/* ============================================================
   Actions — Button, IconButton
   ============================================================ */
.fcs-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--label-font);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--label-tracking);
  line-height: 1;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  text-decoration: none;
  user-select: none;
  -webkit-user-select: none;
  transition: var(--transition-colors), transform var(--dur-fast) var(--ease-standard);
}
.fcs-btn:focus-visible { outline: none; box-shadow: var(--ring-focus); }
.fcs-btn:active { transform: translateY(0.5px); }
.fcs-btn:disabled, .fcs-btn.is-disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }
.fcs-btn--full { width: 100%; }

/* sizes */
.fcs-btn--sm { height: var(--control-h-sm); padding: 0 12px; font-size: 13px; }
.fcs-btn--md { height: var(--control-h-md); padding: 0 18px; font-size: 14px; }
.fcs-btn--lg { height: var(--control-h-lg); padding: 0 24px; font-size: 16px; }

/* variants */
.fcs-btn--primary { background: var(--brand-primary); color: #fff; }
.fcs-btn--primary:hover { background: var(--brand-primary-hover); }
.fcs-btn--primary:active { background: var(--brand-primary-active); }

.fcs-btn--secondary { background: var(--charcoal); color: #fff; }
.fcs-btn--secondary:hover { background: var(--slate-600); }
.fcs-btn--secondary:active { background: var(--slate-800); }

.fcs-btn--outline { background: var(--surface-card); color: var(--text-primary); border-color: var(--border-strong); }
.fcs-btn--outline:hover { background: var(--surface-hover); border-color: var(--neutral-400); }
.fcs-btn--outline:active { background: var(--surface-sunken); }

.fcs-btn--ghost { background: transparent; color: var(--text-primary); }
.fcs-btn--ghost:hover { background: var(--surface-hover); }
.fcs-btn--ghost:active { background: var(--surface-sunken); }

.fcs-btn--danger { background: var(--red-700); color: #fff; }
.fcs-btn--danger:hover { background: var(--red-800); }
.fcs-btn--danger:active { background: var(--red-900); }

.fcs-btn__spinner {
  width: 1em; height: 1em; border-radius: 50%;
  border: 2px solid currentColor; border-right-color: transparent;
  animation: fcs-spin var(--dur-slower) linear infinite;
}
.fcs-btn__label { display: inline-flex; align-items: center; }
.fcs-btn.is-loading .fcs-btn__label { opacity: 0.7; }

/* IconButton — square */
.fcs-iconbtn {
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer; padding: 0;
  transition: var(--transition-colors), transform var(--dur-fast) var(--ease-standard);
}
.fcs-iconbtn:focus-visible { outline: none; box-shadow: var(--ring-focus); }
.fcs-iconbtn:active { transform: translateY(0.5px); }
.fcs-iconbtn:disabled, .fcs-iconbtn.is-disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }
.fcs-iconbtn--sm { width: var(--control-h-sm); height: var(--control-h-sm); }
.fcs-iconbtn--md { width: var(--control-h-md); height: var(--control-h-md); }
.fcs-iconbtn--lg { width: var(--control-h-lg); height: var(--control-h-lg); }
.fcs-iconbtn--round { border-radius: var(--radius-full); }

.fcs-iconbtn--primary { background: var(--brand-primary); color: #fff; }
.fcs-iconbtn--primary:hover { background: var(--brand-primary-hover); }
.fcs-iconbtn--secondary { background: var(--charcoal); color: #fff; }
.fcs-iconbtn--secondary:hover { background: var(--slate-600); }
.fcs-iconbtn--outline { background: var(--surface-card); color: var(--text-primary); border-color: var(--border-strong); }
.fcs-iconbtn--outline:hover { background: var(--surface-hover); border-color: var(--neutral-400); }
.fcs-iconbtn--ghost { background: transparent; color: var(--text-secondary); }
.fcs-iconbtn--ghost:hover { background: var(--surface-hover); color: var(--text-primary); }