/* ==========================================================================
   主题管线
   每个主题就是一组 CSS 变量。想新增主题：
   1. 在下面加一个 [data-theme="你的主题id"] 变量块（照抄 :root 里的变量名）
   2. 在 js/themes.js 的 THEMES 数组里注册 { id, name }
   就完成了，页面会自动支持切换与记忆。
   ========================================================================== */

:root,
[data-theme="classic"] {
  --bg: #faf8ef;
  --text: #776e65;
  --text-strong: #6b6157;
  --board-bg: #bbada0;
  --cell-bg: rgba(238, 228, 218, 0.35);
  --btn-bg: #8f7a66;
  --btn-fg: #f9f6f2;
  --overlay-bg: rgba(250, 248, 239, 0.78);
  --gap: 10px;

  --t2: #eee4da;    --t2f: #776e65;
  --t4: #ede0c8;    --t4f: #776e65;
  --t8: #f2b179;    --t8f: #f9f6f2;
  --t16: #f59563;   --t16f: #f9f6f2;
  --t32: #f67c5f;   --t32f: #f9f6f2;
  --t64: #f65e3b;   --t64f: #f9f6f2;
  --t128: #edcf72;  --t128f: #f9f6f2;
  --t256: #edcc61;  --t256f: #f9f6f2;
  --t512: #edc850;  --t512f: #f9f6f2;
  --t1024: #edc53f; --t1024f: #f9f6f2;
  --t2048: #edc22e; --t2048f: #f9f6f2;
  --tsuper: #3c3a32; --tsuperf: #f9f6f2;
}

[data-theme="dark"] {
  --bg: #17141f;
  --text: #b8b3c8;
  --text-strong: #ece9f5;
  --board-bg: #2b2740;
  --cell-bg: rgba(255, 255, 255, 0.07);
  --btn-bg: #6f5fd8;
  --btn-fg: #ffffff;
  --overlay-bg: rgba(23, 20, 31, 0.85);

  --t2: #3e3a55;    --t2f: #e8e6f0;
  --t4: #4a4470;    --t4f: #e8e6f0;
  --t8: #6f5fd8;    --t8f: #ffffff;
  --t16: #8b5cf6;   --t16f: #ffffff;
  --t32: #a855f7;   --t32f: #ffffff;
  --t64: #d946ef;   --t64f: #ffffff;
  --t128: #ec4899;  --t128f: #ffffff;
  --t256: #f43f5e;  --t256f: #ffffff;
  --t512: #fb923c;  --t512f: #ffffff;
  --t1024: #facc15; --t1024f: #1f1a2e;
  --t2048: #4ade80; --t2048f: #14301f;
  --tsuper: #f9f6f2; --tsuperf: #1f1a2e;
}

[data-theme="milkfrog"] {
  --bg: #f6f2e2;
  --text: #6e6a58;
  --text-strong: #57543f;
  --board-bg: #a9bb92;
  --cell-bg: rgba(255, 255, 255, 0.3);
  --btn-bg: #7a9c68;
  --btn-fg: #ffffff;
  --overlay-bg: rgba(246, 242, 226, 0.82);

  --t2: #ece5c4;    --t2f: #6e6a58;
  --t4: #dfe8b0;    --t4f: #5f6544;
  --t8: #cbe6a0;    --t8f: #556338;
  --t16: #b2df9e;   --t16f: #476637;
  --t32: #93d8a4;   --t32f: #356a49;
  --t64: #74cdab;   --t64f: #286851;
  --t128: #6cc3cc;  --t128f: #245e66;
  --t256: #66abdd;  --t256f: #29526e;
  --t512: #8b97e2;  --t512f: #333a72;
  --t1024: #b48ade; --t1024f: #492c66;
  --t2048: #e78ab6; --t2048f: #672b48;
  --tsuper: #5a6472; --tsuperf: #f2f0e4;
}

/* ==========================================================================
   基础布局
   ========================================================================== */

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

body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: "Clear Sans", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  display: flex;
  justify-content: center;
  padding: 28px 0 48px;
  -webkit-tap-highlight-color: transparent;
}

.game {
  width: min(92vw, 480px);
  user-select: none;
}

.header {
  margin-bottom: 18px;
}

.title-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 12px;
  flex-wrap: wrap;
}

.title {
  font-size: clamp(44px, 13vw, 72px);
  line-height: 1;
  font-weight: 800;
  color: var(--text-strong);
}

.subtitle {
  display: block;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 3px;
  margin-top: 8px;
}

.scores {
  display: flex;
  gap: 8px;
}

.score-box {
  position: relative;
  min-width: 78px;
  padding: 8px 14px;
  border-radius: 6px;
  background: var(--board-bg);
  color: var(--btn-fg);
  text-align: center;
}

.score-label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  opacity: 0.85;
}

.score-value {
  display: block;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
}

.score-gain {
  position: absolute;
  left: 0;
  right: 0;
  top: 4px;
  font-size: 20px;
  font-weight: 700;
  pointer-events: none;
  animation: score-rise 0.7s ease-out forwards;
}

@keyframes score-rise {
  from { transform: translateY(0); opacity: 1; }
  to   { transform: translateY(-38px); opacity: 0; }
}

.actions-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.hint {
  flex: 1 1 220px;
  font-size: 14px;
  line-height: 1.6;
}

.buttons {
  display: flex;
  gap: 8px;
}

.btn {
  border: 0;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font: inherit;
  font-size: 15px;
  font-weight: 700;
  padding: 9px 16px;
  border-radius: 6px;
  cursor: pointer;
  touch-action: manipulation;
  transition: filter 0.1s ease, transform 0.05s ease;
}

.btn:hover { filter: brightness(1.1); }
.btn:active { transform: scale(0.96); }

.btn-icon {
  font-size: 16px;
  padding: 9px 11px;
}

.btn-ghost {
  background: transparent;
  border: 2px solid var(--btn-bg);
  color: var(--text-strong);
}

/* ==========================================================================
   棋盘与方块
   ========================================================================== */

.board {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  padding: var(--gap);
  background: var(--board-bg);
  border-radius: 10px;
  touch-action: none;
}

.cells {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(4, 1fr);
  gap: var(--gap);
  width: 100%;
  height: 100%;
}

.cell {
  background: var(--cell-bg);
  border-radius: 8px;
}

.tiles {
  position: absolute;
  inset: var(--gap);
  container-type: inline-size;
}

.tile {
  position: absolute;
  width: calc((100% - 3 * var(--gap)) / 4);
  aspect-ratio: 1;
  transform: translate(
    calc(var(--c) * (100% + var(--gap))),
    calc(var(--r) * (100% + var(--gap)))
  );
  transition: transform 120ms ease-in-out;
  will-change: transform;
}

.tile-inner {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-weight: 800;
}

/* 素材图层：仅奶蛙主题显示，透明 PNG 叠在色块上 */
.tile-art {
  display: none;
  position: absolute;
  inset: 0;
  border-radius: 8px;
  background-repeat: no-repeat;
  pointer-events: none;
}

.tile-num {
  line-height: 1;
  font-size: 44px;
  font-size: 11cqw;
}

.tile.tile-new .tile-inner {
  animation: tile-pop-in 170ms ease 50ms backwards;
}

@keyframes tile-pop-in {
  from { scale: 0; opacity: 0; }
  to   { scale: 1; opacity: 1; }
}

.tile.tile-merged .tile-inner {
  animation: tile-merge-pop 190ms ease;
}

@keyframes tile-merge-pop {
  0%   { scale: 1; }
  45%  { scale: 1.22; }
  100% { scale: 1; }
}

/* 数字块配色（来自主题变量）；--num-fill 供奶蛙主题的数字取色 */
.tile-2 .tile-inner     { background: var(--t2);     color: var(--t2f);     --num-fill: var(--t2); }
.tile-4 .tile-inner     { background: var(--t4);     color: var(--t4f);     --num-fill: var(--t4); }
.tile-8 .tile-inner     { background: var(--t8);     color: var(--t8f);     --num-fill: var(--t8); }
.tile-16 .tile-inner    { background: var(--t16);    color: var(--t16f);    --num-fill: var(--t16); }
.tile-32 .tile-inner    { background: var(--t32);    color: var(--t32f);    --num-fill: var(--t32); }
.tile-64 .tile-inner    { background: var(--t64);    color: var(--t64f);    --num-fill: var(--t64); }
.tile-128 .tile-inner   { background: var(--t128);   color: var(--t128f);   --num-fill: var(--t128); }
.tile-256 .tile-inner   { background: var(--t256);   color: var(--t256f);   --num-fill: var(--t256); }
.tile-512 .tile-inner   { background: var(--t512);   color: var(--t512f);   --num-fill: var(--t512); }
.tile-1024 .tile-inner  { background: var(--t1024);  color: var(--t1024f);  --num-fill: var(--t1024); }
.tile-2048 .tile-inner  { background: var(--t2048);  color: var(--t2048f);  --num-fill: var(--t2048); }
.tile-super .tile-inner { background: var(--tsuper); color: var(--tsuperf); --num-fill: var(--tsuper); }

/* 数字字号按位数递减 */
.tile-128 .tile-num, .tile-256 .tile-num, .tile-512 .tile-num { font-size: 9cqw; }
.tile-1024 .tile-num, .tile-2048 .tile-num, .tile-super .tile-num { font-size: 7cqw; }

/* 奶蛙主题：显示素材图；数字放左下角，白描边、字色与色块一致 */
[data-theme="milkfrog"] .tile-art {
  display: block;
  background-position: center 38%;
  background-size: 86%;
}

[data-theme="milkfrog"] .tile-num {
  position: absolute;
  left: 1.4cqw;
  bottom: 0.7cqw;
  color: var(--num-fill);
  font-size: 7cqw;
  text-shadow:
    0.09em 0 0 #fff, -0.09em 0 0 #fff,
    0 0.09em 0 #fff, 0 -0.09em 0 #fff,
    0.065em 0.065em 0 #fff, -0.065em -0.065em 0 #fff,
    0.065em -0.065em 0 #fff, -0.065em 0.065em 0 #fff;
}

[data-theme="milkfrog"] .tile-1024 .tile-num,
[data-theme="milkfrog"] .tile-2048 .tile-num,
[data-theme="milkfrog"] .tile-super .tile-num {
  font-size: 5.6cqw;
}

/* ==========================================================================
   胜利 / 失败遮罩
   ========================================================================== */

.overlay {
  position: absolute;
  inset: 0;
  z-index: 10;
  border-radius: 10px;
  background: var(--overlay-bg);
  backdrop-filter: blur(2px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  text-align: center;
  padding: 20px;
  animation: overlay-fade 0.3s ease;
}

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

.overlay.hidden { display: none; }

.overlay-title {
  font-size: clamp(32px, 10vw, 46px);
  font-weight: 800;
  color: var(--text-strong);
}

.overlay-sub {
  font-size: 16px;
  max-width: 260px;
  line-height: 1.5;
}

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

.hidden { display: none; }

/* ==========================================================================
   排行榜弹窗与提交状态
   ========================================================================== */

.lb-status {
  margin-top: 12px;
  font-size: 14px;
  font-weight: 700;
}

.lb-status.ok { color: #2e9e5b; }
.lb-status.err { color: #d9534f; }

.lb-retry {
  margin-left: 8px;
  padding: 4px 10px;
  font-size: 12px;
}

.lb-modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lb-modal.hidden { display: none; }

.lb-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

.lb-panel {
  position: relative;
  width: min(92vw, 420px);
  max-height: min(80vh, 640px);
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
  animation: lb-in 0.22s ease;
}

@keyframes lb-in {
  from { opacity: 0; transform: translateY(14px) scale(0.98); }
  to   { opacity: 1; transform: none; }
}

.lb-head {
  display: flex;
  align-items: center;
  gap: 10px;
}

.lb-head h2 {
  flex: 1;
  font-size: 22px;
  color: var(--text-strong);
}

.lb-mode {
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
}

.lb-mode.online {
  background: #4ade80;
  color: #14301f;
}

.lb-mode.local {
  background: var(--board-bg);
  color: var(--btn-fg);
}

.lb-me {
  font-size: 13px;
  margin: 14px 0 10px;
}

.lb-identity {
  font-weight: 800;
  color: var(--text-strong);
}

.lb-list {
  list-style: none;
  overflow-y: auto;
  flex: 1;
  min-height: 120px;
}

.lb-list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) 48px 64px 64px;
  align-items: center;
  gap: 6px;
  padding: 8px 6px;
  border-bottom: 1px solid rgba(128, 128, 128, 0.15);
  font-size: 14px;
}

.lb-list li.mine {
  background: var(--cell-bg);
  border-radius: 6px;
}

.lb-rank { font-weight: 800; text-align: center; }
li.top1 .lb-rank { color: #d4a017; }
li.top2 .lb-rank { color: #9aa0a6; }
li.top3 .lb-rank { color: #b08d57; }

.lb-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lb-tile {
  font-size: 12px;
  opacity: 0.8;
  text-align: right;
}

.lb-score {
  font-weight: 800;
  color: var(--text-strong);
  text-align: right;
}

.lb-time {
  font-size: 11px;
  opacity: 0.6;
  text-align: right;
}

/* 提示行（空列表/加载中/出错）：覆盖上面 li 的 5 列网格，改为整行居中 */
.lb-list li.lb-msg {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 28px 0;
  border-bottom: none;
  opacity: 0.85;
}

.lb-foot {
  font-size: 12px;
  opacity: 0.7;
  margin-top: 10px;
  line-height: 1.5;
}

/* ==========================================================================
   页脚与响应式
   ========================================================================== */

.footer {
  margin-top: 20px;
  text-align: center;
  font-size: 13px;
  line-height: 1.8;
  opacity: 0.75;
}

@media (max-width: 420px) {
  :root {
    --gap: 8px;
  }

  body {
    padding-top: 18px;
  }

  .subtitle {
    letter-spacing: 2px;
  }

  .hint {
    font-size: 13px;
  }

  .btn {
    padding: 8px 13px;
    font-size: 14px;
  }
}