/* Ego-Exo4D-HM project site — shared stylesheet */

:root {
  --bg: #fafafa;
  --bg-alt: #f0f1f5;
  --text: #1b1e2b;
  --text-dim: #565a6e;
  --border: #e2e3ea;
  --accent: #3454d1;
  --accent-dark: #23388f;
  --card-bg: #ffffff;
  --code-bg: #14162a;
  --code-text: #e8e9f3;
  --hero-bg: #0b0d19;
  --max-width: 1080px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img, video {
  max-width: 100%;
}

h1, h2, h3, h4 {
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.65rem;
  margin-top: 0;
}

h3 {
  font-size: 1.2rem;
}

code, pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.88em;
}

code {
  background: var(--bg-alt);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  overflow-x: auto;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
}

/* --- Nav --- */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.5rem;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 1.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--text-dim);
  font-size: 0.94rem;
  font-weight: 500;
}

.nav-links a.active,
.nav-links a:hover {
  color: var(--accent);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text);
}

@media (max-width: 720px) {
  .nav-toggle {
    display: block;
  }
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 1.5rem 1rem;
    gap: 0.7rem;
    display: none;
  }
  .nav-links.open {
    display: flex;
  }
}

/* --- Hero / collage --- */

.hero {
  position: relative;
  background: var(--hero-bg);
  color: #fff;
  overflow: hidden;
}

.collage-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 2px;
  width: 100%;
  line-height: 0;
}

.collage-grid video {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  display: block;
  filter: brightness(0.9) saturate(0.95);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
  background: linear-gradient(180deg, rgba(6, 7, 15, 0.15) 0%, rgba(6, 7, 15, 0.45) 100%);
}

.hero-overlay h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  margin: 0 0 0.7rem;
  color: #fff;
  text-shadow: 0 2px 12px rgba(6, 7, 15, 0.9), 0 0 4px rgba(6, 7, 15, 0.8);
}

.hero-overlay p {
  max-width: 640px;
  color: #eceef6;
  font-size: 1.05rem;
  margin: 0 0 1.2rem;
  text-shadow: 0 1px 8px rgba(6, 7, 15, 0.9), 0 0 3px rgba(6, 7, 15, 0.8);
}

.hero-cta {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  justify-content: center;
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.3rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.92rem;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dark);
  text-decoration: none;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.35);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  text-decoration: none;
}

/* --- Layout --- */

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.page-header {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem 1rem;
}

.page-header p.lead {
  color: var(--text-dim);
  font-size: 1.05rem;
  max-width: 700px;
}

section {
  padding: 2.6rem 0;
  border-top: 1px solid var(--border);
}

section:first-of-type {
  border-top: none;
}

.doc-page section:first-of-type {
  border-top: 1px solid var(--border);
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1rem;
}

.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.3rem;
  text-align: center;
}

.stat-card .num {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--accent);
  display: block;
}

.stat-card .label {
  color: var(--text-dim);
  font-size: 0.86rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
}

th, td {
  text-align: left;
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  color: var(--text-dim);
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.table-wrap {
  overflow-x: auto;
}

/* --- Interactive viewer --- */

.viewer-layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 1.6rem;
  align-items: start;
}

@media (max-width: 800px) {
  .viewer-layout {
    grid-template-columns: 1fr;
  }
}

.activity-tree {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--card-bg);
}

.activity-tree details {
  border-bottom: 1px solid var(--border);
}

.activity-tree details:last-child {
  border-bottom: none;
}

.activity-tree summary {
  cursor: pointer;
  padding: 0.75rem 1rem;
  font-weight: 600;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.activity-tree summary::-webkit-details-marker {
  display: none;
}

.activity-tree summary::after {
  content: "+";
  color: var(--text-dim);
  font-weight: 400;
}

.activity-tree details[open] summary::after {
  content: "\2212";
}

.place-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0.5rem;
}

.place-list li button {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 0.45rem 1.5rem;
  font-size: 0.92rem;
  color: var(--text-dim);
  cursor: pointer;
}

.place-list li button:hover {
  color: var(--accent);
}

.place-list li button.active {
  color: var(--accent);
  font-weight: 700;
}

.viewer-stage {
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
}

.viewer-stage video {
  width: 100%;
  display: block;
}

.viewer-caption {
  margin-top: 0.6rem;
  color: var(--text-dim);
  font-size: 0.9rem;
}

/* --- Footer --- */

footer {
  border-top: 1px solid var(--border);
  margin-top: 2rem;
  padding: 2.2rem 1.5rem 3rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  color: var(--text-dim);
  font-size: 0.88rem;
}

.footer-inner a {
  color: var(--text-dim);
  text-decoration: underline;
}

ul.tight li, ol.tight li {
  margin-bottom: 0.35rem;
}