Man, the syntax is convoluted.
at-valid-21.css \
at-valid-21.errors \
at-valid-21.ref.css \
+ background-position.css \
+ background-position.errors \
+ background-position.ref.css \
background-repeat.css \
background-repeat.ref.css \
background-shorthand.css \
--- /dev/null
+a {
+ background-position: top;
+}
+
+b {
+ background-position: top top;
+}
+
+c {
+ background-position: top left;
+}
+
+d {
+ background-position: top right;
+}
+
+e {
+ background-position: top bottom;
+}
+
+f {
+ background-position: top center;
+}
+
+g {
+ background-position: top 25%;
+}
+
+h {
+ background-position: left;
+}
+
+i {
+ background-position: left top;
+}
+
+j {
+ background-position: left left;
+}
+
+k {
+ background-position: left right;
+}
+
+l {
+ background-position: left bottom;
+}
+
+m {
+ background-position: left center;
+}
+
+n {
+ background-position: left 25%;
+}
+
+o {
+ background-position: right;
+}
+
+p {
+ background-position: right top;
+}
+
+q {
+ background-position: right left;
+}
+
+r {
+ background-position: right right;
+}
+
+s {
+ background-position: right bottom;
+}
+
+t {
+ background-position: right center;
+}
+
+u {
+ background-position: right 25%;
+}
+
+v {
+ background-position: bottom;
+}
+
+w {
+ background-position: bottom top;
+}
+
+x {
+ background-position: bottom left;
+}
+
+y {
+ background-position: bottom right;
+}
+
+z {
+ background-position: bottom bottom;
+}
+
+ab {
+ background-position: bottom center;
+}
+
+bb {
+ background-position: bottom 25%;
+}
+
+cb {
+ background-position: center;
+}
+
+db {
+ background-position: center top;
+}
+
+eb {
+ background-position: center left;
+}
+
+fb {
+ background-position: center right;
+}
+
+gb {
+ background-position: center bottom;
+}
+
+hb {
+ background-position: center center;
+}
+
+ib {
+ background-position: center 25%;
+}
+
+jb {
+ background-position: 25%;
+}
+
+kb {
+ background-position: 25% top;
+}
+
+lb {
+ background-position: 25% left;
+}
+
+mb {
+ background-position: 25% right;
+}
+
+nb {
+ background-position: 25% bottom;
+}
+
+ob {
+ background-position: 25% center;
+}
+
+pb {
+ background-position: 25% 25%;
+}
--- /dev/null
+background-position.css:6: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:18: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:26: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:38: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:42: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:66: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:70: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:90: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:102: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:110: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:122: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:126: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:150: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+background-position.css:154: error: GTK_CSS_PROVIDER_ERROR_SYNTAX
+
--- /dev/null
+a {
+ background-position: top;
+}
+
+c {
+ background-position: left top;
+}
+
+d {
+ background-position: right top;
+}
+
+f {
+ background-position: top;
+}
+
+h {
+ background-position: left;
+}
+
+i {
+ background-position: left top;
+}
+
+l {
+ background-position: left bottom;
+}
+
+m {
+ background-position: left;
+}
+
+n {
+ background-position: left 25%;
+}
+
+o {
+ background-position: right;
+}
+
+p {
+ background-position: right top;
+}
+
+s {
+ background-position: right bottom;
+}
+
+t {
+ background-position: right;
+}
+
+u {
+ background-position: right 25%;
+}
+
+v {
+ background-position: bottom;
+}
+
+x {
+ background-position: left bottom;
+}
+
+y {
+ background-position: right bottom;
+}
+
+ab {
+ background-position: bottom;
+}
+
+cb {
+ background-position: center;
+}
+
+db {
+ background-position: top;
+}
+
+gb {
+ background-position: bottom;
+}
+
+hb {
+ background-position: center;
+}
+
+ib {
+ background-position: center 25%;
+}
+
+jb {
+ background-position: 25%;
+}
+
+kb {
+ background-position: 25% top;
+}
+
+nb {
+ background-position: 25% bottom;
+}
+
+ob {
+ background-position: 25%;
+}
+
+pb {
+ background-position: 25% 25%;
+}