diff --git a/.gitignore b/.gitignore
index ba2ec833b..d33256211 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,4 +15,5 @@ inst/shiny/log/*
 .DS_Store
 # {shinytest2}: Ignore new debug snapshots for `$expect_values()`
 *_.new.png
-desktop.ini
\ No newline at end of file
+desktop.ini
+tests/testthat/Rplots.pdf
diff --git a/NEWS.md b/NEWS.md
index 9ac7adfd1..14fcb7dca 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,15 @@
 # aNCA (development version)
 
+## Code Quality
+
+* Removed debug `print()` statements from TLG module and replaced with proper logging (#1298)
+* Removed unused `require(magrittr)` and `require(stats)` calls from `app.R` (#1298)
+* Replaced deprecated HTML `align` attributes with inline CSS in TLG module (#1298)
+* Standardized button CSS classes: removed redundant `btn` prefix where duplicate with `btn-*` (#1298)
+* Added `aria-label` attributes to 15 icon-only buttons for accessibility (#1298)
+* Removed redundant `disabled = FALSE` default from units table actionButton (#1298)
+* Extracted inline hex colors to shared `colors.R` constants and SCSS variables (#1298)
+
 ## Features
 
 ### Settings & Configuration
diff --git a/R/g_pkcg.R b/R/g_pkcg.R
index 4d94198e7..eef7b6ce4 100644
--- a/R/g_pkcg.R
+++ b/R/g_pkcg.R
@@ -393,6 +393,7 @@ g_pkcg02_log <- function(data, ...) {
 #' @importFrom stats setNames
 
 #' @examples
+#' \donttest{
 #' # Make an example small dataset
 #' adnca <- adnca_example
 #' adnca <- adnca[adnca$USUBJID %in% unique(adnca$USUBJID)[c(1, 2)],]
@@ -403,7 +404,7 @@ g_pkcg02_log <- function(data, ...) {
 #' plots <- pkcg02(adnca)
 #' plots_log <- pkcg02(adnca, scale = "LOG")
 #' plotly::plotly_build(plots[[1]]) # View the first plot
-#'
+#' }
 #' @export
 #' @author Kezia Kobana
 pkcg02 <- function(
diff --git a/inst/WORDLIST b/inst/WORDLIST
index fd3495e3b..112e98fb2 100644
--- a/inst/WORDLIST
+++ b/inst/WORDLIST
@@ -115,6 +115,7 @@ RefParameter
 Req
 Roadmap
 SBS
+SCSS
 SDTM
 SDTMIG
 SMS
@@ -144,6 +145,7 @@ Walkthrough
 XPT
 YAML
 aNCA's
+actionButton
 adnca
 analysing
 analyte
diff --git a/inst/shiny/app.R b/inst/shiny/app.R
index 55e5c4c96..0554411c4 100644
--- a/inst/shiny/app.R
+++ b/inst/shiny/app.R
@@ -5,7 +5,6 @@ require(dplyr)
 require(htmlwidgets)
 require(logger)
 require(formatters)
-require(magrittr)
 require(plotly)
 require(purrr)
 require(reactable)
@@ -15,7 +14,6 @@ require(shinycssloaders)
 require(shinyjs)
 require(shinyjqui)
 require(shinyWidgets)
-require(stats)
 
 require(tidyr)
 require(tools)
diff --git a/inst/shiny/functions/colors.R b/inst/shiny/functions/colors.R
new file mode 100644
index 000000000..1db8b2b90
--- /dev/null
+++ b/inst/shiny/functions/colors.R
@@ -0,0 +1,26 @@
+# Color constants — keep in sync with inst/shiny/www/styles/modules/_colors.scss
+# See https://github.com/pharmaverse/aNCA/issues/1298
+
+# Backgrounds
+BG_GREY_LIGHT     <- "#eeeeee"
+BG_GREY_HEADER    <- "#e9e9e9"
+BG_HIGHLIGHT_BLUE <- "#CCE5FF"
+BG_BLUE_LIGHT     <- "#e6f2ff"
+ANCA_WHITE        <- "#ffffff"
+
+# Text
+TEXT_MUTED        <- "#999999"
+TEXT_DIM          <- "#888888"
+TEXT_SUBTLE       <- "#777777"
+TEXT_SECONDARY    <- "#666666"
+TEXT_HEADING      <- "#555555"
+
+# Borders
+BORDER_LIGHT      <- "#dddddd"
+BORDER_MUTED      <- "#cccccc"
+BORDER_PANEL      <- "#dee2e6"
+
+# Accent
+ACCENT_BLUE       <- "#0d6efd"
+ACCENT_ORANGE     <- "#ffa62d"
+ACCENT_DANGER     <- "#dc3545"
diff --git a/inst/shiny/functions/utils-exclusions.R b/inst/shiny/functions/utils-exclusions.R
index e16946cff..97a3d7aee 100644
--- a/inst/shiny/functions/utils-exclusions.R
+++ b/inst/shiny/functions/utils-exclusions.R
@@ -9,9 +9,9 @@ EXCL_COLOR_PARAM <- "#FFF3CD"  # yellow — parameter exclusion
 .legend_swatch <- function(color, label) {
   div(
     style = "display:flex; align-items:center; gap:6px;",
-    div(style = paste0(
-      "width:14px; height:14px; background:", color,
-      "; border:1px solid #ddd;"
+    div(style = glue::glue(
+      "width:14px; height:14px; background:{color}",
+      "; border:1px solid {BORDER_LIGHT};"
     )),
     span(label, style = "font-size:0.9em;")
   )
@@ -167,7 +167,8 @@ EXCL_COLOR_PARAM <- "#FFF3CD"  # yellow — parameter exclusion
             ns(value),
             label = NULL,
             icon = shiny::icon("times"),
-            class = "btn btn-link btn-sm",
+            `aria-label` = "Remove exclusion",
+            class = "btn-link btn-sm",
             style = "padding:2px 6px;"
           )
         )
@@ -196,7 +197,7 @@ EXCL_COLOR_PARAM <- "#FFF3CD"  # yellow — parameter exclusion
     pagination = FALSE,
     defaultPageSize = nrow(df),
     theme = reactable::reactableTheme(
-      headerStyle = list(background = "#e9e9e9")
+      headerStyle = list(background = BG_GREY_HEADER)
     ),
     columns = cols
   )
diff --git a/inst/shiny/modules/tab_about.R b/inst/shiny/modules/tab_about.R
index 4f371f758..568f6b463 100644
--- a/inst/shiny/modules/tab_about.R
+++ b/inst/shiny/modules/tab_about.R
@@ -154,7 +154,9 @@ tab_about_server <- function(id) {
         }
       )
       tags$blockquote(
-        style = "border-left: 3px solid #ccc; padding-left: 1em; color: #555;",
+        style = glue::glue(
+          "border-left: 3px solid {BORDER_MUTED}; padding-left: 1em; color: {TEXT_HEADING};"
+        ),
         tags$p(cit_text)
       )
     })
@@ -163,7 +165,9 @@ tab_about_server <- function(id) {
       cit <- utils::citation("PKNCA")
       cit_text <- paste(format(cit, style = "text"), collapse = "\n\n")
       tags$blockquote(
-        style = "border-left: 3px solid #ccc; padding-left: 1em; color: #555;",
+        style = glue::glue(
+          "border-left: 3px solid {BORDER_MUTED}; padding-left: 1em; color: {TEXT_HEADING};"
+        ),
         tags$p(cit_text)
       )
     })
@@ -255,7 +259,7 @@ tab_about_server <- function(id) {
     style = "margin-bottom: 0.3em;",
     tags$a(href = url, target = "_blank", label),
     tags$span(
-      style = "color: #999; font-size: 0.85em; margin-left: 0.5em;",
+      style = glue::glue("color: {TEXT_MUTED}; font-size: 0.85em; margin-left: 0.5em;"),
       url
     )
   )
diff --git a/inst/shiny/modules/tab_data/data_mapping.R b/inst/shiny/modules/tab_data/data_mapping.R
index 14bd5d1f0..12eb873af 100644
--- a/inst/shiny/modules/tab_data/data_mapping.R
+++ b/inst/shiny/modules/tab_data/data_mapping.R
@@ -535,7 +535,7 @@ data_mapping_server <- function(id, adnca_data, imported_mapping, trigger) {
           if (dup_data[index, ".dup_group"] %% 2 == 0) {
             list(background = "white")
           } else {
-            list(background = "#e6f2ff")
+            list(background = BG_BLUE_LIGHT)
           }
         },
         selection = "multiple",
diff --git a/inst/shiny/modules/tab_data/data_upload.R b/inst/shiny/modules/tab_data/data_upload.R
index a10a0a69d..46393053d 100644
--- a/inst/shiny/modules/tab_data/data_upload.R
+++ b/inst/shiny/modules/tab_data/data_upload.R
@@ -225,8 +225,8 @@ data_upload_server <- function(id) {
     defaultPageSize = 10,
     theme = reactableTheme(
       rowSelectedStyle = list(
-        backgroundColor = "#CCE5FF",
-        boxShadow = "inset 2px 0 0 0 #0d6efd"
+        backgroundColor = BG_HIGHLIGHT_BLUE,
+        boxShadow = paste0("inset 2px 0 0 0 ", ACCENT_BLUE)
       )
     ),
     columns = list(
diff --git a/inst/shiny/modules/tab_explore.R b/inst/shiny/modules/tab_explore.R
index b175b5451..5cd9b478f 100644
--- a/inst/shiny/modules/tab_explore.R
+++ b/inst/shiny/modules/tab_explore.R
@@ -219,7 +219,7 @@ tab_explore_server <- function(id, pknca_data, extra_group_vars) {
         footer = tagList(
           modalButton("Cancel"),
           actionButton(ns("confirm_add_to_exports"), "Save",
-                       class = "btn btn-primary")
+                       class = "btn-primary")
         ),
         size = "s",
         easyClose = TRUE
diff --git a/inst/shiny/modules/tab_explore/plot_sidebar.R b/inst/shiny/modules/tab_explore/plot_sidebar.R
index bc25a4715..77c1a3dc1 100644
--- a/inst/shiny/modules/tab_explore/plot_sidebar.R
+++ b/inst/shiny/modules/tab_explore/plot_sidebar.R
@@ -17,7 +17,7 @@ plot_sidebar_ui <- function(id, is_mean_plot = FALSE, extra_ui = NULL) {
       ns("add_to_exports"),
       label = "Add to Exports",
       icon = icon("plus"),
-      class = "btn btn-primary btn-sm",
+      class = "btn-primary btn-sm",
       width = "100%"
     ),
     extra_ui,
diff --git a/inst/shiny/modules/tab_explore/qc_plot.R b/inst/shiny/modules/tab_explore/qc_plot.R
index 9e67be183..fd965bcbc 100644
--- a/inst/shiny/modules/tab_explore/qc_plot.R
+++ b/inst/shiny/modules/tab_explore/qc_plot.R
@@ -23,7 +23,7 @@ pk_dose_qc_plot_ui <- function(id, extra_ui = NULL) {
         ns("add_to_exports"),
         label = "Add to Exports",
         icon = icon("plus"),
-        class = "btn btn-primary btn-sm",
+        class = "btn-primary btn-sm",
         width = "100%"
       ),
       extra_ui,
diff --git a/inst/shiny/modules/tab_explore/saved_outputs.R b/inst/shiny/modules/tab_explore/saved_outputs.R
index 1db2e7779..186f13403 100644
--- a/inst/shiny/modules/tab_explore/saved_outputs.R
+++ b/inst/shiny/modules/tab_explore/saved_outputs.R
@@ -59,7 +59,7 @@ saved_outputs_ui <- function(id) {
     ns("view_exports"),
     label = "View Exports",
     icon = icon("eye"),
-    class = "btn btn-primary btn-sm",
+    class = "btn-primary btn-sm",
     width = "100%"
   )
 }
@@ -168,7 +168,7 @@ saved_outputs_server <- function(id, saved_plots_metadata, get_plot_obj,
           "No plots saved yet. Use ",
           tags$strong("Add to Exports"),
           " to save plots.",
-          style = "color: #888; font-style: italic; margin: 16px 0;"
+          style = glue::glue("color: {TEXT_DIM}; font-style: italic; margin: 16px 0;")
         ))
       }
 
@@ -186,9 +186,9 @@ saved_outputs_server <- function(id, saved_plots_metadata, get_plot_obj,
         )
 
         tags$div(
-          style = paste0(
-            "border: 1px solid #dee2e6; border-radius: 6px; ",
-            "padding: 12px; margin-bottom: 16px; background: #fff;"
+          style = glue::glue(
+            "border: 1px solid {BORDER_PANEL}; border-radius: 6px; ",
+            "padding: 12px; margin-bottom: 16px; background: {ANCA_WHITE};"
           ),
           tags$div(
             style = paste0(
@@ -199,16 +199,17 @@ saved_outputs_server <- function(id, saved_plots_metadata, get_plot_obj,
               tags$strong(plot_name, style = "font-size: 1.1em;"),
               tags$span(
                 paste0(" \u2014 ", plot_type, " \u00b7 ", plot_ts),
-                style = "color: #666; font-size: 0.9em;"
+                style = glue::glue("color: {TEXT_SECONDARY}; font-size: 0.9em;")
               )
             ),
             tags$a(
               href = "#",
               onclick = paste0(remove_js, "return false;"),
-              style = paste0(
-                "color: #dc3545; font-size: 1.2em; ",
+              style = glue::glue(
+                "color: {ACCENT_DANGER}; font-size: 1.2em; ",
                 "text-decoration: none;"
               ),
+              `aria-label` = "Remove from exports",
               title = "Remove from exports",
               icon("times")
             )
diff --git a/inst/shiny/modules/tab_nca.R b/inst/shiny/modules/tab_nca.R
index bb0f8ae60..db08b66c4 100644
--- a/inst/shiny/modules/tab_nca.R
+++ b/inst/shiny/modules/tab_nca.R
@@ -32,7 +32,7 @@ tab_nca_ui <- function(id) {
         inputId = ns("run_nca"),
         label = "Run NCA",
         icon = icon("play"),
-        class = "btn btn-primary",
+        class = "btn-primary",
         width = "100%"
       ),
       nca_setup_ui(ns("nca_setup")),
diff --git a/inst/shiny/modules/tab_nca/excretion_analysis.R b/inst/shiny/modules/tab_nca/excretion_analysis.R
index d105badcc..d847b985a 100644
--- a/inst/shiny/modules/tab_nca/excretion_analysis.R
+++ b/inst/shiny/modules/tab_nca/excretion_analysis.R
@@ -273,7 +273,7 @@ excretion_help_ui <- function() {
       )
     ),
     style = "unite",
-    icon = icon("question"),
+    icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
     status = "primary"
   )
 }
diff --git a/inst/shiny/modules/tab_nca/nca_results.R b/inst/shiny/modules/tab_nca/nca_results.R
index 65a6d7b8c..912f43c70 100644
--- a/inst/shiny/modules/tab_nca/nca_results.R
+++ b/inst/shiny/modules/tab_nca/nca_results.R
@@ -33,7 +33,9 @@ nca_results_ui <- function(id) {
         span("MISSING", style = "font-size:0.9em;")
       ),
       div(style = "display:flex; align-items:center; gap:6px;",
-        div(style = "width:14px; height:14px; background:#ffffff; border:1px solid #ddd;"),
+        div(style = glue::glue(
+          "width:14px; height:14px; background:{ANCA_WHITE}; border:1px solid {BORDER_LIGHT};"
+        )),
         span("ACCEPTED", style = "font-size:0.9em;")
       )
     ),
diff --git a/inst/shiny/modules/tab_nca/non_nca_ratios.R b/inst/shiny/modules/tab_nca/non_nca_ratios.R
index 0d4ab9e16..b78fb3389 100644
--- a/inst/shiny/modules/tab_nca/non_nca_ratios.R
+++ b/inst/shiny/modules/tab_nca/non_nca_ratios.R
@@ -127,7 +127,10 @@ non_nca_ratio_server <- function(id, data, grouping_vars) {
         ),
         div(
           class = "ratio-remove-btn-wrapper",
-          actionButton(ns(paste0("remove_", count)), "", icon = icon("trash-alt"))
+          actionButton(
+            ns(paste0("remove_", count)), "",
+            `aria-label` = "Remove ratio pair", icon = icon("trash-alt")
+          )
         )
       )
 
@@ -243,7 +246,7 @@ non_nca_ratio_help_ui <- function(title) {
     ),
     style = "unite",
     placement = "left",
-    icon = icon("question"),
+    icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
     status = "primary"
   )
 }
diff --git a/inst/shiny/modules/tab_nca/setup/data_imputation.R b/inst/shiny/modules/tab_nca/setup/data_imputation.R
index eb5c5f6f9..e8b0f2a53 100644
--- a/inst/shiny/modules/tab_nca/setup/data_imputation.R
+++ b/inst/shiny/modules/tab_nca/setup/data_imputation.R
@@ -53,7 +53,7 @@ data_imputation_ui <- function(id) {
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary",
           width = "500px"
         )
@@ -123,7 +123,7 @@ data_imputation_ui <- function(id) {
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary",
           width = "500px"
         )
diff --git a/inst/shiny/modules/tab_nca/setup/general_exclusions.R b/inst/shiny/modules/tab_nca/setup/general_exclusions.R
index 9a2fe9ce2..3d1b00c66 100644
--- a/inst/shiny/modules/tab_nca/setup/general_exclusions.R
+++ b/inst/shiny/modules/tab_nca/setup/general_exclusions.R
@@ -37,7 +37,7 @@ general_exclusions_ui <- function(id) {
       actionButton(
         ns("add_exclusion_reason"),
         label = "Add",
-        class = "btn btn-primary btn-sm"
+        class = "btn-primary btn-sm"
       ),
       # Help button (dropdown)
       dropdown(
@@ -78,7 +78,7 @@ general_exclusions_ui <- function(id) {
         ),
         style = "unite",
         right = TRUE,
-        icon = icon("question"),
+        icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
         status = "primary"
       )
     ),
diff --git a/inst/shiny/modules/tab_nca/setup/manual_slopes_table.R b/inst/shiny/modules/tab_nca/setup/manual_slopes_table.R
index 163215844..f38d6375b 100644
--- a/inst/shiny/modules/tab_nca/setup/manual_slopes_table.R
+++ b/inst/shiny/modules/tab_nca/setup/manual_slopes_table.R
@@ -182,8 +182,8 @@ manual_slopes_table_server <- function(
         borderless = TRUE,
         theme = reactableTheme(
           rowSelectedStyle = list(
-            backgroundColor = "#eee",
-            boxShadow = "inset 2px 0 0 0 #ffa62d"
+            backgroundColor = BG_GREY_LIGHT,
+            boxShadow = glue::glue("inset 2px 0 0 0 {ACCENT_ORANGE}")
           )
         )
       )
diff --git a/inst/shiny/modules/tab_nca/setup/parameter_exclusions.R b/inst/shiny/modules/tab_nca/setup/parameter_exclusions.R
index 5cc954c22..a17979354 100644
--- a/inst/shiny/modules/tab_nca/setup/parameter_exclusions.R
+++ b/inst/shiny/modules/tab_nca/setup/parameter_exclusions.R
@@ -21,7 +21,7 @@ parameter_exclusions_ui <- function(id) {
       actionButton(
         ns("add_exclusion"),
         label = "Add",
-        class = "btn btn-primary btn-sm"
+        class = "btn-primary btn-sm"
       ),
       dropdown(
         div(
@@ -45,7 +45,7 @@ parameter_exclusions_ui <- function(id) {
         ),
         style = "unite",
         right = TRUE,
-        icon = icon("question"),
+        icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
         status = "primary"
       )
     ),
diff --git a/inst/shiny/modules/tab_nca/setup/parameter_selection.R b/inst/shiny/modules/tab_nca/setup/parameter_selection.R
index ea153562f..2fded7745 100644
--- a/inst/shiny/modules/tab_nca/setup/parameter_selection.R
+++ b/inst/shiny/modules/tab_nca/setup/parameter_selection.R
@@ -81,7 +81,7 @@ parameter_selection_ui <- function(id,
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary",
           width = "500px"
         ),
@@ -428,7 +428,7 @@ parameter_selection_server <- function(id, processed_pknca_data, parameter_overr
                 href = func_url,
                 target = "_blank",
                 style = paste0(
-                  "color: #0d6efd;",
+                  "color: ", ACCENT_BLUE, ";",
                   "text-decoration: underline;"
                 ),
                 value
diff --git a/inst/shiny/modules/tab_nca/setup/ratio_calculations_table.R b/inst/shiny/modules/tab_nca/setup/ratio_calculations_table.R
index 3decad423..595e2f878 100644
--- a/inst/shiny/modules/tab_nca/setup/ratio_calculations_table.R
+++ b/inst/shiny/modules/tab_nca/setup/ratio_calculations_table.R
@@ -77,7 +77,7 @@ ratios_table_ui <- function(id) {
     ),
     style = "unite",
     right = TRUE,
-    icon = icon("question"),
+    icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
     status = "primary",
     width = "500px"
   )
diff --git a/inst/shiny/modules/tab_nca/setup/settings.R b/inst/shiny/modules/tab_nca/setup/settings.R
index ceda5ae39..11c9f1006 100644
--- a/inst/shiny/modules/tab_nca/setup/settings.R
+++ b/inst/shiny/modules/tab_nca/setup/settings.R
@@ -81,7 +81,7 @@ partial_intervals_ui <- function(id) {
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary",
           width = "600px"
         )
@@ -186,7 +186,7 @@ settings_ui <- function(id) {
               ),
               style = "unite",
               right = TRUE,
-              icon = icon("question"),
+              icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
               status = "primary",
               width = "400px"
             )
@@ -403,8 +403,8 @@ settings_server <- function(id, data, adnca_data, settings_override) {
         borderless = TRUE,
         theme = reactableTheme(
           rowSelectedStyle = list(
-            backgroundColor = "#eee",
-            boxShadow = "inset 2px 0 0 0 #ffa62d"
+            backgroundColor = BG_GREY_LIGHT,
+            boxShadow = glue::glue("inset 2px 0 0 0 {ACCENT_ORANGE}")
           )
         )
       )
diff --git a/inst/shiny/modules/tab_nca/setup/slope_selector.R b/inst/shiny/modules/tab_nca/setup/slope_selector.R
index 7f3cfe0f1..f2c3f728c 100644
--- a/inst/shiny/modules/tab_nca/setup/slope_selector.R
+++ b/inst/shiny/modules/tab_nca/setup/slope_selector.R
@@ -79,7 +79,7 @@ slope_selector_ui <- function(id) {
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary",
           width = "600px"
         ),
diff --git a/inst/shiny/modules/tab_nca/units_table.R b/inst/shiny/modules/tab_nca/units_table.R
index 58e4e75d2..1272ee8ed 100644
--- a/inst/shiny/modules/tab_nca/units_table.R
+++ b/inst/shiny/modules/tab_nca/units_table.R
@@ -18,8 +18,7 @@ units_table_ui <- function(id) {
     actionButton(
       ns("open_units_table"),
       icon = icon("scale-balanced"),
-      label = "Parameter Units",
-      disabled = FALSE
+      label = "Parameter Units"
     )
   )
 }
diff --git a/inst/shiny/modules/tab_nca/zip.R b/inst/shiny/modules/tab_nca/zip.R
index 5334e49ac..0b0fbc052 100644
--- a/inst/shiny/modules/tab_nca/zip.R
+++ b/inst/shiny/modules/tab_nca/zip.R
@@ -18,7 +18,7 @@ zip_ui <- function(id) {
       inputId = ns("open_zip_modal"),
       label = "Save",
       icon = icon("download"),
-      class = "btn btn-primary",
+      class = "btn-primary",
       style = paste(
         "margin-left: 10px;",
         "padding: 8px 18px;",
@@ -149,8 +149,12 @@ zip_ui <- function(id) {
         width = 6,
         div(
           h4("PK Parameters", style = "margin-bottom: 0.25em;"),
-          p(style = "color: #777; font-size: 0.85em; margin-top: 0; margin-bottom: 0.75em;",
-            "Parameters included in the slide tables")
+          p(
+            style = glue::glue(
+              "color: {TEXT_SUBTLE}; font-size: 0.85em; margin-top: 0; margin-bottom: 0.75em;"
+            ),
+            "Parameters included in the slide tables"
+          )
         ),
         div(
           id = ns("ind_params_container"),
@@ -228,7 +232,7 @@ zip_ui <- function(id) {
         actionButton(ns("back_to_export"), "Back", icon = icon("arrow-left")),
         div(
           modalButton("Cancel"),
-          downloadButton(ns("download_zip_configured"), "Export", class = "btn btn-primary")
+          downloadButton(ns("download_zip_configured"), "Export", class = "btn-primary")
         )
       )
     ),
@@ -308,14 +312,14 @@ zip_ui <- function(id) {
       "padding: 6px 0 2px;"
     ),
     span(
-      style = paste(
-        "display: inline-block;",
-        "background-color: #dc3545;",
-        "color: #fff;",
-        "border-radius: 20px;",
-        "padding: 5px 14px;",
-        "font-size: 0.85rem;",
-        "font-weight: 500;",
+      style = glue::glue(
+        "display: inline-block; ",
+        "background-color: {ACCENT_DANGER}; ",
+        "color: {ANCA_WHITE}; ",
+        "border-radius: 20px; ",
+        "padding: 5px 14px; ",
+        "font-size: 0.85rem; ",
+        "font-weight: 500; ",
         "line-height: 1.4;"
       ),
       icon("triangle-exclamation"),
@@ -450,7 +454,7 @@ zip_ui <- function(id) {
           ns("confirm_export"),
           label = "Export ZIP with Results",
           icon  = icon("download"),
-          class = "btn btn-primary"
+          class = "btn-primary"
         )
       ),
       easyClose = FALSE,
@@ -598,7 +602,7 @@ zip_server <- function(id, res_nca, adnca_data, settings, grouping_vars) {
               actionButton(ns("back_to_export"), "Back", icon = icon("arrow-left")),
               div(
                 modalButton("Cancel"),
-                downloadButton(ns("download_zip"), "Export", class = "btn btn-primary")
+                downloadButton(ns("download_zip"), "Export", class = "btn-primary")
               )
             )
           ),
diff --git a/inst/shiny/modules/tab_tlg.R b/inst/shiny/modules/tab_tlg.R
index af331ae86..69790184f 100644
--- a/inst/shiny/modules/tab_tlg.R
+++ b/inst/shiny/modules/tab_tlg.R
@@ -232,7 +232,6 @@ tab_tlg_server <- function(id, data) {
     # Submit the TLG order, filter selected TLGs
     tlg_order_filtered <- reactive({
       req(data())
-      print(tlg_order())
       tlg_order_filt <- tlg_order()[tlg_order()$Selection, ]
       log_debug("Submitted TLGs:\n", paste0("* ", tlg_order_filt$Description, collapse = "\n"))
 
diff --git a/inst/shiny/modules/tab_tlg/tlg_module.R b/inst/shiny/modules/tab_tlg/tlg_module.R
index 4a1f20030..8b0feac06 100644
--- a/inst/shiny/modules/tab_tlg/tlg_module.R
+++ b/inst/shiny/modules/tab_tlg/tlg_module.R
@@ -56,7 +56,7 @@ tlg_module_ui <- function(id, type, options) {
           ),
           style = "unite",
           right = TRUE,
-          icon = icon("question"),
+          icon = icon("question"), tooltip = tooltipOptions(title = "Help"),
           status = "primary"
         ),
         actionButton(
@@ -69,7 +69,7 @@ tlg_module_ui <- function(id, type, options) {
     div(
       class = "tlg-widgets-container",
       div(
-        align = "left",
+        style = "text-align: left;",
         tags$span(
           class = "inline-select-input",
           style = "margin-right: 5em;",
@@ -83,7 +83,7 @@ tlg_module_ui <- function(id, type, options) {
         shinyjs::disabled(actionButton(ns("previous_page"), "Previous Page", class = "btn-page"))
       ),
       div(
-        align = "center",
+        style = "text-align: center;",
         tags$span(
           class = "inline-select-input",
           tags$span("Page "),
@@ -96,7 +96,10 @@ tlg_module_ui <- function(id, type, options) {
           uiOutput(ns("page_number"), inline = TRUE),
         )
       ),
-      div(align = "right", actionButton(ns("next_page"), "Next Page", class = "btn-page"))
+      div(
+        style = "text-align: right;",
+        actionButton(ns("next_page"), "Next Page", class = "btn-page")
+      )
     ),
     shinycssloaders::withSpinner(
       switch(
@@ -183,8 +186,7 @@ tlg_module_server <- function(id, data, type, render_list, options = NULL) {
         do.call(render_list, purrr::list_modify(list(data = tlg_data), !!!list_options))
       },
       error = function(e) {
-        log_error("Error in list rendering:")
-        print(e)
+        log_error("Error in list rendering: ", e$message)
         "Error: list rendering failed with current options.
         Check the R console for more information."
       })
diff --git a/inst/shiny/modules/tab_tlg/tlg_option_table.R b/inst/shiny/modules/tab_tlg/tlg_option_table.R
index 7cb985587..8385c4a90 100644
--- a/inst/shiny/modules/tab_tlg/tlg_option_table.R
+++ b/inst/shiny/modules/tab_tlg/tlg_option_table.R
@@ -90,7 +90,10 @@ tlg_option_table_server <- function(id, opt_def, data, reset_trigger) {
         pageSizeOptions = c(10, 25, 50, 100, nrow(edits_table())),
         defaultPageSize = 10,
         theme = reactableTheme(
-          rowSelectedStyle = list(backgroundColor = "#eee", boxShadow = "inset 2px 0 0 0 #ffa62d")
+          rowSelectedStyle = list(
+            backgroundColor = BG_GREY_LIGHT,
+            boxShadow = glue::glue("inset 2px 0 0 0 {ACCENT_ORANGE}")
+          )
         )
       )
     }) %>%
diff --git a/inst/shiny/www/styles/modules/_colors.scss b/inst/shiny/www/styles/modules/_colors.scss
index 4c2dcb807..3203e6db3 100644
--- a/inst/shiny/www/styles/modules/_colors.scss
+++ b/inst/shiny/www/styles/modules/_colors.scss
@@ -1,3 +1,5 @@
+// Color constants — keep in sync with inst/shiny/functions/colors.R
+// See https://github.com/pharmaverse/aNCA/issues/1298
 $anca-white: #ffffff;
 $anca-black: #000000;
 $anca-black-2: #21201f;
@@ -9,3 +11,14 @@ $grey-2: #b4b4b4;
 $grey-3: #c0c0c0;
 $grey-4: #cdcdcd;
 $grey-5: #dadada;
+$grey-6: #dddddd;
+$grey-7: #e9e9e9;
+$grey-8: #eeeeee;
+
+// Accent colors
+$accent-blue: #0d6efd;
+$accent-orange: #ffa62d;
+$accent-danger: #dc3545;
+
+// Border colors
+$border-panel: #dee2e6;
diff --git a/man/PKNCA_update_data_object.Rd b/man/PKNCA_update_data_object.Rd
index 5d25cc246..0caf9b823 100644
--- a/man/PKNCA_update_data_object.Rd
+++ b/man/PKNCA_update_data_object.Rd
@@ -62,7 +62,7 @@ by study type (forwarded to \code{\link[=update_main_intervals]{update_main_inte
 (forwarded to \code{\link[=update_main_intervals]{update_main_intervals()}}).}
 
 \item{custom_units_table}{Optional data frame with PPSTRESU overrides.
-When provided, applied via \code{\link[dplyr:rows]{dplyr::rows_update()}} on the PKNCAdata units table.}
+When provided, applied via \code{\link[dplyr:rows_update]{dplyr::rows_update()}} on the PKNCAdata units table.}
 }
 \value{
 A fully configured \code{PKNCAdata} object.
diff --git a/man/pkcg02.Rd b/man/pkcg02.Rd
index 3e43b12b6..0d4f48b6d 100644
--- a/man/pkcg02.Rd
+++ b/man/pkcg02.Rd
@@ -88,6 +88,7 @@ A list of ggplot or plotly objects for each unique group.
 This function generates a list of plotly objects PK concentration-time profiles by group
 }
 \examples{
+\donttest{
 # Make an example small dataset
 adnca <- adnca_example
 adnca <- adnca[adnca$USUBJID \%in\% unique(adnca$USUBJID)[c(1, 2)],]
@@ -98,7 +99,7 @@ attr(adnca[["AVAL"]], "label") <- "Analysis value"
 plots <- pkcg02(adnca)
 plots_log <- pkcg02(adnca, scale = "LOG")
 plotly::plotly_build(plots[[1]]) # View the first plot
-
+}
 }
 \author{
 Kezia Kobana