:root {
  --bg-color: #f9f9f9;
  --text-color: #333333;
  --card-bg: #ffffff;
  --accent-color: #0070f3;
  --accent-gradient: linear-gradient(135deg, #0070f3, #00c6ff);
  --border-color: #eaeaea;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --bg-color: #121212;
  --text-color: #f0f0f0;
  --card-bg: #1e1e1e;
  --accent-color: #3291ff;
  --accent-gradient: linear-gradient(135deg, #3291ff, #00e1ff);
  --border-color: #333333;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  transition: background-color 0.3s, color 0.3s;
}

nav {
  display: flex;
  justify-content: space-between;
  padding: 1.5rem 5%;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
}

nav a, nav button {
  margin-left: 1rem;
  text-decoration: none;
  color: var(--text-color);
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  transition: color 0.2s;
}

nav a:hover, nav button:hover {
  color: var(--accent-color);
}

.hero {
  text-align: center;
  padding: 6rem 1rem;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1rem;
}

.action-buttons {
  margin-top: 2rem;
  display: flex;
  gap: 1.5rem;
  justify-content: center;
}

/* Upgraded Buttons */
.btn {
  padding: 0.8rem 2rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  letter-spacing: 0.5px;
  transition: all 0.3s ease;
  display: inline-block;
  cursor: pointer;
}

.btn.primary {
  background: var(--accent-gradient);
  color: white;
  border: none;
  box-shadow: 0 4px 15px rgba(0, 112, 243, 0.2);
}

.btn.primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0, 112, 243, 0.4);
}

.btn.secondary {
  background-color: transparent;
  color: var(--text-color);
  border: 2px solid var(--accent-color);
}

.btn.secondary:hover {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0, 112, 243, 0.3);
}

section {
  padding: 4rem 5%;
  max-width: 1200px;
  margin: 0 auto;
}

h2 {
  margin-bottom: 2rem;
  font-size: 2.2rem;
  border-bottom: 3px solid var(--accent-color);
  display: inline-block;
  padding-bottom: 0.5rem;
  border-radius: 2px;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.card {
  background-color: var(--card-bg);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: 0 4px 20px rgba(0,0,0,0.03);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.08);
}

.card h3 {
  margin-bottom: 0.8rem;
  font-size: 1.4rem;
}

.card p {
  font-size: 1rem;
  margin-bottom: 1.5rem;
  color: inherit;
  opacity: 0.9;
}

.tech-tag {
  display: inline-block;
  background: var(--accent-gradient);
  color: white;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  margin-right: 0.5rem;
  margin-bottom: 0.5rem;
}

.split-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

ul {
  list-style-type: none;
}

ul li {
  background-color: var(--card-bg);
  padding: 1.2rem;
  margin-bottom: 1rem;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  box-shadow: 0 2px 10px rgba(0,0,0,0.02);
  font-size: 1.05rem;
}

footer {
  text-align: center;
  padding: 3rem 1rem;
  border-top: 1px solid var(--border-color);
  margin-top: 4rem;
}

.footer-links a {
  margin: 0 1rem;
  color: var(--accent-color);
  text-decoration: none;
  font-weight: 600;
}

/* --- Mobile Responsiveness Fixes --- */
@media (max-width: 768px) {
  nav {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }
  
  nav a, nav button {
    margin: 0 0.5rem;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .action-buttons {
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }

  .btn {
    width: 100%;
    max-width: 300px;
  }

  .split-section {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  section {
    padding: 2.5rem 5%;
  }
}

/* --- Hide the Default Scrollbar --- */
::-webkit-scrollbar {
  width: 0px;
  background: transparent; 
}

/* --- Vertical Scroll Progress Bar --- */
#scroll-progress {
  position: fixed;
  top: 0;
  right: 0; /* Moves it to the right edge */
  width: 5px; /* Adjust thickness here */
  height: 0%; /* Starts at 0 height */
  background: var(--accent-gradient);
  z-index: 9999;
  box-shadow: -2px 0 10px rgba(0, 112, 243, 0.5); /* Shadow shifts left */
  transition: height 0.1s ease-out; /* Animates the vertical fill */
}

/* --- Skills Section --- */
.skills-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.skill-group {
  background-color: var(--card-bg);
  padding: 1.5rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: 0 4px 20px rgba(0,0,0,0.03);
}

.skill-group h3 {
  margin-bottom: 1rem;
  font-size: 1.2rem;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.skill-tag {
  background: transparent;
  color: var(--text-color);
  border: 1px solid var(--accent-color);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.3s ease;
  cursor: default;
}

.skill-tag:hover {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 4px 10px rgba(0, 112, 243, 0.3);
}