Make the Tweetdeck DarkTheme even darker, change font, wide Home column. Just append it to chromium/Default/Extensions/???/3.5.?_?/web/css/app-dark.???.css or use it in greasemonkey.

tweetdeck-darker.css

html{
	font-family:Droid Sans;
}
.is-wide-columns .column {
	width:300px;
}
.is-wide-columns .column.column-type-home {
	width:361px;
	font-size:1.0rem;
}
.stream-item {
	background-color:black;
	border-bottom:1px solid #1c1c1c;
}
.stream-item.is-selected-tweet {
	background-color:#333;
	background:-webkit-linear-gradient(left, #1a82f7, #225 10px, #225 56px, #222 66px, #222);
}
.app-content {
	background-color: #000;
}
.column-type-interactions .stream-item[data-key^='favorite'] {
	color:#999;
	font-size:0.75rem;
}
.column-type-interactions .stream-item[data-key^='favorite'] .activity-header {
	color: white;
	font-size:0.9rem;
}
.column-type-interactions .stream-item[data-key^='favorite'] .account-link.link-complex.block {
	color: #999;
}
.column-type-interactions .stream-item[data-key^='retweet'] .account-link.link-complex.block {
	color: #999;
}
.column-type-interactions .stream-item[data-key^='retweet'] {
	color:#999;
	font-size:0.75rem;
}
.column-type-interactions .stream-item[data-key^='retweet'] .activity-header {
	color: white;
	font-size:0.9rem;
}
.column-type-interactions .stream-item[data-key^='retweet'] .tweet-header img.tweet-avatar {
	width:70%;
	height:70%;
}
.column-type-interactions .stream-item[data-key^='favorite'] .tweet-header img.tweet-avatar {
	width:70%;
	height:70%;
}
.column-type-interactions .stream-item[data-key^='mention'] .activity-header .account-link {
	color:#999;
}
.column-type-interactions .stream-item[data-key^='mention'] .activity-header {
	color:#999;
	font-size:0.75rem;
}
.stream-item footer .txt-mute {
	color:#2c2c2c;
}
.stream-item:hover footer .txt-mute {
	color:#999;
}
.is-wide-columns .media-size-large {
	height: 230px;
}
.media-item {
	background-repeat: no-repeat;
	background-position: 50% 50%;
	background-size: 100% auto;
}
.media-size-large, .media-size-large-height {
	height: 230px;
}