diff --git a/partials/hero.hbs b/partials/hero.hbs
index 029697a..583f202 100644
--- a/partials/hero.hbs
+++ b/partials/hero.hbs
@@ -25,7 +25,7 @@ for it, and apply those styles to the <header> tag.
   {{/contentFor}}
 
   <section class="m-hero with-picture" data-aos="fade">
-    <div class="m-hero__picture in-post {{#is "post"}}in-post{{/is}}"></div>
+    <div class="m-hero__picture {{#is "post"}}in-post{{/is}}"></div>
 {{else}}
   <section class="m-hero no-picture {{#is "post"}}in-post{{/is}}" data-aos="fade">
 {{/if}}
diff --git a/src/js/app.js b/src/js/app.js
index 6bcda92..2ce8614 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -8,7 +8,8 @@ import AOS from 'aos'
 import Fuse from 'fuse.js'
 import {
   isRTL,
-  formatDate
+  formatDate,
+  isDarkMode
 } from './helpers'
 
 cssVars({})
@@ -34,7 +35,7 @@ $(document).ready(() => {
   const $searchResults = $('.js-search-results')
   const $searchNoResults = $('.js-no-results')
   const $toggleDarkMode = $('.js-toggle-darkmode')
-  const currentTheme = localStorage.getItem('theme')
+  const currentSavedTheme = localStorage.getItem('theme')
 
   let fuse = null
   let submenuIsOpen = false
@@ -184,14 +185,18 @@ $(document).ready(() => {
     }
   })
 
-  if (currentTheme) {
-    $('html').attr('data-theme', currentTheme)
+  if (currentSavedTheme) {
+    $('html').attr('data-theme', currentSavedTheme)
 
-    if (currentTheme === 'dark') {
+    if (currentSavedTheme === 'dark') {
       $toggleDarkMode.attr('checked', true)
     }
   }
 
+  if (isDarkMode()) {
+    $toggleDarkMode.attr('checked', true)
+  }
+
   var headerElement = document.querySelector('.js-header')
 
   if (headerElement) {
diff --git a/src/js/helpers.js b/src/js/helpers.js
index dc16172..d21d6d6 100644
--- a/src/js/helpers.js
+++ b/src/js/helpers.js
@@ -7,6 +7,12 @@ export const isMobile = (width = '768px') => {
   return window.matchMedia(`(max-width: ${width})`).matches
 }
 
+export const isDarkMode = () => {
+  const darkModeMatcher = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)')
+
+  return darkModeMatcher && darkModeMatcher.matches
+}
+
 export const formatDate = (date) => {
   if (date) {
     return new Date(date).toLocaleDateString(
diff --git a/src/sass/components/header/_menu.scss b/src/sass/components/header/_menu.scss
index 1461e0b..e27f37a 100644
--- a/src/sass/components/header/_menu.scss
+++ b/src/sass/components/header/_menu.scss
@@ -4,7 +4,7 @@
   top: 0;
   left: 0;
   width: 100%;
-  height: 100vh;
+  height: 100%;
   opacity: 0;
   overflow-y: auto;
   z-index: 2;
diff --git a/src/sass/components/header/_toggle-darkmode.scss b/src/sass/components/header/_toggle-darkmode.scss
index d73082e..6469398 100644
--- a/src/sass/components/header/_toggle-darkmode.scss
+++ b/src/sass/components/header/_toggle-darkmode.scss
@@ -1,17 +1,19 @@
 .m-toggle-darkmode {
   position: fixed;
   right: $mobile-space;
-  bottom: $mobile-space;
+  bottom: 45px;
   width: 22px;
   height: 22px;
   border-radius: 50%;
   overflow: hidden;
+  z-index: 2;
 
   @include respond-to('medium') {
     position: relative;
     right: auto;
     bottom: auto;
     margin-left: 20px;
+    z-index: auto;
   }
 
   input {
@@ -56,3 +58,7 @@
     }
   }
 }
+
+_:-ms-fullscreen, :root .m-toggle-darkmode {
+  display: none;
+}