HTML tutorial, HTML default style_HTML/Xhtml_Web page production

1. html, address, blockquote, body, dd, div, dl, dt, fieldset, form, frame, frameset, h1, h2, h3, h4, h5, h6, noframes, ol, p, ul, center, dir, hr, menu, pre {display: block } li {display: list-item } head {display: none } table {display: table } tr {display: table-row } thead {display: table-header-group } tbody {display: table-row-group } tfoot {display: table-footer-group } col {display: table-column } colgroup {display: table-column-group } td, th {display: table-cell; } caption {display: table-caption } th {font-weight: bolder; text-align: center } caption {text-align: center } body {margin: 8px; line-height: 1.12 } h1 {font-size: 2em; margin: .67em 0 } h2 {font-size: 1.5em; margin: .75em 0 } h3 {font-size: 1.17em; margin: .83em 0 } h4, p, blockquote, ul, fieldset, form, ol, dl, dir, menu {margin: 1.12em 0 } h5 {font-size: .83em; margin: 1.5em 0 } h6 {font-size: .75em; margin: 1.67em 0 } h1, h2, h3, h4, h5, h6, b, strong {font-weight: bolder } blockquote {margin-left: 40px; margin-right: 40px } i, cite, em, var, address {font-style: italic } pre, tt, code, kbd, samp {font-family: monospace } pre {white-space: pre } button, textarea, input, object, select {display:inline-block; } big {font-size: 1.17em } small, sub, sup{ font-size: .83em } sub {vertical-align: sub } sup {vertical-align: super } table {border-spacing: 2px; } thead, tbody, tfoot {vertical-align: middle } td, th {vertical-align: inherit } s, strike, del {text-decoration: line-through } hr {border: 1px inset } ol, ul, dir, menu, dd {margin-left: 40px } ol {list-style-type: decimal } olul, ul ol, ulul, ol ol { margin-top: 0; margin-bottom: 0 } u, ins {text-decoration: underline } br:before {content: "A" } :before, :after{ white-space: pre-line } center {text-align: center } abbr, acronym {font-variant: small-caps; letter-spacing: 0.1em } :link, :visited{ text-decoration: underline } :focus {outline: thin dotted invert } /*Begin bidirectionality settings (do not change) */ BDO[DIR="ltr"] {direction: ltr; unicode-bidi: bidi-override } BDO[DIR="rtl"] {direction: rtl; unicode-bidi: bidi-override } *[DIR="ltr"] {direction: ltr; unicode-bidi: embed } *[DIR="rtl"] {direction: rtl; unicode-bidi: embed } @mediaprint { h1 {page-break-before: always } h1, h2, h3, h4, h5, h6 {page-break-after: avoid } ul, ol, dl {page-break-before: avoid }