/* 
 * Main Stylesheet for Rahul Podugu's Portfolio
 * Author: Manus AI
 * Version: 2.0
 */

/* ===== VARIABLES ===== */
:root {
  /* Color Scheme */
  --bg-primary: #0a192f;
  --bg-secondary: #112240;
  --bg-tertiary: #1d3557;
  --accent-primary: #64ffda;
  --accent-secondary: #bd93f9;
  --text-primary: #e6f1ff;
  --text-secondary: #a8b2d1;
  --text-tertiary: #8892b0;
  
  /* Gradients */
  --gradient-primary: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
  --gradient-secondary: linear-gradient(270deg, var(--accent-primary), var(--accent-secondary));
  
  /* Shadows */
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-xxl: 5rem;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;
}

/* ===== RESET & BASE STYLES ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-primary) var(--bg-secondary);
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition-normal);
}

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-primary);
  border-radius: var(--radius-full);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
}

p {
  margin-bottom: var(--space-md);
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast), transform var(--transition-fast);
}

a:hover {
  color: var(--accent-secondary);
}

ul, ol {
  list-style-position: inside;
  margin-bottom: var(--space-md);
}

img {
  max-width: 100%;
  height: auto;
}

button {
  cursor: pointer;
  font-family: 'Inter', sans-serif;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.section {
  padding: var(--space-xxl) 0;
  position: relative;
}

/* ===== PRELOADER ===== */
.preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--bg-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 9999;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.preloader.hidden {
  opacity: 0;
  visibility: hidden;
}

.loader {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.loader-text {
  font-family: 'Fira Code', monospace;
  font-size: 1.5rem;
  margin-bottom: var(--space-md);
  color: var(--accent-primary);
}

.loader-dots {
  display: flex;
}

.dot {
  width: 12px;
  height: 12px;
  margin: 0 var(--space-xs);
  border-radius: var(--radius-full);
  background-color: var(--accent-primary);
  animation: dot-pulse 1.5s infinite ease-in-out;
}

.dot:nth-child(2) {
  animation-delay: 0.2s;
  background-color: var(--accent-secondary);
}

.dot:nth-child(3) {
  animation-delay: 0.4s;
  background: var(--gradient-primary);
}

@keyframes dot-pulse {
  0%, 100% {
    transform: scale(0.8);
    opacity: 0.5;
  }
  50% {
    transform: scale(1.2);
    opacity: 1;
  }
}

/* ===== CURSOR FOLLOWER ===== */
.cursor-follower {
  position: fixed;
  width: 40px;
  height: 40px;
  border: 2px solid var(--accent-primary);
  border-radius: var(--radius-full);
  pointer-events: none;
  transform: translate(-50%, -50%);
  transition: width 0.3s, height 0.3s, border-color 0.3s;
  z-index: 9998;
  opacity: 0;
}

@media (hover: hover) {
  .cursor-follower {
    opacity: 0.5;
  }
  
  .cursor-follower.active {
    width: 20px;
    height: 20px;
    background-color: var(--accent-secondary);
    border-color: transparent;
    opacity: 0.8;
  }
}

/* ===== NAVBAR ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: var(--space-md) 0;
  background-color: rgba(10, 25, 47, 0.8);
  backdrop-filter: blur(10px);
  z-index: 100;
  transition: padding var(--transition-normal), background-color var(--transition-normal);
}

.navbar.scrolled {
  padding: var(--space-sm) 0;
  background-color: rgba(10, 25, 47, 0.95);
  box-shadow: var(--shadow-md);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-logo {
  font-family: 'Fira Code', monospace;
  font-size: 1.5rem;
  font-weight: 700;
}

.logo-link {
  display: flex;
  align-items: center;
  color: var(--text-primary);
}

.logo-prefix, .logo-suffix {
  color: var(--accent-primary);
}

.logo-text {
  margin: 0 var(--space-xs);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.menu-toggle {
  display: none;
  cursor: pointer;
}

.hamburger {
  width: 30px;
  height: 20px;
  position: relative;
}

.hamburger span {
  display: block;
  position: absolute;
  height: 2px;
  width: 100%;
  background: var(--text-primary);
  border-radius: var(--radius-full);
  transition: all var(--transition-normal);
}

.hamburger span:nth-child(1) {
  top: 0;
}

.hamburger span:nth-child(2) {
  top: 9px;
}

.hamburger span:nth-child(3) {
  top: 18px;
}

.menu-toggle.active .hamburger span:nth-child(1) {
  transform: rotate(45deg);
  top: 9px;
}

.menu-toggle.active .hamburger span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active .hamburger span:nth-child(3) {
  transform: rotate(-45deg);
  top: 9px;
}

.nav-menu {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  list-style: none;
  margin: 0;
}

.nav-item {
  margin: 0 var(--space-md);
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  position: relative;
  padding: var(--space-xs) 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width var(--transition-normal);
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link:hover::after {
  width: 100%;
}

.theme-toggle {
  margin-left: var(--space-md);
  cursor: pointer;
  width: 40px;
  height: 20px;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-full);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xs);
}

.theme-toggle i {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.theme-toggle::after {
  content: '';
  position: absolute;
  left: 2px;
  width: 16px;
  height: 16px;
  background-color: var(--accent-primary);
  border-radius: var(--radius-full);
  transition: transform var(--transition-normal);
}

.theme-toggle.light-mode::after {
  transform: translateX(20px);
}

/* ===== HERO SECTION ===== */
.hero {
  height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.particles-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero-greeting {
  font-family: 'Fira Code', monospace;
  color: var(--accent-primary);
  font-size: 1.2rem;
  margin-bottom: var(--space-sm);
}

.hero-title {
  margin-bottom: var(--space-lg);
}

.hero-name {
  display: block;
  font-size: 4rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-xs);
}

.hero-profession {
  display: block;
  font-size: 2.5rem;
  color: var(--text-secondary);
}

.hero-description {
  max-width: 600px;
  margin-bottom: var(--space-lg);
  font-size: 1.2rem;
  color: var(--text-secondary);
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: all var(--transition-normal);
  border: none;
  outline: none;
  font-size: 1rem;
}

.btn-primary {
  background-color: var(--accent-primary);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background-color: transparent;
  box-shadow: 0 0 0 2px var(--accent-primary);
  color: var(--accent-primary);
}

.btn-secondary {
  background-color: transparent;
  box-shadow: 0 0 0 2px var(--accent-secondary);
  color: var(--accent-secondary);
}

.btn-secondary:hover {
  background-color: var(--accent-secondary);
  color: var(--bg-primary);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.social-links {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  transition: all var(--transition-normal);
}

.social-link:hover {
  background-color: var(--accent-primary);
  color: var(--bg-primary);
  transform: translateY(-5px);
}

.scroll-indicator {
  display: flex;
  flex-direction: column;
  align-items: center;
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

.scroll-indicator i {
  margin-top: var(--space-xs);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

/* ===== SECTION HEADERS ===== */
.section-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-title {
  display: inline-block;
  font-size: 2.5rem;
  position: relative;
  margin-bottom: var(--space-md);
}

.section-title::before {
  content: '';
  position: absolute;
  top: 50%;
  left: -60px;
  width: 40px;
  height: 2px;
  background: var(--gradient-primary);
}

.section-title::after {
  content: '';
  position: absolute;
  top: 50%;
  right: -60px;
  width: 40px;
  height: 2px;
  background: var(--gradient-secondary);
}

.section-line {
  width: 80px;
  height: 4px;
  background: var(--gradient-primary);
  margin: 0 auto;
  border-radius: var(--radius-full);
}

/* ===== ABOUT SECTION ===== */
.about-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-xl);
  align-items: center;
}

.about-image {
  position: relative;
}

.image-frame {
  position: relative;
  width: 300px;
  height: 300px;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.image-frame::before {
  content: '';
  position: absolute;
  top: var(--space-md);
  left: var(--space-md);
  width: 100%;
  height: 100%;
  border: 2px solid var(--accent-primary);
  border-radius: var(--radius-md);
  z-index: -1;
}

.image-placeholder {
  width: 100%;
  height: 100%;
  background-color: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-placeholder i {
  font-size: 5rem;
  color: var(--accent-primary);
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.about-highlights {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.highlight-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.highlight-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background-color: var(--bg-secondary);
  color: var(--accent-primary);
}

.highlight-text {
  font-weight: 600;
}

/* ===== EXPERIENCE SECTION ===== */
.experience-timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.experience-timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 20px;
  width: 2px;
  height: 100%;
  background: var(--gradient-primary);
  background-size: 100% 400%;
  animation: gradient-shift 8s linear infinite;
}

@keyframes gradient-shift {
  0% {
    background-position: 0% 0%;
  }
  100% {
    background-position: 0% 400%;
  }
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: var(--space-xl);
}

.timeline-marker {
  position: absolute;
  top: 0;
  left: 11px;
  width: 20px;
  height: 20px;
  border-radius: var(--radius-full);
  background-color: var(--accent-primary);
  border: 4px solid var(--bg-primary);
  z-index: 1;
}

.timeline-content {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--space-sm);
}

.timeline-title {
  font-size: 1.5rem;
  margin-bottom: 0;
}

.timeline-period {
  font-family: 'Fira Code', monospace;
  color: var(--accent-primary);
  white-space: nowrap;
}

.timeline-company {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

.timeline-description ul {
  list-style-type: none;
  margin-bottom: var(--space-md);
}

.timeline-description li {
  position: relative;
  padding-left: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.timeline-description li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
}

.highlight {
  color: var(--accent-primary);
  font-weight: 600;
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.tech-tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background-color: rgba(100, 255, 218, 0.1);
  color: var(--accent-primary);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-family: 'Fira Code', monospace;
}

/* ===== EDUCATION SECTION ===== */
.education-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-lg);
}

.education-card {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  display: flex;
  flex-direction: column;
}

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

.education-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 60px;
  height: 60px;
  border-radius: var(--radius-full);
  background-color: var(--bg-tertiary);
  color: var(--accent-primary);
  margin-bottom: var(--space-md);
  font-size: 1.5rem;
}

.education-degree {
  font-size: 1.25rem;
  margin-bottom: var(--space-xs);
}

.education-school {
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.education-location, .education-period {
  color: var(--text-tertiary);
  font-size: 0.875rem;
  margin-bottom: var(--space-sm);
}

.education-description {
  margin-top: var(--space-md);
  color: var(--text-secondary);
}

/* ===== PROJECTS SECTION ===== */
.projects-filter {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}

.filter-btn {
  padding: 0.5rem 1rem;
  background-color: transparent;
  border: 1px solid var(--accent-primary);
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: all var(--transition-normal);
}

.filter-btn:hover, .filter-btn.active {
  background-color: rgba(100, 255, 218, 0.1);
  color: var(--accent-primary);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-lg);
}

.project-card {
  height: 400px;
  perspective: 1000px;
}

.project-content {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.8s;
  transform-style: preserve-3d;
}

.project-card:hover .project-content {
  transform: rotateY(180deg);
}

.project-front, .project-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.project-front {
  background-color: var(--bg-secondary);
}

.project-back {
  background-color: var(--bg-secondary);
  transform: rotateY(180deg);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.project-image {
  height: 60%;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-tertiary);
}

.project-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to bottom, rgba(10, 25, 47, 0.1), rgba(10, 25, 47, 0.9));
}

.project-icon {
  font-size: 3rem;
  color: var(--accent-primary);
  z-index: 1;
}

.project-info {
  padding: var(--space-md);
}

.project-title {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
}

.project-description p {
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.project-features {
  list-style-type: none;
  margin-bottom: var(--space-md);
}

.project-features li {
  position: relative;
  padding-left: var(--space-md);
  margin-bottom: var(--space-xs);
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

.project-features li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
}

.project-links {
  display: flex;
  gap: var(--space-md);
}

.project-link {
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: color var(--transition-normal);
}

.project-link:hover {
  color: var(--accent-primary);
}

.project-link i {
  margin-right: var(--space-xs);
}

/* ===== SKILLS SECTION ===== */
.skills-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-xl);
}

.skill-category {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.category-title {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  color: var(--accent-primary);
  font-size: 1.25rem;
}

.category-title i {
  font-size: 1.5rem;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.skill-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.skill-logo {
  width: 50px;
  height: 50px;
  margin-bottom: var(--space-sm);
  transition: transform var(--transition-normal);
}

.skill-item:hover .skill-logo {
  transform: translateY(-5px);
}

.skill-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.skill-name {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* ===== PUBLICATIONS SECTION ===== */
.publications-list {
  max-width: 800px;
  margin: 0 auto;
}

.publication-card {
  display: flex;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  margin-bottom: var(--space-lg);
}

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

.publication-year {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 100px;
  background-color: var(--bg-tertiary);
  color: var(--accent-primary);
  font-family: 'Fira Code', monospace;
  font-size: 1.5rem;
  font-weight: 700;
}

.publication-content {
  padding: var(--space-lg);
  flex: 1;
}

.publication-title {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
}

.publication-details {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.publication-authors {
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.publication-journal, .publication-doi {
  margin-bottom: var(--space-xs);
}

.publication-abstract {
  color: var(--text-tertiary);
  margin-bottom: var(--space-md);
}

/* ===== CONTACT SECTION ===== */
.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
}

.contact-heading {
  margin-bottom: var(--space-lg);
}

.contact-heading h3 {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
}

.contact-heading p {
  color: var(--text-secondary);
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
}

.contact-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  border-radius: var(--radius-full);
  background-color: var(--bg-secondary);
  color: var(--accent-primary);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.contact-text h4 {
  margin-bottom: var(--space-xs);
  font-size: 1.1rem;
}

.contact-text a {
  color: var(--text-secondary);
  transition: color var(--transition-normal);
}

.contact-text a:hover {
  color: var(--accent-primary);
}

.contact-form-container {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}





.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
}

.form-group input, .form-group textarea {
  padding: var(--space-md);
  background-color: var(--bg-tertiary);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: 'Inter', sans-serif;
  transition: border-color var(--transition-normal);
}

.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

/* ===== FOOTER ===== */
.footer {
  background-color: var(--bg-secondary);
  padding: var(--space-lg) 0;
  margin-top: var(--space-xxl);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.footer-logo {
  font-family: 'Fira Code', monospace;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.footer-social {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.footer-copyright {
  color: var(--text-tertiary);
  font-size: 0.875rem;
  text-align: center;
}

/* ===== BACK TO TOP BUTTON ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background-color: var(--bg-secondary);
  color: var(--accent-primary);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  z-index: 99;
  box-shadow: var(--shadow-md);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--accent-primary);
  color: var(--bg-primary);
  transform: translateY(-5px);
}

/* ===== RESPONSIVE STYLES ===== */
@media (max-width: 1024px) {
  .hero-name {
    font-size: 3.5rem;
  }
  
  .hero-profession {
    font-size: 2rem;
  }
  
  .about-content {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }
  
  .about-image {
    display: flex;
    justify-content: center;
    order: 2;
  }
  
  .about-text {
    order: 1;
  }
  
  .contact-content {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background-color: var(--bg-secondary);
    flex-direction: column;
    justify-content: center;
    transition: right var(--transition-normal);
    z-index: 99;
    box-shadow: var(--shadow-lg);
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .nav-list {
    flex-direction: column;
    align-items: center;
  }
  
  .nav-item {
    margin: var(--space-md) 0;
  }
  
  .hero-name {
    font-size: 3rem;
  }
  
  .hero-profession {
    font-size: 1.75rem;
  }
  
  .hero-description {
    font-size: 1rem;
  }
  
  .hero-cta {
    flex-direction: column;
    gap: var(--space-sm);
  }
  
  .section-title {
    font-size: 2rem;
  }
  
  .section-title::before, .section-title::after {
    display: none;
  }
  
  .timeline-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .timeline-period {
    margin-top: var(--space-xs);
  }
  
  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .publication-card {
    flex-direction: column;
  }
  
  .publication-year {
    padding: var(--space-sm) 0;
    min-width: auto;
  }
}

@media (max-width: 480px) {
  .hero-name {
    font-size: 2.5rem;
  }
  
  .hero-profession {
    font-size: 1.5rem;
  }
  
  .about-highlights {
    grid-template-columns: 1fr;
  }
  
  .timeline-item {
    padding-left: 40px;
  }
  
  .timeline-marker {
    left: 0;
  }
  
  .experience-timeline::before {
    left: 9px;
  }
  
  .skills-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

/* ===== DARK/LIGHT MODE STYLES ===== */
body.light-mode {
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f1f5f9;

  --text-primary: #1f2937;
  --text-secondary: #374151;
  --text-tertiary: #6b7280;

  --accent-primary: #1e40af;     /* Changed: strong royal blue (still dark, but clean) */
  --accent-secondary: #3b82f6;   /* Keeping this for gradient variation */

  --gradient-primary: linear-gradient(135deg, #1e40af, #3b82f6);
  --gradient-secondary: linear-gradient(135deg, #3b82f6, #1e40af);
}









body.light-mode .navbar {
  background-color: rgba(245, 245, 245, 0.8);
}

body.light-mode .navbar.scrolled {
  background-color: rgba(245, 245, 245, 0.95);
}

/* ===== UTILITY CLASSES ===== */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mb-sm {
  margin-bottom: var(--space-sm);
}

.mb-md {
  margin-bottom: var(--space-md);
}

.mb-lg {
  margin-bottom: var(--space-lg);
}

.mb-xl {
  margin-bottom: var(--space-xl);
}