Remove unneeded vendor prefixes

less/common/mixins/vendor-prefixes.less

@@ -1,227 +1,151 @@
 // Vendor Prefixes
-//
-// All vendor mixins are deprecated as of v3.2.0 due to the introduction of
-// Autoprefixer in our Gruntfile. They will be removed in v4.
-
-// - Animations
-// - Backface visibility
-// - Box shadow
-// - Box sizing
-// - Content columns
-// - Hyphens
-// - Placeholder text
-// - Transformations
-// - Transitions
-// - User Select
 
+// These aim to ensure that Flarum remains compatible with most modern devices.
+// The vendor presets below are to try to remain compatible with iOS 9+ and other
+// major browsers (Chrome/Firefox/new Edge/Safari desktop).
 
 // Animations
+// These remain for backwards compatibility with existing styles.
 .animation(@animation) {
-  -webkit-animation: @animation;
-       -o-animation: @animation;
-          animation: @animation;
+  animation: @animation;
 }
 .animation-name(@name) {
-  -webkit-animation-name: @name;
-          animation-name: @name;
+  animation-name: @name;
 }
 .animation-duration(@duration) {
-  -webkit-animation-duration: @duration;
-          animation-duration: @duration;
+  animation-duration: @duration;
 }
 .animation-timing-function(@timing-function) {
-  -webkit-animation-timing-function: @timing-function;
-          animation-timing-function: @timing-function;
+  animation-timing-function: @timing-function;
 }
 .animation-delay(@delay) {
-  -webkit-animation-delay: @delay;
-          animation-delay: @delay;
+  animation-delay: @delay;
 }
 .animation-iteration-count(@iteration-count) {
-  -webkit-animation-iteration-count: @iteration-count;
-          animation-iteration-count: @iteration-count;
+  animation-iteration-count: @iteration-count;
 }
 .animation-direction(@direction) {
-  -webkit-animation-direction: @direction;
-          animation-direction: @direction;
+  animation-direction: @direction;
 }
 .animation-fill-mode(@fill-mode) {
-  -webkit-animation-fill-mode: @fill-mode;
-          animation-fill-mode: @fill-mode;
+  animation-fill-mode: @fill-mode;
 }
 
 // Backface visibility
 // Prevent browsers from flickering when using CSS 3D transforms.
 // Default value is `visible`, but can be changed to `hidden`
-
-.backface-visibility(@visibility){
+.backface-visibility(@visibility) {
+  // Safari
   -webkit-backface-visibility: @visibility;
-     -moz-backface-visibility: @visibility;
-          backface-visibility: @visibility;
+  backface-visibility: @visibility;
 }
 
 // Drop shadows
-//
-// Note: Deprecated `.box-shadow()` as of v3.1.0 since all of Bootstrap's
-// supported browsers that have box shadow capabilities now support it.
-
+// These remain for backwards compatibility with existing styles.
 .box-shadow(@shadow) {
-  -webkit-box-shadow: @shadow; // iOS <4.3 & Android <4.1
-          box-shadow: @shadow;
+  box-shadow: @shadow;
 }
 
 // Box sizing
+// These remain for backwards compatibility with existing styles.
 .box-sizing(@boxmodel) {
-  -webkit-box-sizing: @boxmodel;
-     -moz-box-sizing: @boxmodel;
-          box-sizing: @boxmodel;
+  box-sizing: @boxmodel;
 }
 
 // CSS3 Content Columns
 .content-columns(@column-count; @column-gap: @grid-gutter-width) {
+  // Safari
   -webkit-column-count: @column-count;
-     -moz-column-count: @column-count;
-          column-count: @column-count;
+  column-count: @column-count;
+  // Safari
   -webkit-column-gap: @column-gap;
-     -moz-column-gap: @column-gap;
-          column-gap: @column-gap;
+  column-gap: @column-gap;
 }
 
 // Optional hyphenation
 .hyphens(@mode: auto) {
   word-wrap: break-word;
+  // Safari
   -webkit-hyphens: @mode;
-     -moz-hyphens: @mode;
-      -ms-hyphens: @mode; // IE10+
-       -o-hyphens: @mode;
-          hyphens: @mode;
+  hyphens: @mode;
 }
 
 // Placeholder text
 .placeholder(@color) {
-  // Firefox
-  &::-moz-placeholder {
+  // Safari
+  &::-webkit-input-placeholder,
+  &::placeholder {
     color: @color;
-    opacity: 1; // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526
   }
-  &:-ms-input-placeholder { color: @color; } // Internet Explorer 10+
-  &::-webkit-input-placeholder  { color: @color; } // Safari and Chrome
 }
 
 // Transformations
+// These remain for backwards compatibility with existing styles.
 .scale(@ratio) {
-  -webkit-transform: scale(@ratio);
-      -ms-transform: scale(@ratio); // IE9 only
-       -o-transform: scale(@ratio);
-          transform: scale(@ratio);
+  transform: scale(@ratio);
 }
 .scale(@ratioX; @ratioY) {
-  -webkit-transform: scale(@ratioX, @ratioY);
-      -ms-transform: scale(@ratioX, @ratioY); // IE9 only
-       -o-transform: scale(@ratioX, @ratioY);
-          transform: scale(@ratioX, @ratioY);
+  transform: scale(@ratioX, @ratioY);
 }
 .scaleX(@ratio) {
-  -webkit-transform: scaleX(@ratio);
-      -ms-transform: scaleX(@ratio); // IE9 only
-       -o-transform: scaleX(@ratio);
-          transform: scaleX(@ratio);
+  transform: scaleX(@ratio);
 }
 .scaleY(@ratio) {
-  -webkit-transform: scaleY(@ratio);
-      -ms-transform: scaleY(@ratio); // IE9 only
-       -o-transform: scaleY(@ratio);
-          transform: scaleY(@ratio);
+  transform: scaleY(@ratio);
 }
 .skew(@x; @y) {
-  -webkit-transform: skewX(@x) skewY(@y);
-      -ms-transform: skewX(@x) skewY(@y); // See https://github.com/twbs/bootstrap/issues/4885; IE9+
-       -o-transform: skewX(@x) skewY(@y);
-          transform: skewX(@x) skewY(@y);
+  transform: skewX(@x) skewY(@y);
 }
 .translate(@x; @y) {
-  -webkit-transform: translate(@x, @y);
-      -ms-transform: translate(@x, @y); // IE9 only
-       -o-transform: translate(@x, @y);
-          transform: translate(@x, @y);
+  transform: translate(@x, @y);
 }
 .translate3d(@x; @y; @z) {
-  -webkit-transform: translate3d(@x, @y, @z);
-          transform: translate3d(@x, @y, @z);
+  transform: translate3d(@x, @y, @z);
 }
 .rotate(@degrees) {
-  -webkit-transform: rotate(@degrees);
-      -ms-transform: rotate(@degrees); // IE9 only
-       -o-transform: rotate(@degrees);
-          transform: rotate(@degrees);
+  transform: rotate(@degrees);
 }
 .rotateX(@degrees) {
-  -webkit-transform: rotateX(@degrees);
-      -ms-transform: rotateX(@degrees); // IE9 only
-       -o-transform: rotateX(@degrees);
-          transform: rotateX(@degrees);
+  transform: rotateX(@degrees);
 }
 .rotateY(@degrees) {
-  -webkit-transform: rotateY(@degrees);
-      -ms-transform: rotateY(@degrees); // IE9 only
-       -o-transform: rotateY(@degrees);
-          transform: rotateY(@degrees);
+  transform: rotateY(@degrees);
 }
 .perspective(@perspective) {
-  -webkit-perspective: @perspective;
-     -moz-perspective: @perspective;
-          perspective: @perspective;
+  perspective: @perspective;
 }
 .perspective-origin(@perspective) {
-  -webkit-perspective-origin: @perspective;
-     -moz-perspective-origin: @perspective;
-          perspective-origin: @perspective;
+  perspective-origin: @perspective;
 }
 .transform-origin(@origin) {
-  -webkit-transform-origin: @origin;
-     -moz-transform-origin: @origin;
-      -ms-transform-origin: @origin; // IE9 only
-          transform-origin: @origin;
+  transform-origin: @origin;
 }
 
-
 // Transitions
-
+// These remain for backwards compatibility with existing styles.
 .transition(@transition) {
-  -webkit-transition: @transition;
-       -o-transition: @transition;
-          transition: @transition;
+  transition: @transition;
 }
 .transition-property(@transition-property) {
-  -webkit-transition-property: @transition-property;
-          transition-property: @transition-property;
+  transition-property: @transition-property;
 }
 .transition-delay(@transition-delay) {
-  -webkit-transition-delay: @transition-delay;
-          transition-delay: @transition-delay;
+  transition-delay: @transition-delay;
 }
 .transition-duration(@transition-duration) {
-  -webkit-transition-duration: @transition-duration;
-          transition-duration: @transition-duration;
+  transition-duration: @transition-duration;
 }
 .transition-timing-function(@timing-function) {
-  -webkit-transition-timing-function: @timing-function;
-          transition-timing-function: @timing-function;
+  transition-timing-function: @timing-function;
 }
 .transition-transform(@transition) {
-  -webkit-transition: -webkit-transform @transition;
-     -moz-transition: -moz-transform @transition;
-       -o-transition: -o-transform @transition;
-          transition: transform @transition;
+  transition: transform @transition;
 }
 
-
 // User select
 // For selecting text on the page
-
 .user-select(@select) {
+  // Safari + MS Edge
   -webkit-user-select: @select;
-     -moz-user-select: @select;
-      -ms-user-select: @select; // IE10+
-          user-select: @select;
+  user-select: @select;
 }