/* ============================================
   CSS Custom Properties / Theme System
   ============================================ */

:root {
  --font-sans: 'Hubot Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --max-width: 1100px;
  --radius: 8px;
  --radius-lg: 12px;
  --transition: 200ms ease;
}

[data-theme="dark"] {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --bg-card: #161b22;
  --bg-card-hover: #1c2128;
  --bg-code: #21262d;

  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-tertiary: #6e7681;
  --text-link: #3fb950;

  --border-color: #30363d;
  --border-hover: #484f58;

  --accent: #3fb950;
  --accent-secondary: #56d364;
  --accent-tertiary: #2ea043;
  --accent-warning: #d29922;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);

  --gradient-hero: linear-gradient(135deg, var(--accent) 0%, var(--accent-secondary) 100%);
}

[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f6f8fa;
  --bg-tertiary: #eaeef2;
  --bg-card: #ffffff;
  --bg-card-hover: #f6f8fa;
  --bg-code: #f6f8fa;

  --text-primary: #1f2328;
  --text-secondary: #656d76;
  --text-tertiary: #8c959f;
  --text-link: #1a7f37;

  --border-color: #d0d7de;
  --border-hover: #afb8c1;

  --accent: #1a7f37;
  --accent-secondary: #2ea043;
  --accent-tertiary: #1a7f37;
  --accent-warning: #9a6700;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

  --gradient-hero: linear-gradient(135deg, var(--accent) 0%, var(--accent-secondary) 100%);
}

/* ============================================
   Reset & Base
   ============================================ */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--transition), color var(--transition);
}

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

a:hover {
  text-decoration: underline;
}

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

/* ============================================
   Layout
   ============================================ */

main {
  min-height: calc(100vh - 200px);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 80px 0;
}

section:nth-child(even) {
  background: var(--bg-secondary);
}

.section-header {
  margin-bottom: 48px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::before {
  content: '//';
  color: var(--accent);
  font-family: var(--font-mono);
  font-weight: 400;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* ============================================
   Navbar
   ============================================ */

.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg-primary) 85%, transparent);
}

.navbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary) !important;
  text-decoration: none !important;
  display: flex;
  align-items: center;
  gap: 4px;
}

.brand-prompt {
  color: var(--accent-secondary);
}

.navbar-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  color: var(--text-secondary) !important;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none !important;
  transition: color var(--transition);
}

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

.nav-dropdown {
  position: relative;
}

.nav-dropdown-trigger {
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  display: flex;
  align-items: center;
  gap: 4px;
}

.dropdown-arrow {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform var(--transition);
  margin-top: -2px;
}

.nav-dropdown:hover .dropdown-arrow,
.nav-dropdown.open .dropdown-arrow {
  transform: rotate(-135deg);
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-top: 8px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 4px;
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  z-index: 100;
}

.nav-dropdown:hover .dropdown-menu,
.nav-dropdown.open .dropdown-menu {
  opacity: 1;
  visibility: visible;
}

.dropdown-item {
  display: block;
  padding: 8px 12px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  text-decoration: none;
  border-radius: var(--radius);
  transition: all var(--transition);
  white-space: nowrap;
}

.dropdown-item:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.nav-social {
  display: flex;
  align-items: center;
  gap: 12px;
}

.social-link {
  color: var(--text-secondary) !important;
  display: flex;
  align-items: center;
  transition: color var(--transition);
}

.social-link:hover {
  color: var(--text-primary) !important;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 6px 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.theme-toggle:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.lang-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 6px 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 600;
  transition: all var(--transition);
}

.lang-toggle:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.lang-label {
  line-height: 1;
}

.theme-icon {
  display: none;
}

[data-theme="dark"] .theme-icon.moon {
  display: block;
}

[data-theme="light"] .theme-icon.sun {
  display: block;
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all var(--transition);
}

.mobile-menu {
  display: none;
  flex-direction: column;
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  background: var(--bg-primary);
}

.mobile-menu.active {
  display: flex;
}

.mobile-nav-link {
  color: var(--text-secondary) !important;
  padding: 12px 0;
  font-size: 1rem;
  text-decoration: none !important;
  border-bottom: 1px solid var(--border-color);
}

.mobile-nav-link:last-of-type {
  border-bottom: none;
}

.mobile-dropdown-trigger {
  background: none;
  border: none;
  border-bottom: 1px solid var(--border-color);
  cursor: pointer;
  font: inherit;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.mobile-dropdown-trigger svg {
  transition: transform var(--transition);
}

.mobile-dropdown.open .dropdown-arrow {
  transform: rotate(-135deg);
}

.mobile-dropdown-menu {
  display: none;
  padding-left: 16px;
}

.mobile-dropdown.open .mobile-dropdown-menu {
  display: block;
}

.mobile-dropdown-menu .dropdown-item {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
}

.mobile-dropdown-menu .dropdown-item:last-child {
  border-bottom: none;
}

.mobile-social {
  display: flex;
  gap: 16px;
  padding-top: 12px;
  margin-top: 8px;
}

/* ============================================
   Hero / Presentation
   ============================================ */

.hero {
  padding: 48px 0 80px;
  display: flex;
  align-items: center;
  gap: 64px;
}

.hero-avatar {
  flex-shrink: 0;
}

.avatar-img {
  width: 240px;
  height: 240px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  box-shadow: var(--shadow-lg);
}

.hero-content {
  flex: 1;
}

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--accent);
  margin-bottom: 8px;
}

.hero-name {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 8px;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: 1.5rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 24px;
}

.hero-bio {
  color: var(--text-secondary);
  font-size: 1.1rem;
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none !important;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  font-family: inherit;
}

.btn-primary {
  background: var(--accent);
  color: #fff !important;
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
  border-color: var(--border-hover);
  background: var(--bg-tertiary);
}

/* ============================================
   Skills
   ============================================ */

.skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 48px;
}

.skill-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  transition: all var(--transition);
}

.skill-badge:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

.skill-badge::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-secondary);
}

/* ============================================
   Timeline (Experience & Education)
   ============================================ */

.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
  padding-bottom: 32px;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 2px solid var(--accent);
}

.timeline-item:first-child::before {
  background: var(--accent);
}

.timeline-period {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 4px;
}

.timeline-title {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.timeline-company {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.timeline-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ============================================
   Projects Grid
   ============================================ */

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  margin-bottom: 40px;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.project-image {
  width: 100%;
  height: 180px;
  object-fit: cover;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
}

.project-content {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.project-type {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.project-name {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.project-name a {
  color: var(--text-primary) !important;
  text-decoration: none !important;
}

.project-name a:hover {
  color: var(--accent) !important;
}

.project-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 16px;
  flex: 1;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.tech-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  color: var(--text-secondary);
}

.project-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.project-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-link) !important;
  text-decoration: none !important;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.project-link:hover {
  text-decoration: underline !important;
}

.project-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--border-color);
}

.btn-read-more {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 6px 12px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all var(--transition);
  font-family: inherit;
  white-space: nowrap;
}

.btn-read-more:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--bg-tertiary);
}

.project-highlight {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: color-mix(in srgb, var(--accent-warning) 15%, transparent);
  border: 1px solid var(--accent-warning);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--accent-warning);
  margin-bottom: 12px;
  width: fit-content;
}

/* ============================================
   Pagination
   ============================================ */

.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.pagination-btn {
  padding: 10px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.pagination-btn:hover:not(:disabled) {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

.pagination-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.pagination-info {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ============================================
   Courses Modal
   ============================================ */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 600px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  background: var(--bg-card);
}

.modal-title {
  font-size: 1.3rem;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
  display: flex;
  transition: color var(--transition);
}

.modal-close:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 24px;
}

.modal-lg {
  max-width: 720px;
}

.project-modal-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.project-modal-description {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
}

.project-modal-section {
  margin-top: 8px;
}

.project-modal-section h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
  font-family: var(--font-mono);
}

.project-modal-section p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.project-modal-achievements {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.project-modal-achievements li {
  padding-left: 20px;
  position: relative;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.project-modal-achievements li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-secondary);
}

.project-modal-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.project-modal-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.project-modal-link {
  padding: 8px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary) !important;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none !important;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition);
}

.project-modal-link:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

.courses-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.courses-list li {
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font-size: 0.95rem;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.courses-list li::before {
  content: '✓';
  color: var(--accent-secondary);
  font-weight: 600;
  flex-shrink: 0;
}

.course-link {
  color: var(--text-link) !important;
  text-decoration: none !important;
  font-weight: 500;
  transition: color var(--transition);
}

.course-link:hover {
  color: var(--accent) !important;
  text-decoration: underline !important;
}

.view-courses-btn {
  margin-top: 16px;
  font-size: 0.9rem;
  padding: 8px 16px;
}

/* ============================================
   Footer
   ============================================ */

.footer {
  border-top: 1px solid var(--border-color);
  padding: 32px 0;
  background: var(--bg-secondary);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-badge img {
  height: 24px;
}

.footer-copy {
  color: var(--text-tertiary);
  font-size: 0.9rem;
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 768px) {
  .navbar-links {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero {
    flex-direction: column-reverse;
    text-align: center;
    gap: 32px;
    padding: 32px 0 40px;
  }

  .hero-avatar {
    order: -1;
  }

  .avatar-img {
    width: 180px;
    height: 180px;
  }

  .hero-name {
    font-size: 2.2rem;
  }

  .hero-title {
    font-size: 1.2rem;
  }

  .hero-bio {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .section-title {
    font-size: 1.6rem;
  }

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  section {
    padding: 60px 0;
  }
}

@media (max-width: 480px) {
  .hero-name {
    font-size: 1.8rem;
  }

  .btn {
    padding: 10px 18px;
    font-size: 0.9rem;
  }

  .skills-grid {
    gap: 8px;
  }

  .skill-badge {
    padding: 6px 12px;
    font-size: 0.85rem;
  }
}

/* ============================================
   Utility
   ============================================ */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.text-mono {
  font-family: var(--font-mono);
}