A Pen by Exnius.

index.html

<h1>Un-Pure CSS3 arrow icons</h1>
<div style="float:left">
<span class="arrow arrow-up"></span>
<span class="arrow arrow-right"></span>
<span class="arrow arrow-down"></span>
<span class="arrow arrow-left"></span>
<br>
<span class="arrow arrow-up curve-right"><span class="curve"></span></span>
<span class="arrow arrow-right curve-right"><span class="curve"></span></span>
<span class="arrow arrow-down curve-right"><span class="curve"></span></span>
<span class="arrow arrow-left curve-right"><span class="curve"></span></span>
<br>
<span class="arrow arrow-up curve-left"><span class="curve"></span></span>
<span class="arrow arrow-right curve-left"><span class="curve"></span></span>
<span class="arrow arrow-down curve-left"><span class="curve"></span></span>
<span class="arrow arrow-left curve-left"><span class="curve"></span></span>
</div>
<div style="float:left">
<span class="arrow arrow-animate">
  <span class="arrow-item"><span class="curve"></span></span>
  <i></i>
  <span class="arrow-item"><span class="curve"></span></span>
</span>
</div>  
 

Pure-CSS3-arrow-icons.markdown

Pure CSS3 arrow icons

A Pen by Exnius on CodePen.

License.

style.scss

@import "compass";
// * * *  VARIABLES * * * 
// width of the arrow (icon)
$w   : 40px;
// height of the arrow (icon)
$h   : $w;
// color of the arrow (icon)
$c   : #555;

// * * * MIXINS * * *
// body
@mixin body( $width , $height , $top , $left ){
  border: none;
  background-color: $c;
  height: $height;
  width: $width;
  top: $top;
  left: $left;
}
@mixin clearBody{
  border: none;
  width: 0;
  height: 0;
}
// arrow
@mixin arrow( $width , $height , $top , $left, $way){
  left: $left;
  top: $top;
  border-width:$height $width;
  border-#{$way}-color:$c;
}
// bodyCurve
@mixin bodyCurve( $width , $height, $top , $left, $border  ,$btop ,$bleft){
  height: $height;
  width: $width;
  top: $top;
  left: $left;
  &:before{
    @include border-radius(2000px);
    border:$border solid $c;
    height: $height*2 -$border*2;
    width:  $width*2 -$border*2;
    top: $btop;
    left:$bleft;
  }
}

// * * * GENERAL CSS * * *
body{
  padding:50px 100px;
  background: #FEC;
  color:#CB9;
  font-family: Tahoma,Arial,sans-serif;
}
h1,h2{
  font-weight: 300;
}

.arrow{
  width: $w;
  height: $h;
  position: relative;
  display: inline-block;
  margin: $h/4 $w/4;
  //border:1px solid #EDB;
  
  &:before,
  &:after{
    content:'';
    border-color:transparent;
    border-style:solid;
    position: absolute;
  }
  .curve{
    position: absolute;
    overflow: hidden;
    &:before{
      content:'';
      position:absolute;
    }
  }
}

// * * * ARROWS * * * 
// arrow-up
.arrow-up{
  &:before{ @include body(30%,50%,50%,50% - 30%/2);  }
  &:after { @include arrow($w/2,$h/2,-50%,0,bottom); }
}

// arrow-right
.arrow-right{
  &:before{ @include body(50%,30%,50% - 30%/2,0); }
  &:after { @include arrow($w/2,$h/2,0,50%,left); }
}
// arrow-down
.arrow-down{
  &:before{ @include body(30%,50%,0,50% - 30%/2); }
  &:after { @include arrow($w/2,$h/2,50%,0,top);  }
}

// arrow-left
.arrow-left{
  &:before{ @include body(50%,30%,50% - 30%/2,50%); }
  &:after { @include arrow($w/2,$h/2,0,-50%,right); }
}
// * * * CURVE RIGHT ARROW * * *
// arrow-up
.arrow-up.curve-right{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.65, $h*.5, 
    $h*.5, $w*.35, 
    $w/3.33,
    -$w*.5 , 0 );}
}
// arrow-right
.arrow-right.curve-right{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.5, $h*.65, 
    $h*.35, 0, 
    $w/3.33,
    0, 0 );}
}
// arrow-down
.arrow-down.curve-right{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.65, $h*.5, 
    0, 0, 
    $w/3.33,
    0 , -$w*.65);}
}
// arrow-left
.arrow-left.curve-right{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.5, $h*.65, 
    0, $w*.5, 
    $w/3.33,
    -$h*.65, -$w*.5);}
}
// * * * CURVE LEFT ARROW * * *
// arrow-up
.arrow-up.curve-left{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.65, $h*.5, 
    $h*.5, 0, 
    $w/3.33,
    -$h*.5 , -$w*.65 );}
}
// arrow-right
.arrow-right.curve-left{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.5, $h*.65, 
    0, 0, 
    $w/3.33,
    -$h*.65, 0 );}
}
// arrow-down
.arrow-down.curve-left{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.65, $h*.5, 
    0, $w*.35, 
    $w/3.33,
    0 , 0);}
}
// arrow-left
.arrow-left.curve-left{
  &:before{@include clearBody;}
  .curve{@include bodyCurve(
    $w*.5, $h*.65, 
    $h*.35, $w*.5, 
    $w/3.33,
    0, -$w*.5);}
}

// * * * ARROW ANIMATE * * * (Just for fun)
.arrow-animate{
  -webkit-animation: spin 2s infinite linear;
  margin-left:$w/2;
  
  $h:$h*3+$h*1.25;
  $w:$w*3+$w*1.25;
  
  height: $h;
  width: $w;
  /*
    i{
    @include border-radius(2000px);
    position: absolute;
    top: $h*.115;
    left:$h*.115;
    width: $w*.57;
    height: $h*.57;
    border:$h*.1 solid rgba(255,0,0,.5);
    z-index: 1000;
  }*/
  
  .arrow-item{
    width: $w;
    height: $h*.5;
    position: absolute;
    &:before{
      content:'';
      height: 0;
      width: 0;
      position: absolute;
      border:$h*.18 solid transparent;
    }

    .curve{
       height: $h*.42;
       width: $w;
        //background-color: rgba(255,0,0,.2);
       &:before{
         @include border-radius(2000px);
         border:$w*.1 solid $c;
         height:$h*.57;
         width:$w*.57;
         left:$w*.115;
    
       }
    }
    &:first-child{
      top:0;
      left:0;
      &:before{
        border-top-color:$c;
        bottom: -$h*.18;
      }
      .curve{
        top: 0;
        left: 0;
        &:before{
          top: $h*.115;
        }
      }
    }
    &:last-child{
       top:$h/2;
       left:0;
       &:before{
        border-bottom-color:$c;
        top: -$h*0.2;
        right:0;
      }
      .curve{
        bottom: 0;
        left: 0;
        &:before{
          bottom: $h*.115;
        }
      }
    }
  }
}

@-webkit-keyframes spin {
  0% {@include transform(rotate(0deg));}
  100% {@include transform(rotate(-360deg));}
}