column theme .pull-right and .pull-left not working

[ChuliangXiao]

With css: xaringan-themer.css in the header, .pull-right and .pull-left don't work to divide a slide into two columns.

 sessionInfo("xaringanthemer")
R version 3.3.0 (2016-05-03)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
character(0)

other attached packages:
[1] xaringanthemer_0.1.1

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.16    rstudioapi_0.7  servr_0.9       knitr_1.20      magrittr_1.5    devtools_1.13.5 grDevices_3.3.0
 [8] xtable_1.8-2    R6_2.2.2        stringr_1.3.0   httr_1.3.1      highr_0.6       tools_3.3.0     utils_3.3.0    
[15] DT_0.4.4        xfun_0.1        xaringan_0.6.4  git2r_0.21.0    withr_2.1.2     crosstalk_1.0.0 htmltools_0.3.6
[22] stats_3.3.0     datasets_3.3.0  yaml_2.1.18     leaflet_2.0.0   digest_0.6.15   rprojroot_1.3-2 base_3.3.0     
[29] shiny_1.0.5     later_0.7.1     promises_1.0.1  htmlwidgets_1.2 graphics_3.3.0  rsconnect_0.8.8 curl_3.2       
[36] mime_0.5        memoise_1.1.0   evaluate_0.10.1 rmarkdown_1.9   stringi_1.1.7   methods_3.3.0   backports_1.1.2
[43] jsonlite_1.5    httpuv_1.4.1

[gadenbuie]

Could you share your slide code where .pull-left[] and .pull-right[] aren't working?

I tried to reproduce the issue using the below .Rmd and everything rendered okay.

---
output:
  xaringan::moon_reader:
    lib_dir: libs
    css: xaringan-themer.css
    seal: FALSE
---

```{r setup, include=FALSE}
options(htmltools.dir.version = FALSE)

library(xaringanthemer)
mono_accent(
  base_color = "#175dac",
  text_font_size = "24px",
  text_font_google = google_font("Fira Sans"),
  header_font_google = google_font("Quicksand")
)

Test pull left right

.pull-left[ left side ]

.pull-right[ right side ]

![image](https://user-images.githubusercontent.com/5420529/40033353-14c73c1c-57c6-11e8-8545-7da139ec3189.png)

[ChuliangXiao]

I think I forgot to load library(xaringanthemer) in the code (though it was loaded in the Console) after adding css: xaringan-themer.css to the header. Thank you very much.