/* ============================================================
   BIONA — лендинг. Дизайн под 1920px, контейнер 1600px.
   Структура: токены → reset → утилиты → секции 1–13 → адаптив.
   ============================================================ */

/* ---------- Токены ---------- */
:root {
  --dark:        #070C1D;   /* тёмный фон / основной текст */
  --dark-card:   #12161E;   /* тёмная карточка */
  --teal:        #14B6A7;   /* бирюзовый акцент */
  --cyan:        #09B3D4;
  --blue:        #2469E6;
  --blue-light:  #487BFF;
  --blue-deep:   #1656FF;
  --violet:      #814FFE;
  --light-bg:    #F8FAFC;
  --white:       #FFFFFF;
  --title:       #12161E;   /* тёмный заголовочный текст (Фигма) */
  --text:        #3C404B;
  --text-muted:  #6B7280;
  --text-faint:  #99A0AD;
  --label-lav:   #D0D9F6;   /* светло-лавандовые метки в about */

  --grad-btn:   linear-gradient(90.12deg, #09B3D4 0%, #814FFE 100%);
  --grad-blue:  linear-gradient(180deg, #1656FF 0%, #14B6A7 100%);
  --grad-num:   linear-gradient(180deg, #09B3D4 0%, #814FFE 100%);
  --grad-accent:linear-gradient(180deg, #09B3D4 0%, #814FFE 100%);
  --grad-chip:  linear-gradient(180deg, #1656FF 0%, #14B6A7 100%);

  --container: 1600px;
  --gutter: clamp(16px, 4vw, 40px);
  --radius: 20px;
  --header-h: 68px;

  --font: "Poppins", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

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

html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); overflow-x: hidden; }

body {
  font-family: var(--font);
  font-weight: 400;
  color: var(--text);
  background: var(--white);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: 0; background: none; }
ul { list-style: none; }

/* ---------- Утилиты ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: 1000px; }

.section { padding-block: clamp(56px, 7vw, 110px); }
.section--dark { background: var(--dark); color: var(--white); }

.section__title {
  font-weight: 300;
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--title);
}
.section__title--center { text-align: center; }
.section__title--light { color: var(--white); }

.section__lead {
  max-width: 760px;
  margin: 16px auto 0;
  text-align: center;
  font-size: clamp(15px, 1.1vw, 18px);
  color: var(--text);
}
.section__lead--light { color: rgba(255,255,255,.7); }

.eyebrow {
  font-weight: 500;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--teal);
}
.eyebrow--center { text-align: center; }
.eyebrow--accent { color: var(--teal); }

/* градиентный текст (clip) */
.text-accent {
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 400;
  color: var(--white);
  transition: transform .15s ease, box-shadow .15s ease, opacity .15s ease;
}
.btn--gradient { background: var(--grad-btn); }
.btn--gradient:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(40,80,230,.35); }

/* ============================================================
   1. HEADER
   ============================================================ */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 1000;
  background: transparent;
  transition: background .25s ease, box-shadow .25s ease;
}
.header.is-scrolled {
  background: var(--white);
  box-shadow: 0 2px 20px rgba(7,12,29,.08);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}
.header__logo { display: flex; align-items: center; }
.nav { display: flex; align-items: center; gap: 8px; }
.nav__link {
  padding: 8px 14px;
  font-size: 15px;
  letter-spacing: .02em;
  text-transform: uppercase;
  color: var(--title);
  transition: color .15s ease;
}
.nav__link:hover { color: var(--blue); }

.burger { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.burger span { width: 26px; height: 2px; background: var(--dark); border-radius: 2px; transition: .25s; }
.burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger.is-open span:nth-child(2) { opacity: 0; }
.burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================
   2. HERO
   ============================================================ */
.hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(40px, 6vw, 90px));
  padding-bottom: clamp(50px, 7vw, 110px);
  background-color: var(--light-bg);
  background-image: url("../assets/images/hero-bg.png");
  background-position: right center;
  background-size: cover;
  background-repeat: no-repeat;
}
.hero__inner {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  align-items: center;
  gap: 40px;
}
.hero__eyebrow {
  display: inline-block;
  font-size: 15px; font-weight: 500; letter-spacing: .12em;
  text-transform: uppercase; margin-bottom: 20px;
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__title {
  font-weight: 300;
  font-size: clamp(38px, 5vw, 72px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--title);
}
.hero__text {
  max-width: 560px;
  margin-top: 28px;
  font-size: clamp(15px, 1.05vw, 17px);
  color: var(--text);
}
.hero__text strong { font-weight: 600; }
.hero .btn { margin-top: 28px; }

.hero__cards { position: relative; min-height: 460px; }
.hero__chip {
  position: absolute;
  padding: 22px 34px;
  border-radius: 24px;
  font-size: clamp(16px, 1.3vw, 22px);
  background: linear-gradient(135deg, rgba(255,255,255,.9), rgba(220,232,255,.6));
  border: 1px solid rgba(255,255,255,.8);
  box-shadow: 0 20px 50px rgba(40,80,230,.12);
  backdrop-filter: blur(6px);
}
/* текст чипа — градиент blue→teal (clip), на вложенном span */
.hero__chip > span {
  background: var(--grad-chip);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__chip--1 { top: 0;    right: 0;   }
.hero__chip--2 { top: 42%;  left: 0;    }
.hero__chip--3 { bottom: 0; right: 8%;  }

/* ============================================================
   3. PROBLEMS
   ============================================================ */
.problems__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 48px;
}
.problem-photo {
  position: relative;
  min-height: 420px;
  border-radius: var(--radius);
  background-size: cover;
  background-position: center;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
}
.problem-photo__overlay {
  width: 100%;
  padding: 28px;
  background: linear-gradient(180deg, rgba(255,255,255,0) 0%, rgba(255,255,255,.92) 55%);
}
.problem-photo__title { font-size: 22px; font-weight: 500; color: var(--title); }
.problem-photo__stat  { margin-top: 6px; font-weight: 600; color: var(--blue); }
.problem-photo__text  { margin-top: 10px; font-size: 14px; color: var(--text); }

.problems__cards { display: flex; flex-direction: column; gap: 24px; }
.problem-card {
  background: rgba(208, 217, 246, 0.7);
  border-radius: var(--radius);
  padding: 28px;
}
.problem-card__title { font-size: 20px; font-weight: 500; color: var(--title); }
.problem-card__text  { margin-top: 10px; font-size: 14px; color: var(--text); }

.problems__note {
  max-width: 1000px;
  margin: 48px auto 0;
  text-align: center;
  font-size: clamp(17px, 1.5vw, 22px);
  font-weight: 300;
  color: var(--title);
}
.problems__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
  margin-top: 48px;
  text-align: center;
}
.stat-col__title { font-size: 19px; font-weight: 500; color: var(--title); }
.stat-col__text  { margin-top: 8px; font-size: 14px; color: var(--text); }

/* ============================================================
   4. SOLUTION (dark)
   ============================================================ */
.solution__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: stretch;
  margin-top: 48px;
}
.solution__cards { display: flex; flex-direction: column; gap: 20px; }
.solution-card {
  display: flex;
  gap: 18px;
  padding: 26px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid #EEF1F6;
  box-shadow: 0 16px 40px rgba(7,12,29,.10);
}
.solution-card__icon { width: 34px; height: 34px; flex: none; }
.solution-card__title { font-size: 21px; font-weight: 500; color: var(--title); }
.solution-card__text  { margin-top: 8px; font-size: 14px; color: var(--text); }
.solution__media {
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 320px;
  max-height: 519px;
}
.solution__media img { width: 100%; height: 100%; object-fit: cover; }

/* ============================================================
   5. FUTURE (CTA banner)
   ============================================================ */
.future {
  background: var(--light-bg) center/cover no-repeat;
  padding-block: clamp(60px, 9vw, 130px);
}
.future__inner { text-align: center; }
.future__title {
  font-weight: 300;
  font-size: clamp(28px, 3.4vw, 46px);
  line-height: 1.2;
  color: var(--title);
}
.future .btn { margin-top: 28px; }

/* ============================================================
   6. ECOSYSTEM
   ============================================================ */
.ecosystem__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}
.eco-card {
  padding: 34px 30px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid #E6EAF2;
  box-shadow: 0 14px 40px rgba(7,12,29,.05);
}
.eco-card__label { font-size: 13px; font-weight: 500; color: var(--text-faint); }
.eco-card__label--teal   { color: var(--teal); }
.eco-card__label--cyan   { color: var(--cyan); }
.eco-card__label--violet { color: #9747FF; }
.eco-card__title { margin-top: 12px; font-size: 26px; font-weight: 500; color: var(--title); }
.eco-card__text  { margin-top: 14px; font-size: 14px; color: var(--text); }

/* ============================================================
   7. ABOUT (dark)
   ============================================================ */
.about__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  margin-top: 48px;
}
.about-card {
  padding: 30px 26px;
  border-radius: var(--radius);
  background: var(--dark-card);
  border: 1px solid rgba(255,255,255,.06);
}
.about-card__num {
  display: block;
  font-size: clamp(34px, 3vw, 46px);
  font-weight: 500;
  line-height: 1;
  background: var(--grad-num);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.about-card__label {
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--label-lav);
}
.about-card__title { margin-top: 18px; font-size: 19px; font-weight: 500; text-transform: uppercase; color: var(--white); }
.about-card__text  { margin-top: 12px; font-size: 14px; color: rgba(255,255,255,.6); }

/* ============================================================
   8. ROADMAP (timeline)
   ============================================================ */
.timeline {
  position: relative;
  max-width: 1200px;
  margin: 60px auto 0;
  list-style: none;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 0; bottom: 0; left: 50%;
  width: 2px;
  transform: translateX(-50%);
  background: rgba(20,182,167,.35);
}
.timeline__item {
  position: relative;
  width: 50%;
  padding: 0 48px 56px;
}
.timeline__item:nth-child(odd)  { left: 0;   text-align: right; }
.timeline__item:nth-child(even) { left: 50%; text-align: left;  }
.timeline__item::after {        /* точка на линии */
  content: "";
  position: absolute;
  top: 6px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 0 4px rgba(20,182,167,.2);
}
.timeline__item:nth-child(odd)::after  { right: -8px; }
.timeline__item:nth-child(even)::after { left: -8px;  }
.timeline__year  { font-size: 14px; color: var(--cyan); }
.timeline__title { margin-top: 8px; font-size: clamp(22px, 2vw, 30px); font-weight: 300; color: var(--title); }
.timeline__text  { margin-top: 12px; font-size: 14px; color: var(--text); }
.timeline__ref   { margin-top: 12px; font-size: 13px; color: var(--teal); }

/* ============================================================
   9. TEAM (dark)
   ============================================================ */
.team__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  margin-top: 48px;
}
.team__subhead { margin-top: 72px; }
.team-card {
  border-radius: 16px;
  overflow: hidden;
  background: var(--white);
  border: 1px solid #EEF1F6;
  box-shadow: 0 16px 40px rgba(7,12,29,.10);
}
.team-card__photo { width: 100%; aspect-ratio: 1/1; object-fit: cover; }
.team-card__body { padding: 18px; }
.team-card__name { font-size: 16px; font-weight: 500; color: var(--title); }
.team-card__role { margin-top: 4px; font-size: 12px; color: var(--teal); }
.team-card__list { margin-top: 12px; display: flex; flex-direction: column; gap: 6px; }
.team-card__list li {
  position: relative;
  padding-left: 14px;
  font-size: 12px;
  color: var(--text);
}
.team-card__list li::before {
  content: "•"; position: absolute; left: 0; color: var(--blue-light);
}

/* ============================================================
   10. RESEARCHES (dark)
   ============================================================ */
.researches__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
  margin-top: 48px;
}
.paper {
  display: flex;
  flex-direction: column;
  padding: 28px;
  border-radius: 16px;
  background: var(--white);
  color: var(--title);
  border: 1px solid #EEF1F6;
  box-shadow: 0 16px 40px rgba(7,12,29,.10);
}
/* .paper__logo   { height: 26px; width: auto; object-fit: contain; align-self: flex-start; } */
.paper__logo   { height: 50px; width: auto; object-fit: contain; align-self: flex-start; }
.paper__year   { margin-top: 14px; font-size: 13px; color: var(--text-faint); }
.paper__title  { margin-top: 8px; font-size: 17px; font-weight: 500; line-height: 1.35; }
.paper__authors{ margin-top: 10px; font-size: 13px; color: var(--text-muted); }
.paper__link   { margin-top: auto; padding-top: 16px; font-size: 14px; color: var(--blue); }
.paper__link:hover { text-decoration: underline; }

/* ============================================================
   11. FAQ (accordion, pure CSS)
   ============================================================ */
.faq__list { margin-top: 44px; display: flex; flex-direction: column; gap: 16px; }
.faq-item {
  border-radius: 16px;
  background: var(--white);
  box-shadow: 0 8px 30px rgba(40,80,230,.08);
  overflow: hidden;
}
.faq-item__q {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 28px;
  font-size: clamp(16px, 1.3vw, 20px);
  font-weight: 400;
  color: var(--title);
  cursor: pointer;
}
.faq-item__q::-webkit-details-marker { display: none; }
.faq-item__q::after {
  content: "";
  flex: none;
  width: 12px; height: 12px;
  border-right: 2px solid var(--blue);
  border-bottom: 2px solid var(--blue);
  transform: rotate(45deg);
  transition: transform .3s ease;
}
.faq-item[open] .faq-item__q::after { transform: rotate(-135deg); }

/* плавное раскрытие через grid-rows */
.faq-item__a-wrap {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .35s ease;
}
.faq-item[open] .faq-item__a-wrap { grid-template-rows: 1fr; }
.faq-item__a { overflow: hidden; }
.faq-item__a p { padding: 0 28px 26px; font-size: 15px; color: var(--text); }

/* ============================================================
   12. CONTACT (banner)
   ============================================================ */
.contact {
  background: var(--light-bg) center/cover no-repeat;
  padding-block: clamp(50px, 7vw, 90px);
}
.contact__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}
.contact__title {
  font-weight: 300;
  font-size: clamp(26px, 3vw, 42px);
  line-height: 1.2;
  color: var(--title);
}
.contact__card { text-align: right; }
.contact__label { font-size: 13px; color: var(--text-faint); }
.contact__label--mt { margin-top: 16px; }
.contact__name { font-size: 22px; font-weight: 500; color: var(--title); }
.contact__line { display: block; margin-top: 4px; font-size: 17px; color: var(--blue); }
.contact__line:hover { text-decoration: underline; }
.contact__btn { margin-top: 18px; }

/* ============================================================
   13. FOOTER
   ============================================================ */
.footer { background: var(--white); padding-block: 40px; border-top: 1px solid #EEF1F6; }
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.footer__socials { display: flex; gap: 12px; }
.footer__socials a { transition: transform .15s ease; }
.footer__socials a:hover { transform: translateY(-2px); }
.footer__copy { margin-top: 24px; text-align: center; font-size: 14px; color: var(--text-faint); }

/* ============================================================
   АДАПТИВ
   ============================================================ */

/* --- Планшет --- */
@media (max-width: 1100px) {
  .hero__inner { grid-template-columns: 1fr; }
  .hero__cards { min-height: 300px; margin-top: 20px; }
  .solution__grid { grid-template-columns: 1fr; }
  .ecosystem__grid { grid-template-columns: 1fr; }
  .about__grid { grid-template-columns: repeat(2, 1fr); }
  .problems__stats { grid-template-columns: repeat(2, 1fr); }
  .team__grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 860px) {
  .researches__grid { grid-template-columns: 1fr; }
  .team__grid { grid-template-columns: repeat(2, 1fr); }
}

/* --- Телефон --- */
@media (max-width: 768px) {
  /* меню → бургер */
  .burger { display: flex; }
  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    flex-direction: column;
    gap: 0;
    align-items: stretch;
    background: var(--white);
    box-shadow: 0 14px 30px rgba(7,12,29,.12);
    padding: 8px var(--gutter) 16px;
    transform: translateY(-130%);
    transition: transform .28s ease;
    pointer-events: none;
  }
  .nav.is-open { transform: translateY(0); pointer-events: auto; }
  .nav__link { padding: 14px 4px; border-bottom: 1px solid #F0F2F6; }
  /* меню открыто → даём хедеру фон, чтобы пункты читались */
  .header:has(.nav.is-open) { background: var(--white); }

  /* hero-чипы — в обычный поток, чтобы не вылезали за экран */
  .hero__cards {
    position: static;
    min-height: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 28px;
  }
  .hero__chip { position: static; }

  .problems__grid { grid-template-columns: 1fr; }
  .problems__stats { grid-template-columns: 1fr; }
  .about__grid { grid-template-columns: 1fr; }
  .ecosystem__grid { grid-template-columns: 1fr; }
  .team__grid { grid-template-columns: 1fr 1fr; }

  /* таймлайн → одна колонка слева */
  .timeline::before { left: 8px; }
  .timeline__item {
    width: 100%;
    left: 0 !important;
    text-align: left !important;
    padding: 0 0 40px 36px;
  }
  .timeline__item::after { left: 1px !important; right: auto !important; }

  .contact__inner { flex-direction: column; align-items: flex-start; }
  .contact__card { text-align: left; }

  .footer__inner { flex-direction: column; gap: 20px; text-align: center; }
}

@media (max-width: 460px) {
  .team__grid { grid-template-columns: 1fr; }
  .hero__chip { padding: 16px 22px; }
}