/* ==========================================================================
   Own the Intelligence — design system
   Спецификация: docs/brand-system.md
   ========================================================================== */

:root {
  /* Поверхности */
  --ink-900: #07090c;
  --ink-850: #0a0c10;
  --ink-800: #101319;
  --ink-700: #171b23;
  --navy-900: #0b1220;

  /* Линии */
  --line-1: rgba(255, 255, 255, 0.08);
  --line-2: rgba(255, 255, 255, 0.14);

  /* Акцент: cyan — только вёрстка и интерактив */
  --seam: #22d3ee;
  --seam-dim: rgba(34, 211, 238, 0.08);

  /* Текст */
  --text-1: #f4f7fa;
  --text-2: #a8b3c2;
  --text-3: #6b7788;

  /* Типографика. Системный стек до лицензирования PP Neue Montreal / Geist */
  --font-display: "Inter Tight", "Geist", -apple-system, BlinkMacSystemFont,
    "Helvetica Neue", Arial, sans-serif;
  --font-text: "Geist", "Inter", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial,
    sans-serif;
  --font-mono: "Geist Mono", ui-monospace, SFMono-Regular, "JetBrains Mono", Menlo, monospace;

  --fs-display-xl: clamp(36px, 4.4vw, 58px);
  --fs-display-l: clamp(34px, 4.2vw, 56px);
  --fs-h1: clamp(28px, 3.1vw, 40px);
  --fs-h2: clamp(24px, 2.2vw, 30px);
  --fs-h3: 22px;

  /* Ритм */
  --container: 1280px;
  --gutter: 40px;
  --section-y: 120px;

  /* Движение */
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --ease-seam: cubic-bezier(0.65, 0, 0.35, 1);
}

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

html {
  scroll-behavior: smooth;
  /* Clears the sticky header so anchored sections are not hidden under it. */
  scroll-padding-top: 96px;
}

body {
  margin: 0;
  background: var(--ink-900);
  color: var(--text-1);
  font-family: var(--font-text);
  font-size: 16px;
  line-height: 26px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
  text-decoration: none;
}

/* --------------------------------------------------------------- Утилиты */

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section {
  padding: var(--section-y) 0;
}

.section--alt {
  background: var(--ink-850);
}

/* Шов как разделитель секций */
.rule {
  position: relative;
  height: 1px;
  background: var(--line-1);
}

.rule::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 120px;
  background: var(--seam);
}

.label {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 16px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-3);
}

.label--seam {
  color: var(--seam);
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 500;
  margin: 0;
}

.display-xl {
  font-size: var(--fs-display-xl);
  line-height: 1.08;
  letter-spacing: -0.028em;
  max-width: 18ch;
}

.h1 {
  font-size: var(--fs-h1);
  line-height: 1.15;
  letter-spacing: -0.024em;
  max-width: 26ch;
}

.h2 {
  font-size: var(--fs-h2);
  line-height: 1.26;
  letter-spacing: -0.02em;
}

.h3 {
  font-size: var(--fs-h3);
  line-height: 30px;
  letter-spacing: -0.015em;
}

.lead {
  font-size: 18px;
  line-height: 30px;
  letter-spacing: -0.005em;
  color: var(--text-2);
  max-width: 58ch;
  margin: 0;
}

.body {
  color: var(--text-2);
  max-width: 62ch;
  margin: 0;
}

.small {
  font-size: 14px;
  line-height: 22px;
  color: var(--text-2);
  margin: 0;
}

.stack-8 > * + * {
  margin-top: 8px;
}
.stack-16 > * + * {
  margin-top: 16px;
}
.stack-24 > * + * {
  margin-top: 24px;
}
.stack-40 > * + * {
  margin-top: 40px;
}

.mt-16 {
  margin-top: 16px;
}
.pt-8 {
  padding-top: 8px;
}
.measure-34 {
  max-width: 34ch;
}
.center-row {
  display: flex;
  justify-content: center;
}
.img--narrow {
  width: 100%;
  max-width: 720px;
}
.link-seam {
  color: var(--seam);
}

/* --------------------------------------------------------------- Кнопки */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 24px;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: background 180ms var(--ease), border-color 180ms var(--ease);
}

.btn--primary {
  border: 1px solid var(--seam);
  color: var(--seam);
  background: transparent;
}

.btn--primary::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 1px;
  width: 100%;
  background: var(--seam);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 520ms var(--ease-seam);
}

.btn--primary:hover {
  background: var(--seam-dim);
}

.btn--primary:hover::after {
  transform: scaleX(1);
}

.btn--ghost {
  border: 1px solid transparent;
  color: var(--text-1);
  padding-left: 0;
  padding-right: 0;
}

.btn--ghost .arrow {
  transition: transform 180ms var(--ease);
}

.btn--ghost:hover .arrow {
  transform: translateX(4px);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 28px;
}

/* --------------------------------------------------------------- Шапка */

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(7, 9, 12, 0.82);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line-1);
}

.header__inner {
  display: flex;
  align-items: center;
  gap: 40px;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand__name {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.brand__name span {
  color: var(--text-3);
}

.nav {
  display: flex;
  gap: 32px;
  margin-left: auto;
}

.nav a {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-2);
  transition: color 180ms var(--ease);
}

.nav a:hover {
  color: var(--text-1);
}

.header__actions {
  display: flex;
  align-items: center;
  gap: 24px;
}

.header .btn--primary {
  padding: 10px 18px;
}

/* --------------------------------------------------------------- Hero */

.hero {
  position: relative;
  padding: 96px 0 0;
  overflow: hidden;
}

.hero__grid {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: 48px;
  align-items: center;
  min-height: 520px;
}

.hero__media {
  position: relative;
  margin-right: calc(var(--gutter) * -1);
}

.hero__media img {
  width: 100%;
  height: auto;
}

.hero__copy > * + * {
  margin-top: 24px;
}

.hero__sub {
  font-size: 18px;
  line-height: 30px;
  color: var(--text-2);
  max-width: 46ch;
  margin: 0;
}

.hero__sub strong {
  color: var(--text-1);
  font-weight: 500;
}

.trust {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  padding: 48px 0 var(--section-y);
}

.trust__item > * + * {
  margin-top: 8px;
}

/* --------------------------------------------------------------- Сетки */

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.split {
  display: grid;
  grid-template-columns: 5fr 7fr;
  gap: 64px;
  align-items: start;
}

.split--wide-left {
  grid-template-columns: 7fr 5fr;
}

/* --------------------------------------------------------------- Карточки */

.card {
  position: relative;
  background: var(--ink-800);
  border: 1px solid var(--line-1);
  border-radius: 2px;
  padding: 32px;
  transition: border-color 180ms var(--ease);
}

.card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 1px;
  height: 100%;
  background: var(--seam);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 520ms var(--ease-seam);
}

.card:hover {
  border-color: var(--line-2);
}

.card:hover::before {
  transform: scaleY(1);
}

.card > * + * {
  margin-top: 12px;
}

.card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 8px;
}

.tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-3);
  border: 1px solid var(--line-1);
  border-radius: 2px;
  padding: 4px 8px;
}

.tag--live {
  color: var(--seam);
  border-color: rgba(34, 211, 238, 0.32);
}

/* Блок свойства владения — открытая секция, не карточка */
.prop {
  border-top: 1px solid var(--line-1);
  padding-top: 20px;
}

.prop > * + * {
  margin-top: 10px;
}

.prop__n {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--seam);
}

/* Инженерная заметка — открытый блок со швом на верхней кромке */
.note {
  position: relative;
  border-top: 1px solid var(--line-1);
  padding-top: 24px;
}

.note::before {
  content: "";
  position: absolute;
  left: 0;
  top: -1px;
  height: 1px;
  width: 56px;
  background: var(--seam);
}

.note > * + * {
  margin-top: 12px;
}

.note .h3 {
  max-width: 24ch;
}

/* --------------------------------------------------------------- Спецификации */

.spec {
  display: grid;
  grid-template-columns: minmax(180px, 240px) 1fr;
  gap: 32px;
  padding: 18px 0;
  border-top: 1px solid var(--line-1);
  align-items: baseline;
}

.spec:last-child {
  border-bottom: 1px solid var(--line-1);
}

.spec__value {
  color: var(--text-1);
  margin: 0;
  font-size: 15px;
  line-height: 24px;
}

/* Лестница развёртывания */
.tier {
  display: grid;
  grid-template-columns: 220px 1fr 220px;
  gap: 40px;
  padding: 32px 0;
  border-top: 1px solid var(--line-1);
  align-items: start;
  position: relative;
}

.tier:last-child {
  border-bottom: 1px solid var(--line-1);
}

.tier__bar {
  position: absolute;
  left: 0;
  top: -1px;
  height: 1px;
  background: var(--seam);
  transition: width 520ms var(--ease-seam);
}

.tier--1 .tier__bar {
  width: 33%;
}
.tier--2 .tier__bar {
  width: 66%;
}
.tier--3 .tier__bar {
  width: 100%;
}

.tier__buyer {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 18px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin: 0;
}

/* --------------------------------------------------------------- Таблица */

.table {
  width: 100%;
  border-collapse: collapse;
}

.table th,
.table td {
  text-align: left;
  padding: 18px 24px 18px 0;
  border-top: 1px solid var(--line-1);
  vertical-align: top;
  font-size: 15px;
  line-height: 24px;
}

.table th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-3);
  border-top: none;
}

.table td:first-child {
  color: var(--text-1);
  white-space: nowrap;
}

.table td {
  color: var(--text-2);
}

/* --------------------------------------------------------------- Форма */

.form {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.field--full {
  grid-column: 1 / -1;
}

.field label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-3);
}

.field input,
.field select,
.field textarea {
  background: var(--ink-700);
  border: 1px solid var(--line-1);
  border-radius: 2px;
  padding: 12px 14px;
  color: var(--text-1);
  font-family: var(--font-text);
  font-size: 15px;
  outline: none;
  transition: border-color 180ms var(--ease);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--seam);
}

.field textarea {
  min-height: 96px;
  resize: vertical;
}

.form__note {
  grid-column: 1 / -1;
  font-size: 13px;
  color: var(--text-3);
  margin: 0;
}

.form__note--ok {
  color: var(--seam);
}

.form__note--error {
  color: #f4a4a4;
}

/* Bait for form-filling bots: out of sight, out of the tab order, but not
   display:none, which the better ones skip. */
.honeypot {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* --------------------------------------------------------------- Футер */

.footer {
  border-top: 1px solid var(--line-1);
  padding: 64px 0 40px;
  background: var(--ink-850);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer__col > * + * {
  margin-top: 10px;
}

.footer__col a {
  display: block;
  font-size: 14px;
  color: var(--text-2);
  transition: color 180ms var(--ease);
}

.footer__col a:hover {
  color: var(--text-1);
}

.footer__legal {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--line-1);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-3);
}

/* --------------------------------------------------------------- Появление */

.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 320ms var(--ease), transform 320ms var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* --------------------------------------------------------------- Адаптив */

@media (max-width: 1024px) {
  :root {
    --section-y: 88px;
    --gutter: 24px;
  }

  .hero__grid,
  .split,
  .split--wide-left,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .hero__media {
    margin-right: 0;
  }

  .grid-3,
  .grid-4,
  .trust {
    grid-template-columns: repeat(2, 1fr);
  }

  .tier {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .nav {
    display: none;
  }
}

@media (max-width: 640px) {
  :root {
    --section-y: 72px;
    --gutter: 20px;
  }

  .grid-3,
  .grid-4,
  .trust,
  .form,
  .footer__grid {
    grid-template-columns: 1fr;
  }

  .spec {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .header__actions .btn--ghost {
    display: none;
  }

  .header__inner {
    gap: 16px;
  }

  .header__actions {
    margin-left: auto;
  }

  .brand__name {
    font-size: 11px;
    letter-spacing: 0.1em;
  }

  .header__actions .btn {
    padding: 12px 14px;
    font-size: 11px;
    letter-spacing: 0.06em;
  }

  /* Thumb-sized tap targets for links that are only text-height on desktop. */
  .footer__col a,
  .card .link-seam {
    display: inline-block;
    padding: 7px 0;
  }

  /* Anything under 16px makes iOS Safari zoom the page on focus. */
  .field input,
  .field select,
  .field textarea {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    transform: none;
  }

  .btn--primary::after,
  .card::before,
  .tier__bar {
    transition: none;
  }
}