diff --git a/src/App.jsx b/src/App.jsx
index b67887f..c009a9b 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -1,6 +1,6 @@
 // src/App.js
 
-import React, { useEffect } from 'react';
+import React, { useEffect, useState } from 'react';
 import GlobalStyles from './styles/GlobalStyles';
 import Header from './Components/Header';
 import AboutMe from './Components/AboutMe';
@@ -13,8 +13,31 @@ import Footer from './Components/Footer';
 import GithubRepos from './Components/GithubRepos';
 import ProjectsWithGithub from './Components/ProjectsWithGithub';
 import ScrollReveal from './Components/ScrollReveal';
+import DarkModeToggle from './Components/DarkModeToggle';
+import BackToTop from './Components/BackToTop';
 
 function App() {
+  const [isDark, setIsDark] = useState(() => {
+    try {
+      return localStorage.getItem('darkMode') === 'true';
+    } catch {
+      return false;
+    }
+  });
+
+  useEffect(() => {
+    if (isDark) {
+      document.body.classList.add('dark-mode');
+    } else {
+      document.body.classList.remove('dark-mode');
+    }
+    try {
+      localStorage.setItem('darkMode', isDark);
+    } catch {
+      // ignore storage errors
+    }
+  }, [isDark]);
+
   useEffect(() => {
     let ticking = false;
 
@@ -50,8 +73,12 @@ function App() {
   return (
     <>
       <GlobalStyles />
+      <DarkModeToggle isDark={isDark} onToggle={() => setIsDark(d => !d)} />
       <Header />
       <ScrollReveal>
+        <AboutMe />
+      </ScrollReveal>
+      <ScrollReveal delay={0.05}>
         <Skills />
       </ScrollReveal>
       <ScrollReveal delay={0.1}>
@@ -69,6 +96,7 @@ function App() {
       <ScrollReveal delay={0.3}>
         <Footer />
       </ScrollReveal>
+      <BackToTop />
     </>
   );
 }
diff --git a/src/Components/AboutMe.jsx b/src/Components/AboutMe.jsx
index d573679..c2a45a4 100644
--- a/src/Components/AboutMe.jsx
+++ b/src/Components/AboutMe.jsx
@@ -6,10 +6,9 @@ import styled from 'styled-components';
 
 const AboutSection = styled.section`
   padding: 4rem 0;
-  background-color: #f9f9f9;
-  color: #333;
+  background-color: var(--section-bg, #f9f9f9);
+  color: var(--text-color, #333);
   text-align: center;
-  margin-top: 80px; // Leave space for header
 `;
 
 const AboutContent = styled.div`
diff --git a/src/Components/BackToTop.jsx b/src/Components/BackToTop.jsx
new file mode 100644
index 0000000..8ce5d5c
--- /dev/null
+++ b/src/Components/BackToTop.jsx
@@ -0,0 +1,59 @@
+import React, { useState, useEffect } from 'react';
+import styled from 'styled-components';
+import { FaArrowUp } from 'react-icons/fa';
+
+const BackToTopButton = styled.button`
+  position: fixed;
+  bottom: 2rem;
+  right: 1.5rem;
+  z-index: 999;
+  background: #ff6f61;
+  color: #fff;
+  border: none;
+  border-radius: 50%;
+  width: 48px;
+  height: 48px;
+  font-size: 1.2rem;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
+  opacity: ${({ $visible }) => ($visible ? 1 : 0)};
+  pointer-events: ${({ $visible }) => ($visible ? 'auto' : 'none')};
+  transform: translateY(${({ $visible }) => ($visible ? '0' : '20px')});
+  transition: opacity 0.3s, transform 0.3s, background 0.2s;
+
+  &:hover {
+    background: #e65a51;
+  }
+`;
+
+const BackToTop = () => {
+  const [visible, setVisible] = useState(false);
+
+  useEffect(() => {
+    const handleScroll = () => {
+      setVisible(window.scrollY > 300);
+    };
+
+    window.addEventListener('scroll', handleScroll, { passive: true });
+    return () => window.removeEventListener('scroll', handleScroll);
+  }, []);
+
+  const scrollToTop = () => {
+    window.scrollTo({ top: 0, behavior: 'smooth' });
+  };
+
+  return (
+    <BackToTopButton
+      $visible={visible}
+      onClick={scrollToTop}
+      aria-label="Back to top"
+    >
+      <FaArrowUp />
+    </BackToTopButton>
+  );
+};
+
+export default BackToTop;
diff --git a/src/Components/DarkModeToggle.jsx b/src/Components/DarkModeToggle.jsx
new file mode 100644
index 0000000..c1e0a8d
--- /dev/null
+++ b/src/Components/DarkModeToggle.jsx
@@ -0,0 +1,36 @@
+import React from 'react';
+import styled from 'styled-components';
+import { FaSun, FaMoon } from 'react-icons/fa';
+
+const ToggleButton = styled.button`
+  position: fixed;
+  top: 1.2rem;
+  right: 1.5rem;
+  z-index: 1000;
+  background: var(--toggle-bg, #333);
+  color: var(--toggle-color, #fff);
+  border: none;
+  border-radius: 50px;
+  padding: 0.5rem 1rem;
+  font-size: 1.1rem;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  gap: 0.4rem;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
+  transition: background 0.3s, color 0.3s, box-shadow 0.3s;
+
+  &:hover {
+    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
+  }
+`;
+
+const DarkModeToggle = ({ isDark, onToggle }) => {
+  return (
+    <ToggleButton onClick={onToggle} aria-label="Toggle dark mode">
+      {isDark ? <FaSun /> : <FaMoon />}
+    </ToggleButton>
+  );
+};
+
+export default DarkModeToggle;
diff --git a/src/Components/Header.jsx b/src/Components/Header.jsx
index 4b5a6ec..055fc2d 100644
--- a/src/Components/Header.jsx
+++ b/src/Components/Header.jsx
@@ -1,8 +1,42 @@
-import React from 'react';
+import React, { useState, useEffect } from 'react';
 import styled from 'styled-components';
 import { FaGithub, FaLinkedin, FaEnvelope } from 'react-icons/fa';
 import profilePic from '../images/profile-pic.png';
 
+const TYPING_PHRASES = [
+  'AI Integration & Cloud Computing',
+  'Full-Stack Software Developer',
+  'Building Impactful Solutions',
+];
+
+const useTypewriter = (phrases, typingSpeed = 80, deletingSpeed = 40, pauseMs = 1800) => {
+  const [text, setText] = useState('');
+  const [phraseIndex, setPhraseIndex] = useState(0);
+  const [isDeleting, setIsDeleting] = useState(false);
+
+  useEffect(() => {
+    const current = phrases[phraseIndex % phrases.length];
+    let timeout;
+
+    if (!isDeleting && text === current) {
+      timeout = setTimeout(() => setIsDeleting(true), pauseMs);
+    } else if (isDeleting && text === '') {
+      setIsDeleting(false);
+      setPhraseIndex(i => i + 1);
+    } else {
+      timeout = setTimeout(() => {
+        setText(prev =>
+          isDeleting ? prev.slice(0, -1) : current.slice(0, prev.length + 1)
+        );
+      }, isDeleting ? deletingSpeed : typingSpeed);
+    }
+
+    return () => clearTimeout(timeout);
+  }, [text, isDeleting, phraseIndex, phrases, typingSpeed, deletingSpeed, pauseMs]);
+
+  return text;
+};
+
 const HeaderSection = styled.section`
   display: flex;
   flex-direction: column;
@@ -10,7 +44,7 @@ const HeaderSection = styled.section`
   justify-content: center;
   text-align: center;
   padding: 3rem;
-  background-color: #f8f8f8;
+  background-color: var(--bg-color, #f8f8f8);
   min-height: 80vh;
   position: relative;
   overflow: hidden;
@@ -112,20 +146,36 @@ const ProfileImage = styled.img`
 const Name = styled.h1`
   font-size: 2.5rem;
   font-weight: bold;
-  color: #333;
+  color: var(--text-color, #333);
   margin-bottom: 1rem;
   position: relative;
   z-index: 1;
 `;
 
-const Description = styled.p`
+const TypingText = styled.p`
   font-size: 1.2rem;
-  color: #555;
+  color: var(--subtext-color, #555);
   line-height: 1.6;
   max-width: 600px;
   margin-bottom: 2rem;
   position: relative;
   z-index: 1;
+  min-height: 2em;
+`;
+
+const Cursor = styled.span`
+  display: inline-block;
+  width: 2px;
+  height: 1.1em;
+  background: #ff6f61;
+  margin-left: 2px;
+  vertical-align: text-bottom;
+  animation: blink 0.8s step-end infinite;
+
+  @keyframes blink {
+    0%, 100% { opacity: 1; }
+    50% { opacity: 0; }
+  }
 `;
 
 const ButtonContainer = styled.div`
@@ -182,6 +232,8 @@ const ConnectSection = styled.div`
 `;
 
 const Header = () => {
+  const typedText = useTypewriter(TYPING_PHRASES);
+
   return (
     <HeaderSection>
       <HeroScene>
@@ -193,10 +245,9 @@ const Header = () => {
       </HeroScene>
       <ProfileImage src={profilePic} alt="Yasar Nazzarian" />
       <Name>Yasar Nazzarian</Name>
-      <Description>
-        I'm a passionate software Developer with experience in AI integration,
-        cloud computing, and software development. Let's create impactful solutions together.
-      </Description>
+      <TypingText>
+        {typedText}<Cursor />
+      </TypingText>
       <ButtonContainer>
         <a href="#projects">
           <button>View Projects</button>
diff --git a/src/Components/Skills.jsx b/src/Components/Skills.jsx
index 9f5c913..5535061 100644
--- a/src/Components/Skills.jsx
+++ b/src/Components/Skills.jsx
@@ -1,67 +1,111 @@
-import React from 'react';
+import React, { useRef, useEffect, useState } from 'react';
 import styled from 'styled-components';
 import { FaJava, FaPython, FaJsSquare, FaReact, FaDocker, FaMicrosoft } from 'react-icons/fa'; // Import relevant icons
+import { skills } from '../data/skills';
+
+const ICONS = {
+  Java: <FaJava />,
+  Python: <FaPython />,
+  JavaScript: <FaJsSquare />,
+  React: <FaReact />,
+  Docker: <FaDocker />,
+  Azure: <FaMicrosoft />,
+};
 
 const SkillsSection = styled.section`
-  padding: 3rem 0;
+  padding: 3rem 2rem;
   text-align: center;
+  background-color: var(--section-bg, #f9f9f9);
 
   h2 {
     font-size: 2rem;
     margin-bottom: 2rem;
+    color: var(--text-color, #333);
   }
 
   .skills-container {
     display: flex;
-    justify-content: center;
-    gap: 1rem;
-    flex-wrap: wrap;
+    flex-direction: column;
+    gap: 1.2rem;
+    max-width: 600px;
+    margin: 0 auto;
   }
+`;
 
-  .skill {
-    display: flex;
-    align-items: center;
-    background-color: #f0f0f0;
-    padding: 0.8rem 1.5rem;
-    border-radius: 15px;
-    font-size: 1.2rem;
-    transition: background-color 0.3s;
-    cursor: pointer;
+const SkillRow = styled.div`
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: 0.4rem;
+`;
 
-    &:hover {
-      background-color: #e0e0e0;
-    }
+const SkillLabel = styled.div`
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  font-size: 1.05rem;
+  color: var(--text-color, #333);
 
-    svg {
-      margin-right: 0.5rem;
-      font-size: 1.5rem;
-    }
+  svg {
+    font-size: 1.3rem;
+    color: #ff6f61;
   }
 `;
 
+const LevelPercentage = styled.span`
+  margin-left: auto;
+  color: #ff6f61;
+  font-size: 0.9rem;
+`;
+
+const BarTrack = styled.div`
+  width: 100%;
+  background-color: var(--card-bg, #e0e0e0);
+  border-radius: 8px;
+  height: 10px;
+  overflow: hidden;
+`;
+
+const BarFill = styled.div`
+  height: 100%;
+  border-radius: 8px;
+  background: linear-gradient(90deg, #ff6f61, #ff9a8b);
+  width: ${({ $animated, $level }) => ($animated ? `${$level}%` : '0%')};
+  transition: width 1s ease-out;
+`;
+
 const Skills = () => {
+  const sectionRef = useRef(null);
+  const [animated, setAnimated] = useState(false);
+
+  useEffect(() => {
+    const observer = new IntersectionObserver(
+      ([entry]) => {
+        if (entry.isIntersecting) {
+          setAnimated(true);
+          observer.disconnect();
+        }
+      },
+      { threshold: 0.3 }
+    );
+    if (sectionRef.current) observer.observe(sectionRef.current);
+    return () => observer.disconnect();
+  }, []);
+
   return (
-    <SkillsSection>
+    <SkillsSection ref={sectionRef}>
       <h2>Skills</h2>
       <div className="skills-container">
-        <div className="skill">
-          <FaJava /> Java
-        </div>
-        <div className="skill">
-          <FaPython /> Python
-        </div>
-        <div className="skill">
-          <FaJsSquare /> JavaScript
-        </div>
-        <div className="skill">
-          <FaReact /> React
-        </div>
-        <div className="skill">
-          <FaDocker /> Docker
-        </div>
-        <div className="skill">
-          <FaMicrosoft /> Azure
-        </div>
+        {skills.map(({ name, level }) => (
+          <SkillRow key={name}>
+            <SkillLabel>
+              {ICONS[name]} {name} <LevelPercentage>{level}%</LevelPercentage>
+            </SkillLabel>
+            <BarTrack>
+              <BarFill $animated={animated} $level={level} />
+            </BarTrack>
+          </SkillRow>
+        ))}
       </div>
     </SkillsSection>
   );
diff --git a/src/data/skills.js b/src/data/skills.js
new file mode 100644
index 0000000..c1788c7
--- /dev/null
+++ b/src/data/skills.js
@@ -0,0 +1,11 @@
+// src/data/skills.js
+const skills = [
+  { name: 'Java', level: 85 },
+  { name: 'Python', level: 90 },
+  { name: 'JavaScript', level: 88 },
+  { name: 'React', level: 82 },
+  { name: 'Docker', level: 75 },
+  { name: 'Azure', level: 78 },
+];
+
+module.exports = { skills };
diff --git a/src/styles/GlobalStyles.js b/src/styles/GlobalStyles.js
index 0509acf..3946f8d 100644
--- a/src/styles/GlobalStyles.js
+++ b/src/styles/GlobalStyles.js
@@ -5,6 +5,16 @@ import { createGlobalStyle } from 'styled-components';
 const GlobalStyles = createGlobalStyle`
   :root {
     --scroll-progress: 0;
+
+    /* Light mode defaults */
+    --bg-color: #f8f8f8;
+    --text-color: #222;
+    --subtext-color: #666;
+    --card-bg: #f0f0f0;
+    --card-hover-bg: #e0e0e0;
+    --section-bg: #f9f9f9;
+    --toggle-bg: #333;
+    --toggle-color: #fff;
   }
 
   body {
@@ -12,8 +22,20 @@ const GlobalStyles = createGlobalStyle`
     padding: 0;
     box-sizing: border-box;
     font-family: 'Arial', sans-serif;
-    background-color: #f8f8f8;
-    color: #222;
+    background-color: var(--bg-color);
+    color: var(--text-color);
+    transition: background-color 0.3s, color 0.3s;
+  }
+
+  body.dark-mode {
+    --bg-color: #121212;
+    --text-color: #e0e0e0;
+    --subtext-color: #aaa;
+    --card-bg: #1e1e1e;
+    --card-hover-bg: #2a2a2a;
+    --section-bg: #181818;
+    --toggle-bg: #e0e0e0;
+    --toggle-color: #121212;
   }
 
   body::before,
@@ -65,10 +87,11 @@ const GlobalStyles = createGlobalStyle`
   h2 {
     font-size: 2.5rem;
     margin-bottom: 1.5rem;
+    color: var(--text-color);
   }
 
   p, small {
-    color: #666;
+    color: var(--subtext-color);
   }
 `;
 
diff --git a/tests/skills.test.js b/tests/skills.test.js
new file mode 100644
index 0000000..29f4d7f
--- /dev/null
+++ b/tests/skills.test.js
@@ -0,0 +1,15 @@
+const assert = require('node:assert/strict');
+const test = require('node:test');
+const { skills } = require('../src/data/skills');
+
+test('skills entries include required fields', () => {
+  assert.ok(Array.isArray(skills));
+  assert.ok(skills.length > 0);
+
+  skills.forEach((skill) => {
+    assert.equal(typeof skill.name, 'string');
+    assert.ok(skill.name.trim().length > 0);
+    assert.equal(typeof skill.level, 'number');
+    assert.ok(skill.level >= 0 && skill.level <= 100);
+  });
+});