile-color: #eef4f7;
  border: 1px solid rgba(255, 255, 255, 0.18);
}

/* 新方块出现的动画 */
@keyframes spawn {
  0% {
    transform: scale(0.35);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

/* 合并时的「弹跳」动画 */
@keyframes merge {
  0% {
    transform: scale(0.5);
  }
  55% {
    transform: scale(1.16);
  }
  100% {
    transform: scale(1);
  }
}

/* 结算/排行榜弹窗遮罩 */
.overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(10, 14, 18, 0.78);
  backdrop-filter: blur(7px);
  -webkit-backdrop-filter: blur(7px);
  border-radius: 20px;
  z-index: 10;
  animation: fade-in 240ms ease;
}

/* 弹窗面板 */
.overlay-panel {
  max-width: 78%;
  padding: 26px 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
  background: #151c22;
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}

.overlay-panel h2 {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: 0;
}

.overlay-panel p {
  font-size: 15px;
  color: var(--muted);
  letter-spacing: 0;
}

.overlay-actions {
  display: flex;
  gap: 10px;
  margin-top: 8px;
}

/* 按钮样式：ghost 描边按钮与 primary 主按钮 */
.ghost-btn,
.primary-btn {
  height: 42px;
  padding: 0 18px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 0;
  transition: transform 100ms ease, background 150ms ease, border-color 150ms ease;
}

.ghost-btn {
  background: transparent;
  color: #c6d0d8;
  border: 1px solid var(--line);
}

.ghost-btn:hover {
  border-color: rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.04);
}

.primary-btn {
  background: #62d9a5;
  color: #09231a;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.primary-btn:hover {
  background: #74e3b2;
}

.ghost-btn:active,
.primary-btn:active {
  transform: scale(0.96);
}

/* 页脚 */
.footer {
  margin-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #5d6973;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0;
}

.footer-mark {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  width: 14px;
  height: 14px;
}

.footer-mark i {
  border-radius: 2px;
}

/* 通用隐藏类 */
.hidden {
  display: none !important;
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* 移动端适配：窄屏下压缩字号与间距 */
@media (max-width: 460px) {
  body {
    padding: 18px 12px 24px;
  }

  .shell {
    width: min(94vw, 420px);
  }

  h1 {
    font-size: 38px;
  }

  .logo {
    width: 30px;
    height: 30px;
    border-radius: 8px;
  }

  .score-box {
    min-width: 86px;
    padding: 8px 10px;
  }

  .score-value {
    font-size: 19px;
  }

  .icon-btn {
    width: 38px;
    height: 38px;
  }

  .tile-face.len-1,
  .tile-face.len-2 {
    font-size: 36px;
  }

  .tile-face.len-3 {
    font-size: 28px;
  }

  .tile-face.len-4 {
    font-size: 21px;
  }

  .tile-face.len-5 {
    font-size: 17px;
  }

  .tile-face.len-6 {
    font-size: 13px;
  }
}

/* 系统偏好「减少动效」时关闭动画 */
@media (prefers-reduced-motion: reduce) {
  .tile,
  .tile-face,
  .score-value {
    transition: none;
  }

  .tile.spawn .tile-face,
  .tile.merge .tile-face,
  .overlay {
    animation: none;
  }
}


/* 游戏结束后的成绩保存表单 */
.save-form {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 6px;
}

.save-form .primary-btn {
  width: 100%;
}

.name-input {
  height: 42px;
  padding: 0 14px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: #10161b;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  outline: none;
  letter-spacing: 0;
}

.name-input:focus {
  border-color: #62d9a5;
  box-shadow: 0 0 0 3px rgba(98, 217, 165, 0.15);
}

.name-input::placeholder {
  color: #5d6973;
}

/* ---------- 排行榜 ---------- */
.leaderboard-overlay {
  z-index: 20;
}

.leaderboard-panel {
  width: min(88%, 380px);
  max-width: 88%;
  padding: 22px;
  align-items: stretch;
  gap: 14px;
  text-align: left;
}

.leaderboard-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.leaderboard-head h2 {
  font-size: 24px;
}

.leaderboard-head .icon-btn {
  width: 34px;
  height: 34px;
}

.leaderboard-head .icon-btn svg {
  width: 17px;
  height: 17px;
}

.leaderboard-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 320px;
  overflow-y: auto;
}

/* 排行榜单行：名次 / 名字 / 分数 / 日期 */
.leaderboard-row {
  display: grid;
  grid-template-columns: 34px 1fr auto auto;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  background: #1b232b;
  border: 1px solid var(--line);
  border-radius: 10px;
  font-size: 13px;
}

.leaderboard-rank {
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #242d35;
  color: #9aa7b1;
  font-weight: 800;
  font-size: 12px;
}

/* 前三名的名次徽章配色 */
.leaderboard-row.top .leaderboard-rank {
  color: #12231a;
}

.leaderboard-row.top-1 .leaderboard-rank {
  background: #ffd166;
}

.leaderboard-row.top-2 .leaderboard-rank {
  background: #c9d4dc;
}

.leaderboard-row.top-3 .leaderboard-rank {
  background: #e8a06c;
}

.leaderboard-name {
  font-weight: 700;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.leaderboard-score {
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  color: #62d9a5;
}

.leaderboard-meta {
  color: var(--muted);
  font-size: 12px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.leaderboard-empty {
  padding: 18px 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.leaderboard-panel .ghost-btn {
  align-self: center;
  min-width: 120px;
}

@media (max-width: 460px) {
  .leaderboard-panel {
    width: 92%;
  }

  .leaderboard-row {
    grid-template-columns: 30px 1fr auto;
    gap: 8px;
  }

  .leaderboard-meta {
    display: none;
  }
}