:root {
  --primary-color: #1976d2;
  --primary-dark: #1565c0;
  --primary-light: #42a5f5;
  --secondary-color: #424242;
  --success-color: #4caf50;
  --warning-color: #ff9800;
  --danger-color: #f44336;
  --light-gray: #f5f5f5;
  --medium-gray: #e0e0e0;
  --dark-gray: #757575;
  --text-primary: #212121;
  --text-secondary: #757575;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Roboto", sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  scroll-behavior: smooth;
}

/* Navigation */
.navbar {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)) !important;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: 700;
}

.nav-link {
  font-weight: 500;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: rgba(255, 255, 255, 0.8) !important;
}

/* Introduction Section */
.introduction-section {
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  padding-bottom: 2rem;
}

.intro-content {
  animation: fadeInUp 1s ease-out;
}

.intro-buttons .btn {
  border-radius: 50px;
  padding: 12px 30px;
  font-weight: 500;
  transition: all 0.3s ease;
}

.intro-buttons .btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.intro-details {
  animation: fadeInUp 1s ease-out 0.3s both;
}

.intro-stats {
  margin: 2rem 0;
}

.stat-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.9);
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.stat-card .material-icons {
  font-size: 2rem;
}

.stat-card strong {
  display: block;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1.2;
}

.stat-card span {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.specialties {
  border-top: 1px solid var(--medium-gray);
  padding-top: 1rem;
}

.specialty-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.specialty-tag {
  background: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.3s ease;
}

.specialty-tag:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow);
}

/* Responsive adjustments for introduction section */
@media (max-width: 768px) {
  .introduction-section {
    padding-top: 100px;
    text-align: center;
  }

  .display-3 {
    font-size: 2.5rem;
  }

  .intro-buttons .btn {
    display: block;
    width: 100%;
    margin-bottom: 1rem;
  }

  .intro-details {
    margin-top: 3rem;
  }

  .stat-card {
    justify-content: center;
    text-align: center;
  }

  .specialty-tags {
    justify-content: center;
  }
}

@media (max-width: 576px) {
  .intro-content {
    margin-bottom: 2rem;
  }

  .specialty-tag {
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
  }
}

/* Dividers */
.divider {
  width: 60px;
  height: 4px;
  background: var(--primary-color);
  margin: 0 auto 2rem;
  border-radius: 2px;
}

.divider-white {
  width: 60px;
  height: 4px;
  background: white;
  margin: 0 auto 2rem;
  border-radius: 2px;
}

/* Cards */
.card {
  border: none;
  border-radius: 12px;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

/* Stats */
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 1rem;
}

.stat-item .material-icons {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.stat-item strong {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

/* Current Project */
.current-project-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.current-project-card .text-primary {
  color: white !important;
}

.current-project-card .text-muted {
  color: rgba(255, 255, 255, 0.8) !important;
}

.project-icon {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto;
}

.project-icon .material-icons {
  font-size: 4rem;
  color: white;
}

.responsibility-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.responsibility-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  font-weight: 500;
}

.responsibility-item .material-icons {
  font-size: 1.2rem;
}

/* Tech Stack */
.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.tech-badge {
  background: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.3s ease;
}

.current-project-card .tech-badge {
  background: rgba(255, 255, 255, 0.2);
  color: white;
}

.tech-badge:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow);
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 1rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--primary-color);
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
}

.timeline-marker {
  position: absolute;
  left: -1.5rem;
  top: 1.5rem;
  width: 1rem;
  height: 1rem;
  background: var(--primary-color);
  border-radius: 50%;
  border: 3px solid white;
  box-shadow: var(--shadow);
}

.timeline-content {
  margin-left: 1rem;
}

/* Skills */
.skill-category-header {
  display: flex;
  align-items: center;
  border-bottom: 2px solid var(--light-gray);
  padding-bottom: 1rem;
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.skill-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem;
  background: var(--light-gray);
  border-radius: 8px;
  transition: all 0.3s ease;
}

.skill-item:hover {
  background: var(--medium-gray);
  transform: translateX(5px);
}

.skill-name {
  font-weight: 500;
  color: var(--text-primary);
}

.skill-level {
  padding: 0.25rem 0.75rem;
  border-radius: 15px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.skill-level.expert {
  background: var(--success-color);
  color: white;
}

.skill-level.advanced {
  background: var(--primary-color);
  color: white;
}

.skill-level.intermediate {
  background: var(--warning-color);
  color: white;
}

/* Contact */
.contact-item {
  padding: 2rem 1rem;
}

.contact-item .material-icons {
  font-size: 3rem;
  opacity: 0.9;
}

.contact-item h5 {
  margin: 1rem 0 0.5rem;
  font-weight: 600;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card {
  animation: fadeInUp 0.6s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
  .introduction-section {
    padding-top: 100px;
    text-align: center;
  }

  .display-3 {
    font-size: 2.5rem;
  }

  .intro-buttons .btn {
    display: block;
    width: 100%;
    margin-bottom: 1rem;
  }

  .timeline {
    padding-left: 1rem;
  }

  .timeline::before {
    left: 0.5rem;
  }

  .timeline-marker {
    left: -0.25rem;
  }

  .timeline-content {
    margin-left: 0.5rem;
  }

  .responsibility-grid {
    grid-template-columns: 1fr;
  }

  .project-icon {
    width: 80px;
    height: 80px;
  }

  .project-icon .material-icons {
    font-size: 2.5rem;
  }

  .intro-details {
    margin-top: 3rem;
  }

  .stat-card {
    justify-content: center;
    text-align: center;
  }

  .specialty-tags {
    justify-content: center;
  }
}

@media (max-width: 576px) {
  .intro-buttons .btn {
    display: block;
    width: 100%;
    margin-bottom: 1rem;
  }

  .tech-stack {
    justify-content: center;
  }

  .skill-item {
    flex-direction: column;
    text-align: center;
    gap: 0.5rem;
  }

  .intro-content {
    margin-bottom: 2rem;
  }

  .specialty-tag {
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
  }
}

/* Smooth scrolling offset for fixed navbar */
section {
  scroll-margin-top: 80px;
}

/* Button hover effects */
.btn {
  transition: all 0.3s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

/* Badge animations */
.badge {
  transition: all 0.3s ease;
}

.badge:hover {
  transform: scale(1.1);
}

/* Material Icons consistency */
.material-icons {
  vertical-align: middle;
}

/* Loading animation for smooth page transitions */
.page-loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: white;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 9999;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.page-loader.active {
  opacity: 1;
  visibility: visible;
}