minor fixes

src/level_ladder.rs

@@ -10,9 +10,9 @@ impl Iterator for LevelLadder {
         let current = self.curr;
 
         self.curr = self.next;
-        self.next = current + self.next;
+        self.next += current;
 
-        // Since there's no endpoint to a Fibonacci sequence, the `Iterator` 
+        // Since there's no endpoint to a Fibonacci sequence, the `Iterator`
         // will never return `None`, and `Some` is always returned.
         Some(current * 30)
     }

src/main.rs

@@ -14,7 +14,6 @@ use crossterm::{
     ExecutableCommand,
 };
 use ratatui::prelude::*;
-use ratatui::widgets::block::{Position, Title};
 use ratatui::widgets::{Block, BorderType, Borders, Wrap};
 use ratatui::{
     prelude::{CrosstermBackend, Terminal},
@@ -32,12 +31,12 @@ mod constants;
 mod game;
 mod level;
 mod level_generator;
+mod level_ladder;
 mod level_widget;
 mod monster;
 mod player;
 mod position;
 mod room;
-mod level_ladder;
 
 //
 fn main() -> Result<()> {
@@ -101,10 +100,8 @@ fn main() -> Result<()> {
                 height: map_area.height / 2 + 1,
             };
             let block = Block::default()
-                .title(
-                    Title::from(format!(" {} ", game.get_player().get_name()))
-                        .alignment(Alignment::Center)
-                        .position(Position::Top),
+                .title_top(
+                    Line::from(format!(" {} ", game.get_player().get_name())).centered()
                 )
                 .borders(Borders::TOP)
                 .border_style(Style::default().fg(Color::White))
@@ -134,10 +131,8 @@ fn main() -> Result<()> {
             };
             // Display the latest messages from the game to the user
             let block = Block::default()
-                .title(
-                    Title::from(" messages ")
-                        .alignment(Alignment::Center)
-                        .position(Position::Top),
+                .title_top(
+                    Line::from(" messages ").centered()
                 )
                 .borders(Borders::TOP)
                 .border_style(Style::default().fg(Color::White))
@@ -219,12 +214,8 @@ fn main() -> Result<()> {
             area.width = 40;
             area.height = 20;
             let block = Block::default()
-                .title(
-                    Title::from(" Game ended ")
-                        .alignment(Alignment::Center)
-                        .position(Position::Top),
-                )
-                .title(Title::from("Press `q` to quit!").position(Position::Bottom))
+                .title_top(Line::from(" Game ended ").centered())
+                .title_bottom(Line::from("Press `q` to quit!"))
                 .borders(Borders::ALL)
                 .border_style(Style::default().fg(Color::White))
                 .border_type(BorderType::Rounded)