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

:root {
  --bg:      #0d1117;
  --surface: #161b22;
  --card-bg: #1c2333;
  --border:  #30363d;
  --accent:  #58a6ff;
  --text:    #c9d1d9;
  --dim:     #6e7681;
  --match:   #238636;
  --danger:  #da3633;
  --warn:    #e3b341;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Courier New', Courier, monospace;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hidden { display: none !important; }

/* ── HUD ─────────────────────────────────────────── */

.hud {
  position: sticky;
  top: 0;
  width: 100%;
  max-width: 640px;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.hud-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
  min-width: 0;
}

.hud-label {
  font-size: 0.55rem;
  color: var(--dim);
  letter-spacing: 0.1em;
}

.hud-val {
  font-size: 1.1rem;
  font-weight: bold;
  color: var(--accent);
}

.btn-icon {
  background: none;
  border: 1px solid var(--border);
  color: var(--dim);
  font-size: 1.1rem;
  cursor: pointer;
  border-radius: 6px;
  padding: 0.2rem 0.55rem;
  line-height: 1;
  transition: border-color 0.15s, color 0.15s;
  flex-shrink: 0;
}
.btn-icon:hover { border-color: var(--accent); color: var(--accent); }

/* streak dots */
.streak-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
  padding: 0 0.25rem;
}
.streak-label {
  font-size: 0.5rem;
  color: var(--dim);
  letter-spacing: 0.08em;
  white-space: nowrap;
}
#streak-dots {
  display: flex;
  gap: 3px;
}
#streak-dots span {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: #2d3340;
  border: 1px solid #404758;
  transition: background 0.2s, border-color 0.2s;
}
#streak-dots span.lit  { background: var(--warn); border-color: #c8943d; }
#streak-dots span.warn { background: var(--danger); border-color: #a12828; }

/* penalty flash */
@keyframes penalty-flash {
  0%   { color: var(--danger); transform: scale(1.4); }
  100% { color: var(--accent); transform: scale(1); }
}
.penalty-flash { animation: penalty-flash 0.55s ease-out forwards; }

/* ── SCREENS ─────────────────────────────────────── */

.screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 640px;
  padding: 2rem 1.25rem;
  flex: 1;
}

/* title */
#screen-title h1 {
  font-size: 3rem;
  letter-spacing: 0.35em;
  color: var(--accent);
  margin-bottom: 0.5rem;
  text-align: center;
}
#screen-title p {
  font-size: 0.82rem;
  color: var(--dim);
  text-align: center;
  margin-bottom: 2.5rem;
  line-height: 1.7;
}

.size-btns {
  display: flex;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
  justify-content: center;
}
.size-btns button {
  background: var(--surface);
  border: 2px solid var(--border);
  color: var(--text);
  font-family: inherit;
  font-size: 1.15rem;
  font-weight: bold;
  padding: 0.9rem 1.4rem;
  border-radius: 10px;
  cursor: pointer;
  transition: border-color 0.15s, transform 0.15s;
  text-align: center;
  min-width: 88px;
  line-height: 1.4;
}
.size-btns button small {
  display: block;
  font-size: 0.62rem;
  font-weight: normal;
  color: var(--dim);
  letter-spacing: 0.05em;
}
.size-btns button:hover { border-color: var(--accent); transform: translateY(-2px); }

.rules {
  font-size: 0.8rem;
  color: var(--dim);
  text-align: center;
  line-height: 2.4;
}
.pts  { color: #4caf50; font-weight: bold; }
.pen  { color: var(--danger); font-weight: bold; }

/* game */
#screen-game {
  justify-content: flex-start;
  padding-top: 1rem;
  gap: 1rem;
  min-height: calc(100svh - 52px);
}

.grid {
  display: grid;
  width: 100%;
  max-width: 600px;
}

/* ── CARD ────────────────────────────────────────── */

.card {
  cursor: pointer;
  perspective: 700px;
  aspect-ratio: 1;
  user-select: none;
  touch-action: manipulation;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.34s cubic-bezier(0.4, 0, 0.2, 1);
}
.card-inner.flipped { transform: rotateY(180deg); }

.card-back,
.card-face {
  position: absolute;
  inset: 0;
  border-radius: 8px;
  backface-visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.card-back {
  background: var(--card-bg);
  border: 2px solid var(--border);
  background-image:
    radial-gradient(circle, #2d3a4f 1.5px, transparent 1.5px);
  background-size: 14px 14px;
}

.card-face {
  background: #eef0f5;
  border: 2px solid var(--border);
  transform: rotateY(180deg);
  padding: 14%;
}
.card-face svg { width: 100%; height: 100%; }

.card.matched .card-face {
  background: #0d2118;
  border-color: var(--match);
}
.card.matched .card-inner { opacity: 0.6; }

/* ── WIN SCREEN ──────────────────────────────────── */

#screen-win h1 {
  font-size: 2.6rem;
  color: #4caf50;
  letter-spacing: 0.2em;
  margin-bottom: 2rem;
  text-align: center;
}
.win-stats {
  display: flex;
  gap: 2rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
  justify-content: center;
}
.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}
.stat-label { font-size: 0.6rem; color: var(--dim); letter-spacing: 0.1em; }
.stat-val   { font-size: 1.6rem; font-weight: bold; color: var(--accent); }

.btn-primary {
  background: var(--accent);
  color: #0d1117;
  border: none;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: bold;
  letter-spacing: 0.12em;
  padding: 0.8rem 2.2rem;
  border-radius: 8px;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.15s;
}
.btn-primary:hover { opacity: 0.85; transform: translateY(-2px); }

/* ── RESPONSIVE ──────────────────────────────────── */

@media (max-width: 400px) {
  .card-face { padding: 8%; }
  .card-back {
    background-size: 10px 10px;
    border-radius: 6px;
  }
  .card-face { border-radius: 6px; }
}