/* Zukumba Enterprise — Tesla-inspired design system */
:root {
  --black: #171a20;
  --white: #ffffff;
  --gray-100: #f4f4f4;
  --gray-200: #e8e8e8;
  --gray-400: #8e8e8e;
  --gray-600: #5c5e62;
  --accent: #3e6ae1;
  --nav-height: 56px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --section-pad: clamp(4rem, 10vw, 7rem);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.5;
  color: var(--black);
  background: var(--white);
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: opacity 0.2s var(--ease);
}

a:hover { opacity: 0.65; }

img { max-width: 100%; display: block; }

/* —— Navigation —— */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.35s var(--ease), backdrop-filter 0.35s var(--ease);
}

.site-header.is-scrolled,
.site-header.is-solid {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--gray-200);
}

.site-header.is-dark-top:not(.is-scrolled):not(.is-solid) .nav-link,
.site-header.is-dark-top:not(.is-scrolled):not(.is-solid) .nav-logo {
  color: var(--white);
}

.nav-inner {
  width: 100%;
  max-width: 1400px;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
}

.nav-logo {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  justify-self: start;
}

.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
  justify-self: center;
}

.nav-link {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: capitalize;
  padding: 4px 0;
  position: relative;
}

.nav-link.is-active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: currentColor;
}

.nav-actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: inherit;
}

.nav-menu-btn span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  margin: 4px 0;
  transition: transform 0.3s var(--ease);
}

.mobile-drawer {
  display: none;
  position: fixed;
  inset: 0;
  top: var(--nav-height);
  background: var(--white);
  z-index: 999;
  padding: 24px;
  flex-direction: column;
  gap: 8px;
  overflow-y: auto;
}

.mobile-drawer.is-open { display: flex; }

.mobile-drawer .nav-link {
  font-size: 18px;
  padding: 12px 0;
  border-bottom: 1px solid var(--gray-200);
}

/* —— Hero —— */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 2rem) 24px 4rem;
  background: var(--black);
  color: var(--white);
  position: relative;
}

.hero--short {
  min-height: 55vh;
}

.hero__eyebrow {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: 1rem;
}

.hero__title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.1;
  max-width: 14ch;
  margin-bottom: 1.25rem;
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  font-weight: 400;
  color: var(--gray-400);
  max-width: 36rem;
  line-height: 1.6;
  margin-bottom: 2rem;
}

.hero__cta {
  display: inline-flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 200px;
  padding: 12px 24px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 4px;
  border: 3px solid transparent;
  cursor: pointer;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.btn--primary {
  background: var(--accent);
  color: var(--white);
  border-color: var(--white);
}

.btn--primary:hover {
  background: #3459c4;
  opacity: 1;
}

.btn--outline {
  background: transparent;
  color: var(--white);
  border-color: var(--white);
}

.btn--outline:hover {
  background: var(--white);
  color: var(--black);
  opacity: 1;
}

.btn--dark {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.btn--dark:hover {
  background: #393c41;
  opacity: 1;
}

/* —— Sections —— */
.section {
  padding: var(--section-pad) 24px;
}

.section--gray { background: var(--gray-100); }
.section--dark {
  background: var(--black);
  color: var(--white);
}

.section__inner {
  max-width: 1200px;
  margin: 0 auto;
}

.section__label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gray-600);
  margin-bottom: 0.75rem;
}

.section--dark .section__label { color: var(--gray-400); }

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  line-height: 1.15;
}

.section__lead {
  font-size: 17px;
  color: var(--gray-600);
  max-width: 42rem;
  line-height: 1.65;
  margin-bottom: 3rem;
}

.section--dark .section__lead { color: var(--gray-400); }

/* —— Portfolio grid —— */
.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1px;
  background: var(--gray-200);
  border: 1px solid var(--gray-200);
}

.portfolio-card {
  background: var(--white);
  padding: 2rem 1.75rem;
  display: flex;
  flex-direction: column;
  min-height: 220px;
  transition: background 0.3s var(--ease);
}

.portfolio-card:hover {
  background: var(--gray-100);
  opacity: 1;
}

.portfolio-card__tag {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gray-600);
  margin-bottom: 0.75rem;
}

.portfolio-card__title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.portfolio-card__desc {
  font-size: 14px;
  color: var(--gray-600);
  flex: 1;
  line-height: 1.55;
  margin-bottom: 1.25rem;
}

.portfolio-card__link {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.portfolio-card__link:hover { opacity: 0.7; }

/* —— Content blocks —— */
.content-block {
  max-width: 720px;
  margin-bottom: 2.5rem;
}

.content-block h2 {
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.content-block p,
.content-block li {
  font-size: 15px;
  color: var(--gray-600);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.content-block ul {
  padding-left: 1.25rem;
  margin-bottom: 1rem;
}

.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 3rem;
  margin-top: 2rem;
}

.stat {
  text-align: center;
  padding: 2rem 1rem;
}

.stat__value {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  letter-spacing: -0.03em;
}

.stat__label {
  font-size: 12px;
  color: var(--gray-600);
  margin-top: 0.5rem;
  letter-spacing: 0.05em;
}

/* —— Personnel list —— */
.personnel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.personnel-card {
  border: 1px solid var(--gray-200);
  padding: 1.5rem;
  border-radius: 4px;
  transition: box-shadow 0.3s var(--ease);
}

.personnel-card:hover {
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
  opacity: 1;
}

.personnel-card__role {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.personnel-card__name {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.personnel-card__focus {
  font-size: 13px;
  color: var(--gray-600);
  line-height: 1.5;
}

/* —— Footer —— */
.site-footer {
  padding: 3rem 24px 2rem;
  background: var(--black);
  color: var(--gray-400);
  font-size: 12px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #393c41;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  list-style: none;
}

.footer-links a:hover { color: var(--white); opacity: 1; }

.footer-copy {
  max-width: 1200px;
  margin: 1.5rem auto 0;
  text-align: center;
}

/* —— Reveal animation —— */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* —— Page shell (inner pages) —— */
.page-main {
  padding-top: var(--nav-height);
}

/* —— Responsive —— */
@media (max-width: 900px) {
  .nav-links,
  .nav-actions .btn { display: none; }

  .nav-menu-btn { display: block; }

  .nav-inner {
    grid-template-columns: 1fr auto;
  }

  .nav-logo { justify-self: start; }
  .nav-actions { justify-self: end; }
}

/* —— Tech insights —— */
.tech-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tech-filter {
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 8px 16px;
  border: 1px solid var(--gray-200);
  background: var(--white);
  border-radius: 100px;
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.tech-filter:hover,
.tech-filter.is-active {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1px;
  background: var(--gray-200);
  border: 1px solid var(--gray-200);
}

.tech-card {
  background: var(--white);
  padding: 1.5rem 1.25rem;
  min-height: 140px;
  transition: background 0.25s var(--ease);
}

.tech-card:hover {
  background: var(--gray-100);
}

.tech-card__category {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 0.5rem;
}

.tech-card__term {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
  line-height: 1.25;
}

.tech-card__note {
  font-size: 13px;
  color: var(--gray-600);
  line-height: 1.55;
}

.tech-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 2rem;
}

.tech-chip {
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  padding: 6px 14px;
  background: var(--black);
  color: var(--white);
  border: none;
  border-radius: 100px;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

button.tech-chip:hover {
  transform: scale(1.05);
  opacity: 1;
}

.tech-chip--muted {
  background: var(--gray-100);
  color: var(--gray-600);
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.tech-card[data-tech-slug] {
  cursor: pointer;
}

.tech-card[data-tech-slug]:hover {
  background: var(--gray-100);
}

/* —— Research modal —— */
.research-modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s var(--ease);
}

.research-modal.is-open {
  pointer-events: auto;
  opacity: 1;
}

.research-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(23, 26, 32, 0.75);
  backdrop-filter: blur(4px);
}

.research-modal__panel {
  position: relative;
  background: var(--white);
  max-width: 520px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 2rem 1.75rem;
  border-radius: 8px;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.2);
}

.research-modal__close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
  color: var(--gray-600);
}

.research-modal__title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.research-modal__note {
  font-size: 14px;
  color: var(--gray-600);
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.researcher-row {
  padding: 1rem 0;
  border-top: 1px solid var(--gray-200);
}

.researcher-row h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.researcher-row__affil {
  font-size: 12px;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.researcher-row__role {
  font-size: 13px;
  color: var(--gray-600);
}

/* —— Research shell —— */
.shell-login label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.shell-login input {
  width: 100%;
  max-width: 320px;
  padding: 10px 12px;
  border: 1px solid var(--gray-200);
  font-family: var(--font);
  font-size: 14px;
}

.shell-stats {
  display: flex;
  gap: 2rem;
  margin: 1.5rem 0;
  font-size: 14px;
}

.shell-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--gray-200);
}

.shell-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}

.shell-table th,
.shell-table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--gray-200);
}

.shell-table th {
  background: var(--gray-100);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 10px;
}

.shell-row--alert {
  background: #fff8f0;
}

.shell-row--login {
  background: #f0f7ff;
}

.shell-nowrap {
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.shell-source {
  max-width: 180px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.shell-table code {
  font-size: 11px;
  background: var(--gray-100);
  padding: 2px 6px;
  border-radius: 3px;
}

@media (max-width: 600px) {
  .hero__title { max-width: none; }
  .btn { min-width: 160px; }
}