/* Shared styles for subpages (Leadership, Invited Talks, Links) — matches index.html / certifications.html */
:root {
  --orange: #E87C2A; --orange-hover: #D06D1F; --orange-subtle: rgba(232,124,42,0.07);
  --blue: #1B6FA8; --blue-light: #E9F2F9; --blue-subtle: rgba(27,111,168,0.07);
  --white: #FFFFFF; --off-white: #FAFAFA;
  --black: #111111; --dark-card: #1A1A1A; --dark-border: rgba(255,255,255,0.08);
  --dark-text: #FFFFFF; --dark-muted: rgba(255,255,255,0.55);
  --text-primary: #1A1A1A; --text-body: #3D3D3D; --text-muted: #777777; --text-light: #AAAAAA;
  --border: #EBEBEB;
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Nunito Sans', sans-serif; font-size: 17px; line-height: 1.75;
  background: var(--white); color: var(--text-body); -webkit-font-smoothing: antialiased;
}
.container { max-width: 1140px; margin: 0 auto; padding: 0 48px; }
.section-label {
  font-family: 'IBM Plex Mono', monospace; font-size: 13px; font-weight: 500;
  letter-spacing: 3px; text-transform: uppercase; color: var(--orange);
  margin-bottom: 14px; display: inline-flex; align-items: center; gap: 10px;
}
.section-label .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--orange); }
.section-label.blue { color: var(--blue); }
.section-label.blue .dot { background: var(--blue); }
h1.section-heading, h2.section-heading {
  font-family: 'DM Serif Display', serif; font-size: clamp(32px, 4vw, 50px);
  font-weight: 400; line-height: 1.15; color: var(--text-primary); margin-bottom: 18px;
}
h2.section-heading.sm { font-size: clamp(26px, 3vw, 36px); }
.section-desc { font-size: 17px; line-height: 1.75; color: var(--text-muted); max-width: 700px; }

/* NAV */
nav {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; height: 68px;
  display: flex; align-items: center; justify-content: space-between; padding: 0 48px;
  background: rgba(255,255,255,0.92); backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border); transition: box-shadow 0.3s;
}
nav.scrolled { box-shadow: 0 1px 20px rgba(0,0,0,0.05); }
.nav-logo { font-family: 'DM Serif Display', serif; font-size: 22px; color: var(--text-primary); text-decoration: none; }
.nav-logo span { color: var(--orange); }
.nav-menu { display: flex; gap: 28px; list-style: none; align-items: center; }
.nav-menu a { font-size: 14px; font-weight: 600; color: var(--text-muted); text-decoration: none; transition: color 0.25s; }
.nav-menu a:hover { color: var(--text-primary); }
.nav-menu a.active { color: var(--orange); }
.nav-menu .nav-cta { background: var(--orange); color: var(--white); padding: 10px 22px; border-radius: 8px; font-weight: 700; }
.nav-menu .nav-cta:hover { background: var(--orange-hover); color: var(--white); }
.mobile-toggle { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.mobile-toggle span { display: block; width: 22px; height: 2px; background: var(--text-primary); margin: 5px 0; border-radius: 1px; }

/* PAGE HERO */
.page-hero { padding: 130px 0 60px; background: var(--off-white); border-bottom: 1px solid var(--border); }
.breadcrumb { font-family: 'IBM Plex Mono', monospace; font-size: 12px; color: var(--text-light); margin-bottom: 16px; }
.breadcrumb a { color: var(--blue); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }

/* SECTIONS */
.page-section { padding: 80px 0; }
.page-section.alt { background: var(--off-white); }
.page-section.dark { background: var(--black); color: var(--dark-text); }
.page-section.dark .section-heading { color: var(--dark-text); }
.section-header { margin-bottom: 40px; }

/* TIMELINE */
.timeline { position: relative; }
.timeline::before { content: ''; position: absolute; left: 23px; top: 0; bottom: 0; width: 2px; background: var(--border); }
.tl-item { display: flex; gap: 28px; padding: 18px 0; position: relative; align-items: flex-start; }
.tl-icon {
  width: 48px; height: 48px; min-width: 48px; border-radius: 50%; z-index: 2;
  display: flex; align-items: center; justify-content: center; font-size: 17px;
  background: #FDF1E7; color: var(--orange); box-shadow: 0 0 0 4px var(--white);
  transition: background 0.25s, color 0.25s;
}
.tl-icon.blue { background: var(--blue-light); color: var(--blue); }
.page-section.alt .tl-icon { box-shadow: 0 0 0 4px var(--off-white); }
.tl-item:hover .tl-icon { background: var(--orange); color: var(--white); }
.tl-body { flex: 1; }
.tl-year { font-family: 'IBM Plex Mono', monospace; font-size: 12px; color: var(--blue); font-weight: 500; letter-spacing: 0.5px; }
.tl-role { font-weight: 800; font-size: 16px; color: var(--text-primary); }
.tl-role a { color: var(--orange); text-decoration: none; }
.tl-role a:hover { text-decoration: underline; }
.tl-org { font-size: 15px; color: var(--text-muted); }

/* CARDS */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }
.card {
  display: flex; gap: 18px; padding: 24px; background: var(--white);
  border: 1px solid var(--border); border-radius: 14px; align-items: flex-start;
  text-decoration: none; color: inherit;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}
.card:hover { transform: translateY(-2px); box-shadow: 0 6px 24px rgba(0,0,0,0.05); border-color: var(--orange); }
.page-section.dark .card { background: var(--dark-card); border-color: var(--dark-border); }
.page-section.dark .card:hover { border-color: rgba(232,124,42,0.4); box-shadow: none; }
.card-icon {
  width: 44px; height: 44px; min-width: 44px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center; font-size: 18px;
  background: var(--orange-subtle); color: var(--orange);
}
.card-icon.blue { background: var(--blue-subtle); color: var(--blue); }
.page-section.dark .card-icon { background: rgba(232,124,42,0.1); }
.card-body { flex: 1; }
.card-meta { font-family: 'IBM Plex Mono', monospace; font-size: 11px; color: var(--orange); letter-spacing: 0.5px; font-weight: 500; text-transform: uppercase; }
.card-title { font-weight: 800; font-size: 16px; color: var(--text-primary); margin: 4px 0 4px; line-height: 1.4; }
.page-section.dark .card-title { color: var(--dark-text); }
.card-text { font-size: 14px; color: var(--text-muted); line-height: 1.6; }
.page-section.dark .card-text { color: var(--dark-muted); }
.card-link { display: inline-flex; align-items: center; gap: 6px; margin-top: 10px; font-size: 13px; font-weight: 700; color: var(--orange); transition: gap 0.25s; }
.card:hover .card-link { gap: 10px; }

/* BACK TO TOP */
.back-top { display: flex; justify-content: center; padding: 40px 0 0; }
.back-top a { font-size: 13px; font-weight: 700; color: var(--orange); text-decoration: none; display: inline-flex; align-items: center; gap: 6px; }

/* FOOTER */
footer { padding: 28px 48px; text-align: center; background: var(--white); border-top: 1px solid var(--border); }
footer p { font-size: 13px; color: var(--text-light); }

/* ANIMATIONS */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.65s ease, transform 0.65s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 768px) {
  .container { padding: 0 24px; }
  nav { padding: 0 24px; }
  .nav-menu {
    display: none; position: absolute; top: 68px; left: 0; right: 0;
    background: rgba(255,255,255,0.97); backdrop-filter: blur(16px);
    flex-direction: column; padding: 20px 24px; gap: 14px; border-bottom: 1px solid var(--border);
  }
  .nav-menu.open { display: flex; }
  .mobile-toggle { display: block; }
  .card-grid { grid-template-columns: 1fr; }
  .tl-item { gap: 18px; }
}