:root {
  --primary: #1a8a7a;
  --primary-hover: #147a6b;
  --primary-light: #f0f5f4;
  --primary-dark: #52b9a8;
  --bg: #f4f6f8;
  --bg-card: #ffffff;
  --text: #1e272e;
  --text-secondary: #4a5568;
  --text-muted: #6b7a85;
  --border: #e4e7eb;
  --border-card: #e8ecf0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.06);
  --radius: 10px;
  --radius-sm: 6px;
  --nav-height: 64px;
  --transition: 0.2s ease;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

[data-theme="dark"] {
  --bg: #0f1419;
  --bg-card: #1a202c;
  --text: #e2e8f0;
  --text-secondary: #a0aec0;
  --text-muted: #718096;
  --border: #2d3748;
  --border-card: #2d3748;
  --primary-light: #1a2e2a;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.3);
}

[data-theme="dark"] .hero {
  background: linear-gradient(135deg, #0f1419 0%, #1a2e2a 100%) !important;
}
[data-theme="dark"] section[style*="background: #ffffff"] {
  background: var(--bg-card) !important;
}
[data-theme="dark"] .cta-section {
  background: #1a202c !important;
}
[data-theme="dark"] .project-featured {
  background: #1a202c !important;
}
[data-theme="dark"] .btn-outline {
  border-color: #4a5568;
  color: var(--text);
}
[data-theme="dark"] nav {
  background: var(--bg-card);
  border-bottom-color: var(--border);
}
[data-theme="dark"] nav ul li a {
  color: var(--text-secondary);
}
[data-theme="dark"] .highlight-card,
[data-theme="dark"] .fp-card,
[data-theme="dark"] .project-card,
[data-theme="dark"] .contact-card,
[data-theme="dark"] .value-card,
[data-theme="dark"] .card {
  background: var(--bg-card);
  border-color: var(--border-card);
}
[data-theme="dark"] .achievement-item {
  background: #1a202c;
}
[data-theme="dark"] .skill-tags span {
  background: #1a2e2a;
  border-color: #2d3748;
  color: var(--text-secondary);
}
[data-theme="dark"] .tag {
  background: #1a2e2a;
}
[data-theme="dark"] .hero-quick-stats {
  border-top-color: var(--border);
}
[data-theme="dark"] .info-block .icon-box {
  background: #1a2e2a;
}
[data-theme="dark"] .contact-form input,
[data-theme="dark"] .contact-form textarea {
  background: #1a202c;
  border-color: #2d3748;
  color: var(--text);
}
[data-theme="dark"] .contact-form input:focus,
[data-theme="dark"] .contact-form textarea:focus {
  background: var(--bg-card);
}
[data-theme="dark"] .page-header {
  background: var(--bg-card) !important;
  border-bottom-color: var(--border) !important;
}
[data-theme="dark"] .map-box {
  background: #1a2e2a;
  border-color: var(--border);
}
[data-theme="dark"] .page-nav a {
  background: var(--bg-card);
  border-color: var(--border);
  color: var(--text-secondary);
}
[data-theme="dark"] footer {
  background: #0a0e14;
}

[data-theme="dark"] .search-overlay {
  background: rgba(0,0,0,0.85);
}
[data-theme="dark"] .search-modal {
  background: var(--bg-card);
}
[data-theme="dark"] .search-modal input {
  background: #1a202c;
  color: var(--text);
}
[data-theme="dark"] .theme-toggle {
  color: #f6e05e;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
}
a {
  text-decoration: none;
  color: inherit;
}
img {
  max-width: 100%;
  height: auto;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 10000;
  font-weight: 600;
  font-size: 0.88rem;
}
.skip-link:focus {
  top: 0;
}

nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  padding: 0 2rem;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: box-shadow var(--transition), background var(--transition), border-color var(--transition);
}
nav.scrolled {
  box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}
nav .logo {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--text);
}
nav .logo span {
  color: var(--primary);
}
nav ul {
  list-style: none;
  display: flex;
  gap: 1.8rem;
  align-items: center;
}
nav ul li a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
  padding: 0.3rem 0;
  position: relative;
}
nav ul li a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition);
  border-radius: 1px;
}
nav ul li a:hover::after,
nav ul li a.active::after {
  width: 100%;
}
nav ul li a:hover,
nav ul li a.active {
  color: var(--primary);
}
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text);
  cursor: pointer;
  padding: 0.25rem;
  z-index: 1001;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: all var(--transition);
}
.theme-toggle:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 6rem 0;
}

.page-header {
  padding-top: 8rem;
  padding-bottom: 2rem;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-card);
}
.page-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
}
.page-header h1 span {
  color: var(--primary);
}
.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.breadcrumb a {
  color: var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition);
  border: none;
  cursor: pointer;
}
.btn-primary {
  background: var(--primary);
  color: #ffffff;
}
.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(26, 138, 122, 0.3);
}
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}
.btn-sm {
  padding: 0.5rem 1.2rem;
  font-size: 0.82rem;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}
.section-title h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
}
.section-title p {
  color: var(--text-muted);
  margin-top: 0.5rem;
  font-size: 1.05rem;
}
.section-title .line {
  width: 50px;
  height: 3px;
  background: var(--primary);
  margin: 1rem auto 0;
  border-radius: 2px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-card);
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.7rem;
  border-radius: 4px;
}

footer {
  background: #151d24;
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  font-size: 1.1rem;
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all 0.3s ease;
  z-index: 999;
  box-shadow: 0 2px 12px rgba(26,138,122,0.3);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}
.back-to-top:hover {
  background: var(--primary-hover);
  transform: translateY(-3px);
}

.page-nav {
  display: flex;
  justify-content: space-between;
  margin: 2rem 0;
}
.page-nav a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: all var(--transition);
  background: var(--bg-card);
}
.page-nav a:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}
.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}
.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}
.fade-in-scale {
  opacity: 0;
  transform: scale(0.95);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}
.fade-in-scale.visible {
  opacity: 1;
  transform: scale(1);
}
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}
.stagger-children.visible > *:nth-child(1) { transition-delay: 0s; }
.stagger-children.visible > *:nth-child(2) { transition-delay: 0.08s; }
.stagger-children.visible > *:nth-child(3) { transition-delay: 0.16s; }
.stagger-children.visible > *:nth-child(4) { transition-delay: 0.24s; }
.stagger-children.visible > *:nth-child(5) { transition-delay: 0.32s; }
.stagger-children.visible > *:nth-child(6) { transition-delay: 0.4s; }
.stagger-children.visible > *:nth-child(7) { transition-delay: 0.48s; }
.stagger-children.visible > *:nth-child(8) { transition-delay: 0.56s; }
.stagger-children.visible > * {
  opacity: 1;
  transform: translateY(0);
}

@media print {
  nav, footer, .menu-toggle, .theme-toggle, .page-nav, .breadcrumb, .cta-section, .btn, .back-to-top, .skip-link { display: none !important; }
  body { background: #fff !important; color: #000 !important; font-size: 11pt; }
  section { padding: 1rem 0 !important; }
  .container { max-width: 100% !important; padding: 0 !important; }
  .card { box-shadow: none !important; border: 1px solid #ddd !important; }
  .fade-in, .fade-in-left, .fade-in-right, .fade-in-scale { opacity: 1 !important; transform: none !important; }
  .stagger-children > * { opacity: 1 !important; transform: none !important; }
}

@media (max-width: 768px) {
  nav ul {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    flex-direction: column;
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--border);
    gap: 1rem;
    box-shadow: var(--shadow-md);
  }
  nav ul.open {
    display: flex;
  }
  .menu-toggle {
    display: block;
  }
  .section-title h2 {
    font-size: 1.5rem;
  }
  body.nav-open {
    overflow: hidden;
  }
}