/* ================================================================
   COMPONENT: Button
   FILE: components/button/button.css
   ================================================================ */

.ui-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 22px;
  font-family: var(--ui-font);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
  border: 1.5px solid transparent;
  border-radius: var(--r-md);
  cursor: pointer;
  outline: none;
  text-decoration: none;
  user-select: none;
  transition:
    background var(--t-base),
    color var(--t-base),
    border-color var(--t-base),
    box-shadow var(--t-base),
    transform var(--t-fast);
  overflow: hidden;
}
.ui-btn:active:not(:disabled) { transform: scale(0.975); }
.ui-btn:focus-visible          { box-shadow: var(--sh-focus); }
.ui-btn:disabled               { opacity: 0.45; cursor: not-allowed; pointer-events: none; }

/* ---- Inner label (hidden while loading) ---- */
.ui-btn__lbl {
  display: flex;
  align-items: center;
  gap: 6px;
  transition: opacity var(--t-fast);
}

/* ---- Spinner ---- */
.ui-btn__spin {
  position: absolute;
  width: 18px; height: 18px;
  border: 2.5px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: uiBtnSpin 0.7s linear infinite;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-fast);
}
@keyframes uiBtnSpin { to { transform: rotate(360deg); } }

/* ---- Loading state ---- */
.ui-btn--loading .ui-btn__lbl  { opacity: 0; }
.ui-btn--loading .ui-btn__spin { opacity: 1; }
.ui-btn--loading               { pointer-events: none; }

/* ---- Sizes ---- */
.ui-btn--sm   { height: 36px; padding: 0 16px; font-size: 13px; }
.ui-btn--full { width: 100%; }

/* ---- Variant: Primary ---- */
.ui-btn--primary {
  background: var(--ui-primary);
  color: #fff;
  border-color: var(--ui-primary);
  box-shadow: 0 1px 3px rgba(26,107,74,.28), inset 0 1px 0 rgba(255,255,255,.08);
}
.ui-btn--primary:hover:not(:disabled) {
  background: var(--ui-primary-dark);
  border-color: var(--ui-primary-dark);
  box-shadow: 0 4px 14px rgba(26,107,74,.35);
}
.ui-btn--primary:focus-visible {
  box-shadow: var(--sh-focus), 0 1px 3px rgba(26,107,74,.28);
}

/* ---- Variant: Secondary ---- */
.ui-btn--secondary {
  background: var(--ui-white);
  color: var(--ui-primary);
  border-color: var(--ui-primary);
}
.ui-btn--secondary:hover:not(:disabled) { background: var(--ui-primary-light); }

/* ---- Variant: Ghost ---- */
.ui-btn--ghost {
  background: transparent;
  color: var(--ui-text-2);
  border-color: var(--ui-border);
}
.ui-btn--ghost:hover:not(:disabled) {
  background: var(--ui-surface-alt);
  border-color: var(--ui-border-mid);
  color: var(--ui-text-1);
}

/* ---- Variant: Danger ---- */
.ui-btn--danger {
  background: var(--ui-error);
  color: #fff;
  border-color: var(--ui-error);
}
.ui-btn--danger:hover:not(:disabled) { background: #a8211a; border-color: #a8211a; }
.ui-btn--danger:focus-visible        { box-shadow: 0 0 0 3px var(--ui-error-glow); }