@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:opsz,wght@8..60,400;8..60,500;8..60,600;8..60,700&family=Inter:wght@300;400;500;600;700&display=swap');

/* --- Theme Variables --- */
:root {
  --bg: #ffffff;
  --bg-alt: #f7f6f2;
  --bg-card: #ffffff;

  --border: #e3e2db;
  --border-strong: #cfcec4;

  --accent: #1f3a5f;
  --accent-dark: #14263f;
  --accent-soft: rgba(31, 58, 95, 0.07);
  --accent-soft-strong: rgba(31, 58, 95, 0.16);

  --gold: #8f6a2e;
  --gold-soft: rgba(143, 106, 46, 0.1);

  --text-primary: #1a1b1e;
  --text-secondary: #52555c;
  --text-muted: #8b8e94;

  --font-display: 'Source Serif 4', Georgia, serif;
  --font-body: 'Inter', sans-serif;

  --shadow-sm: 0 1px 2px rgba(20, 20, 15, 0.04), 0 1px 3px rgba(20, 20, 15, 0.05);
  --shadow-md: 0 10px 28px rgba(20, 20, 15, 0.08);

  --transition-smooth: all 0.2s ease;
}

/* --- Base Resets & Global Styles --- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  background-color: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

li {
  list-style: none;
}

.text-muted {
  color: var(--text-muted);
}

/* --- Scrollbar Styling --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-alt);
}

::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

/* --- Layout Containers --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  position: relative;
}

section {
  padding: 7rem 0 4rem;
  border-bottom: 1px solid var(--border);
}

section:nth-of-type(even) {
  background-color: var(--bg-alt);
}

/* --- Typography System --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.section-tag {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin-bottom: 0.85rem;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin-bottom: 3.5rem;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.8rem 1.6rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn i {
  width: 16px;
  height: 16px;
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
  border: 1px solid var(--accent);
}

.btn-primary:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

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

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

/* --- Navigation Header --- */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition-smooth);
}

header.scrolled {
  padding: 0.5rem 0;
  box-shadow: var(--shadow-sm);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 76px;
}

header.scrolled .nav-container {
  height: 58px;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent);
  border-radius: 50%;
}

.nav-menu {
  display: flex;
  gap: 2.1rem;
  align-items: center;
}

.nav-link {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition-smooth);
  position: relative;
  padding: 0.25rem 0;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition-smooth);
}

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

.nav-socials {
  display: flex;
  gap: 1rem;
}

.social-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: transparent;
  border: 1px solid var(--border-strong);
  color: var(--text-secondary);
  transition: var(--transition-smooth);
}

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

.mobile-socials-item {
  display: none;
}

/* Mobile Hamburger Menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 5px;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 2px;
  background-color: var(--text-primary);
  transition: var(--transition-smooth);
}

/* --- Hero Section --- */
.hero {
  min-height: 92vh;
  display: flex;
  align-items: center;
  position: relative;
  padding-top: 100px;
  background-color: var(--bg);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 4rem;
  align-items: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 1rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-strong);
  border-radius: 4px;
  color: var(--accent);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.hero-role {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.4rem;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 2.25rem;
  max-width: 560px;
}

.hero-ctas {
  display: flex;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-upwork-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 1.15rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.88rem;
}

.upwork-logo-badge {
  color: #14a800; /* Upwork Green */
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.hero-upwork-badge span {
  color: var(--text-secondary);
}

.hero-upwork-badge strong {
  color: var(--gold);
  font-weight: 600;
}

/* Image Container */
.hero-image-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-frame {
  position: relative;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  padding: 5px;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow-md);
}

.hero-image {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  background-color: var(--bg-alt);
}

/* --- Research Interests Section --- */
.interests-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.interest-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.25rem 1.75rem;
  border-radius: 10px;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
}

.interest-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.interest-icon-box {
  width: 46px;
  height: 46px;
  border-radius: 8px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
}

.interest-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
}

.interest-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* --- Experience & Upwork Section --- */
.experience-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

/* Upwork Highlight Banner */
.upwork-highlight-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2.75rem;
  box-shadow: var(--shadow-sm);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  align-items: center;
}

.upwork-info h3 {
  font-size: 1.65rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.badge-gold {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.75rem;
  background: var(--gold-soft);
  color: var(--gold);
  font-size: 0.72rem;
  font-weight: 700;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border: 1px solid rgba(143, 106, 46, 0.2);
}

.upwork-badge-icon {
  font-size: 0.8rem;
}

.upwork-info p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 1.75rem;
}

.upwork-bullets {
  margin-bottom: 1.75rem;
}

.upwork-bullets li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.65rem;
  color: var(--text-primary);
  font-size: 0.92rem;
}

.upwork-bullets li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--accent);
}

.upwork-stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.upwork-stat-box {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 1.35rem;
  border-radius: 8px;
  text-align: center;
}

.upwork-stat-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.2rem;
}

.upwork-stat-num.gold {
  color: var(--gold);
}

.upwork-stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Timeline Components */
.timeline {
  position: relative;
  padding-left: 2rem;
  margin-top: 1rem;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 3px;
  width: 2px;
  height: 100%;
  background: var(--border-strong);
}

.timeline-item {
  position: relative;
  margin-bottom: 3rem;
}

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

.timeline-dot {
  position: absolute;
  left: -2rem;
  top: 6px;
  transform: translateX(-50%);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--accent);
  z-index: 2;
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.1rem;
  border-radius: 10px;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
}

.timeline-item:hover .timeline-content {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.role-title {
  font-size: 1.35rem;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
}

.company-info {
  font-size: 0.95rem;
  color: var(--accent);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.company-info i {
  width: 16px;
  height: 16px;
}

.timeline-date {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--text-secondary);
  background: var(--bg-alt);
  padding: 0.35rem 0.85rem;
  border-radius: 30px;
  border: 1px solid var(--border);
  white-space: nowrap;
}

.timeline-desc {
  margin-bottom: 1.5rem;
}

.timeline-desc li {
  position: relative;
  padding-left: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

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

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

.tech-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 0.28rem 0.65rem;
  border-radius: 4px;
  letter-spacing: 0.01em;
  transition: var(--transition-smooth);
}

.tech-tag:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

/* --- Publications Section --- */
.publication-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.25rem;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 1.35rem;
  transition: var(--transition-smooth);
}

.publication-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.pub-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.pub-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3rem 0.7rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-strong);
  color: var(--accent);
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 600;
}

.pub-badge i {
  width: 14px;
  height: 14px;
}

.pub-year {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.pub-title {
  font-size: 1.5rem;
  line-height: 1.35;
  font-weight: 600;
}

.pub-authors {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.pub-authors strong {
  color: var(--text-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}

.pub-venue {
  font-size: 0.92rem;
  color: var(--text-secondary);
  font-style: italic;
}

.pub-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 0.25rem;
}

.pub-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-size: 0.83rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.pub-btn i {
  width: 14px;
  height: 14px;
}

.pub-btn-doi {
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-strong);
  color: var(--accent);
}

.pub-btn-doi:hover {
  background: var(--accent-soft-strong);
}

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

.pub-btn-cite:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* BibTeX Collapsible Block */
.citation-collapse {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
  background: var(--bg-alt);
  border-radius: 8px;
}

.citation-collapse.show {
  max-height: 250px;
  border: 1px solid var(--border);
  margin-top: 0.5rem;
}

.citation-block {
  padding: 1.25rem;
  position: relative;
}

.citation-block pre {
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.8rem;
  color: var(--text-secondary);
  overflow-x: auto;
  white-space: pre-wrap;
}

.copy-citation-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.copy-citation-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* --- Projects Section --- */
.project-filters {
  display: flex;
  gap: 0.65rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  color: var(--text-secondary);
  padding: 0.55rem 1.25rem;
  border-radius: 30px;
  font-family: var(--font-body);
  font-size: 0.87rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.filter-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.filter-btn.active {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
  height: 100%;
  box-shadow: var(--shadow-sm);
}

.project-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.project-visual {
  height: 140px;
  position: relative;
  background: var(--bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--border);
}

.project-icon-circle {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--accent);
}

.project-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-title {
  font-size: 1.25rem;
  margin-bottom: 0.4rem;
  color: var(--text-primary);
}

.project-date {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.project-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.55;
}

.project-bullets-hidden {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.project-bullets-hidden li {
  font-size: 0.85rem;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1rem;
}

.project-bullets-hidden li::before {
  content: '▪';
  position: absolute;
  left: 0;
  color: var(--accent);
}

.project-footer {
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.project-links {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.project-link-icon {
  font-size: 1.15rem;
  color: var(--text-secondary);
  transition: var(--transition-smooth);
}

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

/* --- Certificates & Skills Section --- */
.certificates-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
}

.skills-column h3, .certs-column h3 {
  font-size: 1.6rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Skills dynamic tags */
.skills-container {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.skill-category h4 {
  font-size: 0.95rem;
  font-family: var(--font-body);
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.skill-tag {
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  color: var(--text-secondary);
  padding: 0.45rem 0.95rem;
  border-radius: 6px;
  font-size: 0.82rem;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.skill-tag:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

/* Certificates Grid */
.certs-grid {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.cert-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.4rem 1.5rem;
  border-radius: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
}

.cert-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.cert-info h4 {
  font-size: 1.05rem;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.cert-issuer {
  font-size: 0.85rem;
  color: var(--accent);
}

.cert-year {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.cert-link {
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: var(--transition-smooth);
}

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

/* --- Contact Section --- */
.contact-grid {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 4rem;
}

.contact-info-cards {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.contact-info-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.6rem;
  border-radius: 10px;
  display: flex;
  gap: 1.25rem;
  align-items: center;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
}

.contact-info-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.contact-info-icon {
  width: 46px;
  height: 46px;
  border-radius: 8px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 1.25rem;
}

.contact-info-text h4 {
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.contact-info-text p, .contact-info-text a {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
}

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

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.form-control {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  padding: 0.8rem 1rem;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.95rem;
  transition: var(--transition-smooth);
}

.form-control:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

/* --- Footer --- */
footer {
  padding: 3.5rem 0;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  text-align: center;
}

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

.footer-nav {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-nav a {
  color: var(--text-secondary);
  font-size: 0.88rem;
  transition: var(--transition-smooth);
}

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

.footer-text {
  font-size: 0.83rem;
  color: var(--text-muted);
}

/* --- Mobile Responsiveness Media Queries --- */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.9rem;
  }

  .experience-layout, .certificates-layout, .contact-grid {
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  section {
    padding: 6rem 0 3rem;
  }

  .hamburger {
    display: flex;
  }

  /* Hide desktop header socials on mobile */
  header .nav-socials {
    display: none;
  }

  /* Show socials inside slide-out menu drawer on mobile */
  .mobile-socials-item {
    display: block;
    width: 100%;
    margin-top: 1rem;
    padding: 0 2rem;
  }

  .nav-menu .mobile-socials {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
  }

  .nav-menu {
    position: fixed;
    top: 76px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 76px);
    background: var(--bg);
    flex-direction: column;
    padding: 3rem 0;
    gap: 2rem;
    transition: var(--transition-smooth);
    border-top: 1px solid var(--border);
    z-index: 999;
  }

  .nav-menu.active {
    left: 0;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
    text-align: center;
  }

  .hero-tag, .hero-desc, .hero-role {
    margin-left: auto;
    margin-right: auto;
  }

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

  .hero-upwork-badge {
    justify-content: center;
  }

  .hero-image-wrapper {
    order: -1;
  }

  .upwork-highlight-card {
    grid-template-columns: 1fr;
    padding: 2rem;
    gap: 2rem;
  }

  .certificates-layout, .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2.25rem;
  }

  .hero-role {
    font-size: 1.15rem;
  }

  .hero-ctas {
    flex-direction: column;
    align-items: stretch;
  }

  .section-title {
    font-size: 2rem;
  }

  .timeline-header {
    flex-direction: column;
    align-items: flex-start;
  }
}