/* CSS Custom Properties */
:root {
  --color-primary: #003366;
  --color-secondary: #1ABC9C;
  --color-accent: #1ABC9C;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-background: #FFFFFF;
  --color-surface: #F8F9FA;
  --color-border: #E9ECEF;
  --color-success: #28A745;
  --color-error: #DC3545;
  --color-warning: #FFC107;
  
  --font-primary: 'Poppins', sans-serif;
  --font-secondary: 'Open Sans', sans-serif;
  
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
  
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --transition: all 0.3s ease;
  --transition-fast: all 0.15s ease;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --color-text: #E9ECEF;
  --color-text-light: #ADB5BD;
  --color-background: #121212;
  --color-surface: #1E1E1E;
  --color-border: #343A40;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-secondary);
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  transition: var(--transition);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: 1rem;
  line-height: 1.5;
}

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

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

/* Utility Classes */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: 2.5rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -0.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: 2px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 2rem;
  font-family: var(--font-primary);
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid transparent;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-secondary);
  border-color: var(--color-secondary);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: var(--transition);
}

[data-theme="dark"] .navbar {
  background: rgba(18, 18, 18, 0.95);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.nav-brand {
  font-family: var(--font-primary);
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--color-primary);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-weight: 500;
  color: var(--color-text);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  transition: var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
  background: rgba(0, 51, 102, 0.1);
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  transition: var(--transition-fast);
}

.theme-toggle:hover {
  background: rgba(0, 51, 102, 0.1);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition-fast);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary) 0%, #004080 100%);
  color: white;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><polygon fill="rgba(255,255,255,0.05)" points="0,1000 1000,0 1000,1000"/></svg>');
  background-size: cover;
}

.hero-container {
  position: relative;
  z-index: 2;
}

.hero-image {
  width: 200px;
  height: 200px;
  margin: 0 auto 2rem;
  border-radius: 50%;
  overflow: hidden;
  border: 4px solid rgba(255, 255, 255, 0.2);
  box-shadow: var(--shadow-xl);
  transition: var(--transition);
}

.hero-image:hover {
  transform: scale(1.05);
  border-color: var(--color-secondary);
}

.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-title {
  font-size: 4rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--color-secondary);
  margin-bottom: 1rem;
  animation: fadeInUp 1s ease-out 0.2s both;
}

.hero-tagline {
  font-size: 1.25rem;
  margin-bottom: 3rem;
  opacity: 0.9;
  animation: fadeInUp 1s ease-out 0.4s both;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease-out 0.6s both;
}

.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.scroll-indicator {
  width: 2px;
  height: 30px;
  background: rgba(255, 255, 255, 0.5);
  border-radius: 1px;
}

/* About Section */
.about {
  padding: 6rem 0;
  background: var(--color-surface);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

.about-text {
  font-size: 1.1rem;
  line-height: 1.7;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.skill-card {
  background: var(--color-background);
  padding: 2rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
}

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

.skill-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.skill-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--color-primary);
}

.skill-card p {
  color: var(--color-text-light);
  margin: 0;
}

/* Experience Section */
.experience {
  padding: 6rem 0;
}

.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
  transform: translateX(-50%);
}

.timeline-item {
  position: relative;
  margin-bottom: 4rem;
  opacity: 0;
  transform: translateY(30px);
  transition: var(--transition);
}

.timeline-item.animate {
  opacity: 1;
  transform: translateY(0);
}

.timeline-item:nth-child(odd) .timeline-content {
  margin-right: calc(50% + 2rem);
  text-align: right;
}

.timeline-item:nth-child(even) .timeline-content {
  margin-left: calc(50% + 2rem);
}

.timeline-marker {
  position: absolute;
  left: 50%;
  top: 2rem;
  width: 20px;
  height: 20px;
  background: var(--color-primary);
  border: 4px solid var(--color-background);
  border-radius: 50%;
  transform: translateX(-50%);
  z-index: 2;
  box-shadow: var(--shadow-md);
}

.timeline-content {
  background: var(--color-background);
  padding: 2rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  position: relative;
}

.timeline-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.timeline-item:nth-child(odd) .timeline-header {
  flex-direction: row-reverse;
}

.company-logo {
  width: 60px;
  height: 60px;
  border-radius: var(--border-radius);
  overflow: hidden;
  background: var(--color-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

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

.timeline-info h3 {
  color: var(--color-primary);
  margin-bottom: 0.25rem;
}

.timeline-info h4 {
  color: var(--color-text);
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.timeline-date {
  color: var(--color-text-light);
  font-size: 0.9rem;
}

.timeline-achievements {
  list-style: none;
  padding: 0;
}

.timeline-achievements li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.75rem;
  line-height: 1.5;
}

.timeline-achievements li::before {
  content: '▶';
  position: absolute;
  left: 0;
  color: var(--color-secondary);
  font-size: 0.8rem;
}

/* Education Section */
.education {
  padding: 6rem 0;
  background: var(--color-surface);
}

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

.education-card {
  background: var(--color-background);
  padding: 2.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: var(--transition);
}

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

.education-icon {
  font-size: 3rem;
  margin-bottom: 1.5rem;
}

.education-card h3 {
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.education-card p {
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.education-card span {
  color: var(--color-text-light);
  font-size: 0.9rem;
}

/* Testimonials Section */
.testimonials {
  padding: 6rem 0;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
}

.testimonial-card {
  background: var(--color-background);
  padding: 2.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  position: relative;
  transition: var(--transition);
}

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

.testimonial-card::before {
  content: '"';
  position: absolute;
  top: 1rem;
  left: 2rem;
  font-size: 4rem;
  color: var(--color-secondary);
  opacity: 0.3;
  font-family: serif;
}

.testimonial-text {
  font-style: italic;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.testimonial-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--color-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  color: var(--color-primary);
}

.testimonial-info h4 {
  margin: 0;
  color: var(--color-primary);
}

.testimonial-info p {
  margin: 0;
  color: var(--color-text-light);
  font-size: 0.9rem;
}

/* Contact Section */
.contact {
  padding: 6rem 0;
  background: var(--color-surface);
}

.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  max-width: 1000px;
  margin: 0 auto;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
  background: var(--color-background);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.contact-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.contact-icon {
  font-size: 1.5rem;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  flex-shrink: 0;
}

.contact-item h3 {
  margin: 0 0 0.25rem 0;
  color: var(--color-primary);
}

.contact-item a {
  color: var(--color-text);
  font-weight: 500;
}

/* Contact Form */
.contact-form {
  background: var(--color-background);
  padding: 2.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--color-text);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--border-radius);
  font-family: var(--font-secondary);
  font-size: 1rem;
  transition: var(--transition-fast);
  background: var(--color-background);
  color: var(--color-text);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 51, 102, 0.1);
}

.form-success,
.form-error {
  padding: 1rem;
  border-radius: var(--border-radius);
  margin-bottom: 1.5rem;
}

.form-success {
  background: rgba(40, 167, 69, 0.1);
  color: var(--color-success);
  border: 1px solid rgba(40, 167, 69, 0.2);
}

.form-error {
  background: rgba(220, 53, 69, 0.1);
  color: var(--color-error);
  border: 1px solid rgba(220, 53, 69, 0.2);
}

/* Footer */
.footer {
  background: var(--color-primary);
  color: white;
  padding: 2rem 0;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-social a {
  color: white;
  font-size: 1.5rem;
  padding: 0.5rem;
  border-radius: 50%;
  transition: var(--transition-fast);
}

.footer-social a:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

/* Toast Notification */
.toast {
  position: fixed;
  top: 2rem;
  right: 2rem;
  background: var(--color-success);
  color: white;
  padding: 1rem 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  transition: var(--transition);
  z-index: 1001;
}

.toast.show {
  transform: translateX(0);
}

.toast-content {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.toast-close {
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0;
  line-height: 1;
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 1rem;
  }
  
  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--color-background);
    flex-direction: column;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    transition: var(--transition);
  }
  
  .nav-menu.active {
    transform: translateY(0);
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .about-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .skills-grid {
    grid-template-columns: 1fr;
  }
  
  .timeline::before {
    left: 2rem;
  }
  
  .timeline-item:nth-child(odd) .timeline-content,
  .timeline-item:nth-child(even) .timeline-content {
    margin-left: 4rem;
    margin-right: 0;
    text-align: left;
  }
  
  .timeline-item:nth-child(odd) .timeline-header {
    flex-direction: row;
  }
  
  .timeline-marker {
    left: 2rem;
  }
  
  .contact-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .education-grid {
    grid-template-columns: 1fr;
  }
  
  .testimonials-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .section-title {
    font-size: 2rem;
  }
  
  .timeline-content {
    padding: 1.5rem;
  }
  
  .contact-form {
    padding: 1.5rem;
  }
}

/* Print Styles */
@media print {
  .navbar,
  .hero-scroll,
  .contact-form,
  .footer {
    display: none;
  }
  
  .hero {
    min-height: auto;
    padding: 2rem 0;
  }
  
  section {
    padding: 1rem 0;
  }
  
  .timeline::before {
    display: none;
  }
  
  .timeline-marker {
    display: none;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  :root {
    --color-border: #000000;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3);
  }
}

/* Focus Styles for Accessibility */
*:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

button:focus,
input:focus,
textarea:focus,
select:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}