:root {
  --bg: #fff;
  --fg: #111;
  --muted: #777;
  --line: #e6e6e6;
  --radius: 18px;
  --maxw: 1150px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%;
}

body {
  background: var(--bg);
  color: var(--fg);
  font: 400 16px/1.6 ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial;
  letter-spacing: .2px;
}

a {
  color: inherit;
  text-underline-offset: 2px;
}

/* Hero */
header.hero {
  height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
  border-bottom: 1px solid var(--line);
  padding: 32px;
  overflow: hidden;
}

.hero-inner {
  opacity: 0;
  animation: fadeIn 2s ease forwards;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-title {
  margin: 18px 0 40px;
  font-weight: 300;
  letter-spacing: -.01em;
  font-size: clamp(48px, 8vw, 88px);
  line-height: 1.1;
}

.tagline {
  color: var(--fg);
  opacity: .9;
  font-size: clamp(16px, 2vw, 22px);
}

.lede {
  color: var(--muted);
  max-width: 780px;
  margin: 14px auto 0;
}

/* Layout */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 56px 24px;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 16px;
  margin-bottom: 18px;
}

.section-head h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: .6px;
}

.section-head .rule {
  flex: 1;
  height: 1px;
  background: var(--line);
}

.section-desc {
  color: var(--muted);
  max-width: 850px;
  margin: 8px 0 22px;
}

/* Problems */
.problems-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(3, 1fr);
  justify-items: center;
}

.pill {
  border: 1px solid var(--fg);
  border-radius: 12px;
  padding: 50px 24px;
  text-align: center;
  font-size: 18px;
  font-weight: 400;
  min-height: 160px;
  width: 100%;
  max-width: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.problems-grid::after {
  content: '';
  grid-column: 2;
  justify-self: center;
  width: 0;
  height: 0;
}

/* Tooling */
.tools {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.tool {
  border: 1px solid var(--fg);
  border-radius: var(--radius);
  padding: 24px;
  display: grid;
  gap: 10px;
}

.tool h3 {
  font-weight: 500;
  letter-spacing: .4px;
  font-size: 20px;
}

.tool p {
  color: var(--muted);
}

/* Research */
.research-list {
  display: grid;
  gap: 16px;
}

.paper {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 24px;
  display: grid;
  gap: 6px;
}

.paper h4 {
  font-weight: 500;
  font-size: 17px;
}

.paper .meta {
  color: var(--muted);
  font-size: 14px;
}

.paper a.btn {
  justify-self: start;
  border: 1px solid var(--fg);
  padding: 6px 12px;
  border-radius: 999px;
  text-decoration: none;
}

.paper a.btn:hover {
  background: var(--fg);
  color: #fff;
}

/* Simple Page Header */
.page-header {
  border-bottom: 1px solid var(--line);
  padding: 32px 24px;
}

.page-header .wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0;
}

.page-header h1 {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: .4px;
}

/* Blog Entry (compact) */
.blog-entry {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
  display: grid;
  gap: 4px;
  text-decoration: none;
  color: inherit;
  transition: background .2s;
}

.blog-entry:hover {
  background: #fafafa;
}

.blog-entry h4 {
  font-weight: 500;
  font-size: 16px;
  margin: 0;
}

.blog-entry .meta {
  color: var(--muted);
  font-size: 13px;
}

.blog-entry p {
  color: var(--muted);
  margin: 4px 0 0;
  font-size: 14px;
  line-height: 1.5;
}

/* Footer */
footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
}

footer .wrap {
  padding: 28px 24px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  align-items: center;
}

nav.inline a {
  text-decoration: none;
  margin-right: 14px;
}