/* ============================================================
   styles.css — mobile-first, single stylesheet
   ============================================================ */

/* 3.1 CSS reset + custom properties + base typography */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-primary:    #3b82f6;
  --color-primary-dk: #1d4ed8;
  --color-text:       #1f2937;
  --color-text-muted: #6b7280;
  --color-bg:         #ffffff;
  --color-bg-alt:     #f9fafb;
  --color-border:     #e5e7eb;
  --color-featured-bg: #eff6ff;
  --color-featured-border: #93c5fd;
  --color-error:      #ef4444;

  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  1.5rem;
  --space-lg:  2rem;
  --space-xl:  3rem;

  --radius:    0.5rem;
  --shadow:    0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

h1, h2, h3, h4 { line-height: 1.25; font-weight: 700; }
h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; margin-bottom: var(--space-sm); }
h3 { font-size: 1.125rem; }

a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-dk); text-decoration: underline; }

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

ul { list-style: disc; padding-left: 1.25rem; }

/* 3.3 Layout */
.container {
  width: 100%;
  max-width: 1100px;
  margin-inline: auto;
  padding-inline: var(--space-sm);
}

.section { margin-top: var(--space-xl); }
.page-title { margin-bottom: var(--space-lg); }

/* ============================================================
   3.2 Navigation — mobile-first (collapsed hamburger)
   ============================================================ */
.site-nav {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-text);
}
.nav-brand:hover { text-decoration: none; color: var(--color-primary); }

/* Hamburger button — visible on mobile */
.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

.hamburger,
.hamburger::before,
.hamburger::after {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform .2s, opacity .2s;
  position: relative;
}
.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  left: 0;
}
.hamburger::before { top: -7px; }
.hamburger::after  { top:  7px; }

/* Mobile: links hidden until nav-open */
.nav-links {
  display: none;
  flex-direction: column;
  position: absolute;
  top: 60px;
  left: 0;
  right: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-xs) 0;
}

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

.nav-link {
  padding: var(--space-xs) var(--space-sm);
  color: var(--color-text);
  font-weight: 500;
  min-height: 44px;
  display: flex;
  align-items: center;
}
.nav-link:hover { color: var(--color-primary); text-decoration: none; background: var(--color-bg-alt); }
.nav-link.active { color: var(--color-primary); border-left: 3px solid var(--color-primary); }

/* ============================================================
   Hero section
   ============================================================ */
#hero { padding: var(--space-xl) 0 var(--space-lg); }

.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  text-align: center;
}

.hero-photo {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
}

.hero-title  { color: var(--color-text-muted); font-size: 1.125rem; margin-top: var(--space-xs); }
.hero-tagline { color: var(--color-text-muted); font-style: italic; margin-top: var(--space-xs); }

/* ============================================================
   Summary
   ============================================================ */
.summary-body { color: var(--color-text); }
.summary-body p { margin-bottom: var(--space-sm); }

/* ============================================================
   3.4 Skills grid (CSS Grid)
   ============================================================ */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

.skill-category {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
}

.skill-category h3 { color: var(--color-primary); margin-bottom: var(--space-xs); }

/* ============================================================
   3.4 Highlights row (Flexbox)
   ============================================================ */
.highlights-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.highlight-card {
  flex: 1 1 260px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-sm);
  box-shadow: var(--shadow);
}

.highlight-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: calc(var(--radius) - 2px);
  margin-bottom: var(--space-xs);
}

.highlight-card h3 { margin-bottom: var(--space-xs); }

/* ============================================================
   Experience
   ============================================================ */
.experience-card {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--color-border);
}

.company-logo {
  width: 56px;
  height: 56px;
  object-fit: contain;
  flex-shrink: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 4px;
}

.experience-body { flex: 1; }
.exp-role  { font-weight: 600; color: var(--color-primary); margin-top: 2px; }
.exp-meta  { color: var(--color-text-muted); font-size: .875rem; margin: var(--space-xs) 0; }
.exp-bullets { margin: var(--space-xs) 0 var(--space-sm); }
.exp-bullets li { margin-bottom: 4px; font-size: .9375rem; }

.detail-link {
  font-size: .875rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}

/* Experience detail */
.back-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin-bottom: var(--space-md);
  font-weight: 500;
}

.detail-banner-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius);
  margin-bottom: var(--space-md);
}

#detail-header { margin-bottom: var(--space-md); }
#detail-body p  { margin-bottom: var(--space-sm); }

/* ============================================================
   Education
   ============================================================ */
.education-card {
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--color-border);
}

.edu-institution { font-weight: 600; color: var(--color-primary); margin-top: 4px; }
.edu-meta  { color: var(--color-text-muted); font-size: .875rem; margin: var(--space-xs) 0; }
.edu-notes { font-size: .9375rem; }

/* Languages */
.language-list { list-style: none; padding: 0; }

.language-item {
  display: flex;
  align-items: baseline;
  gap: var(--space-sm);
  padding: var(--space-xs) 0;
  border-bottom: 1px solid var(--color-border);
}

.lang-name        { font-weight: 600; min-width: 120px; }
.lang-proficiency { color: var(--color-text-muted); font-size: .875rem; }
.lang-notes       { color: var(--color-text-muted); font-size: .8125rem; }

/* ============================================================
   3.4 + 3.5 Certifications grid (CSS Grid) + .featured
   ============================================================ */
.certs-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

.cert-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  box-shadow: var(--shadow);
  position: relative;
}

.cert-badge {
  width: 64px;
  height: 64px;
  object-fit: contain;
  margin-bottom: var(--space-xs);
}

.cert-card h3    { margin-bottom: var(--space-xs); }
.cert-issuer     { color: var(--color-text-muted); font-size: .875rem; margin-bottom: 4px; }
.cert-level      { font-size: .8125rem; color: var(--color-text-muted); margin-bottom: var(--space-xs); }
.cert-verify-link {
  display: inline-flex;
  align-items: center;
  font-size: .875rem;
  font-weight: 600;
  min-height: 44px;
}

/* 3.5 Featured card */
.cert-card.featured {
  background: var(--color-featured-bg);
  border-color: var(--color-featured-border);
  box-shadow: var(--shadow-md);
}

.featured-badge {
  position: absolute;
  top: var(--space-xs);
  right: var(--space-xs);
  background: var(--color-primary);
  color: #fff;
  font-size: .75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 999px;
}

/* ============================================================
   3.6 Loading spinner + error state
   ============================================================ */
.loading {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xl) 0;
  color: var(--color-text-muted);
}

.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin .7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.error-state {
  padding: var(--space-lg) 0;
  color: var(--color-error);
}

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  margin-top: var(--space-xl);
  padding: var(--space-md) 0;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: .875rem;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.social-links { display: flex; gap: var(--space-sm); flex-wrap: wrap; }
.social-link  {
  min-height: 44px;
  min-width: 44px;
  display: inline-flex;
  align-items: center;
  text-transform: capitalize;
}

/* ============================================================
   3.7 Desktop breakpoint — min-width: 769px
   ============================================================ */
@media (min-width: 769px) {
  /* Nav: hide hamburger, show horizontal links */
  .nav-toggle { display: none; }

  .nav-links {
    display: flex;
    flex-direction: row;
    position: static;
    border: none;
    padding: 0;
    background: transparent;
    gap: var(--space-xs);
  }

  .nav-link {
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius);
    min-height: 44px;
  }

  .nav-link.active {
    border-left: none;
    background: var(--color-bg-alt);
    color: var(--color-primary);
  }

  /* Hero: side-by-side */
  .hero-inner {
    flex-direction: row;
    text-align: left;
    align-items: flex-start;
  }

  .hero-photo { width: 150px; height: 150px; }

  /* Skills: 2-column grid */
  .skills-grid { grid-template-columns: repeat(2, 1fr); }

  /* Certs: 2-column grid */
  .certs-grid { grid-template-columns: repeat(2, 1fr); }

  .footer-inner { flex-direction: row; justify-content: space-between; align-items: center; }
}

/* ============================================================
   3.7 Wide desktop — min-width: 1200px
   ============================================================ */
@media (min-width: 1200px) {
  h1 { font-size: 2.5rem; }

  /* Skills: 3-column grid */
  .skills-grid { grid-template-columns: repeat(3, 1fr); }

  /* Certs: 3-column grid */
  .certs-grid { grid-template-columns: repeat(3, 1fr); }
}