/* ============================================================
   Userlite — hand-rolled stylesheet
   Clean, minimal, editorial. No framework.
   ============================================================ */

/* ---- Design tokens ---------------------------------------- */
:root {
  /* Palette — warm paper light, near-black ink */
  --paper: #f7f6f3;
  --paper-2: #efeee9;
  --surface: #ffffff;
  --ink: #14130f;
  --ink-2: #45433c;
  --ink-3: #78756b;
  --line: #e2e0d8;
  --line-2: #d3d0c6;
  --accent: #d5502b;      /* muted vermilion */
  --accent-ink: #b83f1e;

  /* Typography */
  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system,
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo,
    Consolas, monospace;

  /* Fluid type scale */
  --step--1: clamp(0.82rem, 0.79rem + 0.15vw, 0.9rem);
  --step-0: clamp(1rem, 0.96rem + 0.2vw, 1.1rem);
  --step-1: clamp(1.2rem, 1.1rem + 0.5vw, 1.5rem);
  --step-2: clamp(1.6rem, 1.4rem + 1vw, 2.25rem);
  --step-3: clamp(2.1rem, 1.7rem + 2vw, 3.25rem);
  --step-4: clamp(2.8rem, 2rem + 4vw, 5.5rem);

  /* Spacing / layout */
  --gutter: clamp(1.25rem, 4vw, 3rem);
  --maxw: 1200px;
  --radius: 14px;
  --radius-sm: 9px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---- Reset ------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}
* {
  margin: 0;
}
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}
body {
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img,
svg {
  display: block;
  max-width: 100%;
}
a {
  color: inherit;
  text-decoration: none;
}
button {
  font: inherit;
  color: inherit;
  cursor: pointer;
  border: none;
  background: none;
}
h1,
h2,
h3 {
  font-weight: 560;
  letter-spacing: -0.02em;
  line-height: 1.05;
}
::selection {
  background: var(--ink);
  color: var(--paper);
}

/* ---- Layout primitives ------------------------------------ */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section {
  padding-block: clamp(4rem, 9vw, 8rem);
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ---- Buttons ---------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.72em 1.3em;
  border-radius: 999px;
  font-size: var(--step--1);
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: transform 0.35s var(--ease), background 0.25s var(--ease),
    color 0.25s var(--ease), border-color 0.25s var(--ease);
  will-change: transform;
}
.btn:active {
  transform: translateY(1px);
}
.btn--primary {
  background: var(--ink);
  color: var(--paper);
}
.btn--primary:hover {
  background: var(--accent-ink);
}
.btn--ghost {
  border: 1px solid var(--line-2);
  color: var(--ink);
}
.btn--ghost:hover {
  border-color: var(--ink);
  background: var(--surface);
}
.btn .arrow {
  transition: transform 0.35s var(--ease);
}
.btn:hover .arrow {
  transform: translateX(3px);
}

/* ---- Nav --------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  color: #fff;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease),
    color 0.3s var(--ease), backdrop-filter 0.3s var(--ease);
}
.nav.is-scrolled {
  color: var(--ink);
  backdrop-filter: saturate(1.4) blur(14px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom-color: var(--line);
}
.nav .btn--ghost {
  border-color: color-mix(in srgb, currentColor 42%, transparent);
  color: inherit;
}
.nav .btn--ghost:hover {
  border-color: currentColor;
  background: color-mix(in srgb, currentColor 12%, transparent);
}
.nav.is-scrolled .btn--ghost {
  border-color: var(--line-2);
}
.nav.is-scrolled .btn--ghost:hover {
  border-color: var(--ink);
  background: var(--surface);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 560;
  letter-spacing: -0.02em;
  font-size: 1.15rem;
}
.brand__mark {
  width: 22px;
  height: 22px;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(1.2rem, 2.5vw, 2.2rem);
  list-style: none;
}
.nav__links a {
  font-size: var(--step--1);
  color: inherit;
  opacity: 0.82;
  transition: opacity 0.2s var(--ease);
}
.nav__links a:hover {
  opacity: 1;
}
.nav__cta {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.nav__toggle {
  display: none;
}

/* ---- Hero (full-screen video) ------------------------------ */
.hero {
  position: relative;
  min-height: 100svh;
  margin-top: -68px; /* pull under the sticky nav */
  display: flex;
  align-items: flex-end;
  padding-block: 120px clamp(3rem, 7vw, 5.5rem);
  overflow: hidden;
  color: #fff;
  background: #0a0a08;
}
.hero__video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}
.hero__scrim {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(
    to top,
    rgba(8, 8, 6, 0.86) 0%,
    rgba(8, 8, 6, 0.42) 42%,
    rgba(8, 8, 6, 0.18) 68%,
    rgba(8, 8, 6, 0.5) 100%
  );
}
.hero__inner {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
}
.hero .eyebrow {
  color: rgba(255, 255, 255, 0.7);
}
.hero h1 {
  font-size: clamp(3.2rem, 2rem + 6vw, 7rem);
  letter-spacing: -0.035em;
  margin-top: 1.4rem;
  color: #fff;
  font-weight: 200;
  text-wrap: balance;
}
.hero h1 em {
  font-style: normal;
  font-weight: 600;
  color: inherit;
}
.hero__lede {
  margin-top: 1.6rem;
  max-width: 52ch;
  font-size: var(--step-2);
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.4;
  letter-spacing: -0.01em;
  font-weight: 300;
}
.hero__lede em,
.hero__lede strong {
  font-style: normal;
  font-weight: 600;
}
.hero__lede-line {
  display: block;
}
.hero__lede-line:nth-child(n + 2) {
  opacity: 0;
  transform: translateY(14px);
  animation: ledeLineIn 1.75s var(--ease) forwards;
}
.hero__lede-line:nth-child(2),
.hero__lede-line:nth-child(3) {
  display: inline-block;
}
.hero__lede-line:nth-child(2) {
  animation-delay: 5.925s;
}
.hero__lede-line:nth-child(3) {
  animation-delay: 7.275s;
}
.hero__lede-line:nth-child(4) {
  animation-delay: 8.273s;
}
.hero__phrase {
  display: inline-block;
  opacity: 0;
  transform: translateY(8px);
  animation: ledeLineIn 1.375s var(--ease) forwards;
}
.hero__phrase:nth-child(1) {
  animation-delay: 1.313s;
}
.hero__phrase:nth-child(2) {
  animation-delay: 2.363s;
}
.hero__phrase:nth-child(3) {
  animation-delay: 3.038s;
}
.hero__phrase:nth-child(4) {
  animation-delay: 3.713s;
}
.hero__phrase:nth-child(5) {
  animation-delay: 4.388s;
}
@keyframes ledeLineIn {
  to {
    opacity: 1;
    transform: none;
  }
}
.hero__actions {
  margin-top: 2.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}
.hero .btn--primary {
  background: #fff;
  color: var(--ink);
}
.hero .btn--primary:hover {
  background: var(--accent);
  color: #fff;
}
.hero .btn--ghost {
  border-color: rgba(255, 255, 255, 0.5);
  color: #fff;
}
.hero .btn--ghost:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.1);
}
.hero__scroll {
  position: absolute;
  z-index: 2;
  right: var(--gutter);
  bottom: clamp(1.6rem, 4vw, 2.4rem);
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.6);
  transition: color 0.25s var(--ease);
}
.hero__scroll:hover {
  color: #fff;
}
.hero__scroll-line {
  width: 46px;
  height: 1px;
  background: currentColor;
  transform-origin: left;
  animation: scrollLine 2.4s var(--ease) infinite;
}
@keyframes scrollLine {
  0%,
  100% {
    transform: scaleX(0.35);
    opacity: 0.5;
  }
  50% {
    transform: scaleX(1);
    opacity: 1;
  }
}

/* ---- Stats strip ------------------------------------------- */
.stats {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.stats__inner {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(1.6rem, 5vw, 4rem);
  padding-block: clamp(1.6rem, 3vw, 2.4rem);
}
.stats__inner div {
  display: flex;
  flex-direction: column;
}
.stats dt {
  font-size: var(--step-2);
  font-weight: 560;
  letter-spacing: -0.03em;
}
.stats dd {
  font-size: var(--step--1);
  color: var(--ink-3);
}

/* ---- Section heading -------------------------------------- */
.head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  margin-bottom: clamp(2rem, 4vw, 3.4rem);
}
.head h2 {
  font-size: var(--step-3);
  max-width: 18ch;
  margin-top: 0.8rem;
  font-weight: 300;
}
.head h2 strong {
  font-weight: 800;
}
.head p {
  max-width: 42ch;
  color: var(--ink-2);
}

/* ---- Product ----------------------------------------------- */
.products {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.1rem;
}
.card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(1.6rem, 3vw, 2.4rem);
  display: flex;
  flex-direction: column;
  min-height: 260px;
  overflow: hidden;
  transition: transform 0.5s var(--ease), border-color 0.35s var(--ease),
    box-shadow 0.5s var(--ease);
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--line-2);
  box-shadow: 0 24px 60px -34px rgba(20, 19, 15, 0.35);
}
.card--wide {
  grid-column: span 7;
}
.card--tall {
  grid-column: span 5;
}
.card--half {
  grid-column: span 6;
}
.card--third {
  grid-column: span 4;
}
.card__tag {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  color: var(--accent-ink);
  letter-spacing: 0.04em;
}
.card h3 {
  font-size: var(--step-2);
  margin-top: 0.7rem;
}
.card p {
  margin-top: 0.8rem;
  color: var(--ink-2);
  max-width: 40ch;
}
.card__spacer {
  flex: 1;
}
.card__link {
  margin-top: 1.6rem;
  display: inline-flex;
  align-items: center;
  gap: 0.45em;
  font-size: var(--step--1);
  font-weight: 500;
  color: var(--ink);
}
.card__link .arrow {
  transition: transform 0.35s var(--ease);
}
.card:hover .card__link .arrow {
  transform: translateX(4px);
}
.card--feature {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.card--feature .card__tag {
  color: #f0a58c;
}
.card--feature p {
  color: #c9c6bd;
}
.card--feature .card__link {
  color: var(--paper);
}
.card__glow {
  position: absolute;
  right: -30%;
  top: -40%;
  width: 70%;
  aspect-ratio: 1;
  background: radial-gradient(
    circle,
    rgba(213, 80, 43, 0.5),
    transparent 62%
  );
  filter: blur(10px);
  pointer-events: none;
}

/* ---- Research list ---------------------------------------- */
.research {
  background: var(--paper-2);
  border-block: 1px solid var(--line);
}
.list {
  border-top: 1px solid var(--line);
}
.row {
  display: grid;
  grid-template-columns: 108px 1fr auto;
  gap: 1.5rem;
  align-items: baseline;
  padding: 1.5rem 0.4rem;
  border-bottom: 1px solid var(--line);
  transition: padding 0.4s var(--ease), background 0.3s var(--ease);
}
.row:hover {
  background: color-mix(in srgb, var(--surface) 60%, transparent);
  padding-inline: 1rem;
}
.row__date {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  color: var(--ink-3);
}
.row__title {
  font-size: var(--step-1);
  letter-spacing: -0.02em;
  font-weight: 500;
}
.row__cat {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.row__title span {
  display: block;
  font-family: var(--font-sans);
  font-size: var(--step--1);
  font-weight: 400;
  color: var(--ink-3);
  letter-spacing: 0;
  margin-top: 0.3rem;
}

/* ---- Mission band ----------------------------------------- */
.mission__quote {
  font-size: var(--step-3);
  letter-spacing: -0.03em;
  line-height: 1.12;
  max-width: 24ch;
  font-weight: 560;
}
.mission__quote b {
  color: var(--accent-ink);
  font-weight: inherit;
}
.mission__lede {
  margin-top: 1.6rem;
  max-width: 54ch;
  font-size: var(--step-1);
  color: var(--ink-2);
  line-height: 1.4;
  letter-spacing: -0.01em;
}
.mission__body {
  margin-top: 2.6rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.pillar h4 {
  font-size: var(--step-0);
  font-weight: 560;
  padding-top: 1rem;
  border-top: 1px solid var(--line-2);
}
.pillar p {
  margin-top: 0.6rem;
  font-size: var(--step--1);
  color: var(--ink-2);
}

/* ---- CTA / contact ---------------------------------------- */
.cta {
  background: var(--ink);
  color: var(--paper);
}
.cta__inner {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
.cta h2 {
  font-size: var(--step-3);
  max-width: 14ch;
}
.cta p {
  margin-top: 1.2rem;
  color: #b8b5ab;
  max-width: 40ch;
}
.form {
  display: grid;
  gap: 0.9rem;
}
.field {
  display: grid;
  gap: 0.4rem;
}
.field label {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #9a978d;
}
.field input,
.field textarea {
  font: inherit;
  font-size: var(--step--1);
  color: var(--paper);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius-sm);
  padding: 0.75em 0.9em;
  transition: border-color 0.25s var(--ease), background 0.25s var(--ease);
}
.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.07);
}
.field textarea {
  resize: vertical;
  min-height: 96px;
}
.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}
.form button {
  justify-self: start;
  background: var(--paper);
  color: var(--ink);
}
.form button:hover {
  background: var(--accent);
  color: var(--paper);
}
.form__status {
  font-size: var(--step--1);
  min-height: 1.2em;
  color: #9a978d;
}
.form__status.is-ok {
  color: #8fd39f;
}
.form__status.is-err {
  color: #f0a58c;
}

/* ---- Footer ------------------------------------------------ */
.footer {
  padding-block: clamp(3rem, 6vw, 5rem) 2.5rem;
}
.footer__top {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 2rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--line);
}
.footer__brand p {
  margin-top: 1rem;
  max-width: 30ch;
  color: var(--ink-2);
  font-size: var(--step--1);
}
.footer__col h5 {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
  margin-bottom: 1rem;
}
.footer__col ul {
  list-style: none;
  display: grid;
  gap: 0.6rem;
}
.footer__col a {
  font-size: var(--step--1);
  color: var(--ink-2);
  transition: color 0.2s var(--ease);
}
.footer__col a:hover {
  color: var(--ink);
}
.footer__bottom {
  margin-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: var(--step--1);
  color: var(--ink-3);
}

/* ---- Reveal animation ------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-in {
  opacity: 1;
  transform: none;
}
[data-stagger] > * {
  transition-delay: calc(var(--i, 0) * 70ms);
}

/* ---- Responsive ------------------------------------------- */
@media (max-width: 900px) {
  .card--wide,
  .card--tall,
  .card--half,
  .card--third {
    grid-column: span 12;
  }
  .cta__inner {
    grid-template-columns: 1fr;
  }
  .mission__body {
    grid-template-columns: 1fr;
  }
  .footer__top {
    grid-template-columns: 1fr 1fr;
  }
}
@media (max-width: 680px) {
  .nav__links {
    display: none;
  }
  .nav__toggle {
    display: inline-flex;
  }
  .nav.is-open .nav__links {
    display: flex;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 1.1rem;
    padding: 1.5rem var(--gutter) 2rem;
    background: var(--paper);
    color: var(--ink);
    border-bottom: 1px solid var(--line);
  }
  .row {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }
  .row__cat {
    display: none;
  }
  .form__row {
    grid-template-columns: 1fr;
  }
  .footer__top {
    grid-template-columns: 1fr;
  }
}

/* ---- Document / subpages ---------------------------------- */
.doc .nav {
  color: var(--ink);
  backdrop-filter: saturate(1.4) blur(14px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom-color: var(--line);
}
.doc .nav .btn--ghost {
  border-color: var(--line-2);
}
.doc .field label {
  color: var(--ink-3);
}
.doc .field input,
.doc .field textarea {
  color: var(--ink);
  background: var(--surface);
  border-color: var(--line-2);
}
.doc .field input:focus,
.doc .field textarea:focus {
  border-color: var(--accent);
  background: var(--surface);
}
.doc .form button {
  background: var(--ink);
  color: var(--paper);
}
.doc .form button:hover {
  background: var(--accent);
  color: var(--paper);
}
.doc .form__status {
  color: var(--ink-3);
}
.doc .form__status.is-ok {
  color: #2f8a4a;
}
.doc .form__status.is-err {
  color: var(--accent-ink);
}
.page-head {
  padding: clamp(3.5rem, 3rem + 6vw, 7rem) 0 clamp(1.5rem, 1rem + 2vw, 2.5rem);
  border-bottom: 1px solid var(--line);
}
.page-head h1 {
  font-size: var(--step-4);
  letter-spacing: -0.03em;
  font-weight: 300;
  max-width: 20ch;
}
.page-head h1 strong {
  font-weight: 700;
}
.page-head__lede {
  margin-top: 1.2rem;
  max-width: 60ch;
  font-size: var(--step-1);
  color: var(--ink-2);
  font-weight: 300;
}
.doc-section {
  padding: clamp(2.5rem, 2rem + 3vw, 4.5rem) 0;
}
.prose {
  max-width: 68ch;
}
.prose > * + * {
  margin-top: 1.1rem;
}
.prose h2 {
  font-size: var(--step-2);
  margin-top: 2.4rem;
}
.prose h3 {
  font-size: var(--step-1);
  margin-top: 1.8rem;
}
.prose p {
  color: var(--ink-2);
}
.prose a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.prose ul,
.prose ol {
  color: var(--ink-2);
  padding-left: 1.4rem;
}
.prose li + li {
  margin-top: 0.4rem;
}
.prose strong {
  font-weight: 600;
  color: var(--ink);
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--paper-2);
  padding: 0.12em 0.35em;
  border-radius: 4px;
}
.prose pre {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  overflow-x: auto;
}
.prose pre code {
  background: none;
  padding: 0;
}
.prose blockquote {
  border-left: 2px solid var(--line);
  padding-left: 1rem;
  color: var(--ink-3);
}
.article-back {
  margin-top: 1.5rem;
  font-size: var(--step--1);
}
.article-back a {
  color: var(--ink-3);
}
.bench-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--step-0);
  margin-top: 1.5rem;
}
.bench-table th,
.bench-table td {
  text-align: left;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--line);
}
.bench-table thead th {
  font-size: var(--step--1);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-3);
  font-weight: 600;
}
.bench-table td:not(:first-child) {
  font-variant-numeric: tabular-nums;
  font-family: var(--font-mono);
  color: var(--ink);
}
.bench-table tbody tr:hover {
  background: var(--paper-2);
}
.role {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line);
}
.role__meta {
  color: var(--ink-3);
  font-size: var(--step--1);
  white-space: nowrap;
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
  .hero__lede-line,
  .hero__phrase {
    animation: none;
    opacity: 1;
    transform: none;
  }
  .hero__scroll-line {
    animation: none;
  }
}