/* ============================================================
   Design Tokens
   ============================================================ */
:root {
  --color-bg:        #ffffff;
  --color-text:      #1a1a1a;
  --color-muted:     #666666;
  --color-accent:    #0066cc;
  --color-accent-h:  #004fa3;
  --color-border:    #e8e8e8;
  --color-alt-bg:    #f7f7f7;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;

  --max-w: 720px;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;

  --radius: 9999px;
  --transition: 150ms ease;
}

/* ============================================================
   Reset & Base
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

a:hover {
  color: var(--color-accent-h);
}

ul, ol {
  list-style: none;
}

/* ============================================================
   Layout Utilities
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--space-md);
}

.section {
  padding-block: var(--space-xl);
}

.section-alt {
  background: var(--color-alt-bg);
}

.section-title {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: var(--space-lg);
}

/* ============================================================
   Navigation
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.nav-logo:hover {
  color: var(--color-text);
}

.nav-links {
  display: flex;
  gap: var(--space-md);
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--color-muted);
  transition: color var(--transition);
}

.nav-links a:hover {
  color: var(--color-text);
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-text);
  transition: transform var(--transition), opacity var(--transition);
}

/* Open state */
.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* ============================================================
   Hero
   ============================================================ */
.hero {
  padding-block: var(--space-xl);
  padding-top: calc(var(--space-xl) + var(--space-md));
}

.hero-eyebrow {
  font-size: 0.875rem;
  color: var(--color-muted);
  margin-bottom: var(--space-xs);
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.hero-tagline {
  font-size: 1.125rem;
  color: var(--color-muted);
  font-weight: 300;
  margin-bottom: var(--space-md);
}

/* Hero social icons */
.hero-icons {
  display: flex;
  gap: 0.75rem;
  margin-bottom: var(--space-sm);
}

.hero-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  transition: color var(--transition);
}

.hero-icon svg {
  width: 16px;
  height: 16px;
}

.hero-icon:hover {
  color: var(--color-text);
}

/* ============================================================
   Button
   ============================================================ */
.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  border: 1.5px solid var(--color-text);
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  transition: background var(--transition), color var(--transition);
}

.btn:hover {
  background: var(--color-text);
  color: var(--color-bg);
}

/* ============================================================
   About
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.profile-img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
}

.about-text p + p {
  margin-top: var(--space-sm);
}

.about-text p {
  color: var(--color-text);
}

/* ============================================================
   Experience / Timeline
   ============================================================ */
.timeline {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.timeline-item {
  padding-left: var(--space-md);
  border-left: 1.5px solid var(--color-border);
}

.timeline-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem var(--space-md);
  margin-bottom: 0.25rem;
}

.timeline-date {
  font-size: 0.8rem;
  color: var(--color-muted);
  font-weight: 400;
}

.timeline-company {
  font-size: 0.8rem;
  color: var(--color-accent);
  font-weight: 500;
}

.timeline-role {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.timeline-bullets {
  list-style: disc;
  padding-left: var(--space-sm);
}

.timeline-bullets li {
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 1.6;
}

.timeline-bullets li + li {
  margin-top: 0.25rem;
}

/* ============================================================
   Projects
   ============================================================ */
.projects-subtitle {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  letter-spacing: -0.01em;
}

.projects-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.project-card {
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: border-color var(--transition);
}

.project-card:hover {
  border-color: var(--color-muted);
}

.project-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
}

.project-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.25rem;
}

.project-card-header .project-name {
  margin-bottom: 0;
}

.project-icon {
  width: 16px;
  height: 16px;
  color: var(--color-muted);
  flex-shrink: 0;
  opacity: 0.6;
}

.project-card:hover .project-icon {
  opacity: 1;
}

.project-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.25rem;
  letter-spacing: -0.01em;
}

.project-desc {
  font-size: 0.85rem;
  color: var(--color-muted);
  line-height: 1.5;
}

@media (max-width: 640px) {
  .projects-grid {
    grid-template-columns: 1fr;
  }
}

/* Resume download */
.resume-btn {
  margin-top: var(--space-lg);
}

/* ============================================================
   Contact
   ============================================================ */
.contact-container {
  text-align: center;
}

.contact-intro {
  color: var(--color-muted);
  margin-bottom: var(--space-sm);
}

.contact-email {
  display: inline-block;
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--color-text);
  border-bottom: 1.5px solid var(--color-text);
  padding-bottom: 2px;
  margin-bottom: var(--space-md);
  transition: color var(--transition), border-color var(--transition);
}

.contact-email:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.contact-icons {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
}

.contact-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  color: var(--color-muted);
  transition: color var(--transition), transform var(--transition);
}

.contact-icon svg {
  width: 22px;
  height: 22px;
}

.contact-icon:hover {
  color: var(--color-text);
  transform: translateY(-2px);
}

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-md);
}

.site-footer p {
  font-size: 0.8rem;
  color: var(--color-muted);
  text-align: center;
}

/* ============================================================
   Responsive — Mobile
   ============================================================ */
@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 65px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: 0;
    padding-block: var(--space-sm);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li {
    padding-inline: var(--space-md);
    padding-block: 0.6rem;
  }

  .nav-links a {
    font-size: 1rem;
  }

  .hero-name {
    font-size: 2.25rem;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .profile-img {
    width: 96px;
    height: 96px;
  }

  .section {
    padding-block: var(--space-lg);
  }
}