/* ============================================
   DESIGN SYSTEM & CSS VARIABLES
   ============================================ */
:root {
  /* Colors - Professional Blue/Teal Theme */
  --clr-bg-primary: #0a1929;
  --clr-bg-secondary: #0d2238;
  --clr-bg-card: rgba(13, 34, 56, 0.8);
  --clr-text-primary: #eceff4;
  --clr-text-secondary: #a0aec0;
  --clr-accent-primary: #0066cc;
  --clr-accent-secondary: #00acc1;
  --clr-accent-gradient: linear-gradient(135deg, #0066cc 0%, #00acc1 100%);
  --clr-accent-glow: rgba(0, 102, 204, 0.3);

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-base: 1.0625rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.75rem;
  --font-size-4xl: 3.5rem;

  /* Effects */
  --blur-sm: 8px;
  --blur-md: 16px;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.15);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 30px var(--clr-accent-glow);
  --shadow-3d: 0 20px 60px rgba(0, 0, 0, 0.3), 0 10px 20px rgba(0, 0, 0, 0.2);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ============================================
   BASE STYLES
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.7;
  color: var(--clr-text-primary);
  background: var(--clr-bg-primary);
  overflow-x: hidden;
}

/* Animated Background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(circle at 20% 50%, rgba(0, 102, 204, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(0, 172, 193, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 40% 20%, rgba(0, 102, 204, 0.05) 0%, transparent 40%);
  z-index: -1;
  animation: gradientShift 20s ease infinite;
}

@keyframes gradientShift {

  0%,
  100% {
    opacity: 1;
  }

  50% {
    opacity: 0.6;
  }
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--space-sm);
}

h1 {
  font-size: var(--font-size-4xl);
  background: linear-gradient(135deg, #0066cc 0%, #00acc1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: var(--font-size-3xl);
  color: var(--clr-text-primary);
}

h3 {
  font-size: var(--font-size-2xl);
  color: var(--clr-text-primary);
}

p {
  margin-bottom: var(--space-sm);
  color: var(--clr-text-secondary);
  line-height: 1.8;
}

/* ============================================
   LAYOUT & CONTAINERS
   ============================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

section {
  min-height: 100vh;
  padding: var(--space-xl) 0;
  display: flex;
  align-items: center;
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: var(--space-md);
  background: rgba(10, 25, 41, 0.85);
  backdrop-filter: blur(var(--blur-sm));
  z-index: 1000;
  border-bottom: 1px solid rgba(0, 102, 204, 0.15);
  transition: all var(--transition-base);
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  background: var(--clr-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  cursor: pointer;
}

.nav-links {
  display: flex;
  gap: var(--space-md);
  list-style: none;
}

.nav-links a {
  color: var(--clr-text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 1.1rem;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--clr-accent-gradient);
  transition: width var(--transition-base);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--clr-text-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* ============================================
   HERO SECTION WITH 3D PROFILE CARD
   ============================================ */
#hero {
  position: relative;
  padding-top: calc(var(--space-xl) + 60px);
  min-height: 100vh;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-lg);
  align-items: center;
  z-index: 1;
}

/* 3D Profile Card */
.profile-card {
  position: relative;
  background: var(--clr-bg-card);
  padding: var(--space-lg);
  border-radius: 24px;
  box-shadow: var(--shadow-3d);
  border: 1px solid rgba(0, 102, 204, 0.2);
  transition: all var(--transition-base);
  animation: fadeInLeft 1s ease;
  backdrop-filter: blur(var(--blur-md));
}

.profile-card:hover {
  transform: translateY(-10px) rotateX(5deg);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.4), 0 15px 30px rgba(0, 102, 204, 0.2);
}

.profile-image-container {
  position: relative;
  width: 250px;
  height: 250px;
  margin: 0 auto var(--space-md);
}

.profile-image {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--clr-accent-primary);
  box-shadow: 0 10px 40px rgba(0, 102, 204, 0.3), 0 0 20px rgba(0, 172, 193, 0.2);
  transition: all var(--transition-base);
}

.profile-card:hover .profile-image {
  transform: scale(1.05);
  box-shadow: 0 15px 60px rgba(0, 102, 204, 0.4), 0 0 30px rgba(0, 172, 193, 0.3);
}

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

.profile-name {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-xs);
  background: var(--clr-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.profile-title {
  font-size: var(--font-size-lg);
  color: var(--clr-text-secondary);
  margin-bottom: var(--space-md);
  font-weight: 500;
}

.profile-contact {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid rgba(0, 102, 204, 0.2);
}

.contact-item {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  color: var(--clr-text-secondary);
  font-size: 0.65rem;
  transition: color var(--transition-fast);
}

.contact-item:hover {
  color: var(--clr-accent-primary);
}

.contact-item svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.contact-link {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* Hero Text Content */
.hero-text {
  animation: fadeInRight 1s ease;
}

.hero-name {
  font-size: 2.35rem;
  line-height: 1.2;
}

.hero-title {
  font-size: 2rem;
  margin-bottom: var(--space-md);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--clr-text-secondary);
  margin-bottom: var(--space-md);
  font-weight: 600;
}

.hero-description {
  font-size: var(--font-size-lg);
  line-height: 1.8;
  margin-bottom: var(--space-lg);
  color: var(--clr-text-secondary);
}

.cta-button {
  display: inline-block;
  padding: 1rem 2.5rem;
  background: var(--clr-accent-gradient);
  color: white;
  text-decoration: none;
  border-radius: 50px;
  font-weight: 600;
  font-size: var(--font-size-lg);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-glow);
}

.cta-button:hover {
  transform: translateY(-4px);
  box-shadow: 0 0 50px var(--clr-accent-glow), var(--shadow-md);
}

/* ============================================
   ABOUT SECTION
   ============================================ */
#about {
  background: var(--clr-bg-secondary);
}

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

.about-card {
  background: var(--clr-bg-card);
  padding: var(--space-md);
  border-radius: 16px;
  border: 1px solid rgba(0, 102, 204, 0.15);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  text-align: center;
}

.about-card:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 102, 204, 0.4);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.about-card span {
  font-size: var(--font-size-3xl);
  display: block;
  margin-bottom: var(--space-sm);
}

.about-card h3 {
  color: var(--clr-accent-primary);
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-2xl);
}

.about-card p {
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ============================================
   SKILLS SECTION
   ============================================ */
.section-title {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.skill-category {
  background: var(--clr-bg-card);
  padding: var(--space-md);
  border-radius: 16px;
  border: 1px solid rgba(0, 102, 204, 0.15);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.skill-category:hover {
  transform: translateY(-6px);
  border-color: rgba(0, 102, 204, 0.4);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.skill-category h3 {
  color: var(--clr-accent-primary);
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.3rem;
}

.skill-category h3::before {
  content: '▸';
  font-size: var(--font-size-xl);
  background: var(--clr-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.skill-list {
  list-style: none;
}

.skill-list li {
  padding: var(--space-xs) 0;
  color: var(--clr-text-secondary);
  position: relative;
  padding-left: var(--space-md);
  line-height: 1.6;
  font-size: 1.2rem;
}

.skill-list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--clr-accent-primary);
  font-size: 1.6rem;
}

/* ============================================
   EXPERIENCE SECTION
   ============================================ */
#experience {
  background: var(--clr-bg-secondary);
}

.timeline {
  position: relative;
  max-width: 900px;
  margin: var(--space-lg) auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100%;
  background: linear-gradient(180deg,
      rgba(0, 102, 204, 0) 0%,
      rgba(0, 102, 204, 0.5) 20%,
      rgba(0, 102, 204, 0.5) 80%,
      rgba(0, 102, 204, 0) 100%);
}

.timeline-item {
  margin-bottom: var(--space-lg);
  position: relative;
}

.timeline-content {
  background: var(--clr-bg-card);
  padding: var(--space-md);
  border-radius: 16px;
  border: 1px solid rgba(0, 102, 204, 0.15);
  width: calc(50% - 40px);
  position: relative;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.timeline-item:nth-child(odd) .timeline-content {
  margin-left: auto;
}

.timeline-content:hover {
  transform: scale(1.03);
  border-color: rgba(0, 102, 204, 0.4);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.timeline-marker {
  position: absolute;
  left: 50%;
  top: 30px;
  transform: translateX(-50%);
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--clr-accent-gradient);
  border: 3px solid var(--clr-bg-secondary);
  box-shadow: var(--shadow-glow);
  z-index: 1;
}

.timeline-content h3 {
  color: var(--clr-accent-primary);
  margin-bottom: var(--space-xs);
  font-size: 1.35rem;
}

.timeline-year {
  color: var(--clr-text-secondary);
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.timeline-content p {
  line-height: 1.7;
  margin-bottom: var(--space-sm);
  font-size: 1.2rem;
}

.timeline-content ul {
  list-style: none;
  margin-top: var(--space-sm);
}

.timeline-content li {
  padding-left: var(--space-md);
  position: relative;
  margin-bottom: var(--space-xs);
  color: var(--clr-text-secondary);
  line-height: 1.6;
  font-size: 1.2rem;
}

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

/* ============================================
   PROJECTS SECTION
   ============================================ */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  max-width: 900px;
  margin: var(--space-lg) auto 0;
}

.project-card {
  background: var(--clr-bg-card);
  padding: var(--space-lg);
  border-radius: 16px;
  border: 1px solid rgba(0, 102, 204, 0.15);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.project-card:hover {
  transform: translateY(-5px);
  border-color: rgba(0, 102, 204, 0.4);
  box-shadow: var(--shadow-lg);
}

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

.project-header h3 {
  color: var(--clr-accent-primary);
  font-size: 1.4rem;
  margin: 0;
}

.project-period {
  background: rgba(0, 102, 204, 0.1);
  color: var(--clr-accent-primary);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
}

.project-company {
  color: var(--clr-text-primary);
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: var(--space-md);
}

.project-description {
  color: var(--clr-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

.project-details {
  background: rgba(10, 25, 41, 0.5);
  padding: var(--space-md);
  border-radius: 8px;
  margin-bottom: var(--space-md);
}

.project-details p {
  margin-bottom: var(--space-xs);
  font-size: 0.95rem;
  color: var(--clr-text-secondary);
}

.project-details strong {
  color: var(--clr-text-primary);
}

.project-details p:last-child {
  margin-bottom: 0;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.project-tags span {
  background: rgba(0, 172, 193, 0.1);
  color: var(--clr-accent-secondary);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 500;
}

/* ============================================
   ACHIEVEMENTS SECTION
   ============================================ */
.achievements-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-lg);
  max-width: 1400px;
  margin-left: auto;
  margin-right: auto;
}

@media (max-width: 1200px) {
  .achievements-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .achievements-grid {
    grid-template-columns: 1fr;
  }
}

.achievement-card {
  background: var(--clr-bg-card);
  padding: var(--space-md);
  border-radius: 16px;
  border: 1px solid rgba(0, 102, 204, 0.15);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  align-items: center;
  text-align: center;
}

.achievement-card:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 102, 204, 0.4);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.achievement-icon {
  font-size: 3rem;
  line-height: 1;
  flex-shrink: 0;
}

.achievement-content h3 {
  color: var(--clr-accent-primary);
  margin-bottom: var(--space-xs);
  font-size: 1.4rem;
}

.achievement-org {
  color: var(--clr-text-secondary);
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: var(--space-sm);
  font-style: italic;
}

.achievement-description {
  color: var(--clr-text-secondary);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: var(--space-md);
    text-align: center;
  }

  .hero-text {
    order: 2;
  }

  .profile-card {
    order: 1;
    max-width: 400px;
    margin: 0 auto;
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2.5rem;
    --font-size-3xl: 2rem;
    --font-size-2xl: 1.5rem;
  }

  .nav-links {
    gap: var(--space-sm);
    font-size: 0.9rem;
  }

  section {
    min-height: auto;
    padding: var(--space-lg) 0;
  }

  .timeline::before {
    left: 20px;
  }

  .timeline-content {
    width: calc(100% - 60px);
    margin-left: 60px !important;
  }

  .timeline-marker {
    left: 20px;
  }

  .about-grid,
  .skills-grid {
    grid-template-columns: 1fr;
  }

  .profile-image-container {
    width: 200px;
    height: 200px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-sm);
  }

  header {
    padding: var(--space-sm);
  }

  .nav-links {
    gap: var(--space-xs);
    font-size: 0.85rem;
  }

  .cta-button {
    padding: 0.8rem 2rem;
    font-size: var(--font-size-base);
  }

  .profile-card {
    padding: var(--space-md);
  }

  .profile-image-container {
    width: 180px;
    height: 180px;
  }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center {
  text-align: center;
}

.text-gradient {
  background: var(--clr-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

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

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