message: Update styles of index header
diff: import React, { RefObject } from 'react'
  import { useTranslation } from 'next-i18next'
  import { Grid, Typography } from '@material-ui/core'
  -import { makeStyles, createStyles } from '@material-ui/core/styles'
  +import { makeStyles, createStyles, darken } from '@material-ui/core/styles'
  import KeyboardArrowDownIcon from '@material-ui/icons/KeyboardArrowDown'
  import { Favorite } from '@material-ui/icons'
  @@ -22,8 +22,9 @@ const useStyles = makeStyles((theme) =>
  backgroundPosition: 'center',
  backgroundSize: 'cover',
  color: theme.palette.common.white,
  - [theme.breakpoints.down(380)]: {
  - backgroundImage: 'url(/img/jumbotron-background-image-mobile.jpg)',
  + [theme.breakpoints.down('sm')]: {
  + backgroundImage: 'url(/img/header-image-mobile.jpg)',
  + backgroundSize: 'cover',
  },
  [theme.breakpoints.up(1600)]: {
  height: '950px',
  @@ -42,9 +43,9 @@ const useStyles = makeStyles((theme) =>
  fontWeight: 400,
  },
  aboutProjectButton: {
  - color: theme.palette.common.white,
  - border: `2px solid ${theme.palette.primary.main}`,
  - borderRadius: theme.spacing(3),
  + color: darken(theme.palette.secondary.main, 0.8),
  + border: `none`,
  + borderRadius: '500px',
  padding: theme.spacing(1.5, 4),
  fontWeight: 500,
  fontSize: theme.typography.pxToRem(15),
  @@ -56,10 +57,8 @@ const useStyles = makeStyles((theme) =>
  },
  },
  podkrepiButton: {
  - color: theme.palette.common.white,
  - backgroundColor: theme.palette.primary.main,
  - border: `2px solid ${theme.palette.primary.main}`,
  - borderRadius: theme.spacing(3),
  + border: `none`,
  + borderRadius: '500px',
  fontWeight: 500,
  fontSize: theme.typography.pxToRem(15),
  minWidth: theme.spacing(27),
  @@ -82,7 +81,7 @@ const useStyles = makeStyles((theme) =>
  height: theme.spacing(5),
  '&:hover': {
  cursor: 'pointer',
  - backgroundColor: theme.palette.primary.dark,
  + color: theme.palette.secondary.main,
  },
  },
  }),
  @@ -119,13 +118,15 @@ export default function Jumbotron({ scrollTo }: JumbotronProps) {
  <Grid item>
  <LinkButton
  href={routes.aboutProject}
  - variant="outlined"
  + variant="contained"
  + color="secondary"
  className={classes.aboutProjectButton}>
  {t('index:jumbotron.about-project-button')}
  </LinkButton>
  <LinkButton
  href={routes.support}
  - variant="outlined"
  + variant="contained"
  + color="primary"
  className={classes.podkrepiButton}
  endIcon={<Favorite />}>
  {t('index:jumbotron.support-us-button')}
  