/* ==========================================================================
   James Nguyen — jamesnguyen79.com
   Design system: restrained international executive aesthetic
   Deep navy + warm off-white + muted copper/gold accent, editorial type.
   ========================================================================== */

:root {
  --navy: #101826;
  --navy-2: #182238;
  --navy-3: #21304a;
  --offwhite: #FAF7F1;
  --white: #FFFFFF;
  --card: #FFFFFF;
  --accent: #B08D57;
  --accent-dark: #8C6F42;
  --accent-tint: rgba(176, 141, 87, 0.12);
  --text-primary: #17202E;
  --text-secondary: #4A5163;
  --text-tertiary: #6D7486;
  --text-on-navy: #F3EFE7;
  --text-on-navy-secondary: #B9C0D2;
  --border: rgba(16, 24, 38, 0.10);
  --border-strong: rgba(16, 24, 38, 0.18);
  --shadow-sm: 0 2px 10px rgba(16, 24, 38, 0.06);
  --shadow-md: 0 10px 30px rgba(16, 24, 38, 0.08);
  --radius: 10px;
  --radius-lg: 16px;
  --container: 1180px;
  --header-h: 84px;
  --font-serif: 'Fraunces', 'Source Serif 4', Georgia, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  /* Scroll-jank fix: stop the browser chaining a rubber-band bounce into
     back/forward navigation gestures — this is the primary cause of the
     "scroll drifts / cannot scroll back" symptom on trackpads. */
  overscroll-behavior-y: none;
}

body {
  font-family: var(--font-sans);
  background: var(--offwhite);
  color: var(--text-primary);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  overscroll-behavior-x: none;
}

img { max-width: 100%; display: block; }
a { color: inherit; }
ul, ol { list-style: none; }

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.75rem;
}

/* ---- Focus states (accessibility) ---- */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ==========================================================================
   Header / Nav
   NOTE: sticky header uses a solid/near-solid background instead of
   backdrop-filter blur. Backdrop blur behind a sticky element forces the
   browser to resample everything beneath it on every scroll frame, which is
   the other main contributor to the janky, dropped-frame scroll the old
   site had. A solid background costs almost nothing to composite.
   ========================================================================== */
header.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(250, 247, 241, 0.97);
  border-bottom: 1px solid var(--border);
  will-change: transform;
}

nav.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  text-decoration: none;
  color: var(--navy);
}
.logo span { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 1.9rem;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color 0.2s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent-dark); }

.nav-cta {
  padding: 0.55rem 1.15rem;
  background: var(--navy);
  color: var(--text-on-navy) !important;
  border-radius: 999px;
  font-size: 0.85rem !important;
  font-weight: 600 !important;
}
.nav-cta:hover { background: var(--accent-dark); color: #fff !important; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--navy);
  margin: 5px 0;
}

/* ==========================================================================
   Eyebrow / labels
   ========================================================================== */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-dark);
  font-weight: 600;
  display: inline-block;
  margin-bottom: 0.9rem;
}

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  padding: 5rem 0 4.5rem;
  background: linear-gradient(180deg, var(--offwhite) 0%, #F4EFE5 100%);
  border-bottom: 1px solid var(--border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 3.5rem;
  align-items: center;
}

.hero h1 {
  font-size: 3rem;
  line-height: 1.12;
  margin-bottom: 1.4rem;
  max-width: 15ch;
}

.hero .lead {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 46ch;
  margin-bottom: 1.1rem;
  line-height: 1.7;
}

.hero p.body {
  color: var(--text-tertiary);
  max-width: 50ch;
  margin-bottom: 0.6rem;
  line-height: 1.75;
}

.hero-ctas {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.hero-portrait {
  position: relative;
  justify-self: center;
}
.hero-portrait img {
  width: 100%;
  max-width: 340px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow-md);
}
.hero-portrait .frame-accent {
  position: absolute;
  top: 16px;
  left: 16px;
  right: -16px;
  bottom: -16px;
  border: 1px solid var(--accent);
  border-radius: var(--radius-lg);
  z-index: -1;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.6rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: var(--font-sans);
}
.btn-primary {
  background: var(--navy);
  color: var(--text-on-navy);
}
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-secondary {
  background: transparent;
  color: var(--navy);
  border-color: var(--border-strong);
}
.btn-secondary:hover { border-color: var(--navy); background: var(--white); transform: translateY(-2px); }
.btn-outline-light {
  background: transparent;
  color: var(--text-on-navy);
  border-color: rgba(243, 239, 231, 0.4);
}
.btn-outline-light:hover { border-color: var(--text-on-navy); background: rgba(255,255,255,0.06); }
.btn-sm { padding: 0.6rem 1.15rem; font-size: 0.82rem; }

/* ==========================================================================
   Sections
   ========================================================================== */
section { padding: 4.5rem 0; }
section.tight { padding: 3rem 0; }
section.on-navy { background: var(--navy); color: var(--text-on-navy); }
section.on-tint { background: #F4EFE5; }
section + section { border-top: 1px solid var(--border); }
section.on-navy + section, section + section.on-navy { border-top: none; }

.section-head { max-width: 720px; margin-bottom: 2.75rem; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-title {
  font-size: 2.1rem;
  margin-bottom: 0.85rem;
}
.section-lead {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}
.on-navy .section-title { color: var(--text-on-navy); }
.on-navy .section-lead { color: var(--text-on-navy-secondary); }
.on-navy .eyebrow { color: var(--accent); }

/* ==========================================================================
   Stat / proof strip
   ========================================================================== */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}
.stat-item { border-left: 2px solid var(--accent); padding-left: 1.1rem; }
.stat-number {
  font-family: var(--font-serif);
  font-size: 2.1rem;
  font-weight: 600;
  color: var(--navy);
  display: block;
  line-height: 1.1;
}
.on-navy .stat-number { color: var(--text-on-navy); }
.stat-label {
  font-size: 0.82rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-top: 0.35rem;
  display: block;
}
.on-navy .stat-label { color: var(--text-on-navy-secondary); }

/* ==========================================================================
   Cards
   ========================================================================== */
.grid {
  display: grid;
  gap: 1.75rem;
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.9rem;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}
.card:hover { border-color: var(--accent); box-shadow: var(--shadow-md); transform: translateY(-4px); }
.card h3 { font-size: 1.2rem; margin-bottom: 0.7rem; }
.card p { color: var(--text-tertiary); font-size: 0.94rem; line-height: 1.7; }
.card-link { text-decoration: none; display: block; }
.card-link:hover h3 { color: var(--accent-dark); }

.card-icon {
  width: 46px;
  height: 46px;
  border-radius: 10px;
  background: var(--accent-tint);
  color: var(--accent-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 1.2rem;
}

.badge {
  display: inline-block;
  padding: 0.32rem 0.75rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  border: 1px solid var(--border-strong);
  color: var(--text-secondary);
  background: var(--offwhite);
}
.badge-accent { background: var(--accent-tint); border-color: transparent; color: var(--accent-dark); }
.badge-navy { background: var(--navy); border-color: var(--navy); color: var(--text-on-navy); }

/* ==========================================================================
   Timeline (education / experience)
   ========================================================================== */
.timeline-item {
  padding: 1.6rem 0;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 1.5rem;
}
.timeline-item:last-child { border-bottom: 1px solid var(--border); }
.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-dark);
  font-weight: 600;
}
.timeline-item h4 { font-size: 1.08rem; margin-bottom: 0.3rem; }
.timeline-org { color: var(--text-secondary); font-size: 0.93rem; margin-bottom: 0.4rem; }
.timeline-role { color: var(--accent-dark); font-weight: 600; font-size: 0.88rem; margin-bottom: 0.4rem; }
.timeline-item p.desc { color: var(--text-tertiary); font-size: 0.92rem; }

/* ==========================================================================
   Company / venture rows
   ========================================================================== */
.entity-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.2rem;
  box-shadow: var(--shadow-sm);
}
.entity-card + .entity-card { margin-top: 1.5rem; }
.entity-head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 0.6rem; margin-bottom: 0.4rem; }
.entity-head h3 { font-size: 1.4rem; }
.entity-tag { font-size: 0.88rem; color: var(--accent-dark); font-weight: 600; }
.entity-card p.desc { color: var(--text-secondary); margin: 0.9rem 0 1.2rem; line-height: 1.75; }
.entity-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.5rem 1.5rem; }
.entity-list li { color: var(--text-tertiary); font-size: 0.9rem; padding-left: 1.1rem; position: relative; }
.entity-list li::before { content: '—'; position: absolute; left: 0; color: var(--accent); }

/* ==========================================================================
   Case study cards (index)
   ========================================================================== */
.case-card {
  display: grid;
  grid-template-columns: 90px 1fr auto;
  gap: 1.75rem;
  align-items: center;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}
.case-card + .case-card { margin-top: 1.5rem; }
.case-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.case-number {
  font-family: var(--font-serif);
  font-size: 3rem;
  color: var(--accent);
  opacity: 0.55;
  line-height: 1;
}
.case-card h3 { font-size: 1.3rem; margin-bottom: 0.5rem; }
.case-card p { color: var(--text-tertiary); font-size: 0.93rem; line-height: 1.7; }

/* ==========================================================================
   Book cards
   ========================================================================== */
.book-card {
  display: flex;
  gap: 1.75rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}
.book-card + .book-card { margin-top: 1.5rem; }
.book-spine {
  width: 8px;
  border-radius: 4px;
  background: var(--accent);
  flex-shrink: 0;
}
.book-card h3 { font-size: 1.25rem; margin-bottom: 0.3rem; }
.book-card .book-subtitle { font-family: var(--font-serif); font-style: italic; color: var(--text-secondary); margin-bottom: 0.9rem; }
.book-card p.desc { color: var(--text-tertiary); font-size: 0.93rem; line-height: 1.75; }

/* ==========================================================================
   Case-study page layout
   ========================================================================== */
.case-hero {
  background: var(--navy);
  color: var(--text-on-navy);
  padding: 4.5rem 0 3.5rem;
}
.case-hero .eyebrow { color: var(--accent); }
.case-hero h1 { color: var(--text-on-navy); font-size: 2.5rem; max-width: 20ch; margin-bottom: 1rem; }
.case-hero .lead { color: var(--text-on-navy-secondary); font-size: 1.1rem; max-width: 60ch; line-height: 1.75; }

.case-meta-panel {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(243,239,231,0.15);
  border-radius: var(--radius);
  padding: 1.6rem 1.8rem;
  margin-top: 2.5rem;
}
.case-meta-panel dt { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-on-navy-secondary); margin-bottom: 0.3rem; }
.case-meta-panel dd { font-size: 0.92rem; font-weight: 600; color: var(--text-on-navy); }

.stat-panel {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin: 2.5rem 0 1rem;
}
.stat-panel .stat-block {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.stat-panel .stat-block .num { font-family: var(--font-serif); font-size: 1.9rem; color: var(--accent-dark); font-weight: 600; display: block; }
.stat-panel .stat-block .lbl { font-size: 0.8rem; color: var(--text-tertiary); margin-top: 0.3rem; display: block; }

.case-body { max-width: 760px; }
.case-body h2 { font-size: 1.65rem; margin: 2.6rem 0 1rem; }
.case-body h2:first-child { margin-top: 0; }
.case-body h3 { font-size: 1.15rem; margin: 1.6rem 0 0.7rem; color: var(--accent-dark); }
.case-body p { color: var(--text-secondary); margin-bottom: 1rem; line-height: 1.8; }
.case-body ul { margin: 0 0 1.2rem; }
.case-body ul li {
  color: var(--text-secondary);
  padding-left: 1.3rem;
  position: relative;
  margin-bottom: 0.55rem;
  line-height: 1.65;
}
.case-body ul li::before { content: '—'; position: absolute; left: 0; color: var(--accent); }
.case-body ol { margin: 0 0 1.2rem 1.3rem; }
.case-body ol li { color: var(--text-secondary); margin-bottom: 0.55rem; line-height: 1.7; }

.pull-quote {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.3rem;
  line-height: 1.55;
  color: var(--navy);
  border-left: 3px solid var(--accent);
  padding: 0.3rem 0 0.3rem 1.5rem;
  margin: 2rem 0;
}

.visual-placeholder {
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius);
  background: #F4EFE5;
  padding: 2rem;
  text-align: center;
  color: var(--text-tertiary);
  font-size: 0.85rem;
  margin: 2rem 0;
  line-height: 1.6;
}
.visual-placeholder .vp-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-dark);
  display: block;
  margin-bottom: 0.5rem;
}

.closing-panel {
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 2rem;
  margin: 2.5rem 0;
}

/* ==========================================================================
   Contact
   ========================================================================== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; }
.contact-reasons { display: grid; gap: 0.9rem; }
.contact-reason {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1rem 1.2rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.contact-reason .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); flex-shrink: 0; }
.contact-card {
  background: var(--navy);
  color: var(--text-on-navy);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}
.contact-card a.email {
  display: block;
  color: var(--text-on-navy);
  text-decoration: none;
  font-weight: 600;
  padding: 0.9rem 0;
  border-bottom: 1px solid rgba(243,239,231,0.15);
}
.contact-card a.email:hover { color: var(--accent); }

/* ==========================================================================
   Footer
   ========================================================================== */
footer.site-footer {
  background: var(--navy);
  color: var(--text-on-navy-secondary);
  padding: 3.5rem 0 2.5rem;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 2.5rem; margin-bottom: 2.5rem; }
.footer-grid h5 { font-family: var(--font-sans); font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-on-navy); margin-bottom: 1rem; }
.footer-grid a { display: block; color: var(--text-on-navy-secondary); text-decoration: none; font-size: 0.9rem; margin-bottom: 0.65rem; }
.footer-grid a:hover { color: var(--accent); }
.footer-quote { font-family: var(--font-serif); font-style: italic; font-size: 1.05rem; color: var(--text-on-navy); max-width: 40ch; margin-bottom: 1rem; }
.footer-bottom { border-top: 1px solid rgba(243,239,231,0.12); padding-top: 1.5rem; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem; font-size: 0.82rem; }

/* ==========================================================================
   Breadcrumb
   ========================================================================== */
.breadcrumb { font-size: 0.85rem; color: var(--text-tertiary); margin-bottom: 1.5rem; }
.breadcrumb a { color: var(--text-tertiary); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent-dark); }
.breadcrumb .sep { margin: 0 0.4rem; opacity: 0.6; }

/* ==========================================================================
   404
   ========================================================================== */
.error-page { padding: 7rem 0; text-align: center; }
.error-page .error-code { font-family: var(--font-serif); font-size: 5rem; color: var(--accent); line-height: 1; margin-bottom: 1rem; }

/* ==========================================================================
   Reveal-on-scroll (lightweight; unobserved after trigger — see main.js)
   ========================================================================== */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-portrait { order: -1; max-width: 240px; margin: 0 auto; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stat-strip { grid-template-columns: repeat(2, 1fr); }
  .case-meta-panel { grid-template-columns: repeat(2, 1fr); }
  .stat-panel { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav-links { position: fixed; top: var(--header-h); left: 0; right: 0; background: var(--offwhite); flex-direction: column; align-items: flex-start; padding: 1.5rem 1.75rem; border-bottom: 1px solid var(--border); gap: 1.1rem; transform: translateY(-8px); opacity: 0; pointer-events: none; transition: opacity 0.2s ease, transform 0.2s ease; }
  .nav-links.open { opacity: 1; transform: translateY(0); pointer-events: auto; }
  .nav-toggle { display: block; }
  .hero h1 { font-size: 2.2rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .entity-list { grid-template-columns: 1fr; }
  .case-card { grid-template-columns: 1fr; text-align: left; }
  .case-meta-panel, .stat-panel { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .book-card { flex-direction: column; }
  .timeline-item { grid-template-columns: 1fr; gap: 0.4rem; }
}