feat: create settings modal

inertia/components/common/modal/_modal_header.tsx

@@ -0,0 +1,20 @@
+import styled from '@emotion/styled';
+
+const ModalHeader = styled.h3({
+  width: '100%',
+  marginBottom: '0.75em',
+  display: 'flex',
+  alignItems: 'center',
+  justifyContent: 'space-between',
+});
+
+const ModalCloseBtn = styled.button(({ theme }) => ({
+  cursor: 'pointer',
+  color: theme.colors.primary,
+  backgroundColor: 'transparent',
+  border: 0,
+  padding: 0,
+  margin: 0,
+}));
+
+export { ModalHeader, ModalCloseBtn };