feat: Changes to io

Keyword "io" now has many more usage scenarios.

- Default margin for io now 0
- New config value for inline element margin
- Rename first classes
- Io classes integrated to sections and groups

elements/_interactive.scss

@@ -57,7 +57,7 @@ label + input {
 }
 
 input, button, textarea, select {
-	margin: $margin_io;
+	margin: $margin_inline;
 
 	&[disabled="disabled"],
 	&[disabled] {
@@ -79,6 +79,10 @@ td > textarea {
 	}
 }
 
+.input_io, .button_io, .io_textarea, .io_select {
+	margin: $margin_io;
+}
+
 .input_io, .io_textarea, .io_select {
 	padding: $space_half;
 	color: $color_text_io;

elements/_sections.scss

@@ -1,3 +1,5 @@
+@use "sass:map";
+
 // Root
 // -----------------------------------------------------------------------------
 html {
@@ -81,7 +83,16 @@ section {}
 
 // Navigation
 // -----------------------------------------------------------------------------
-nav {}
+nav {
+
+	ul {
+		margin: 0;
+
+		&.inline li {
+			display: inline-block;
+		}
+	}
+}
 
 // Aside element
 // -----------------------------------------------------------------------------
@@ -107,6 +118,33 @@ aside {
 	*:first-child {
 		margin-top: 0;
 	}
+
+	&.io {
+
+		input,
+		textarea,
+		select,
+		button {
+			display: block;
+			width: 100%;
+		}
+
+		input {
+			@extend .input_io;
+		}
+
+		textarea {
+			@extend .io_textarea;
+		}
+
+		select {
+			@extend .io_select;
+		}
+
+		button {
+			@extend .button_io;
+		}
+	}
 }
 
 // Headings
@@ -180,12 +218,26 @@ header {}
 	}
 }
 
-header.io {
-	z-index: map.get($z-indexes, "content-top");
+header,
+aside,
+footer {
+	&.io {
+		.span_solo {
+			border: $width_border_io solid transparent;
+			padding: $padding_basic;
+		}
+	}
+}
+
+header.io,
+aside.io {
 	padding: $space_basic;
 
-	h1 {
-		margin: 0;
+	input,
+	button,
+	textarea,
+	select {
+		margin-inline: $space_half;
 	}
 
 	input {
@@ -205,6 +257,62 @@ header.io {
 	}
 }
 
+header,
+footer {
+	&.io {
+		@extend %flex-inline;
+		align-items: stretch;
+	}
+}
+
+header.io {
+	z-index: map.get($z-indexes, "content-top");
+
+	&>*:last-child *:last-child {
+		margin-right: 0;
+	}
+
+	&>*:first-child *:first-child {
+		margin-left: 0;
+	}
+
+	nav,
+	ul {
+		@extend %flex-inline;
+		align-items: stretch;
+	}
+
+	nav li {
+		margin: 0;
+	}
+
+	nav:last-child {
+		margin-left: auto;
+	}
+
+	h1 {
+		margin: 0;
+	}
+}
+
 // Footer
 // -----------------------------------------------------------------------------
-footer {}
+footer {
+	&.io {
+		input {
+			@extend .input_io;
+		}
+
+		textarea {
+			@extend .io_textarea;
+		}
+
+		select {
+			@extend .io_select;
+		}
+
+		button {
+			@extend .button_io;
+		}
+	}
+}