Add minireset, Fix color luminance

sass/components/level.sass

@@ -1,4 +1,3 @@
-@import "../base/placeholders.sass"
 @import "../utilities/mixins.sass"
 @import "../utilities/variables.sass"
 
@@ -37,7 +36,7 @@
     justify-content: flex-end
 
 .level
-  @extend %block
+  +block
   align-items: center
   justify-content: space-between
   code

sass/components/message.sass

@@ -1,4 +1,3 @@
-@import "../base/placeholders.sass"
 @import "../utilities/functions.sass"
 @import "../utilities/variables.sass"
 
@@ -21,7 +20,7 @@
     border-top: none
 
 .message
-  @extend %block
+  +block
   background-color: $background
   border-radius: $radius
   // Colors

sass/components/modal.sass

@@ -1,4 +1,3 @@
-@import "../base/placeholders.sass"
 @import "../utilities/mixins.sass"
 @import "../utilities/variables.sass"
 
@@ -20,7 +19,7 @@
     width: 640px
 
 .modal-close
-  @extend %delete
+  +delete
   background: none
   height: 40px
   position: fixed

sass/components/nav.sass

@@ -1,11 +1,10 @@
-@import "../base/placeholders.sass"
 @import "../utilities/mixins.sass"
 @import "../utilities/variables.sass"
 
 // Components
 
 .nav-toggle
-  @extend %hamburger
+  +hamburger
   // Responsiveness
   +tablet
     display: none

sass/components/tabs.sass

@@ -1,9 +1,9 @@
-@import "../base/placeholders.sass"
+@import "../utilities/mixins.sass"
 @import "../utilities/variables.sass"
 
 .tabs
-  @extend %block
-  @extend %unselectable
+  +block
+  +unselectable
   align-items: stretch
   display: flex
   justify-content: space-between