/* ============================================================
   ENVISION LAB — design tokens + component styles
   Brand accent derived from logo: deep indigo #132F80
   ============================================================ */

:root,
[data-theme='light'] {
  /* Surfaces — cool, quiet neutral so the indigo accent carries weight */
  --color-bg: #f9f9fb;
  --color-surface: #ffffff;
  --color-surface-2: #f2f2f7;
  --color-surface-offset: #eef0f8;
  --color-surface-offset-2: #e3e6f3;
  --color-divider: #e2e2ea;
  --color-border: #d7d8e2;

  /* Text */
  --color-text: #16171f;
  --color-text-muted: #5b5d6b;
  --color-text-faint: #9799a8;
  --color-text-inverse: #f9f9fb;

  /* Primary accent — Envision Indigo */
  --color-primary: #132f80;
  --color-primary-hover: #0d2159;
  --color-primary-active: #0a1a45;
  --color-primary-highlight: #dde2f5;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;

  /* Motion */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Shadows — cool-tinted to match surfaces */
  --shadow-sm: 0 1px 2px oklch(0.25 0.03 265 / 0.07);
  --shadow-md: 0 6px 20px oklch(0.25 0.03 265 / 0.09);
  --shadow-lg: 0 20px 48px oklch(0.25 0.03 265 / 0.14);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 1040px;
  --content-wide: 1200px;
  --content-full: 100%;

  --font-display: 'DM Sans', 'Segoe UI', sans-serif;
  --font-body: 'Inter', 'Segoe UI', sans-serif;
}

[data-theme='dark'] {
  --color-bg: #0d0e14;
  --color-surface: #14151d;
  --color-surface-2: #191b25;
  --color-surface-offset: #1a1e33;
  --color-surface-offset-2: #212642;
  --color-divider: #262838;
  --color-border: #30323f;

  --color-text: #e7e7ee;
  --color-text-muted: #9c9eac;
  --color-text-faint: #62636f;
  --color-text-inverse: #14151d;

  --color-primary: #7f92dd;
  --color-primary-hover: #a0b0e8;
  --color-primary-active: #b9c5ef;
  --color-primary-highlight: #26305a;

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.35);
  --shadow-md: 0 6px 20px oklch(0 0 0 / 0.4);
  --shadow-lg: 0 20px 48px oklch(0 0 0 / 0.5);
}

/* Type scale — fluid clamp() */
:root {
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.125rem);
  --text-2xl: clamp(2rem, 1.3rem + 2.2vw, 3.25rem);
  --text-hero: clamp(2.5rem, 1.4rem + 3.4vw, 4.5rem);
}

/* Spacing — 4px system */
:root {
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;
}

/* ============================================================
   Base type
   ============================================================ */

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
}

p {
  max-width: 62ch;
}

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

/* ============================================================
   Layout primitives
   ============================================================ */

.container {
  max-width: var(--content-default);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.container--wide {
  max-width: var(--content-wide);
}

section {
  padding-block: clamp(var(--space-16), 9vw, var(--space-24));
}

/* ============================================================
   Header / Nav
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: oklch(from var(--color-bg) l c h / 0.86);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid oklch(from var(--color-text) l c h / 0.08);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
}

.brand img {
  height: 2rem;
  width: auto;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-links a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
}
.nav-links a:hover {
  color: var(--color-text);
}

.nav-links-cta {
  display: none;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
}
.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

.nav-toggle {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  place-items: center;
  color: var(--color-text);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  color: var(--color-text-inverse);
}

.btn-ghost {
  color: var(--color-text);
  border: 1px solid oklch(from var(--color-text) l c h / 0.18);
}
.btn-ghost:hover {
  border-color: oklch(from var(--color-text) l c h / 0.32);
  background: var(--color-surface-2);
}

/* ============================================================
   Hero
   ============================================================ */

.hero {
  padding-block: clamp(var(--space-20), 12vw, var(--space-32)) clamp(var(--space-16), 8vw, var(--space-20));
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 82% -10%, oklch(from var(--color-primary) l c h / 0.14), transparent 70%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  display: grid;
  gap: var(--space-10);
  max-width: 780px;
}

.hero h1 {
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: 1.06;
}

.hero h1 em {
  font-style: normal;
  color: var(--color-primary);
}

.hero-lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 56ch;
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.hero-meta {
  display: flex;
  gap: var(--space-8);
  padding-top: var(--space-10);
  border-top: 1px solid var(--color-divider);
  flex-wrap: wrap;
}

.hero-meta-item {
  display: grid;
  gap: var(--space-1);
}

.hero-meta-value {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  color: var(--color-text);
}

.hero-meta-label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ============================================================
   Section headings
   ============================================================ */

.section-head {
  display: grid;
  gap: var(--space-4);
  max-width: 640px;
  margin-bottom: var(--space-12);
}

.section-head h2 {
  font-size: var(--text-xl);
  font-weight: 700;
}

.section-head p {
  color: var(--color-text-muted);
}

/* ============================================================
   Mission
   ============================================================ */

.mission {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: var(--space-16);
  align-items: start;
}

.mission-label {
  display: grid;
  gap: var(--space-3);
  align-content: start;
}

.mission-label h2 {
  font-size: var(--text-xl);
}

.mission-copy p {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-text);
}

.mission-copy p + p {
  margin-top: var(--space-5);
  color: var(--color-text-muted);
  font-size: var(--text-base);
}

/* ============================================================
   Research focus — asymmetric bento, not a uniform 3-col grid
   ============================================================ */

.research-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  grid-template-rows: auto auto;
  gap: var(--space-5);
}

.research-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  display: grid;
  align-content: start;
  gap: var(--space-4);
}

.research-card--feature {
  grid-row: span 2;
  padding: var(--space-10);
  background: linear-gradient(180deg, var(--color-surface), var(--color-surface-2));
}

.research-index {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text-faint);
}

.research-card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
}

.research-card--feature h3 {
  font-size: var(--text-xl);
}

.research-card p {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  line-height: 1.55;
}

.research-tag {
  justify-self: start;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-primary);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-primary-highlight);
  margin-top: var(--space-2);
}

/* ============================================================
   Approach & Methods
   ============================================================ */

.approach {
  display: grid;
  grid-template-columns: 1fr 0.85fr;
  gap: var(--space-16);
  align-items: center;
}

.approach-copy h2 {
  font-size: var(--text-xl);
  margin-bottom: var(--space-5);
}

.approach-copy p {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  line-height: 1.6;
}

.method-list {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-8);
}

.method-list li {
  display: flex;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
  align-items: baseline;
}

.method-list li::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  flex-shrink: 0;
  transform: translateY(-2px);
}

.diagram-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
}

.diagram-caption {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-align: center;
}

/* ============================================================
   Director
   ============================================================ */

.director {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: var(--space-16);
  align-items: start;
}

.director-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-10);
  display: grid;
  gap: var(--space-1);
  align-content: start;
}

.director-mark {
  width: 3rem;
  margin-bottom: var(--space-6);
  opacity: 0.9;
}

.director-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
}

.director-role {
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-weight: 600;
}

.director-affiliation {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

.director-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-6);
}

.director-tags span {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-3);
}

.director-bio p {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-text);
}

.director-bio p + p {
  margin-top: var(--space-5);
  font-size: var(--text-base);
  color: var(--color-text-muted);
}

/* ============================================================
   Join the lab / footer
   ============================================================ */

.join {
  background: var(--color-surface-offset);
  border-top: 1px solid var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}

.join-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: start;
}

.join h2 {
  font-size: var(--text-xl);
}

.join-lede {
  color: var(--color-text-muted);
  margin-top: var(--space-4);
}

.join-list {
  display: grid;
  gap: var(--space-5);
}

.join-list li {
  display: grid;
  gap: var(--space-1);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--color-divider);
}

.join-list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.join-role {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
}

.join-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.join-contact {
  margin-top: var(--space-10);
  display: grid;
  gap: var(--space-2);
}

.join-contact a {
  font-weight: 600;
}

.join-contact-note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.site-footer {
  padding-block: var(--space-10);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
}

.footer-brand img {
  height: 1.25rem;
  opacity: 0.85;
}

.footer-links {
  display: flex;
  gap: var(--space-6);
}

.footer-links a {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.footer-links a:hover {
  color: var(--color-text-muted);
}

/* ============================================================
   Scroll reveal
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition:
    opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 900px) {
  .mission,
  .approach,
  .director,
  .join-inner {
    grid-template-columns: 1fr;
    gap: var(--space-10);
  }

  .approach-copy {
    order: 1;
  }
  .diagram-panel {
    order: 2;
  }

  .research-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }
  .research-card--feature {
    grid-row: auto;
  }
}

@media (max-width: 720px) {
  .nav-links {
    position: fixed;
    inset: 4.25rem var(--space-4) auto var(--space-4);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-1);
    padding: var(--space-3);
    display: none;
  }
  .nav-links.is-open {
    display: flex;
  }
  .nav-links a {
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-md);
    color: var(--color-text);
  }
  .nav-links a:hover {
    background: var(--color-surface-2);
  }
  .nav-links-cta {
    display: block;
    margin-top: var(--space-1);
    color: var(--color-primary);
    font-weight: 700;
  }
  .nav-toggle {
    display: grid;
  }
  .nav-actions .btn-primary {
    display: none;
  }
  .hero-meta {
    gap: var(--space-6);
  }
}

@media (max-width: 400px) {
  .brand-name {
    font-size: var(--text-xs);
  }
}

@media (max-width: 560px) {
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-actions .btn {
    justify-content: center;
  }
}