This gist demonstrates some uses of the new sass feature: Passing content blocks to mixins.

0_selector_hacks.scss

@mixin ie6 { * html & { @content } }

#logo {
  background-image: url("/images/logo.png");
  @include ie6 { background-image: url("/images/logo.gif"); }
}

1_selector_hacks.sass

=ie6
  * html &
    @content

#logo
  background-image: url("/images/logo.png")
  +ie6
    background-image: url("/images/logo.gif")

2_selector_hacks.css

#logo { background-image: url("/images/logo.png"); }
* html #logo { background-image: url("/images/logo.gif"); }

3_animation.scss

@mixin keyframes {
  @-moz-keyframes    { @content; }
  @-webkit-keyframes { @content; }
}


@include keyframes {
   0%   { opacity: 0; }
   100% { opacity: 1; }
}

4_animation.sass

=keyframes
  @-moz-keyframes
    @content

  @-webkit-keyframes
    @content

+keyframes
  0%
    opacity: 0
  100%
    opacity: 1

5_animation.css

@-moz-keyframes {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}

@-webkit-keyframes {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}

6_media_queries.scss

@mixin respond-to($media) {
  @if $media == handhelds {
    @media only screen and (max-width: 479px) { @content; }
  }
  @else if $media == wide-handhelds {
    @media only screen and (min-width: 480px) and (max-width: 767px) { @content; }
  }
  @else if $media == tablets {
    @media only screen and (min-width: 768px) and (max-width: 959px) { @content; }
  }
}

#sidebar {
  float: left;
  width: 300px;
  @include respond-to(handhelds) { float: none; }
  @include respond-to(wide-handhelds) { float: none; }
  @include respond-to(tablets) { width: 240px; }
}

7_media_queries.sass

=respond-to($media)
  @if $media == handhelds
    @media only screen and (max-width: 479px)
      @content
  @else if $media == wide-handhelds
    @media only screen and (min-width: 480px) and (max-width: 767px)
      @content
  @else if $media == tablets
    @media only screen and (min-width: 768px) and (max-width: 959px)
      @content

#sidebar
  float: left
  width: 300px
  +respond-to(handhelds)
    float: none

  +respond-to(wide-handhelds)
    float: none

  +respond-to(tablets)
    width: 240px

8_media_queries.css

#sidebar { float: left; width: 300px; }
@media only screen and (max-width: 479px) { #sidebar { float: none; } }
@media only screen and (min-width: 480px) and (max-width: 767px) { #sidebar { float: none; } }
@media only screen and (min-width: 768px) and (max-width: 959px) { #sidebar { width: 240px; } }

The respond-to mixin makes for much better organisation of my layout styles. One (current) drawback is the duplication of media queries though - for other visitors to this gist, there's plenty of discussion on potential fixes over at the Sass GitHub page you might like to read.

All the best, Karl

As an IE 7 & 8 media queries workaround, I'm playing with the idea below.

Does anybody see any drawbacks to this? or maybe there's a better way?

@mixin respond-to($media) {
  @if $media == handhelds {
    @media only screen and (max-width: 479px) { @content; }
  }
  @else if $media == wide-handhelds {
    @media only screen and (min-width: 480px) and (max-width: 767px) { @content; }
  }
  @else if $media == tablets {
    @media only screen and (min-width: 768px) and (max-width: 959px) { @content; }
    .lt-ie9 & { @content; }
  }
}

Help me to make my web http://www.security.com.bd >> problem is content wide than screen. my email is [email protected]. I just pest my css.

*{
margin:0px;
font-family:arial;
font-size:13px;
line-height:130%;
}
body{
background:#ccc url(../images/128-129.jpg) fixed;
}

#wrapper{
width:900px;
margin:0px auto 10px;
/* background-color:#ed1f24; */
display:table;
border-radius:8px;
overflow:hidden;
}

#banner{
height:110px;
background-color:#000000;
width:900px;
margin:0 auto;
border-radius:0 8px;
border-bottom:1px red dotted;
border-top:1px red dotted;
background-image:url(../images/hb1.jpg);
background-repeat:no-repeat;
background-position:right top;
}
#banner #logo{
width:;
float:left;
height:95px;
margin-top:5px;
margin-left:15px;
}

#banner h2{
position:relative;
margin-left:340px;
padding-top:20px;
color:#ed2025;
font-size:35px;
text-transform:uppercase;
word-spacing:7px;
letter-spacing:2px;
text-shadow:2px 1px 3px #000;

}
#banner span{
font-size:35px;
color:#fff;

}
#banner #slogan{
color:#fff;
letter-spacing:12px;
margin-left:319px;
font-size:14px;
}
#slide{
height:310px;
background-color:#999;
margin:5px 0 10px 0;
}

#content{
display:table;
background-color:rgba(255,255,255,0.5);
}
#left_c{
float:left;
width:65%;
border-right:5px #fff solid;
box-sizing:border-box;
padding:90px 0;
min-height:600px;
min-width:585px;

}
#left_c div{
padding:7px 50px;
text-align:justify;
background:#fff;
font-size:14px;
line-height:20px;
}
#right_c{
float:right;
width:315px;
padding:90px 0;
}
#right_c h1{
text-align:center;
font-size:20px;
color:white;
font-weight:normal;
background-color: #000;
}
#right_c h1 span{
font-weight:bold;
font-size:18px;
color:white;
}
#right_c .featured_p{
width:260px;
height:200px;
margin:35px 25px;
border-radius:10px;
border:2px solid #BA5757;
padding:1px;
background-color:#fff;
}
#footer{
height:60px;
clear:both;
margin-top:10px;
background-color:#ed1f24;
text-align:center;
color:white;
padding:0 50px;
}
#footer p, #footer span{
line-height:50px;
}
#footer a{
color:#000;
}
/contact.php/
#left_c dt{
margin-left:20px;
}
#left_c dd{
margin-left:40px;
}
#q1_dd,#q2_dd,#q3_dd,#q4_dd{
display:none;
}

#left_c form{
width:490px;
margin:0 auto;
display:block;
}
#left_c input[type="text"],#left_c input[type="email"]{
width:490px;
height:35px;
margin-bottom:5px;
}
#left_c textarea{
width:490px;
height:350px;
margin-bottom:5px;
}
#left_c input[type="submit"]{
width:120px;
height:40px;
float:right;
}

/contact.php/

/gallery/
.gallery_box{
background-color:rgba(255,255,255,0.5);
padding:10px 16px;
}
.gallery_box .vlightbox1_thumb{
width:160px;
height: 120px;
}
/gallery/

@mixin keyframes( $animationName )
{
    @-webkit-keyframes $animationName {
        @content;
    }
    @-moz-keyframes $animationName {
        @content;
    }
    @-o-keyframes $animationName {
        @content;
    }
    @keyframes $animationName {
        @content;
    }
}