:root {
  --primary: #d9a441;
  --primary-dark: #c28f34;
  --accent: #2f6a54;
  --accent-dark: #1f4a3d;
  --ink-on-gold: #4a3413;
  --success: #16a34a;
  --danger: #dc2626;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Karla', sans-serif;
  background: radial-gradient(circle at top, var(--accent) 0%, var(--accent-dark) 70%);
  color: #eef0ea;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.wrap { width: 100%; max-width: 480px; position: relative; }

.back-link { display: inline-block; margin-bottom: 20px; color: #eef0ea; text-decoration: none; font-size: 14px; opacity: 0.8; }
.back-link:hover { opacity: 1; }

.header-row { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; flex-wrap: wrap; }
.header-icon {
  width: 44px; height: 44px; border-radius: 12px;
  background: rgba(217, 164, 65, 0.15);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; flex-shrink: 0;
}
.title { font-family: 'Bitter', serif; font-size: 21px; margin: 0 0 2px; color: #fff; }
.subtitle { font-size: 13px; opacity: 0.8; margin: 0; }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.score-chip {
  font-size: 13px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(217, 164, 65, 0.3);
  border-radius: 999px;
  padding: 6px 12px;
}
.score-chip strong { color: var(--primary); font-family: 'JetBrains Mono', monospace; }
.restart-btn {
  border: 1px solid rgba(217, 164, 65, 0.4);
  background: transparent;
  color: #eef0ea;
  border-radius: 10px;
  padding: 7px 14px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
}
.restart-btn:hover { background: var(--primary); border-color: var(--primary); color: var(--ink-on-gold); }

.problem-card {
  background: rgba(0, 0, 0, 0.18);
  border-radius: 16px;
  padding: 28px 20px;
  text-align: center;
}

.cross-grid {
  display: grid;
  grid-template-columns: repeat(5, 52px);
  grid-auto-rows: 52px;
  gap: 6px;
  justify-content: center;
  margin: 0 auto 20px;
}
.cross-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 20px;
  font-weight: 700;
}
.cross-cell.number { color: #fff; }
.cross-cell.symbol { color: var(--primary); opacity: 0.85; }
.cross-cell.blank input {
  width: 100%;
  height: 100%;
  text-align: center;
  border-radius: 8px;
  border: 2px solid var(--primary);
  background: rgba(255, 255, 255, 0.95);
  color: #1f2a24;
  font-family: 'JetBrains Mono', monospace;
  font-size: 18px;
  font-weight: 700;
}
.cross-cell.blank input:focus { outline: none; box-shadow: 0 0 0 3px rgba(217, 164, 65, 0.4); }
.cross-cell.blank.correct input { border-color: var(--success); background: rgba(22, 163, 74, 0.25); color: #fff; }
.cross-cell.blank.wrong input { border-color: var(--danger); }

.primary-btn {
  background: var(--primary);
  color: var(--ink-on-gold);
  border: none;
  border-radius: 12px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 4px 0 0 var(--primary-dark);
}
.primary-btn:hover { filter: brightness(1.08); }
.primary-btn:active { transform: translateY(3px); box-shadow: 0 1px 0 0 var(--primary-dark); }

.feedback { min-height: 20px; margin-top: 14px; font-weight: 700; font-size: 14px; }
.feedback.correct { color: #7be3a0; }
.feedback.wrong { color: #ff9b9b; }

.win-banner {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 12px;
  background: rgba(22, 163, 74, 0.18);
  border: 1px solid var(--success);
  text-align: center;
  font-size: 14px;
}
.win-banner strong { color: var(--primary); font-family: 'JetBrains Mono', monospace; }
.hidden { display: none; }