dans theme.html :
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="<{$xoops_langcode}>" lang="<{$xoops_langcode}>">
<head>
<{* Center blocks display order valid values are: lrc (left right / center) lcr (left center right) clr (center / left right) *}>
<{assign var=theme_top_order value=clr}>
<{assign var=theme_bottom_order value=clr}>
<!-- Theme name -->
<{assign var=theme_name value=$xoTheme->folderName}>
<!-- Directory html blocks files or additional html files by include -->
<{assign var=theme_name value=$xoTheme->folderName|cat:'/xotpl'}>
<!-- Directory html plugins files -->
<{assign var=theme_plugin value=$xoTheme->folderName|cat:'/xoplugins'}>
<!-- Metas, Titles, and Style Sheets -->
<{includeq file="$theme_name/xometas.html"}>
<!-- Additionals Scripts -->
<{includeq file="$theme_name/xoscripts.html"}>
</head>
<body id="<{$xoops_dirname}>" class="<{$xoops_langcode}>">
<{if $xoBlocks.canvas_left and $xoBlocks.canvas_right}><{assign var=columns_layout value='threecolumns-layout'}>
<{elseif $xoBlocks.canvas_left}><{assign var=columns_layout value='leftcolumn-layout'}>
<{elseif $xoBlocks.canvas_right}><{assign var=columns_layout value='rightcolumn-layout'}>
<{/if}>
<div id="xo-wrapper" class="<{$xoops_dirname}>">
<div id="xo-bgstatic" class="<{$xoops_dirname}>"></div>
<div id="xo-canvas"<{if $columns_layout}> class="<{$columns_layout}>"<{/if}>>
<div id="xo-canvas-content">
<table id="xo-canvas-columns" cellspacing="0">
<tr>
<{if $xoBlocks.canvas_left}>
<{includeq file="$theme_name/blockszone.html" blocks=$xoBlocks.canvas_left
zoneClass='xo-canvas-column' zoneId='xo-canvas-leftcolumn' zoneTag='td'
}>
<{/if}>
<td id="xo-page">
<{if $xoBlocks.page_topleft or $xoBlocks.page_topcenter or $xoBlocks.page_topright}>
<div class="xo-blockszone xo-<{$theme_top_order}>pageblocks" id="xo-page-topblocks">
<{includeq file="$theme_name/centerblocks.html" topbottom=top lcr=$theme_top_order|substr:0:1}>
<{includeq file="$theme_name/centerblocks.html" topbottom=top lcr=$theme_top_order|substr:1:1}>
<{includeq file="$theme_name/centerblocks.html" topbottom=top lcr=$theme_top_order|substr:2:1}>
</div>
<{/if}>
<{if $xoops_contents}><div id="xo-content"><{$xoops_contents}></div><{/if}>
<{if $xoBlocks.page_bottomleft or $xoBlocks.page_bottomcenter or $xoBlocks.page_bottomright}>
<div class="xo-blockszone xo-<{$theme_bottom_order}>pageblocks" id="xo-page-bottomblocks">
<{includeq file="$theme_name/centerblocks.html" topbottom=bottom lcr=$theme_bottom_order|substr:0:1}>
<{includeq file="$theme_name/centerblocks.html" topbottom=bottom lcr=$theme_bottom_order|substr:1:1}>
<{includeq file="$theme_name/centerblocks.html" topbottom=bottom lcr=$theme_bottom_order|substr:2:1}>
</div>
<{/if}>
</td>
<{if $xoBlocks.canvas_right}>
<{includeq file="$theme_name/blockszone.html" blocks=$xoBlocks.canvas_right
zoneClass='xo-canvas-column' zoneId='xo-canvas-rightcolumn' zoneTag='td'
}>
<{/if}>
</tr>
</table>
<!-- include du "up top" -->
<{includeq file="$theme_name/uptop.html"}>
</div>
<!-- include du PIED DE PAGE -->
<{includeq file="$theme_name/xofooter.html"}>
<div id="xo-header" class="<{$xoops_dirname}>">
<!-- include du TOPHEADER -->
<{includeq file="$theme_name/xotopheader.html"}>
<!-- include du HEADER avec logo et bannière -->
<!-- vérification si l'affichage de la bannière est activée ou non dans l'administration du site -->
<{if $xoops_banner and $xoops_banner != ' '}>
<!-- include avec affichage de la bannière activé-->
<{includeq file="$theme_name/xobanner_commercial.html"}>
<{else}>
<!-- include avec affichage de la bannière désactivé -->
<{includeq file="$theme_name/xobanner.html"}>
<{/if}>
<!-- fin de la condition d'affichage en fonction de l'activation de la bannière -->
<{includeq file="$theme_name/globalnav.html"}>
</div>
</div>
<!--{xo-logger-output}-->
</div>
</body>
</html>
Et ensuite tu adaptes les feuilles de style
@++
