more theming: search block, multiblock header, generale layout, fonts, colors, background

web_main/themes/custom/mathallo/assets/img/grid_0.svg

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="80"
+   height="80"
+   viewBox="0 0 21.166666 21.166666"
+   version="1.1"
+   id="svg1"
+   inkscape:version="1.4.2 (ebf0e940d0, 2025-05-08)"
+   sodipodi:docname="grid_0.svg"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="px"
+     inkscape:zoom="4.094343"
+     inkscape:cx="51.29028"
+     inkscape:cy="56.175068"
+     inkscape:window-width="1920"
+     inkscape:window-height="1149"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="layer1" />
+  <defs
+     id="defs1" />
+  <g
+     inkscape:label="Calque 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <path
+       style="fill:none;fill-rule:evenodd;stroke:#afbeea;stroke-width:0.264584px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+       d="M 21.034375,1.3229166 V 19.84375"
+       id="path1" />
+    <path
+       style="fill:none;fill-rule:evenodd;stroke:#afbeea;stroke-width:0.264584px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+       d="M 1.3229167,21.034375 H 19.84375"
+       id="path1-3" />
+  </g>
+</svg>