:root {
  --bg: #07080f;
  --panel: #0c0e1a;
  --border: #1a1d35;
  --x: #ff3c6f;
  --o: #00e5ff;
  --win: #f5c400;
  --text: #dde3ff;
  --muted: #3a3f6a;
  --easy: #2ecc71;
  --med: #f39c12;
  --hard: #e74c3c;
  --impossible: #9b59b6;
}
* { margin:0; padding:0; box-sizing:border-box; }

body {
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: 'Rajdhani', sans-serif;
  color: var(--text);
  position: relative;
  overflow: hidden;
}

.bg-grid {
  position: fixed; inset: 0; z-index: 0;
  background-image:
    linear-gradient(rgba(0,229,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,229,255,0.03) 1px, transparent 1px);
  background-size: 44px 44px;
  animation: gridDrift 20s linear infinite;
}
@keyframes gridDrift { from { background-position: 0 0; } to { background-position: 44px 44px; } }

body::after {
  content:''; position:fixed; inset:0; z-index:200; pointer-events:none;
  background: repeating-linear-gradient(transparent 0px, transparent 3px, rgba(0,0,0,0.06) 3px, rgba(0,0,0,0.06) 4px);
}

.wrap {
  position: relative; z-index: 1;
  display: flex; flex-direction: column; align-items: center;
  gap: 16px; padding: 20px;
  max-width: 500px; width: 100%;
}

h1 {
  font-family: 'Orbitron', sans-serif;
  font-size: clamp(1.6rem, 5vw, 2.6rem);
  font-weight: 900;
  letter-spacing: 0.12em;
  background: linear-gradient(135deg, var(--x) 0%, var(--o) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 18px rgba(0,229,255,0.4));
  animation: titlePulse 4s ease-in-out infinite alternate;
}
@keyframes titlePulse {
  from { filter: drop-shadow(0 0 10px rgba(0,229,255,0.3)); }
  to   { filter: drop-shadow(0 0 28px rgba(255,60,111,0.5)); }
}

.section-label {
  font-size: 0.68rem; letter-spacing: 0.25em; text-transform: uppercase;
  color: var(--muted); align-self: flex-start;
}

.mode-row { display: flex; gap: 10px; width: 100%; }
.mode-btn {
  flex: 1; padding: 10px 0;
  font-family: 'Rajdhani', sans-serif;
  font-size: 0.8rem; font-weight: 600;
  letter-spacing: 0.15em; text-transform: uppercase;
  border: 1px solid var(--border); background: var(--panel);
  color: var(--muted); border-radius: 6px; cursor: pointer;
  transition: all 0.2s;
}
.mode-btn:hover { color: var(--text); border-color: var(--muted); }
.mode-btn.active {
  border-color: var(--o); color: var(--o);
  background: rgba(0,229,255,0.07);
  box-shadow: 0 0 14px rgba(0,229,255,0.2);
}

.diff-row {
  display: flex; gap: 8px; width: 100%;
  transition: opacity 0.3s;
  overflow: hidden;
}
.diff-row.hidden { opacity: 0; pointer-events: none; max-height: 0; margin-top: -16px; }
.diff-row:not(.hidden) { max-height: 60px; }

.diff-btn {
  flex: 1; padding: 8px 4px;
  font-family: 'Rajdhani', sans-serif;
  font-size: 0.7rem; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase;
  border: 1px solid var(--border); background: var(--panel);
  color: var(--muted); border-radius: 6px; cursor: pointer;
  transition: all 0.2s;
}
.diff-btn[data-d="easy"].active   { border-color:var(--easy); color:var(--easy); background:rgba(46,204,113,0.07); box-shadow:0 0 10px rgba(46,204,113,0.2); }
.diff-btn[data-d="medium"].active { border-color:var(--med);  color:var(--med);  background:rgba(243,156,18,0.07);  box-shadow:0 0 10px rgba(243,156,18,0.2); }
.diff-btn[data-d="hard"].active   { border-color:var(--hard); color:var(--hard); background:rgba(231,76,60,0.07);   box-shadow:0 0 10px rgba(231,76,60,0.2); }
.diff-btn[data-d="impossible"].active { border-color:var(--impossible); color:var(--impossible); background:rgba(155,89,182,0.07); box-shadow:0 0 10px rgba(155,89,182,0.2); }

.scoreboard { display: flex; gap: 14px; align-items: center; width: 100%; }
.score-box {
  flex: 1; display: flex; flex-direction: column; align-items: center;
  padding: 10px 8px; border: 1px solid var(--border);
  background: var(--panel); border-radius: 8px;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.score-box.glow-x { border-color: var(--x); box-shadow: 0 0 14px rgba(255,60,111,0.3); }
.score-box.glow-o { border-color: var(--o); box-shadow: 0 0 14px rgba(0,229,255,0.3); }
.score-name { font-size: 0.63rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--muted); }
.score-mark { font-family: 'Orbitron', sans-serif; font-size: 1.2rem; font-weight: 900; }
.score-mark.x { color: var(--x); text-shadow: 0 0 8px rgba(255,60,111,0.7); }
.score-mark.o { color: var(--o); text-shadow: 0 0 8px rgba(0,229,255,0.7); }
.score-num { font-size: 1.8rem; font-weight: 600; line-height: 1; }
.score-mid { font-family:'Orbitron',sans-serif; font-size:0.75rem; color:var(--muted); display:flex; flex-direction:column; align-items:center; gap:4px; }
.draws-lbl { font-size:0.65rem; }

.status {
  font-family: 'Orbitron', sans-serif;
  font-size: 0.7rem; letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--muted); height: 1.3em; transition: color 0.3s;
}
.status.win-x { color:var(--x); text-shadow:0 0 10px rgba(255,60,111,0.6); animation:blink .7s ease infinite alternate; }
.status.win-o { color:var(--o); text-shadow:0 0 10px rgba(0,229,255,0.6);  animation:blink .7s ease infinite alternate; }
.status.draw  { color:var(--win); }
@keyframes blink { from{opacity:.7} to{opacity:1} }

.board {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 7px;
  background: var(--border);
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 7px;
  box-shadow: 0 0 50px rgba(0,0,0,0.7);
}
.cell {
  width: clamp(86px,21vw,126px);
  height: clamp(86px,21vw,126px);
  background: var(--panel);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; position: relative; overflow: hidden;
  transition: background 0.15s;
}
.cell:not(.taken):hover { background: #11142a; }
.cell:not(.taken):hover::after {
  content: attr(data-h);
  position: absolute; font-family:'Orbitron',sans-serif;
  font-size:2.6rem; font-weight:900; opacity:0.09; color:var(--text);
}
.cell.taken { cursor: default; }
.cell svg { width:55%; height:55%; animation: popIn .22s cubic-bezier(.34,1.56,.64,1); }
@keyframes popIn { from{transform:scale(0) rotate(-15deg);opacity:0} to{transform:scale(1) rotate(0);opacity:1} }

.mark-x line { stroke:var(--x); stroke-width:9; stroke-linecap:round; filter:drop-shadow(0 0 5px rgba(255,60,111,.9)); }
.mark-o circle { stroke:var(--o); stroke-width:8; fill:none; filter:drop-shadow(0 0 5px rgba(0,229,255,.9)); stroke-dasharray:251; stroke-dashoffset:251; animation:drawO .28s ease forwards; }
@keyframes drawO { to{stroke-dashoffset:0} }

.cell.winner { background: rgba(245,196,0,0.06); }
.cell.winner::before {
  content:''; position:absolute; inset:0; border-radius:6px;
  border:2px solid var(--win); box-shadow:inset 0 0 14px rgba(245,196,0,0.15);
  animation:winPulse .9s ease infinite alternate;
}
@keyframes winPulse { from{opacity:.5} to{opacity:1} }

.cell.thinking { animation:thinkPulse .6s ease infinite alternate; }
@keyframes thinkPulse { from{background:rgba(0,229,255,.02)} to{background:rgba(0,229,255,.08)} }

/* Music button */
.music-bar {
  display: flex; align-items: center; gap: 10px;
  width: 100%; justify-content: center;
}
.music-btn {
  font-family:'Rajdhani',sans-serif; font-size:0.72rem; font-weight:600;
  letter-spacing:0.16em; text-transform:uppercase;
  padding:7px 18px; border:1px solid var(--muted);
  background:transparent; color:var(--muted);
  border-radius:6px; cursor:pointer; transition:all .2s;
  display:flex; align-items:center; gap:7px;
}
.music-btn:hover { border-color:var(--o); color:var(--o); }
.music-btn.on { border-color:var(--o); color:var(--o); background:rgba(0,229,255,0.07); box-shadow:0 0 10px rgba(0,229,255,.2); }
.music-btn .bars {
  display:flex; align-items:flex-end; gap:2px; height:14px;
}
.music-btn .bar {
  width:3px; background:currentColor; border-radius:2px;
  animation: none; transform-origin: bottom;
}
.music-btn.on .bar { animation: barBounce 0.7s ease-in-out infinite alternate; }
.music-btn.on .bar:nth-child(1) { animation-delay:0s;    height:6px; }
.music-btn.on .bar:nth-child(2) { animation-delay:0.15s; height:12px; }
.music-btn.on .bar:nth-child(3) { animation-delay:0.05s; height:9px; }
.music-btn.on .bar:nth-child(4) { animation-delay:0.2s;  height:14px; }
.music-btn:not(.on) .bar { height:4px; }
@keyframes barBounce {
  from { transform: scaleY(0.4); }
  to   { transform: scaleY(1.1); }
}
.vol-slider {
  -webkit-appearance:none; appearance:none;
  width:80px; height:4px; border-radius:2px;
  background: var(--border); outline:none; cursor:pointer;
  accent-color: var(--o);
}

.controls { display:flex; gap:10px; }
.btn {
  font-family:'Rajdhani',sans-serif; font-size:0.72rem; font-weight:600;
  letter-spacing:0.18em; text-transform:uppercase;
  padding:9px 22px; border:1px solid var(--muted);
  background:transparent; color:var(--muted);
  border-radius:6px; cursor:pointer; transition:all .2s;
}
.btn:hover { border-color:var(--o); color:var(--o); box-shadow:0 0 10px rgba(0,229,255,.15); }
.btn.primary { border-color:var(--x); color:var(--x); }
.btn.primary:hover { background:rgba(255,60,111,.08); box-shadow:0 0 14px rgba(255,60,111,.25); }

#overlay {
  position:fixed; inset:0; z-index:50;
  background:rgba(7,8,15,0.88);
  display:flex; align-items:center; justify-content:center;
  backdrop-filter:blur(4px);
  animation:fadeIn .25s ease;
}
#overlay.hidden { display:none; }
@keyframes fadeIn { from{opacity:0} to{opacity:1} }
.ov-box {
  background:var(--panel); border:1px solid var(--border); border-radius:14px;
  padding:36px 42px; text-align:center;
  display:flex; flex-direction:column; align-items:center; gap:14px;
  box-shadow:0 0 60px rgba(0,0,0,0.8);
  animation:slideUp .3s cubic-bezier(.34,1.56,.64,1);
}
@keyframes slideUp { from{transform:translateY(30px) scale(.95);opacity:0} to{transform:translateY(0) scale(1);opacity:1} }
.ov-emoji { font-size:3rem; }
.ov-title { font-family:'Orbitron',sans-serif; font-size:1.35rem; font-weight:900; }
.ov-title.win-x { color:var(--x); text-shadow:0 0 20px rgba(255,60,111,.6); }
.ov-title.win-o { color:var(--o); text-shadow:0 0 20px rgba(0,229,255,.6); }
.ov-title.draw  { color:var(--win); }
.ov-sub { font-size:0.78rem; letter-spacing:0.15em; text-transform:uppercase; color:var(--muted); }
.ov-btns { display:flex; gap:10px; margin-top:6px; }