refactor: clean-up of some unused options after the template rework

.env.example

@@ -0,0 +1,66 @@
+# Port to listen on (binds to 127.0.0.1).
+BOOK_PORT=8123
+
+# Directory for guestbook entry files.
+BOOK_DATA_DIR=./data
+
+# Site title shown in nav and page title.
+BOOK_SITE_TITLE=guestbook
+
+# Telegram bot token.
+BOOK_TELEGRAM_BOT_TOKEN=your-bot-token-here
+
+# Telegram chat ID for moderation messages.
+BOOK_TELEGRAM_CHAT_ID=0
+
+# Enable honeypot field for spam prevention.
+BOOK_HONEYPOT=true
+
+# Maximum length for names. 0 for unlimited.
+BOOK_MAX_NAME_LENGTH=50
+
+# Maximum length for messages. 0 for unlimited.
+BOOK_MAX_MESSAGE_LENGTH=1000
+
+# Maximum length for website URLs. 0 for unlimited.
+BOOK_MAX_WEBSITE_LENGTH=100
+
+# Allow new guestbook submissions. When false, the form is hidden and submissions are rejected.
+BOOK_OPEN_REGISTRATION=true
+
+# Separator between guestbook entries.
+BOOK_SEPARATOR=------------------------------------------------------------
+
+# Path to a CSS file. Takes precedence over BOOK_STYLE.
+# BOOK_STYLE_FILE=./templates/default.css
+
+# Custom CSS injected into a style tag.
+# Classes: .guestbook-form, .guestbook-prompt, .guestbook-label, .guestbook-input,
+#          .guestbook-textarea, .guestbook-button, .entry-header, .entry-name,
+#          .entry-website, .entry-body, .entry-separator
+# BOOK_STYLE=
+
+# Text shown above the form.
+BOOK_FORM_PROMPT=If you visited my site, please sign my guestbook!
+
+# Submit button text.
+BOOK_BUTTON_TEXT=sign
+
+# Label for the name field.
+BOOK_LABEL_NAME=Your name:
+
+# Label for the website field.
+BOOK_LABEL_WEBSITE=Your website (optional):
+
+# Label for the message field.
+BOOK_LABEL_MESSAGE=Your message:
+
+# Number of rows for the message textarea.
+BOOK_TEXTAREA_ROWS=8
+
+# Number of columns for the message textarea.
+BOOK_TEXTAREA_COLS=60
+
+# Custom HTML template file with {{title}}, {{form}}, {{entries}}, and {{style}} placeholders.
+# Uses built-in default if unset.
+# BOOK_TEMPLATE=./templates/default.html

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2026 Llywelwyn
+Copyright (c) 2026 Lewis Wynne
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

module.nix

@@ -30,11 +30,6 @@ in
       description = "Site title shown in nav and page title.";
     };
 
-    siteUrl = mkOption {
-      type = types.str;
-      description = "Base URL of the main site (for absolute nav links).";
-    };
-
     telegramChatId = mkOption {
       type = types.int;
       description = "Telegram chat ID for moderation messages.";
@@ -75,6 +70,72 @@ in
       description = "Allow new guestbook submissions. When false, the form is hidden and submissions are rejected.";
     };
 
+    separator = mkOption {
+      type = types.str;
+      default = "------------------------------------------------------------";
+      description = "Separator between guestbook entries.";
+    };
+
+    style = mkOption {
+      type = types.str;
+      default = "";
+      description = "Custom CSS injected into a style tag. Use class names: .guestbook-form, .guestbook-prompt, .guestbook-label, .guestbook-input, .guestbook-textarea, .guestbook-button, .entry-header, .entry-name, .entry-website, .entry-body, .entry-separator";
+    };
+
+    styleFile = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      description = "Path to a CSS file. Takes precedence over style.";
+    };
+
+    formPrompt = mkOption {
+      type = types.str;
+      default = "If you visited my site, please sign my guestbook!";
+      description = "Text shown above the form.";
+    };
+
+    buttonText = mkOption {
+      type = types.str;
+      default = "sign";
+      description = "Submit button text.";
+    };
+
+    labelName = mkOption {
+      type = types.str;
+      default = "Your name:";
+      description = "Label for the name field.";
+    };
+
+    labelWebsite = mkOption {
+      type = types.str;
+      default = "Your website (optional):";
+      description = "Label for the website field.";
+    };
+
+    labelMessage = mkOption {
+      type = types.str;
+      default = "Your message:";
+      description = "Label for the message field.";
+    };
+
+    textareaRows = mkOption {
+      type = types.int;
+      default = 8;
+      description = "Number of rows for the message textarea.";
+    };
+
+    textareaCols = mkOption {
+      type = types.int;
+      default = 60;
+      description = "Number of columns for the message textarea.";
+    };
+
+    templateFile = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      description = "Custom HTML template file with {{title}}, {{form}}, and {{entries}} placeholders. Uses built-in default if null.";
+    };
+
     user = mkOption {
       type = types.str;
       default = "guestbook";
@@ -108,13 +169,26 @@ in
           BOOK_PORT = toString cfg.port;
           BOOK_DATA_DIR = cfg.dataDir;
           BOOK_SITE_TITLE = cfg.siteTitle;
-          BOOK_SITE_URL = cfg.siteUrl;
+
           BOOK_TELEGRAM_CHAT_ID = toString cfg.telegramChatId;
           BOOK_HONEYPOT = if cfg.honeypot then "true" else "false";
           BOOK_MAX_NAME_LENGTH = toString cfg.maxNameLength;
           BOOK_MAX_MESSAGE_LENGTH = toString cfg.maxMessageLength;
           BOOK_MAX_WEBSITE_LENGTH = toString cfg.maxWebsiteLength;
           BOOK_OPEN_REGISTRATION = if cfg.openRegistration then "true" else "false";
+          BOOK_SEPARATOR = cfg.separator;
+          BOOK_STYLE = cfg.style;
+        } // lib.optionalAttrs (cfg.styleFile != null) {
+          BOOK_STYLE_FILE = cfg.styleFile;
+          BOOK_FORM_PROMPT = cfg.formPrompt;
+          BOOK_BUTTON_TEXT = cfg.buttonText;
+          BOOK_LABEL_NAME = cfg.labelName;
+          BOOK_LABEL_WEBSITE = cfg.labelWebsite;
+          BOOK_LABEL_MESSAGE = cfg.labelMessage;
+          BOOK_TEXTAREA_ROWS = toString cfg.textareaRows;
+          BOOK_TEXTAREA_COLS = toString cfg.textareaCols;
+        } // lib.optionalAttrs (cfg.templateFile != null) {
+          BOOK_TEMPLATE = cfg.templateFile;
         };
         serviceConfig = {
           Type = "simple";

src/config.rs

@@ -6,7 +6,7 @@ pub struct Config {
     pub port: u16,
     pub data_dir: PathBuf,
     pub site_title: String,
-    pub site_url: String,
+
     pub telegram_bot_token: String,
     pub telegram_chat_id: i64,
     pub honeypot: bool,
@@ -14,6 +14,16 @@ pub struct Config {
     pub max_message_length: usize,
     pub max_website_length: usize,
     pub open_registration: bool,
+    pub template: Option<String>,
+    pub separator: String,
+    pub style: String,
+    pub form_prompt: String,
+    pub button_text: String,
+    pub label_name: String,
+    pub label_website: String,
+    pub label_message: String,
+    pub textarea_rows: u32,
+    pub textarea_cols: u32,
 }
 
 impl Config {
@@ -31,7 +41,7 @@ impl Config {
                 .map(PathBuf::from)
                 .unwrap_or_else(|_| PathBuf::from("./data")),
             site_title: env::var("BOOK_SITE_TITLE").unwrap_or_else(|_| "guestbook".into()),
-            site_url: env::var("BOOK_SITE_URL").map_err(|_| "BOOK_SITE_URL is required")?,
+
             telegram_bot_token: env::var("BOOK_TELEGRAM_BOT_TOKEN")
                 .map_err(|_| "BOOK_TELEGRAM_BOT_TOKEN is required")?,
             telegram_chat_id: env::var("BOOK_TELEGRAM_CHAT_ID")
@@ -56,6 +66,38 @@ impl Config {
             open_registration: env::var("BOOK_OPEN_REGISTRATION")
                 .map(|v| v != "false")
                 .unwrap_or(true),
+            separator: env::var("BOOK_SEPARATOR")
+                .unwrap_or_else(|_| "------------------------------------------------------------".into()),
+            template: env::var("BOOK_TEMPLATE").ok().map(|path| {
+                std::fs::read_to_string(&path)
+                    .unwrap_or_else(|e| panic!("failed to read template {path}: {e}"))
+            }),
+            style: env::var("BOOK_STYLE_FILE")
+                .ok()
+                .map(|path| {
+                    std::fs::read_to_string(&path)
+                        .unwrap_or_else(|e| panic!("failed to read style file {path}: {e}"))
+                })
+                .or_else(|| env::var("BOOK_STYLE").ok())
+                .unwrap_or_default(),
+            form_prompt: env::var("BOOK_FORM_PROMPT")
+                .unwrap_or_else(|_| "If you visited my site, please sign my guestbook!".into()),
+            button_text: env::var("BOOK_BUTTON_TEXT")
+                .unwrap_or_else(|_| "sign".into()),
+            label_name: env::var("BOOK_LABEL_NAME")
+                .unwrap_or_else(|_| "Your name:".into()),
+            label_website: env::var("BOOK_LABEL_WEBSITE")
+                .unwrap_or_else(|_| "Your website (optional):".into()),
+            label_message: env::var("BOOK_LABEL_MESSAGE")
+                .unwrap_or_else(|_| "Your message:".into()),
+            textarea_rows: env::var("BOOK_TEXTAREA_ROWS")
+                .unwrap_or_else(|_| "8".into())
+                .parse()
+                .map_err(|_| "BOOK_TEXTAREA_ROWS must be a number")?,
+            textarea_cols: env::var("BOOK_TEXTAREA_COLS")
+                .unwrap_or_else(|_| "60".into())
+                .parse()
+                .map_err(|_| "BOOK_TEXTAREA_COLS must be a number")?,
         })
     }
 }
@@ -73,7 +115,6 @@ mod tests {
         env::set_var("BOOK_PORT", "9999");
         env::set_var("BOOK_DATA_DIR", "/tmp/gb");
         env::set_var("BOOK_SITE_TITLE", "test.rs");
-        env::set_var("BOOK_SITE_URL", "https://test.rs");
         env::set_var("BOOK_TELEGRAM_BOT_TOKEN", "123:ABC");
         env::set_var("BOOK_TELEGRAM_CHAT_ID", "12345");
 
@@ -82,14 +123,12 @@ mod tests {
         assert_eq!(config.listen_addr(), "127.0.0.1:9999");
         assert_eq!(config.data_dir, PathBuf::from("/tmp/gb"));
         assert_eq!(config.site_title, "test.rs");
-        assert_eq!(config.site_url, "https://test.rs");
         assert_eq!(config.telegram_chat_id, 12345);
 
         // Clean up
         env::remove_var("BOOK_PORT");
         env::remove_var("BOOK_DATA_DIR");
         env::remove_var("BOOK_SITE_TITLE");
-        env::remove_var("BOOK_SITE_URL");
         env::remove_var("BOOK_TELEGRAM_BOT_TOKEN");
         env::remove_var("BOOK_TELEGRAM_CHAT_ID");
     }
@@ -97,7 +136,6 @@ mod tests {
     #[test]
     fn test_defaults() {
         let _lock = ENV_LOCK.lock().unwrap();
-        env::set_var("BOOK_SITE_URL", "https://test.rs");
         env::set_var("BOOK_TELEGRAM_BOT_TOKEN", "123:ABC");
         env::set_var("BOOK_TELEGRAM_CHAT_ID", "12345");
 
@@ -106,7 +144,6 @@ mod tests {
         assert_eq!(config.data_dir, PathBuf::from("./data"));
         assert_eq!(config.site_title, "guestbook");
 
-        env::remove_var("BOOK_SITE_URL");
         env::remove_var("BOOK_TELEGRAM_BOT_TOKEN");
         env::remove_var("BOOK_TELEGRAM_CHAT_ID");
     }
@@ -114,7 +151,6 @@ mod tests {
     #[test]
     fn test_missing_required() {
         let _lock = ENV_LOCK.lock().unwrap();
-        env::remove_var("BOOK_SITE_URL");
         env::remove_var("BOOK_TELEGRAM_BOT_TOKEN");
         env::remove_var("BOOK_TELEGRAM_CHAT_ID");
 

src/render.rs

@@ -1,69 +1,106 @@
+use crate::config::Config;
 use crate::entries::Entry;
 
-pub fn render_page(site_title: &str, site_url: &str, entries: &[Entry], form_html: &str) -> String {
+pub const DEFAULT_TEMPLATE: &str = include_str!("../templates/default.html");
-    let nav_url = site_url.trim_end_matches('/');
+pub const DEFAULT_STYLE: &str = include_str!("../templates/default.css");
-    let mut html = format!(
-        r#"<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta charset="utf-8">
-  <meta name="viewport" content="width=device-width, initial-scale=1">
-  <title>{site_title}</title>
-  <link rel="stylesheet" href="/style.css">
-</head>
-<body>
-  <nav>
-    <a href="{nav_url}/">{site_title}</a> |
-    <a href="{nav_url}/links/">links</a> |
-    <a href="{nav_url}/now/">now</a> |
-    sign the <a href="/">guestbook</a>
-  </nav>
-  <h1>guestbook</h1>
-  <p>If you visited my site, please sign my guestbook!</p>
-{form_html}
-"#
-    );
 
+pub fn render_page(template: &str, config: &Config, entries: &[Entry], form_html: &str) -> String {
+    let entries_html = render_entries(entries, &config.separator);
+    let css = if config.style.is_empty() {
+        DEFAULT_STYLE
+    } else {
+        &config.style
+    };
+    let style = format!("<style>\n{css}\n  </style>");
+    template
+        .replace("{{title}}", &config.site_title)
+        .replace("{{form}}", form_html)
+        .replace("{{entries}}", &entries_html)
+        .replace("{{style}}", &style)
+}
+
+pub fn render_form(config: &Config) -> String {
+    format!(
+        r#"<span class="guestbook-prompt">{prompt}</span>
+<form class="guestbook-form" method="post" action="/submit" accept-charset="UTF-8">
+<label class="guestbook-label">{label_name}</label>
+<input class="guestbook-input" name="name" required>
+
+<label class="guestbook-label">{label_website}</label>
+<input class="guestbook-input" name="website">
+
+<label class="guestbook-label">{label_message}</label>
+<textarea class="guestbook-textarea" name="message" rows="{rows}" cols="{cols}" required></textarea>
+<input name="url" style="display:none" tabindex="-1" autocomplete="off">
+<button class="guestbook-button" type="submit">{button}</button>
+</form>"#,
+        prompt = config.form_prompt,
+        label_name = config.label_name,
+        label_website = config.label_website,
+        label_message = config.label_message,
+        rows = config.textarea_rows,
+        cols = config.textarea_cols,
+        button = config.button_text,
+    )
+}
+
+fn render_entries(entries: &[Entry], separator: &str) -> String {
+    let mut html = String::new();
     for entry in entries {
-        html.push_str(&render_entry(entry));
+        html.push_str(&render_entry(entry, separator));
     }
-
-    html.push_str("</body>\n</html>\n");
     html
 }
 
-fn render_entry(entry: &Entry) -> String {
+fn render_entry(entry: &Entry, separator: &str) -> String {
-    let mut header = format!("  <div class=\"entry\">\n    <p>{} - <b>{}</b>", entry.meta.date, entry.meta.name);
+    let mut header = format!(
+        "<span class=\"entry-header\">{} - <span class=\"entry-name\">{}</span>",
+        entry.meta.date, entry.meta.name
+    );
     if !entry.meta.website.is_empty() {
         header.push_str(&format!(
-            " (<a href=\"{}\">{}</a>)",
+            " (<a class=\"entry-website\" href=\"{}\">{}</a>)",
             entry.meta.website, entry.meta.website
         ));
     }
-    header.push_str("</p>\n");
+    header.push_str("</span>");
-    format!("{header}    {}\n  </div>\n", entry.body)
+    format!(
+        "\n{header}\n\n<span class=\"entry-body\">{}</span>\n\n<span class=\"entry-separator\">{separator}</span>\n",
+        entry.body
+    )
 }
 
-pub const FORM_HTML: &str = r#"  <form method="post" action="/submit">
-    <input name="name" placeholder="name" required>
-    <input name="website" placeholder="website (optional)">
-    <textarea name="message" placeholder="message" required></textarea>
-    <input name="url" style="display:none" tabindex="-1" autocomplete="off">
-    <button type="submit">sign</button>
-  </form>"#;
-
-pub const STYLE_CSS: &str = "body {
-  max-width: 70ch;
-  line-height: 1.5;
-  margin: 0 auto;
-  padding: 1rem;
-}
-";
-
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::entries::{Entry, EntryMeta, Status};
+    use std::path::PathBuf;
+
+    fn test_config() -> Config {
+        Config {
+            port: 0,
+            data_dir: PathBuf::from("./data"),
+            site_title: "test".into(),
+
+            telegram_bot_token: "fake".into(),
+            telegram_chat_id: 0,
+            honeypot: true,
+            max_name_length: 50,
+            max_message_length: 1000,
+            max_website_length: 100,
+            open_registration: true,
+            template: None,
+            separator: "---".into(),
+            style: String::new(),
+            form_prompt: "Sign my guestbook!".into(),
+            button_text: "sign".into(),
+            label_name: "Your name:".into(),
+            label_website: "Your website (optional):".into(),
+            label_message: "Your message:".into(),
+            textarea_rows: 8,
+            textarea_cols: 60,
+        }
+    }
 
     fn make_entry(name: &str, date: &str, body: &str) -> Entry {
         Entry {
@@ -79,41 +116,91 @@ mod tests {
     }
 
     #[test]
-    fn test_render_page_contains_nav() {
+    fn test_render_default_template() {
-        let html = render_page("ily.rs", "https://ily.rs", &[], FORM_HTML);
+        let config = test_config();
-        assert!(html.contains(r#"<a href="https://ily.rs/">ily.rs</a>"#));
+        let form = render_form(&config);
-        assert!(html.contains(r#"<a href="https://ily.rs/links/">links</a>"#));
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[], &form);
+        assert!(html.contains("<title>test</title>"));
+        assert!(html.contains("guestbook-form"));
     }
 
     #[test]
-    fn test_render_page_contains_form() {
+    fn test_render_custom_template() {
-        let html = render_page("ily.rs", "https://ily.rs", &[], FORM_HTML);
+        let config = test_config();
-        assert!(html.contains(r#"action="/submit""#));
+        let custom = "<html>{{title}} {{form}} {{entries}} {{style}}</html>";
-        assert!(html.contains(r#"style="display:none""#)); // honeypot
+        let form = render_form(&config);
+        let html = render_page(custom, &config, &[], &form);
+        assert!(html.contains("test"));
+        assert!(html.contains("guestbook-form"));
     }
 
     #[test]
-    fn test_render_entry_no_website() {
+    fn test_render_entry_classes() {
+        let config = test_config();
         let entry = make_entry("alice", "2026-04-09", "Hello!");
-        let html = render_page("ily.rs", "https://ily.rs", &[entry], FORM_HTML);
+        let form = render_form(&config);
-        assert!(html.contains("<b>alice</b>"));
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[entry], &form);
-        assert!(html.contains("Hello!"));
+        assert!(html.contains("entry-header"));
-        assert!(!html.contains("<hr"));
+        assert!(html.contains("entry-name"));
+        assert!(html.contains("entry-body"));
+        assert!(html.contains("entry-separator"));
     }
 
     #[test]
     fn test_render_entry_with_website() {
+        let config = test_config();
         let mut entry = make_entry("bob", "2026-04-09", "Hi!");
         entry.meta.website = "https://bob.com".into();
-        let html = render_page("ily.rs", "https://ily.rs", &[entry], FORM_HTML);
+        let form = render_form(&config);
-        assert!(html.contains(r#"<a href="https://bob.com">"#));
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[entry], &form);
+        assert!(html.contains("entry-website"));
+        assert!(html.contains(r#"href="https://bob.com">"#));
     }
 
     #[test]
     fn test_render_preserves_html_in_body() {
-        let entry = make_entry("carol", "2026-04-09", "<b>Bold</b> <script>alert(1)</script>");
+        let config = test_config();
-        let html = render_page("ily.rs", "https://ily.rs", &[entry], FORM_HTML);
+        let entry = make_entry("carol", "2026-04-09", "<b>Bold</b>");
+        let form = render_form(&config);
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[entry], &form);
         assert!(html.contains("<b>Bold</b>"));
-        assert!(html.contains("<script>alert(1)</script>"));
+    }
+
+    #[test]
+    fn test_render_empty_form_when_closed() {
+        let config = test_config();
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[], "");
+        assert!(!html.contains("action=\"/submit\""));
+    }
+
+    #[test]
+    fn test_render_custom_style() {
+        let mut config = test_config();
+        config.style = ".entry-name { color: red; }".into();
+        let html = render_page(DEFAULT_TEMPLATE, &config, &[], "");
+        assert!(html.contains(".entry-name { color: red; }"));
+        assert!(html.contains("<style>"));
+    }
+
+    #[test]
+    fn test_render_form_custom_labels() {
+        let mut config = test_config();
+        config.form_prompt = "Leave a note!".into();
+        config.button_text = "submit".into();
+        config.label_name = "Name:".into();
+        let form = render_form(&config);
+        assert!(form.contains("Leave a note!"));
+        assert!(form.contains("submit"));
+        assert!(form.contains("Name:"));
+    }
+
+    #[test]
+    fn test_render_form_custom_textarea() {
+        let mut config = test_config();
+        config.textarea_rows = 12;
+        config.textarea_cols = 40;
+        let form = render_form(&config);
+        assert!(form.contains("rows=\"12\""));
+        assert!(form.contains("cols=\"40\""));
     }
 }

src/web.rs

@@ -1,7 +1,6 @@
 use axum::{
     extract::State,
-    http::header,
+    response::Html,
-    response::{Html, IntoResponse},
     routing::{get, post},
     Form, Router,
 };
@@ -11,7 +10,7 @@ use uuid::Uuid;
 
 use crate::config::Config;
 use crate::entries::{self, Entry, EntryMeta, Status};
-use crate::render::{self, FORM_HTML, STYLE_CSS};
+use crate::render::{self, DEFAULT_TEMPLATE};
 
 pub struct AppState {
     pub config: Config,
@@ -32,19 +31,23 @@ pub fn router(state: Arc<AppState>) -> Router {
     Router::new()
         .route("/", get(index))
         .route("/submit", post(submit))
-        .route("/style.css", get(style))
         .with_state(state)
 }
 
 async fn index(State(state): State<Arc<AppState>>) -> Html<String> {
     let entries_dir = state.config.data_dir.join("entries");
     let entries = entries::read_approved(&entries_dir);
-    let form = if state.config.open_registration { FORM_HTML } else { "" };
+    let form = if state.config.open_registration {
+        render::render_form(&state.config)
+    } else {
+        String::new()
+    };
+    let template = state.config.template.as_deref().unwrap_or(DEFAULT_TEMPLATE);
     let html = render::render_page(
-        &state.config.site_title,
+        template,
-        &state.config.site_url,
+        &state.config,
         &entries,
-        form,
+        &form,
     );
     Html(html)
 }
@@ -113,10 +116,6 @@ async fn submit(
     Html("Thanks! Your message is pending approval.".to_string())
 }
 
-async fn style() -> impl IntoResponse {
-    ([(header::CONTENT_TYPE, "text/css")], STYLE_CSS)
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -130,7 +129,7 @@ mod tests {
             port: 0,
             data_dir: dir.to_path_buf(),
             site_title: "test".into(),
-            site_url: "https://test.rs".into(),
+
             telegram_bot_token: "fake".into(),
             telegram_chat_id: 0,
             honeypot: true,
@@ -138,6 +137,16 @@ mod tests {
             max_message_length: 1000,
             max_website_length: 100,
             open_registration: true,
+            template: None,
+            separator: "---".into(),
+            style: String::new(),
+            form_prompt: "Sign my guestbook!".into(),
+            button_text: "sign".into(),
+            label_name: "Your name:".into(),
+            label_website: "Your website (optional):".into(),
+            label_message: "Your message:".into(),
+            textarea_rows: 8,
+            textarea_cols: 60,
         }
     }
 
@@ -270,6 +279,17 @@ mod tests {
         assert!(body.contains("too long"));
     }
 
+    #[tokio::test]
+    async fn test_custom_template() {
+        let dir = tempfile::tempdir().unwrap();
+        let mut config = test_config(dir.path());
+        config.template = Some("<html><nav>custom nav</nav>{{form}}{{entries}}</html>".into());
+        let (app, _rx) = test_app(config);
+        let html = get_index(&app).await;
+        assert!(html.contains("custom nav"));
+        assert!(html.contains("action=\"/submit\""));
+    }
+
     #[tokio::test]
     async fn test_valid_submission_creates_entry() {
         let dir = tempfile::tempdir().unwrap();

templates/default.css

@@ -0,0 +1,23 @@
+/* Page container */
+.page-container {
+  max-width: 70ch;
+  margin: 0 auto;
+  padding: 1rem;
+  white-space: pre-wrap;
+  word-wrap: break-word;
+}
+
+/* Form */
+.guestbook-prompt {}
+.guestbook-form {}
+.guestbook-label {}
+.guestbook-input {}
+.guestbook-textarea {}
+.guestbook-button {}
+
+/* Entries */
+.entry-header {}
+.entry-name {}
+.entry-website {}
+.entry-body {}
+.entry-separator {}

templates/default.html

@@ -0,0 +1,43 @@
+<!--
+  Default guestbook template.
+  Copy this file and point BOOK_TEMPLATE at your copy to customize.
+
+  Placeholders are inserted with double curly braces, e.g. curly-title-curly.
+
+  Available placeholders:
+
+    title   - Site title (BOOK_SITE_TITLE). Useful in <title> and headings.
+    form    - The submission form (labels, inputs, button). Controlled by
+              BOOK_FORM_PROMPT, BOOK_LABEL_NAME, BOOK_LABEL_WEBSITE,
+              BOOK_LABEL_MESSAGE, BOOK_BUTTON_TEXT, BOOK_TEXTAREA_ROWS,
+              BOOK_TEXTAREA_COLS. Empty when BOOK_OPEN_REGISTRATION=false.
+    entries - Approved guestbook entries, newest first. Entry separator
+              controlled by BOOK_SEPARATOR.
+    style   - Custom CSS from BOOK_STYLE or BOOK_STYLE_FILE, wrapped in
+              a <style> tag. Uses built-in default.css when neither is set.
+
+  See default.css for available CSS classes on rendered elements.
+-->
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>{{title}}</title>
+  {{style}}
+</head>
+<body>
+<div class="page-container">
+{{title}}
+
+guestbook
+=========
+
+{{form}}
+
+entries
+=======
+{{entries}}
+</div>
+</body>
+</html>