:root {
  --color-dark: #000000;
  --color-dark-bg: #0a0a0a;
  --color-text: #ffffff;
  --color-text-secondary: #999999;
  --color-primary: #ffffff;
  --color-accent: #0a66c2;
  --color-border: rgba(255, 255, 255, 0.1);
  --color-shadow: rgba(0, 0, 0, 0.5);

  --spacing-xs: 8px;
  --spacing-sm: 12px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;

  --border-radius: 8px;
  --font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --line-height: 1.6;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 1rem;
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-dark-bg);
  background-image: radial-gradient(circle at 20% 50%, rgba(10, 102, 194, 0.1) 0%, transparent 50%), 
                    radial-gradient(circle at 80% 80%, rgba(10, 102, 194, 0.05) 0%, transparent 50%);
}

h1, h2, h3, h4, h5, h6 {
  margin-bottom: var(--spacing-md);
  font-weight: 700;
  letter-spacing: -1px;
}

h1 {
  font-size: 3.5rem;
  color: var(--color-text);
}

h2 {
  font-size: 2.8rem;
  color: var(--color-text);
}

h3 {
  font-size: 1.8rem;
  color: var(--color-text);
}

h4 {
  font-size: 1.3rem;
  color: var(--color-text);
}

a {
  color: var(--color-text);
  text-decoration: none;
  transition: opacity 0.3s ease;
}

a:hover {
  opacity: 0.8;
}

button {
  cursor: pointer;
  border: none;
  font-family: inherit;
  transition: all 0.3s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ============================================================
   HEADER & NAVIGATION
   ============================================================ */
.header {
  background-color: transparent;
  padding: var(--spacing-lg) 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--color-border);
}

.navbar-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 2px;
}

.logo-icon {
  font-size: 1.8rem;
}

.nav-menu {
  list-style: none;
  display: flex;
  gap: var(--spacing-xl);
  align-items: center;
}

.nav-link {
  color: var(--color-text);
  font-size: 0.95rem;
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
}

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

.nav-contact {
  border: 2px solid var(--color-text);
  border-radius: 25px;
  padding: 8px 24px;
}

.nav-contact:hover {
  background-color: var(--color-text);
  color: var(--color-dark);
}

/* ============================================================
   ABOUT SECTION
   ============================================================ */
.about-section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.breadcrumb {
  text-align: center;
  color: var(--color-text-secondary);
  margin-bottom: 60px;
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--color-text-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 60px;
}

.about-image img {
  width: 75%;
  border-radius: var(--border-radius);
  object-fit: cover;
}

.about-label {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.about-heading {
  margin-bottom: var(--spacing-lg);
  line-height: 1.2;
}

.about-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.8;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  padding: 12px 32px;
  border-radius: 25px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.3s ease;
}

.btn-primary {
  background-color: var(--color-text);
  color: var(--color-dark);
}

.btn-primary:hover {
  background-color: var(--color-accent);
  color: var(--color-text);
  transform: translateY(-2px);
}

.btn-light {
  background-color: var(--color-text);
  color: var(--color-dark);
}

.btn-light:hover {
  background-color: var(--color-accent);
  transform: translateY(-2px);
}

/* ============================================================
   SKILLS SECTION
   ============================================================ */
.skills-section {
  padding: 80px 0;
  background: linear-gradient(135deg, rgba(10, 102, 194, 0.05) 0%, transparent 50%);
}

.skills-title {
  margin-bottom: var(--spacing-md);
}

.skills-subtitle {
  color: var(--color-text-secondary);
  max-width: 600px;
  margin-bottom: 60px;
  line-height: 1.8;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
  margin-bottom: 80px;
}


.skill-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
  font-size: 0.95rem;
  font-weight: 600;
}

.skill-percent {
  color: var(--color-accent);
}

.progress-bar {
  width: 100%;
  height: 3px;
  background-color: var(--color-border);
  border-radius: 10px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), #00d4ff);
  border-radius: 10px;
  transition: width 1s ease;
}

/* ============================================================
   STATS SECTION
   ============================================================ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
}

.stat-item {
  text-align: center;
  padding: var(--spacing-lg);
  border-bottom: 2px solid var(--color-border);
}

.stat-number {
  font-size: 2.5rem;
  color: var(--color-accent);
  margin-bottom: var(--spacing-sm);
}

.stat-label {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

/* ============================================================
   PROJECTS SECTION
   ============================================================ */
.projects-section {
  padding: 80px 0;
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-secondary);
  max-width: 700px;
  margin: 0 auto 60px;
  line-height: 1.8;
  font-size: 0.95rem;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 40px;
  margin-bottom: 80px;
}

.project-card {
  background: linear-gradient(135deg, rgba(10, 102, 194, 0.1) 0%, transparent 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: 40px;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
}

.project-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(10, 102, 194, 0.15);
}

.project-logo {
  width: 100px;
  height: 100px;
  margin: 0 auto var(--spacing-lg);
  background: rgba(10, 102, 194, 0.1);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.project-logo1 {
  height: 100px;
  margin: 0 auto var(--spacing-lg);
  background: rgba(10, 102, 194, 0.1);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.project-logo1 img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-logo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-title {
  font-size: 1.3rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.project-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  flex-grow: 1;
  line-height: 1.7;
  font-size: 0.9rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.tag {
  display: inline-block;
  background: rgba(10, 102, 194, 0.2);
  color: var(--color-accent);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border: 1px solid rgba(10, 102, 194, 0.3);
}

.project-link {
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  display: inline-block;
}

.project-link:hover {
  color: #00d4ff;
  transform: translateX(5px);
}

/* ============================================================
   PUBLICATIONS SECTION
   ============================================================ */
.publications-section {
  padding: 80px 0;
  background: linear-gradient(135deg, rgba(10, 102, 194, 0.03) 0%, transparent 100%);
}

.publications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 40px;
  margin-bottom: 80px;
}

.publication-card {
  background: rgba(10, 10, 10, 0.8);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: 40px;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  backdrop-filter: blur(10px);
}

.publication-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-5px);
  box-shadow: 0 25px 50px rgba(10, 102, 194, 0.2);
  background: rgba(10, 30, 60, 0.5);
}

.publication-header {
  display: flex;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  align-items: flex-start;
}

.publication-icon {
  font-size: 2rem;
  min-width: 60px;
}

.publication-meta {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.publication-date {
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.85rem;
}

.publication-type {
  color: var(--color-text-secondary);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.publication-title {
  font-size: 1.2rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  line-height: 1.4;
}

.publication-authors {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

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

.publication-abstract {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  flex-grow: 1;
  line-height: 1.7;
  font-size: 0.9rem;
}

.publication-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.pub-tag {
  display: inline-block;
  background: rgba(10, 102, 194, 0.15);
  color: #00d4ff;
  padding: 5px 12px;
  border-radius: 15px;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border: 1px solid rgba(0, 212, 255, 0.2);
}

.publication-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
}

.publication-doi {
  color: var(--color-text-secondary);
  font-size: 0.75rem;
  font-family: 'Courier New', monospace;
}

.publication-link {
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.85rem;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.publication-link:hover {
  color: #00d4ff;
  transform: translateX(5px);
}

/* ============================================================
   CTA SECTION
   ============================================================ */
.cta-section {
  padding: 100px var(--spacing-lg);
  background: linear-gradient(135deg, rgba(0, 0, 0, 0.5) 0%, rgba(10, 102, 194, 0.1) 100%), 
              url('https://via.placeholder.com/1200x400?text=CTA+Background') center/cover;
  text-align: center;
  position: relative;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: -1;
}

.cta-content {
  position: relative;
  z-index: 1;
}

.cta-label {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.cta-title {
  margin-bottom: var(--spacing-lg);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background-color: #111111;
  padding: 80px var(--spacing-lg) 20px;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h4 {
  margin-bottom: var(--spacing-lg);
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  transition: color 0.3s ease;
}

.footer-section a {
  color: var(--color-text-secondary);
}

.footer-section a:hover {
  color: var(--color-text);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  font-size: 1rem;
  font-weight: 700;
}

.studio-text {
  font-size: 0.8rem;
}

.footer-section p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.8;
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
}

.social-icon {
  width: 40px;
  height: 40px;
  border: 2px solid var(--color-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.social-icon:hover {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-dark);
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  padding-top: var(--spacing$

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  h1 {
    font-size: 2.5rem;
  }

  h2 {
    font-size: 1.8rem;
  }

  .nav-menu {
    gap: var(--spacing-md);
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .cta-section {
    padding: 60px var(--spacing-md);
  }

  .footer-content {
    grid-template-columns: 1fr;
  }
}