ADDED: Now you can turn on or off Ripple effect on buttons (not for icon buttons, soon it's fixed), density for segmented-buttons, typography mixins, and etc.

CHANGED: For optimizing write styles added a few mixins
FIXED: Bug with width in segmented-buttons

src/styles/input-styles/checkbox.sass

@@ -13,16 +13,15 @@ div.m3.m3-checkbox-container
         position: absolute
 
 input[type="checkbox"].m3.m3-checkbox
+    @include center(flex)
+
     z-index: 10
-    display: flex
     width: 1.125rem
     height: 1.125rem
     appearance: none
     position: absolute
-    align-items: center
     border-radius: .14rem
     box-sizing: content-box
-    justify-content: center
     transition: background-color .2s cubic-bezier(0.2, 0, 0, 1)
 
     & ~ span.m3-checkbox-state
@@ -54,14 +53,13 @@ input[type="checkbox"].m3.m3-checkbox
             opacity: 38%
 
     & ~ span.m3-checkbox-state
+        @include center(flex)
+
         z-index: 10
-        display: flex
         font-size: 24px
         font-weight: 700
         line-height: 24px
-        align-items: center
         pointer-events: none
-        justify-content: center
         font-family: Material-Symbols-Outlined-Regular, sans-serif
         font-variation-settings: 'FILL' 1, 'wght' 300, 'GRAD' 0, 'opsz' 24