.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 10px 18px; border-radius: var(--border-radius);
  font-family: var(--font); font-size: 0.95rem; font-weight: 500;
  cursor: pointer; transition: background 0.15s, opacity 0.15s, border-color 0.15s;
  color: var(--text-primary); background: var(--bg-card);
  /* Outline keeps button distinguishable in light theme where bg-card ≈ page bg. */
  border: 1px solid var(--border-color);
}
/* Light-theme: 10% alpha vanishes on near-white; bump to ~22%. */
[data-theme="light"] .btn {
  border-color: rgba(0, 0, 0, 0.22);
}
/* Board stays dark in light theme; reset outline back to dark border. */
[data-theme="light"] .board-wrap .btn {
  border-color: var(--border-color);
}
/* popup-card opts back into cream (see theme.css); restore darker outline. */
[data-theme="light"] .board-wrap .popup-card .btn {
  border-color: rgba(0, 0, 0, 0.22);
}
.btn:hover:not(:disabled) { background: var(--bg-hover); border-color: var(--bg-hover); }
.btn:disabled { opacity: 0.35; cursor: not-allowed; }

.btn-primary {
  background: var(--accent-green); color: #fff; font-weight: 600;
  border-color: transparent;
}
.btn-primary:hover:not(:disabled) { background: var(--accent-green-hover); border-color: transparent; }

.btn-danger { background: var(--accent-red); color: #fff; border-color: transparent; }
.btn-danger:hover:not(:disabled) { background: var(--accent-red-hover); border-color: transparent; }

.btn-sm { padding: 6px 12px; font-size: 0.85rem; }
.btn-lg { padding: 14px 32px; font-size: 1.1rem; }

.btn-warning {
  background: var(--accent-gold);
  color: var(--text-dark);
  border: 1px solid var(--accent-gold);
  font-weight: 700;
}
.btn-warning:hover { background: color-mix(in srgb, var(--accent-gold) 88%, black); }

.btn-remove { padding: 2px 6px; font-size: 0.7rem; background: var(--accent-red); color: #fff; flex-shrink: 0; }
.btn-action {
  width: 100%; text-align: left; padding: 9px 12px; font-size: 0.9rem;
  display: flex; align-items: center; gap: 8px;
  background: var(--bg-card); border: 2px solid transparent;
  border-radius: var(--border-radius); transition: border-color 0.15s, background 0.15s;
}
.btn-action:hover:not(:disabled) { background: var(--bg-hover); }
.btn-action.active { border-color: var(--accent-green); background: var(--bg-hover); }
.btn-action.active .a-cost { color: var(--text-primary); }
.btn-action:disabled { cursor: help; }
.btn-end-turn {
  width: 100%; padding: 10px; font-size: 0.95rem; font-weight: 600;
  background: var(--accent-green); color: #fff; border: none;
  border-radius: var(--border-radius); cursor: pointer;
  transition: background 0.15s, color 0.15s, opacity 0.15s; flex-shrink: 0;
}
.btn-end-turn:hover:not(:disabled) { background: var(--accent-green-hover); }
.btn-end-turn:disabled,
.btn-end-turn-disabled {
  background: var(--bg-hover);
  color: var(--text-muted);
  cursor: not-allowed;
  opacity: 0.7;
}
.btn-xs { font-size: 0.65rem; padding: 2px 6px; border-radius: 4px; }
.btn-copy-log { font-size: 0.75rem; padding: 2px 8px; }
.btn-chase-unit {
  font-size: 0.8rem; padding: 6px 10px; display: inline-flex;
  align-items: center; gap: 6px;
}