/* Tachyon Resilient Modeling — shared stylesheet
 * Self-contained, dependency-free. Works for static S3 hosting.
 */

:root {
  --bg: #0d1117;
  --bg-alt: #131a24;
  --panel: #161d29;
  --border: #26303d;
  --text: #e6edf3;
  --text-muted: #9aa7b6;
  --accent: #4cc9f0;
  --accent-2: #7b8cff;
  --accent-glow: rgba(76, 201, 240, 0.25);
  --max-width: 1080px;
  --radius: 10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  color: var(--text);
  font-size: 1.05rem;
  letter-spacing: 0.2px;
}
.brand:hover {
  text-decoration: none;
}
.brand .logo {
  width: 30px;
  height: 30px;
  display: inline-block;
  filter: drop-shadow(0 0 6px var(--accent-glow));
}
.nav-links {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  color: var(--text-muted);
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
  font-size: 0.92rem;
  transition: background 0.15s, color 0.15s;
}
.nav-links a:hover {
  color: var(--text);
  background: var(--panel);
  text-decoration: none;
}
.nav-links a.active {
  color: var(--accent);
  background: var(--panel);
}
.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 0.35rem 0.55rem;
  cursor: pointer;
  font-size: 1.1rem;
}

/* ---------- Layout ---------- */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}
.section {
  margin-bottom: 3rem;
}
.section h2 {
  font-size: 1.6rem;
  margin: 0 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.lead {
  font-size: 1.12rem;
  color: var(--text-muted);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(900px 400px at 80% -10%, rgba(123, 140, 255, 0.15), transparent),
    radial-gradient(700px 350px at 10% 10%, rgba(76, 201, 240, 0.12), transparent);
}
.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4.5rem 1.25rem 3.5rem;
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.1;
  margin: 0 0 1rem;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero p {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 680px;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.75rem;
}
.btn-row {
  margin-top: 1.75rem;
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  transition: transform 0.12s, box-shadow 0.12s;
}
.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}
.btn-primary {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #06131c;
  border-color: transparent;
  box-shadow: 0 4px 18px var(--accent-glow);
}
.btn-ghost {
  color: var(--text);
  background: var(--panel);
}

/* ---------- Cards ---------- */
.grid {
  display: grid;
  gap: 1.25rem;
}
.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  transition: border-color 0.15s, transform 0.15s;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
}
.card .icon {
  font-size: 1.6rem;
  margin-bottom: 0.6rem;
}
.card p {
  color: var(--text-muted);
  margin: 0.25rem 0 0;
  font-size: 0.96rem;
}

/* ---------- People ---------- */
.person {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.avatar {
  flex: 0 0 auto;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #06131c;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.3rem;
}
.person .role {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.person .affil {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ---------- Publications ---------- */
.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.pub {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.1rem 1.3rem;
  margin-bottom: 1rem;
}
.pub .title {
  font-weight: 600;
  font-size: 1.05rem;
}
.pub .authors {
  color: var(--text-muted);
  font-size: 0.92rem;
}
.pub .venue {
  font-style: italic;
  color: var(--text-muted);
  font-size: 0.92rem;
}
.pub .tags {
  margin-top: 0.5rem;
}
.tag {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.1rem 0.6rem;
  margin-right: 0.35rem;
}
.year-badge {
  float: right;
  font-family: var(--mono);
  color: var(--accent-2);
  font-size: 0.9rem;
}

/* ---------- Resource / tools list ---------- */
.resource {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.resource .kind {
  font-family: var(--mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: #06131c;
  background: var(--accent);
  border-radius: 5px;
  padding: 0.15rem 0.5rem;
  white-space: nowrap;
  margin-top: 0.2rem;
}
.resource .kind.data {
  background: var(--accent-2);
}
.resource .kind.code {
  background: #57d38c;
}

/* ---------- Tables ---------- */
.table-wrap {
  overflow-x: auto;
}
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.94rem;
}
th,
td {
  text-align: left;
  padding: 0.6rem 0.8rem;
  border-bottom: 1px solid var(--border);
}
th {
  color: var(--text-muted);
  font-weight: 600;
}
code {
  font-family: var(--mono);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.1rem 0.4rem;
  font-size: 0.88em;
}

/* ---------- Callout ---------- */
.note {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-2);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.94rem;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.footer-inner a {
  color: var(--text-muted);
}
.footer-inner a:hover {
  color: var(--accent);
}

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .nav-toggle {
    display: inline-block;
  }
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
  }
  .nav-links.open {
    display: flex;
  }
  .nav {
    flex-wrap: wrap;
  }
}