diff --git a/index.qmd b/index.qmd
index 07cbdb2..92580b7 100644
--- a/index.qmd
+++ b/index.qmd
@@ -80,6 +80,6 @@ We very much welcome your feedback, contributions and collaboration. Here are a
 
 2.  Submit a [New Issue](https://github.com/marinebon/MarineSDMs/issues/new/choose) on Github.
 
-3.  Click on the "Edit this Page" in the upper right. If you have a Github account, then you can fork this repository from owner "marinebon" to your username, edit the page(s) and submit a pull request.
+3.  Click on the <i class="bi bi-github"></i> "Edit this Page" in the upper right. If you have a Github account, then you can fork this repository from owner "marinebon" to your username, edit the page(s) and submit a pull request.
 
-4.  If you are a regular contributor, you can be added to the collaborators of this repository to make push changes directly (without needing a pull request).
+4.  If you are a regular contributor, you can be added to the collaborators of this repository to push changes directly (without needing a pull request).
diff --git a/indicators.qmd b/indicators.qmd
index 87d75c0..4c5404e 100644
--- a/indicators.qmd
+++ b/indicators.qmd
@@ -6,13 +6,15 @@ title: "Indicators"
 
 Here are the classic diversity indices from the R package `vegan`:
 
-$$
-\begin{aligned}
-H   &= - \sum_{i=1}^S p_i \log_b  p_i  &\text{Shannon-Weaver}  \\
-D_1 &= 1 - \sum_{i=1}^S p_i^2          &\text{Simpson}         \\
-D_2 &= \frac{1}{\sum_{i=1}^S p_i^2}    &\text{inverse Simpson}
-\end{aligned}
-$$
+> $$
+> \begin{aligned}
+> H   &= - \sum_{i=1}^S p_i \log_b  p_i  &\text{Shannon-Weaver}  \\
+> D_1 &= 1 - \sum_{i=1}^S p_i^2          &\text{Simpson}         \\
+> D_2 &= \frac{1}{\sum_{i=1}^S p_i^2}    &\text{inverse Simpson}
+> \end{aligned}
+> $$
+> 
+> where $p_i$ is the proportion of species $i$, and $S$ is the number of species so that $\sum_{i=1}^S p_i = 1$, and $b$ is the base of the logarithm.
 
 ## Endemism