:root {
  color-scheme: light;
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --text: #111827;
  --muted: #4b5563;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --border: #e5e7eb;
}

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

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0.5rem;
  gap: 1.5rem;
}

.site-title h1 {
  font-size: 1.5rem;
  margin: 0;
}

.tagline {
  margin: 0.1rem 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.site-nav {
  display: flex;
  gap: 1rem;
  font-size: 0.95rem;
}

.site-nav a {
  text-decoration: none;
  color: var(--muted);
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
}

main {
  padding: 1.5rem 0 3rem;
}

.section {
  padding: 2rem 0;
}

h2 {
  font-size: 1.4rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin: 0 0 1rem;
}

p {
  margin: 0.4rem 0 0.75rem;
  color: var(--muted);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1.2rem;
  border-radius: 999px;
  border: 1px solid var(--accent);
  background-color: var(--accent);
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  margin-top: 0.25rem;
  box-shadow: 0 8px 16px rgba(37, 99, 235, 0.18);
  transition: background-color 0.18s ease, border-color 0.18s ease,
    box-shadow 0.18s ease, transform 0.18s ease;
}

.button:hover,
.button:focus-visible {
  background-color: #1d4ed8;
  border-color: #1d4ed8;
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.28);
  transform: translateY(-1px);
}

.contact-list {
  list-style: none;
  padding-left: 0;
  margin: 0.8rem 0 0;
}

.contact-list li + li {
  margin-top: 0.25rem;
}

.contact-list span {
  color: var(--muted);
}

/* Section cards */
.section .container {
  background-color: #ffffff;
  border-radius: 1rem;
  padding: 1.4rem 1.35rem 1.6rem;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  border: 1px solid rgba(148, 163, 184, 0.25);
}

.section + .section .container {
  margin-top: 1rem;
}

.section .container p:last-child {
  margin-bottom: 0;
}

/* Inline links */
a {
  color: var(--accent);
}

a:hover,
a:focus-visible {
  text-decoration: underline;
}

/* About layout with headshot */
.about-layout {
  display: flex;
  align-items: flex-start;
  gap: 1.75rem;
}

.about-photo {
  flex: 0 0 auto;
}

.about-headshot {
  display: block;
  max-width: 160px;
  width: 100%;
  height: auto;
  border-radius: 999px;
  border: 2px solid rgba(148, 163, 184, 0.6);
}

.about-text {
  flex: 1 1 0;
}

/* Conferences section */
.conferences-block {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
}

.conferences-column {
  flex: 1 1 240px;
}

.conferences-subheading {
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

.conferences-list {
  list-style: none;
  margin: 0;
  padding-left: 0;
}

.conferences-list li + li {
  margin-top: 0.4rem;
}

.conference-name {
  font-weight: 600;
}

.conference-title {
  font-style: italic;
}

.conference-date {
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--border);
  background-color: var(--bg-alt);
  padding: 1.25rem 0;
  font-size: 0.85rem;
  color: var(--muted);
}

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-nav {
    width: 100%;
  }

  .about-layout {
    flex-direction: column;
    align-items: flex-start;
  }
}