/* ─────────────────────────────────────────────
   VX AI Lab — main.css
   Breakpoints: mobile-first
   sm: 640px  md: 768px  lg: 1024px  xl: 1280px
───────────────────────────────────────────── */

/* ── Reset & tokens ─────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --accent:      #E40521;
  --black:       #000000;
  --silk:        #1D1D1D;
  --light-gray:  #F2F2F2;
  --gray:        #DEDEDE;
  --dark-gray:   #8D8D8D;
  --white:       #FFFFFF;
  --font:        'Barlow Semi Condensed', sans-serif;
  --max-w:       1280px;
  --px:          clamp(1rem, 5vw, 2.5rem);
}

html  { scroll-behavior: smooth; }
body  { font-family: var(--font); background: var(--white); color: var(--black); }
img   { display: block; max-width: 100%; }
a     { text-decoration: none; color: inherit; }

/* ── Utilities ───────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--px);
}

.red-bar   { height: 4px; background: var(--accent); }
.eyebrow   {
  display: block;
  font-size: .75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .12em;
  color: var(--accent); margin-bottom: .5rem;
}
.text-accent { color: var(--accent); }
.dot { display: inline-block; width: 3px; height: 3px; background: var(--dark-gray); vertical-align: middle; }
.label { font-size: .6875rem; color: var(--dark-gray); text-transform: uppercase; letter-spacing: .06em; font-weight: 700; }

/* ── Buttons ─────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  font-family: var(--font); font-size: .875rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .06em;
  padding: .75rem 1.5rem; border: 2px solid transparent;
  cursor: pointer; transition: filter .15s, background .15s, border-color .15s;
  white-space: nowrap;
}
.btn svg { width: 1rem; height: 1rem; flex-shrink: 0; }

.btn--primary     { background: var(--accent); color: var(--white); border-color: var(--accent); }
.btn--primary:hover { filter: brightness(.85); }

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

.btn--white       { background: var(--white); color: var(--accent); }
.btn--white:hover { background: var(--light-gray); }

.btn--outline     { background: transparent; border-color: var(--gray); color: var(--black); }
.btn--outline:hover { border-color: var(--black); }

.btn--outline-dark { background: transparent; border-color: var(--black); color: var(--black); }
.btn--outline-dark:hover { background: rgba(0,0,0,.05); }

.btn--outline-white { background: transparent; border-color: rgba(255,255,255,.5); color: var(--white); }
.btn--outline-white:hover { border-color: var(--white); }

/* ── Section shared ──────────────────────────── */
.section-header   { margin-bottom: 2.5rem; }
.section-title    { font-size: clamp(2rem, 5vw, 3rem); font-weight: 700; text-transform: uppercase; line-height: 1.0; margin-bottom: 1rem; }
.section-title--light { color: var(--white); }
.section-body     { font-size: 1rem; line-height: 1.6; color: var(--silk); max-width: 36rem; }
.section-body--light { color: var(--gray); }

.section-header--row {
  display: flex; flex-wrap: wrap;
  align-items: flex-end; justify-content: space-between; gap: 1rem;
}

/* ── Nav ─────────────────────────────────────── */
.nav {
  background: var(--black);
  border-bottom: 2px solid var(--accent);
  position: sticky; top: 0; z-index: 100;
}
.nav__inner {
  display: flex; align-items: center;
  justify-content: space-between; height: 4rem;
}
.nav__brand {
  display: flex; align-items: center; gap: 1rem;
  text-decoration: none;
}
.nav__logo    { height: 2rem; object-fit: contain; }
.nav__divider { display: block; width: 1px; height: 1.5rem; background: #333; }
.nav__name    { font-size: .875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .1em; color: var(--white); }

.nav__toggle {
  display: none;
  background: none; border: none; color: var(--white); cursor: pointer; padding: .5rem;
}
.nav__toggle svg { width: 1.5rem; height: 1.5rem; }

.nav__menu   { display: flex; align-items: center; gap: .25rem; }
.nav__link   {
  font-size: .8125rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em;
  color: #adadad; padding: .5rem .875rem;
  border-bottom: 2px solid transparent; transition: color .15s, border-color .15s;
}
.nav__link:hover,
.nav__link.is-active { color: var(--white); border-bottom-color: var(--accent); }
.nav__cta {
  font-size: .8125rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em;
  background: var(--accent); color: var(--white);
  padding: .625rem 1.25rem; margin-left: .75rem;
  transition: filter .15s;
}
.nav__cta:hover { filter: brightness(.85); }

/* Mobile nav */
@media (max-width: 767px) {
  .nav__toggle { display: flex; }
  .nav__menu {
    display: none; flex-direction: column; align-items: stretch;
    position: absolute; top: 4rem; left: 0; right: 0;
    background: var(--black); border-top: 1px solid #222;
    padding: 1rem var(--px) 1.5rem;
    gap: .25rem;
  }
  .nav__menu.is-open { display: flex; }
  .nav__link { padding: .75rem 0; border-bottom: 1px solid #1a1a1a; border-left: none; }
  .nav__link.is-active { border-bottom-color: #1a1a1a; color: var(--white); }
  .nav__cta { margin: .75rem 0 0; text-align: center; padding: .875rem; }
}

/* ── Hero ─────────────────────────────────────── */
.hero { background: var(--white); position: relative; overflow: hidden; }
.hero__inner {
  position: relative;
  padding-top: clamp(3rem, 8vw, 6rem);
  padding-bottom: clamp(2.5rem, 6vw, 5rem);
}
.hero__content { position: relative; z-index: 1; max-width: 36rem; }
.hero__h1 {
  font-size: clamp(2.5rem, 8vw, 5rem);
  font-weight: 700; text-transform: uppercase; line-height: 1.0;
  color: var(--black); margin-bottom: 1.5rem;
}
.hero__body {
  font-size: clamp(1rem, 2vw, 1.125rem);
  line-height: 1.6; color: var(--silk); max-width: 32rem; margin-bottom: 2rem;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: .75rem; }
.hero__watermark {
  position: absolute; right: -2rem; top: 50%; transform: translateY(-50%);
  opacity: .04; pointer-events: none; z-index: 0;
}
.hero__watermark img { width: clamp(200px, 30vw, 400px); height: auto; }

.hero__stats { background: var(--light-gray); border-top: 1px solid var(--gray); }
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.stats-strip__item {
  padding: 1.5rem 0 1.5rem 2rem;
  border-right: 1px solid var(--gray);
  display: flex; flex-direction: column; gap: .25rem;
}
.stats-strip__num   { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; color: var(--accent); line-height: 1; }
.stats-strip__label { font-size: .75rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: #666; }

@media (max-width: 639px) {
  .stats-strip { grid-template-columns: repeat(2, 1fr); }
  .stats-strip__item { padding: 1.25rem 0 1.25rem 1.25rem; }
  .hero__watermark { display: none; }
}

/* ── Experiments ─────────────────────────────── */
.experiments { background: var(--light-gray); padding: 5rem 0; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
}
@media (max-width: 1023px) { .card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 639px)  { .card-grid { grid-template-columns: 1fr; } }

.exp-card {
  background: var(--white); padding: 2rem 1.75rem;
  display: flex; flex-direction: column; gap: .875rem;
  transition: background .2s; cursor: pointer;
}
.exp-card:hover { background: var(--silk); }
.exp-card:hover .exp-card__tag    { color: var(--dark-gray); }
.exp-card:hover .exp-card__title  { color: var(--white); }
.exp-card:hover .exp-card__body   { color: var(--gray); }
.exp-card:hover .exp-card__icon   { stroke: var(--accent); }
.exp-card:hover .exp-card__arrow  { stroke: var(--accent); }
.exp-card:hover .status           { color: var(--gray); }

.exp-card__top  { display: flex; align-items: center; justify-content: space-between; }
.exp-card__id   { font-size: .6875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--accent); }
.exp-card__icon { width: 1.25rem; height: 1.25rem; stroke: var(--dark-gray); stroke-width: 1.5; fill: none; transition: stroke .2s; }
.exp-card__tag  { display: block; font-size: .6875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: #999; margin-bottom: .375rem; transition: color .2s; }
.exp-card__title { font-size: 1.25rem; font-weight: 700; text-transform: uppercase; color: var(--black); line-height: 1.15; transition: color .2s; }
.exp-card__body  { font-size: .9375rem; line-height: 1.55; color: var(--silk); flex: 1; transition: color .2s; }
.exp-card__footer { display: flex; align-items: center; justify-content: space-between; }
.exp-card__arrow  { width: .875rem; height: .875rem; stroke: var(--accent); fill: none; flex-shrink: 0; }

/* Status indicators */
.status {
  display: inline-flex; align-items: center; gap: .375rem;
  font-size: .6875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--dark-gray);
}
.status::before { content: ''; display: inline-block; width: 6px; height: 6px; border-radius: 0; flex-shrink: 0; }
.status--active::before   { background: var(--accent); }
.status--done::before     { background: #2E7D32; }
.status--research::before { background: #B06000; }

/* ── Whitepapers ─────────────────────────────── */
.whitepapers { background: var(--white); padding: 5rem 0; }

.wp-list { display: flex; flex-direction: column; gap: 2px; }
.wp-row {
  background: var(--white);
  border-left: 4px solid var(--light-gray);
  padding: 1.75rem 2rem;
  display: grid;
  grid-template-columns: 5rem 1fr auto;
  gap: 2rem; align-items: center;
  transition: background .15s, border-color .15s;
  cursor: pointer;
}
.wp-row:hover { background: var(--light-gray); border-left-color: var(--accent); }
.wp-row:hover .wp-row__icon  { stroke: var(--accent); }
.wp-row:hover .btn--dark { background: var(--accent); }

.wp-row__meta   { display: flex; flex-direction: column; gap: .5rem; }
.wp-row__id     { font-size: .6875rem; font-weight: 700; color: var(--accent); letter-spacing: .06em; }
.wp-row__icon   { width: 1.375rem; height: 1.375rem; stroke: var(--dark-gray); stroke-width: 1.5; fill: none; transition: stroke .2s; }
.wp-row__content { min-width: 0; }
.wp-row__details { display: flex; flex-wrap: wrap; align-items: center; gap: .625rem; margin-bottom: .5rem; }
.wp-row__title  { font-size: 1.375rem; font-weight: 700; text-transform: uppercase; color: var(--black); line-height: 1.1; margin-bottom: .5rem; }
.wp-row__desc   { font-size: .9375rem; line-height: 1.55; color: var(--silk); }
.wp-row__action { flex-shrink: 0; }

@media (max-width: 767px) {
  .wp-row {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .wp-row__meta   { flex-direction: row; align-items: center; gap: 1rem; }
  .wp-row__action { justify-self: start; }
}

/* ── Team ────────────────────────────────────── */
.team { background: var(--silk); padding: 5rem 0; }

.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
}
@media (max-width: 1023px) { .team-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 639px)  { .team-grid { grid-template-columns: 1fr; } }

.team-card {
  background: var(--black); padding: 1.75rem;
  display: flex; flex-direction: column; gap: 1rem;
  transition: background .15s; cursor: pointer;
}
.team-card:hover { background: #111; }
.team-card:hover .team-card__avatar { background: var(--accent); }

.team-card__header { display: flex; align-items: center; gap: 1rem; }
.team-card__avatar {
  width: 3.25rem; height: 3.25rem; flex-shrink: 0;
  background: var(--silk);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.125rem; font-weight: 700; color: var(--white); text-transform: uppercase;
  transition: background .2s;
}
.team-card__name { font-size: 1.0625rem; font-weight: 700; text-transform: uppercase; color: var(--white); line-height: 1.1; }
.team-card__role { font-size: .75rem; text-transform: uppercase; letter-spacing: .05em; color: var(--dark-gray); margin-top: .125rem; }

.team-card__tags { display: flex; flex-wrap: wrap; gap: .25rem; }
.tag {
  background: var(--silk); color: var(--gray);
  font-size: .6875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .04em;
  padding: .1875rem .5rem;
}

/* ── CTA ─────────────────────────────────────── */
.cta { background: var(--accent); padding: 5rem 0; }
.cta__inner {
  display: flex; flex-wrap: wrap;
  align-items: center; justify-content: space-between; gap: 2.5rem;
}
.cta__title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700; text-transform: uppercase; color: var(--white); line-height: 1.0; margin-bottom: .75rem;
}
.cta__body  { font-size: 1rem; color: rgba(255,255,255,.85); line-height: 1.6; max-width: 30rem; }
.cta__actions { display: flex; flex-direction: column; gap: .75rem; flex-shrink: 0; }

@media (max-width: 639px) {
  .cta__actions { flex-direction: column; width: 100%; }
  .cta__actions .btn { justify-content: center; }
}

/* ── Footer ──────────────────────────────────── */
.footer { background: var(--black); color: var(--white); }
.footer__inner {
  display: flex; flex-wrap: wrap;
  gap: 3rem; padding: 3.5rem 0 2.5rem;
}
.footer__brand { flex-shrink: 0; }
.footer__logo   { height: 2.25rem; object-fit: contain; margin-bottom: .5rem; }
.footer__lab    { display: block; font-size: .8125rem; font-weight: 700; text-transform: uppercase; letter-spacing: .1em; color: var(--accent); margin-bottom: .5rem; }
.footer__tagline { font-size: .875rem; color: var(--dark-gray); font-style: italic; }

.footer__cols { display: flex; flex-wrap: wrap; gap: 2.5rem; flex: 1; }
.footer__col  { display: flex; flex-direction: column; gap: .5rem; min-width: 8rem; }
.footer__col-head {
  font-size: .6875rem; font-weight: 700; text-transform: uppercase; letter-spacing: .1em;
  color: var(--white); margin-bottom: .25rem;
}
.footer__link { font-size: .875rem; color: var(--dark-gray); transition: color .15s; }
.footer__link:hover { color: var(--white); }

.footer__bottom { border-top: 1px solid #1d1d1d; }
.footer__bottom-inner {
  display: flex; flex-wrap: wrap;
  justify-content: space-between; align-items: center; gap: .5rem;
  padding: 1.25rem 0;
  font-size: .75rem; color: var(--dark-gray);
}
.footer__payoff { font-style: italic; }

@media (max-width: 639px) {
  .footer__inner { flex-direction: column; }
  .footer__bottom-inner { flex-direction: column; text-align: center; }
}