OK - I'm trying your method but failing to find the tweak epub feature :-( I have calibre open at the relevant book - cant see a suitable menu option anywhere ?
so tried 2nd route - could not get 7z to work - used winzip - found the css file margins - they look ok in there at 1st glance (5pt)
here's what is in the epub, ( via caliibre wizard)
[code]
</head>
<body text="#000000" link="#0000ff" dir="LTR" class="calibre">
<p class="western">
<span class="calibre1"><b class="calibre2">Excession</b></span></p>
<p class="calibre3">
Culture Book 4</p>
<p class="calibre3">
Iain M. Banks</p>
<p class="calibre4">
<br class="calibre5"/></p>
<p class="calibre6">
Two and a half millennia ago, the artifact appeared in a remote
corner of space, beside a trillion-year old dying sun from a
different universe. It was a perfect black-body sphere, and it did
nothing. Then it disappeared. Now it is back.</p>
<p class="calibre6">
Silent, motionless, and resisting all efforts to make contact, the
[code]
everything after culture book 4 Iain Banks gets indented in mobi, but not in epub viewer ???
so is it something to do with calibre 6 class ??
back to the css file - i guess I have to edit & save this chunk: ( which is using inches, not pts ? )
.calibre6 {
direction: ltr;
display: block;
margin-bottom: 0.02in;
margin-left: 0.1in;
margin-right: 0.1in;
margin-top: 0.02in;
orphans: 2;
text-align: LEFT;
text-indent: 0;
widows: 2
NB the styles go all the way up to calibre 15, + some other western ones. would I have to edit every style for consistency - look complex !