:root {
  /* Light theme by default */
  --bg: #ffffff;
  --text: #1a1a1a;
  --text-muted: #555560;
  --primary: #6366f1;
  --accent: #8b5cf6;
  --success: #10b981;
  --glass: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(0, 0, 0, 0.08);
  --radius: 16px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

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

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

/* Light theme (default) – no data-theme attribute needed */
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Loader */
.loader {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  transition: opacity 0.5s ease, visibility 0.5s;
}

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

.loader-spinner {
  width: 50px;
  height: 50px;
  border: 3px solid var(--glass-border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loader p {
  color: var(--text-muted);
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Mesh gradient background */
/* Background mesh gradient – subtil en light */
.bg-mesh {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  background: 
    radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.06) 0%, transparent 50%),
    radial-gradient(circle at 40% 90%, rgba(16, 185, 129, 0.04) 0%, transparent 40%);
  filter: blur(60px);
  animation: meshMove 20s ease-in-out infinite alternate;
}

@keyframes meshMove {
  0% { transform: scale(1) translate(0, 0); }
  100% { transform: scale(1.1) translate(-2%, 2%); }
}

/* Cursor glow */
.cursor-glow {
  position: fixed;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  transform: translate(-50%, -50%);
  z-index: 9999;
  opacity: 0;
  transition: opacity 0.3s;
}

body:hover .cursor-glow {
  opacity: 1;
}

/* Glass effect – light theme */
.glass {
  background: var(--glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

/* Container */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 clamp(1rem, 4vw, 4rem);
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1.5rem 0;
  transition: var(--transition);
}

.nav.scrolled {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  padding: 1rem 0;
  border-bottom: 1px solid var(--glass-border);
}

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

.logo {
  font-family: 'Playfair Display', serif;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

.nav-links a:hover {
  color: var(--text);
}

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

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 5px;
}

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

/* Hero */
.hero {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  padding: 8rem 2rem 4rem;
  max-width: 1400px;
  margin: 0 auto;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--primary);
  margin-bottom: 2rem;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.hero-title .line {
  display: block;
}

.hero-title .highlight {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  max-width: 650px;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--glass-border);
}

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

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

.hero-card {
  padding: 2rem;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(0, 0, 0, 0.06);
  position: relative;
  overflow: hidden;
  animation: cardFloat 6s ease-in-out infinite;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.hero-card:nth-child(2) {
  animation-delay: -2s;
}

.hero-card:nth-child(3) {
  animation-delay: -4s;
}

@keyframes cardFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

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

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

.card-content .big {
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Section styles */
section {
  padding: 6rem 0;
}

.section-title {
  font-family: 'Playfair Display', serif;
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: 4rem;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -1rem;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text p {
  margin-bottom: 1.5rem;
  font-size: 1.125rem;
  color: var(--text-muted);
}

.about-text strong {
  color: var(--text);
}

.about-details {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.detail-item {
  display: flex;
  justify-content: space-between;
  padding: 1rem;
  background: var(--glass);
  border-radius: var(--radius);
  border: 1px solid var(--glass-border);
}

.detail-item .label {
  color: var(--text-muted);
  font-weight: 500;
}

.detail-item .value {
  color: var(--text);
  font-weight: 600;
}

.about-image {
  display: flex;
  justify-content: center;
}

.profile-photo {
  width: 300px;
  height: 400px;
  object-fit: cover;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* Experience – Timeline */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 20px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: 3rem;
}

.timeline-marker {
  position: absolute;
  left: 11px;
  top: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 3px var(--primary);
}

.timeline-content {
  padding: 2rem;
  transition: var(--transition);
}

.timeline-content:hover {
  transform: translateX(10px);
  border-color: var(--primary);
}

.timeline-content .date {
  display: inline-block;
  font-size: 0.875rem;
  color: var(--accent);
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.timeline-content h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.timeline-content p {
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
}

.tags li {
  padding: 0.25rem 0.75rem;
  background: rgba(99, 102, 241, 0.1);
  border-radius: 50px;
  font-size: 0.875rem;
  color: var(--primary);
}

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

.skill-card {
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.skill-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
}

.skill-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.skill-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.skill-card p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 0.875rem;
}

.skill-level {
  height: 6px;
  background: rgba(255,255,255,0.1);
  border-radius: 3px;
  position: relative;
  overflow: hidden;
}

.skill-level::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: calc(var(--level) * 1%);
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 3px;
}

/* Contact */
.contact-content {
  text-align: center;
  padding: 4rem 2rem;
  max-width: 800px;
  margin: 0 auto;
}

.contact-content p {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.contact-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text);
  text-decoration: none;
  font-size: 1.125rem;
  padding: 1rem 2rem;
  background: var(--glass);
  border-radius: 50px;
  border: 1px solid var(--glass-border);
  transition: var(--transition);
}

.contact-link:hover {
  background: var(--primary);
  transform: translateY(-2px);
}

.social-links {
  display: flex;
  gap: 1rem;
}

.social-link {
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  transition: var(--transition);
}

.social-link:hover {
  background: var(--primary);
  transform: translateY(-3px);
}

/* Contact form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
  padding: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}
.contact-form input,
.contact-form textarea {
  padding: 0.75rem 1rem;
  border: 1px solid rgba(0,0,0,0.1);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: var(--transition);
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}
.form-message {
  animation: fadeInUp 0.5s ease-out;
}

/* Projects */
.projects {
  padding: 6rem 0;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.project-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.project-card:hover {
  transform: translateY(-8px);
  border-color: var(--primary);
}

.project-image {
  height: 200px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(139, 92, 246, 0.2));
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-placeholder {
  font-size: 4rem;
}

.project-content {
  padding: 2rem;
}

.project-content h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.project-content p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 0.9375rem;
}

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

.project-tags span {
  padding: 0.25rem 0.75rem;
  background: rgba(99, 102, 241, 0.1);
  border-radius: 50px;
  font-size: 0.875rem;
  color: var(--primary);
}

/* Footer */
.footer {
  padding: 2rem 0;
  text-align: center;
  color: var(--text-muted);
  border-top: 1px solid var(--glass-border);
}

/* Responsive */
@media (max-width: 968px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 3rem;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-visual {
    grid-template-columns: 1fr;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.95);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--glass-border);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

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

  .about-image {
    order: -1;
  }

  .image-placeholder {
    width: 200px;
    height: 260px;
  }
}

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

.fade-in-up {
  opacity: 0;
  animation: fadeInUp 0.8s ease-out forwards;
}

/* Reveal on scroll classes */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delays */
.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }

/* Theme toggle – fixed button */
.theme-toggle {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 10000;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  color: var(--text);
  font-size: 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.theme-toggle:hover {
  transform: scale(1.05);
  background: var(--primary);
}

/* Light theme */
[data-theme="light"] {
  --bg: #f5f5f7;
  --text: #1a1a1a;
  --text-muted: #555560;
  --glass: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0, 0, 0, 0.1);
}
[data-theme="light"] .nav {
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--glass-border);
}
[data-theme="light"] .bg-mesh {
  background: 
    radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.08) 0%, transparent 50%);
}

/* Skill level animation */
.skill-level {
  position: relative;
  height: 6px;
  background: rgba(255,255,255,0.1);
  border-radius: 3px;
  overflow: hidden;
}
.skill-level::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 3px;
  transition: width 1.2s ease-out;
}
.reveal.visible .skill-level::after {
  width: calc(var(--level) * 1%);
}

/* Project card – images & hover */
.project-image {
  height: 200px;
  overflow: hidden;
  position: relative;
}
.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.project-card:hover .project-image img {
  transform: scale(1.05);
}
.project-card {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(0, 0, 0, 0.06);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}
.project-card:hover {
  transform: translateY(-12px);
  box-shadow: 0 12px 32px rgba(99, 102, 241, 0.15);
  border-color: var(--primary);
}

/* Testimonials */
.testimonials { padding: 6rem 0; }
.testimonials-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; }
.testimonial-card { 
  padding: 2rem; 
  position: relative;
}
.testimonial-card::before {
  content: '“';
  position: absolute;
  top: 10px;
  left: 20px;
  font-size: 4rem;
  color: var(--primary);
  opacity: 0.3;
  font-family: var(--font-serif);
  line-height: 1;
}
.testimonial-card p {
  font-style: italic;
  margin-bottom: 1.5rem;
  color: var(--text-muted);
  position: relative;
  z-index: 1;
}
.testimonial-card .author {
  display: block;
  text-align: right;
  font-weight: 600;
  color: var(--primary);
}

/* Accessibility – reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* Mobile tweaks */
@media (max-height: 700px) {
  .hero { gap: 2rem; padding: 6rem 2rem 3rem; }
  section { padding: 3rem 0; }
}
:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
.skip-link { position: absolute; top: -40px; left: 0; background: #000; color: #fff; padding: 8px; z-index: 10001; }
.skip-link:focus { top: 0; }