Just forked your repo and I noticed an issue with the _layout.scss file:
When running Jekyll serve i get error Conversion error: Jekyll::Converters::Scss encountered an error while converting 'css/main.scss': Undefined mixin 'transition'. on line 28 This happens additionally in all other lines where transition is defined. I took out all instanced of this in the file to get it to compile.

Another issue is was found in the main.scss file:
Additionally, I noticed there was nothing in the initscss folder, so the error of Conversion error: Jekyll::Converters::Scss encountered an error while converting 'css/main.scss': File to import not found or unreadable: initscss/scss/init. Load path: /Users/brittanyvacchiano/zetsu/_sass on line 10 occurs. I fixed this by removing the empty initscss folder and removing that import from the main.scss file on line 13. What did you mean to put in this folder?

Great job with the layout - can't wait to get my site looking exactly like yours & writing some posts.

The user @carlsonsantana validate your site template "https://nandomoreirame.github.io/zetsu/" and found these accessibility errors:

• Page https://nandomoreirame.github.io/zetsu/:
  • Issue e985b67a-f2ce-4385-9419-50703e8f158a:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 3.99:1. Recommendation: change background to #fff.
    • Selector: html > body > main > footer > div > small:nth-child(3) > a
    • Context: <a href="http://nandomoreira.me" target="_blank">nandomoreira.me</a>
  • Issue 2c71bdf9-8abe-47fe-8ab0-fc909ed45e5f:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.11:1. Recommendation: change text colour to #6e6e6e.
    • Selector: html > body > main > footer > div > small:nth-child(3)
    • Context: <small>by <a href="http://nandomoreira...</small>
  • Issue 2bb760fb-1239-4e57-aeca-7b9e33ce0498:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 3.99:1. Recommendation: change background to #fff.
    • Selector: html > body > main > footer > div > small:nth-child(2) > a
    • Context: <a href="http://jekyllrb.com" target="_blank">Jekyll</a>
  • Issue 391ea08b-a990-4c77-9a0c-48c91b6b3465:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.11:1. Recommendation: change text colour to #6e6e6e.
    • Selector: html > body > main > footer > div > small:nth-child(2)
    • Context: <small>© 2015 All rights reserved. Mad...</small>
  • Issue c9cb5af5-906f-4d84-b25c-4e6b159b6784:
    • Type: Error
    • Code: WCAG2AA.Principle4.Guideline4_1.4_1_2.H91.A.NoContent
    • Message: Anchor element found with a valid href attribute, but no link content has been supplied.
    • Selector: html > body > main > footer > div > div > ul > li:nth-child(2) > a
    • Context: <a href="http://twitter.com/nandomoreirame" target="_blank"><i class="fa fa-twitter"></i></a>
  • Issue 9e838d6d-3975-45a7-80e5-57b6eaa6029f:
    • Type: Error
    • Code: WCAG2AA.Principle4.Guideline4_1.4_1_2.H91.A.NoContent
    • Message: Anchor element found with a valid href attribute, but no link content has been supplied.
    • Selector: html > body > main > footer > div > div > ul > li:nth-child(1) > a
    • Context: <a href="http://facebook.com/fernando.dev" target="_blank"><i class="fa fa-facebook"></i></a>
  • Issue 4ade9e33-c1c3-4674-9328-e2d07ee01ae5:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.39:1. Recommendation: change text colour to #6a6a6a.
    • Selector: html > body > main > div > div > nav > ul > li:nth-child(1) > span
    • Context: <span class="page-number">Page 1 of 3</span>
  • Issue 82492eb3-e724-4142-a9f6-636b4ed8ce55:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.81:1. Recommendation: change text colour to #767676.
    • Selector: html > body > main > div > article:nth-child(2) > header > span > span
    • Context: <span class="post-author">by Fernando Moreira</span>
  • Issue 99884283-e983-46ff-8486-973a55b51058:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.81:1. Recommendation: change text colour to #767676.
    • Selector: html > body > main > div > article:nth-child(2) > header > span > time
    • Context: <time class="post-date" datetime="">Aug 7, 2015</time>
  • Issue 361ab394-b0f7-45be-a49f-63be2fe0b271:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.81:1. Recommendation: change text colour to #767676.
    • Selector: html > body > main > div > article:nth-child(1) > header > span > span
    • Context: <span class="post-author">by Fernando Moreira</span>
  • Issue 81bf8983-0a06-4e22-a529-761666c94723:
    • Type: Error
    • Code: WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail
    • Message: This element has insufficient contrast at this conformance level. Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.81:1. Recommendation: change text colour to #767676.
    • Selector: html > body > main > div > article:nth-child(1) > header > span > time
    • Context: <time class="post-date" datetime="">Aug 8, 2015</time>
  • Issue 26e2579d-5e51-43ba-9ae7-1b54f74d467e:
    • Type: Error
    • Code: WCAG2AA.Principle4.Guideline4_1.4_1_2.H91.A.NoContent
    • Message: Anchor element found with a valid href attribute, but no link content has been supplied.
    • Selector: html > body > main > header > div > div > nav > a
    • Context: <a href="#" class="menu-icon"> <span></span> <span></span> <s...</a>

You can check these accessibility errors using pa11y.
You can view the full validation results in our website.

Attempting to access the demo link from this repository returns a 404 error page:

https://nandomoreira.me/zetsu/

The link is also broken from the jekyll themes website: http://jekyllthemes.org/themes/zetsu/

Thank you for closing my last issue! The styling issue is now fixed.

I did notice, however, that when publishing your site using rake site:publish to my github page using the Rakefile, that my page is unstyled. The server responded with a 404 not found for the main.css file.