.ui-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
  font-family: var(--font);
}

.ui-btn:active { transform: scale(0.97); }
.ui-btn--primary { background: var(--color-primary); color: #fff; }
.ui-btn--primary:hover { background: var(--color-primary-hover); }
.ui-btn--danger { background: var(--color-danger); color: #fff; }
.ui-btn--danger:hover { background: var(--color-danger-hover); }
.ui-btn--neutral { background: var(--color-neutral); color: #fff; }
.ui-btn--neutral:hover { background: var(--color-neutral-hover); }
.ui-btn--outline { background: transparent; border: 1.5px solid var(--color-primary); color: var(--color-primary); }
.ui-btn--outline:hover { background: var(--color-primary); color: #fff; }
.ui-btn--sm { padding: 4px 10px; font-size: 12px; }
.ui-btn--lg { padding: 12px 24px; font-size: 16px; }
.ui-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.ui-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.ui-card__header { padding: 16px 20px; border-bottom: 1px solid var(--color-border); font-weight: 600; }
.ui-card__body { padding: 20px; }
.ui-card__footer { padding: 12px 20px; border-top: 1px solid var(--color-border); background: var(--color-surface); }

.ui-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.ui-modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.ui-modal {
  background: var(--color-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  width: 90%;
  max-width: 480px;
  transform: translateY(-10px);
  transition: transform var(--transition);
}

.ui-modal-overlay.open .ui-modal { transform: translateY(0); }
.ui-modal__header { padding: 16px 20px; border-bottom: 1px solid var(--color-border); display: flex; justify-content: space-between; align-items: center; font-weight: 600; }
.ui-modal__close { background: none; border: none; cursor: pointer; font-size: 18px; color: var(--color-text-muted); }
.ui-modal__body { padding: 20px; }
.ui-modal__footer { padding: 12px 20px; border-top: 1px solid var(--color-border); display: flex; justify-content: flex-end; gap: 8px; }

.ui-dropdown { position: relative; display: inline-block; }
.ui-dropdown__trigger { cursor: pointer; }
.ui-dropdown__menu {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  z-index: 100;
  display: none;
}

.ui-dropdown.open .ui-dropdown__menu { display: block; }
.ui-dropdown__item { padding: 8px 16px; cursor: pointer; font-size: 14px; }
.ui-dropdown__item:hover { background: var(--color-surface); }

.ui-toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 2000;
}

.ui-toast {
  padding: 12px 16px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  font-size: 14px;
  color: #fff;
  min-width: 240px;
  display: flex;
  align-items: center;
  gap: 10px;
  animation: slideIn 200ms ease forwards;
}

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

.ui-toast--success { background: var(--color-success); }
.ui-toast--danger { background: var(--color-danger); }
.ui-toast--warning { background: var(--color-warning); }
.ui-toast--info { background: var(--color-primary); }