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

:root {
  --accent:       #0ea5e9;
  --accent-hover: #0284c7;
  --gray-900: #111827;
  --gray-700: #374151;
  --gray-600: #4b5563;
  --gray-500: #6b7280;
  --gray-400: #9ca3af;
  --gray-200: #e5e7eb;
  --gray-100: #f3f4f6;
  --gray-50:  #f9fafb;
  --white:    #ffffff;
  --max-w:    1024px;
  --radius:   6px;
}

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

body {
  font-family: Arial, sans-serif;
  background: var(--white);
  color: var(--gray-900);
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }
button { background: none; border: none; cursor: pointer; font-family: inherit; }
ul { list-style: none; }

/* Navbar */
.navbar { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: var(--white); border-bottom: 1px solid var(--gray-100); }
.nav-inner { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; height: 64px; display: flex; align-items: center; justify-content: space-between; }
.nav-brand { font-size: 1rem; font-weight: 600; color: var(--gray-900); transition: color 0.2s; }
.nav-brand:hover { color: var(--gray-600); }
.nav-links { display: flex; gap: 32px; }
.nav-links button { font-size: 0.875rem; color: var(--gray-500); transition: color 0.2s; }
.nav-links button:hover { color: var(--gray-900); }
.nav-toggle { display: none; color: var(--gray-600); transition: color 0.2s; }
.nav-toggle:hover { color: var(--gray-900); }
.nav-toggle svg { display: block; }
.mobile-menu { display: none; flex-direction: column; gap: 16px; padding: 16px 24px; border-top: 1px solid var(--gray-100); background: var(--white); }
.mobile-menu.open { display: flex; }
.mobile-menu button { text-align: left; font-size: 0.875rem; color: var(--gray-600); transition: color 0.2s; }
.mobile-menu button:hover { color: var(--gray-900); }

/* Shared */
section { padding: 80px 24px; }
.section-inner { max-width: var(--max-w); margin: 0 auto; }
h2 { font-size: 1.25rem; font-weight: 600; color: var(--gray-900); margin-bottom: 8px; line-height: 1.5; }
.section-bar { width: 32px; height: 2px; background: var(--accent); margin-bottom: 40px; }

/* Hero */
#hero { padding-top: 128px; padding-bottom: 80px; padding-left: 24px; padding-right: 24px; }
.hero-label { font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--gray-400); margin-bottom: 12px; }
.hero-name { font-size: 2.5rem; font-weight: 700; line-height: 1.2; color: var(--gray-900); margin-bottom: 16px; }
.hero-name .accent { color: var(--accent); }
.hero-subtitle { font-size: 1.25rem; font-weight: 400; color: var(--gray-500); margin-bottom: 24px; line-height: 1.5; }
.hero-bio { font-size: 0.875rem; color: var(--gray-600); max-width: 560px; line-height: 1.75; margin-bottom: 32px; }
.hero-buttons { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 32px; }
.btn-primary { display: inline-flex; align-items: center; gap: 6px; background: var(--accent); color: var(--white); padding: 10px 20px; border-radius: var(--radius); font-size: 0.875rem; font-weight: 500; transition: background 0.2s; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-secondary { display: inline-flex; align-items: center; gap: 6px; color: var(--gray-700); padding: 10px 20px; border-radius: var(--radius); font-size: 0.875rem; font-weight: 500; border: 1px solid var(--gray-200); transition: border-color 0.2s; }
.btn-secondary:hover { border-color: var(--gray-400); }
.hero-socials { display: flex; gap: 16px; }
.hero-socials a { color: var(--gray-400); transition: color 0.2s; display: flex; align-items: center; }
.hero-socials a:hover { color: var(--gray-700); }

/* About & Experience */
#about { background: var(--gray-50); }
#experience { background: var(--white); }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.about-text p { font-size: 0.875rem; color: var(--gray-600); line-height: 1.75; }
.about-text p + p { margin-top: 16px; }
.about-items { display: flex; flex-direction: column; gap: 16px; }
.about-item { display: flex; align-items: flex-start; gap: 12px; }
.about-item-title { font-size: 0.875rem; font-weight: 500; color: var(--gray-900); }
.about-item-sub { font-size: 0.75rem; color: var(--gray-500); }
.exp-block { margin-bottom: 24px; }
.exp-role { font-size: 1rem; font-weight: 600; color: var(--gray-900); }
.exp-meta { font-size: 0.75rem; color: var(--gray-500); margin-bottom: 8px; }

/* Projects */
#projects { background: var(--gray-50); }
.projects-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.project-card { background: var(--white); border: 1px solid var(--gray-200); border-radius: var(--radius); padding: 24px; transition: border-color 0.2s, box-shadow 0.2s; }
.project-card:hover { border-color: #d1d5db; box-shadow: 0 1px 6px rgba(0,0,0,0.06); }
.project-title { font-size: 1rem; font-weight: 600; color: var(--gray-900); margin-bottom: 8px; line-height: 1.4; }
.project-desc { font-size: 0.875rem; color: var(--gray-500); line-height: 1.7; margin-bottom: 16px; }
.project-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.tag { background: var(--gray-100); color: var(--gray-600); font-size: 0.75rem; padding: 4px 10px; border-radius: 4px; }
.project-links { display: flex; gap: 12px; }
.project-links a { display: inline-flex; align-items: center; gap: 6px; font-size: 0.75rem; color: var(--gray-500); transition: color 0.2s; }
.project-links a:hover { color: var(--gray-900); }

/* Skills */
#skills { background: var(--white); }
.skills-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.skill-group-title { font-size: 0.7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--gray-700); margin-bottom: 12px; }
.skill-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-tag { background: var(--white); border: 1px solid var(--gray-200); color: var(--gray-600); font-size: 0.75rem; padding: 4px 10px; border-radius: 4px; }

/* Contact */
#contact { background: var(--gray-50); }
.contact-desc { font-size: 0.875rem; color: var(--gray-600); line-height: 1.75; max-width: 560px; margin-bottom: 32px; }
.contact-list { display: flex; flex-direction: column; gap: 16px; }
.contact-list a, .contact-list span { display: inline-flex; align-items: center; gap: 12px; font-size: 0.875rem; color: var(--gray-600); transition: color 0.2s; }
.contact-list a:hover { color: var(--gray-900); }

/* Footer */
footer { border-top: 1px solid var(--gray-100); padding: 32px 24px; background: var(--white); }
.footer-inner { max-width: var(--max-w); margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.footer-inner p { font-size: 0.75rem; color: var(--gray-400); }

/* Responsive */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .hero-name { font-size: 1.875rem; }
  .hero-subtitle { font-size: 1rem; }
  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .projects-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .footer-inner { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
}