Multiple fixes for CSS, added proper auth checking

src/boot/routes.js

src/components/modal/modal.vue

src/components/settings_modal/settings_modal.scss

src/components/settings_modal/settings_modal.vue

src/components/settings_modal/tabs/mutes_and_blocks_tab.vue

src/components/settings_modal/tabs/theme_tab/theme_tab.scss

src/components/tab_switcher/tab_switcher.js

src/components/tab_switcher/tab_switcher.scss