My custom stylesheets for Chrome plugin Just-Read https://github.com/ZachSaucier/Just-Read.

DarkRead.css

@font-face {
    font-family: "Source Sans Pro Semibold";
    src: url("chrome-extension://dgmanlpmmkibanfdgjocnabmcaclkmod/fonts/SourceSansPro-Semibold.ttf");
}

@font-face {
    font-family: "Source Sans Pro Bold";
    src: url("chrome-extension://dgmanlpmmkibanfdgjocnabmcaclkmod/fonts/SourceSansPro-Bold.ttf");
}

@font-face {
    font-family: "Source Sans Pro Light";
    src: url("chrome-extension://dgmanlpmmkibanfdgjocnabmcaclkmod/fonts/SourceSansPro-Light.ttf");
}

@font-face {
    font-family: Merriweather;
    src: url("chrome-extension://dgmanlpmmkibanfdgjocnabmcaclkmod/fonts/Merriweather-Light.ttf");
}

@media screen {
    * {
        box-sizing: border-box;
    }
}

body {
    font-family: Merriweather, serif;
    line-height: 2.75em;
    font-size: 16px;
    color: rgb(255, 167, 38);
    background-color: rgb(45, 99, 125);
}

h1, h2 {
    font-family: "Source Sans Pro Bold", sans-serif;
}

h1 {
    font-size: 1.875em;
    line-height: 2.125em;
}

h2 {
    font-size: 1.25em;
    line-height: 2.125em;
}

h3 {
    font-family: Merriweather, serif;
    font-size: 1em;
    line-height: 2em;
    padding-top: 0.9375em;
    padding-bottom: 0.9375em;
    border-bottom: 1px solid rgb(216, 216, 216);
    border-top: 1px solid rgb(216, 216, 216);
}

hr {
    height: 1px;
    background-color: rgb(216, 216, 216);
    border: none;
    width: 100%;
    margin: 0px;
}

a[href] {
    color: rgb(39, 170, 225);
}

a[href]:hover {
    color: rgb(78, 202, 255);
}

.youtubeContainer {
    position: relative;
    width: 100%;
    height: 0px;
    padding-bottom: 56.25%;
    padding-top: 25px;
}

iframe[src*="youtube.com/embed/"] {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0px;
    left: 0px;
}

img {
    max-width: 100%;
}

li {
    line-height: 2.5em;
}

pre {
    background-color: rgb(224, 224, 224);
    padding: 10px;
    overflow: auto;
}

aside, [class*="sidebar"], [id*="sidebar"] {
    max-width: 90%;
    margin: 0px auto;
    border: 1px solid lightgrey;
    padding: 5px 15px;
}

.simple-date {
    display: inline-block;
    font-family: "Source Sans Pro Light", sans-serif;
    font-size: 18px;
    padding-right: 15px;
    padding-top: 10px;
    padding-bottom: 10px;
    border-right: 1px solid rgb(216, 216, 216);
}

.rtl .simple-date {
    border-left: 1px solid rgb(216, 216, 216);
    border-right: none;
    padding-right: 0px;
    padding-left: 15px;
}

.simple-author {
    display: inline-block;
    font-family: "Source Sans Pro Semibold", sans-serif;
    font-size: 18px;
    color: rgb(39, 170, 225);
    line-height: 22px;
    padding-left: 10px;
    padding-top: 10px;
    padding-bottom: 10px;
}

.rtl .simple-author {
    padding-left: 0px;
    padding-right: 10px;
}

.simple-container {
    max-width: 600px;
    margin: 0px auto;
    padding-top: 70px;
    padding-bottom: 20px;
}

@media (max-width: 750px) {
    .simple-container {
        padding-left: 50px;
        padding-right: 50px;
    }
}

@media (max-width: 450px) {
    .simple-container {
        padding-top: 30px;
        padding-left: 20px;
        padding-right: 20px;
    }
}

[class*="emoji"], [class*="icon"] {
    width: 1em;
}

script {
    display: none;
}

[class="ad"], [class*="ads"], [class^="ad-"], [class^="ad_"], [class*="-ad-"], [class$="-ad"], [class$="_ad"], [class~="ad"] {
    display: none;
}

[class*="navigation"], [class*="nav"], nav, [class*="search"], [class*="menu"], [class*="print"]:not(.simple-print) {
    display: none;
}

[class*="nocontent"], .hidden {
    display: none;
}

[class*="popup"] {
    display: none;
}

[class*="share"], [class*="sharing"], [class*="social"], [class*="follow"], [class*="newsletter"] {
    display: none;
}

form, [class^="form-"], [class^="form"], [class*="-form-"], [class$="-form"], [class$="form"], [class~="form"] {
    display: none;
}

[class*="related"], [class*="recommended"], [class*="see-also"], [class*="popular"], [class*="trail"] {
    display: none;
}

[class*="comment"], [class*="disqus"], [id*="disqus"] {
    display: none;
}

[class^="tag"], [class*="-tag-"], [class$="-tag"], [class$="_tag"], [class~="tag"], [class*="-tags-"], [class$="-tags"], [class$="_tags"], [class~="tags"], [id*="-tags-"], [id$="-tags"], [id$="_tags"], [id~="tags"] {
    display: none;
}

[class*="subscribe"], [id*="subscribe"], [class*="subscription"], [id*="subscription"] {
    display: none;
}

[class^="fav"], [class*="-fav-"], [class$="-fav"], [class$="_fav"], [class~="fav"], [id^="fav"], [id*="-fav-"], [id$="-fav"], [id$="_fav"], [id~="fav"], [class*="favorites"], [id*="favorites"] {
    display: none;
}

[class*="signup"], [id*="signup"], [class*="signin"], [id*="signin"], [class*="signIn"], [id*="signIn"] {
    display: none;
}

footer, [class*="footer"], [id*="footer"] {
    display: none;
}

svg[class*="pinterest"], [class*="pinterest"] svg, svg[id*="pinterest"], [id*="pinterest"] svg, svg[class*="pinit"], [class*="pinit"] svg, svg[id*="pinit"], [id*="pinit"] svg, svg[class*="facebook"], [class*="facebook"] svg, svg[id*="facebook"], [id*="facebook"] svg, svg[class*="github"], [class*="github"] svg, svg[id*="github"], [id*="github"] svg, svg[class*="twitter"], [class*="twitter"] svg, svg[id*="twitter"], [id*="twitter"] svg, svg[class*="instagram"], [class*="instagram"] svg, svg[id*="instagram"], [id*="instagram"] svg, svg[class*="tumblr"], [class*="tumblr"] svg, svg[id*="tumblr"], [id*="tumblr"] svg, svg[class*="youtube"], [class*="youtube"] svg, svg[id*="youtube"], [id*="youtube"] svg, svg[class*="codepen"], [class*="codepen"] svg, svg[id*="codepen"], [id*="codepen"] svg, svg[class*="dribble"], [class*="dribble"] svg, svg[id*="dribble"], [id*="dribble"] svg, svg[class*="soundcloud"], [class*="soundcloud"] svg, svg[id*="soundcloud"], [id*="soundcloud"] svg, svg[class*="rss"], [class*="rss"] svg, svg[id*="rss"], [id*="rss"] svg, svg[class*="linkedin"], [class*="linkedin"] svg, svg[id*="linkedin"], [id*="linkedin"] svg, svg[class*="vimeo"], [class*="vimeo"] svg, svg[id*="vimeo"], [id*="vimeo"] svg, svg[class*="email"], [class*="email"] svg, svg[id*="email"], [id*="email"] svg {
    display: none;
}

An dark theme that is easy to the eye and easy to read. With big font and big line width.