I only did responsive CSS changes using 2 browsers + about 7 theme variants. There were quite a few issues with responsive display showing different behavior on those themes which I adjusted.

One of the things I had in place that I forgot about were some responsive CSS that adjusted things like background & text colors which I removed in its entirety.

Also I had a lot of responsive CSS in a source file which is now in a CSS file less some that require server-side (PHP) settings.
There are still some pending adjustments that I want to apply but overall it is much better than before.

I will look into the desktop CSS issues that you have reported.

Thanks for testing.

ah okay...  i have taken a quick look localy on my Wampserver.. in the default theme..

in the normal Desktop version.. there are a few problems..
mainly the calendar..
left and right block widths..
on the admin side.. most of the colum widths..

in the Mobile version (responsive)
i didnt notice any changes..

as i say.. it was a quick look.. i am away from the computer untill monday, then i can take a closer look..

RC7 is now available.

---

This one has improvements but I'm still testing things out.
Let me know if it works better on all those themes you previously tested.
 

yes.. the Shadowing in the themes looks much better..  thanks for the pointer.. 

thanks for the feed back..
the rc6 version looks much better on the default theme.. diffinatly a big improvment..
i do not see any errors with the floating problem.. its disapeard..
the over all display issue is much better..

i see what you mean with the Shadowing.. yes, and i agree, it would be better to use the themes attributes

i will have to look into that, or will you be doing a configuration for the block settings..?

again thanks

RC6 is available which includes some responsive CSS adjustments.

The text color for some themes based off of curve2 has been fixed as well as the centering of the copyrights.
I also zeroed out the margin for the #main_content_section which was causing a display issue.

As for the other changes you posted, please keep in mind that using specific text/background colors is not going to look proper across all custom themes. I do not disagree with attempting the make highlights stand out more but in my opinion it will be best to apply a method which will look proper on most theme variations.
Perhaps some shadowing along with the CSS "currentColor" attribute? 

the version seems to be having its problems to...

not to sure if you would like to implement these changes..

i have made some changes to the calendar in the portalblocks.php
on line 1763 and 1766 so that the relevant dates stand out a bit more..
i have changed the Strong, in the portal.css

sp_strong{
    font-weight: bold;
    color: hsl(208, 65%, 38%);
    background: hsl(149, 39%, 65%);
    padding: 1px 3px 1px 3px;
}


if (!empty($day['holidays']) || !empty($day['birthdays']) || !empty($day['events']))
echo '
<a href="#day" onclick="return sp_collapseCalendar(\'', $day['day'], '\');"><sp_strong>', $day['is_today'] ? '[' : '', $day['day'], $day['is_today'] ? ']' : '', '</sp_strong></a>';
else
echo '
<a href="#day" onclick="return sp_collapseCalendar(\'0\');">', $day['is_today'] ?  '<strong>[' : '', $day['day'], $day['is_today'] ? ']</strong>' : '', '</a>';


also in the portal.css so that the news round tabs are smaller and inside the news window..

/* **************************************/
/* News specific styles    */
/* **************************************/
a.sp-inactive
{
background-color: #CCC;
background-size: 2em auto;
border-radius: 50%;
text-decoration: none;
cursor: pointer;
border: 0;
opacity: 1;
height: 10px;
width: 10px;
display: inline-block;
position: absolute;
top: 65%;
}
a.sp-active
{
background-color: #557EA0;
background-size: 2em auto;
border-radius: 50%;
text-decoration: none;
cursor: pointer;
border: 0;
opacity: 1;
height: 10px;
width: 10px;
display: inline-block;
position: absolute;
top: 65%;
}


some things have changed.. not to sure if thats good or not...  

the float left problem remains.. but disapers when loged in..!
if the float left is disabled.. then things are okay..

thanks for the feedback Chen..

i will give it a try..

I'm working on these issues.
You can try RC5 which may work a bit better across all those themes you're testing.
However, I have found that the footer copyrights are not centered properly nor is the text color for some themes.
Font color is not adjusted directly from EhPortal's native code but somehow it is affecting it in some scenarios.