@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

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

:root {
  --bg:           #0e0d0d;
  --surface:      #161515;
  --surface-2:    #1e1c1c;
  --border:       #2d2b2b;
  --border-bright:#3d3b3b;
  --accent:       #47D8D7;
  --accent-dim:   rgba(71, 216, 215, 0.1);
  --accent-glow:  rgba(71, 216, 215, 0.2);
  --text:         #ffffff;
  --text-muted:   #7a7575;
  --text-dim:     #3d3b3b;
  --green:        #22c55e;
  --red:          #ef4444;
  --orange:       #f97316;
  --radius-sm:    6px;
  --radius:       10px;
  --radius-lg:    14px;
  --radius-pill:  999px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  line-height: 1.6;
}

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 3px; }

/* ── Navigation ── */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 200;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  background: rgba(21, 19, 19, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
}
.nav-logo em { font-style: normal; color: var(--accent); }

.nav-back {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: color 0.15s;
}
.nav-back svg { transition: transform 0.15s; }
.nav-back:hover { color: var(--text); }
.nav-back:hover svg { transform: translateX(-2px); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-pill);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: all 0.15s ease;
  white-space: nowrap;
  user-select: none;
}

.btn-primary {
  background: var(--accent);
  color: #0a0909;
}
.btn-primary:hover { background: #65e4e3; }
.btn-primary:active { background: #3bc5c4; }

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--border-bright); color: var(--text); }

.btn-lg {
  padding: 0.75rem 1.8rem;
  font-size: 0.9rem;
}

.btn-xl {
  padding: 0.9rem 2.4rem;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
}

/* ── Cards ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: border-color 0.2s;
}

.card:hover { border-color: var(--border-bright); }

/* ── Difficulty indicator ── */
.diff { display: flex; gap: 5px; align-items: center; }
.diff-pip {
  width: 28px;
  height: 4px;
  border-radius: 2px;
  background: var(--border-bright);
}
.diff-pip.on-easy   { background: var(--green); }
.diff-pip.on-medium { background: var(--orange); }
.diff-pip.on-hard   { background: var(--red); }

/* ── Stat boxes ── */
.stat-box {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1.25rem;
  text-align: center;
  min-width: 80px;
}
.stat-box .stat-val {
  font-size: 1.6rem;
  font-weight: 800;
  line-height: 1;
  color: var(--accent);
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}
.stat-box .stat-lbl {
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-top: 0.3rem;
}

/* ── Game overlay ── */
.overlay {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  background: rgba(14, 13, 13, 0.94);
  backdrop-filter: blur(6px);
}
.overlay.hidden { display: none; }

/* ── Game area ── */
.game-area {
  position: relative;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  cursor: crosshair;
}

/* ── Animations ── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.9); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes ripple {
  0% { transform: translate(-50%,-50%) scale(0); opacity: 0.5; }
  100% { transform: translate(-50%,-50%) scale(2.5); opacity: 0; }
}

.animate-in { animation: fadeIn 0.35s ease both; }

/* ── Layout ── */
.container { max-width: 1160px; margin: 0 auto; padding: 0 2rem; }
.page-content { padding-top: 60px; }

/* ── Text helpers ── */
.text-accent { color: var(--accent); }
.text-muted  { color: var(--text-muted); }
.font-mono   { font-family: 'Courier New', monospace; }

/* ── Grids ── */
@media (max-width: 900px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr) !important; }
  .grid-3 { grid-template-columns: repeat(2, 1fr) !important; }
}
@media (max-width: 600px) {
  .container { padding: 0 1rem; }
  .nav { padding: 0 1rem; }
}