/* =========================================================
   АЛЬТЕРА ТЕХНОЛОГИИ — стили лендинга
   ========================================================= */

:root {
  --c-bg: #ffffff;
  --c-bg-alt: #f4f6fb;
  --c-dark: #0b1326;
  --c-dark-2: #111c36;
  --c-text: #1b2338;
  --c-muted: #5d6680;
  --c-border: #e2e6f0;
  --c-primary: #2f6bff;
  --c-primary-dark: #1f52d6;
  --c-accent: #19d3c5;
  --c-error: #e5484d;

  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 10px 30px rgba(15, 30, 70, .08);
  --shadow-lg: 0 20px 50px rgba(15, 30, 70, .14);
  --header-h: 76px;
  --container: 1200px;
  --t: .25s ease;
}

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

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

body {
  margin: 0;
  font-family: "Manrope", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; line-height: 1.2; font-weight: 800; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.accent {
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- Кнопки ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font: inherit;
  font-weight: 700;
  font-size: 15px;
  border-radius: 999px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--t), color var(--t), border-color var(--t), transform var(--t), box-shadow var(--t);
}
.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--c-primary);
  color: #fff;
  box-shadow: 0 8px 20px rgba(47, 107, 255, .35);
}
.btn--primary:hover { background: var(--c-primary-dark); }

.btn--ghost {
  background: transparent;
  color: var(--c-primary);
  border-color: var(--c-primary);
}
.btn--ghost:hover { background: var(--c-primary); color: #fff; }

.btn--block { width: 100%; }

/* ---------- Логотип ---------- */
.logo { display: inline-flex; align-items: center; gap: 10px; }
.logo__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #fff;
  font-weight: 800;
  font-size: 20px;
}
.logo__text {
  display: flex;
  flex-direction: column;
  font-weight: 800;
  font-size: 17px;
  letter-spacing: .04em;
  line-height: 1.05;
}
.logo__text small {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .22em;
  color: var(--c-muted);
}
.logo--light .logo__text { color: #fff; }
.logo--light .logo__text small { color: rgba(255, 255, 255, .6); }

/* ---------- Шапка ---------- */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t), box-shadow var(--t);
}
.header.is-scrolled { border-color: var(--c-border); box-shadow: 0 4px 20px rgba(15, 30, 70, .06); }

.header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav { display: flex; gap: 28px; margin-left: auto; }
.nav__link {
  position: relative;
  font-weight: 600;
  font-size: 15px;
  color: var(--c-muted);
  transition: color var(--t);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 0; bottom: -6px;
  width: 100%; height: 2px;
  background: var(--c-primary);
  transform: scaleX(0);
  transition: transform var(--t);
}
.nav__link:hover,
.nav__link.is-active { color: var(--c-text); }
.nav__link.is-active::after { transform: scaleX(1); }

.header__phone {
  font-weight: 700;
  white-space: nowrap;
  color: var(--c-primary);
}

.burger {
  display: none;
  width: 44px; height: 44px;
  padding: 10px;
  margin-left: auto;
  background: none;
  border: 0;
  cursor: pointer;
}
.burger span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--c-text);
  border-radius: 2px;
  transition: transform var(--t), opacity var(--t);
}
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Первый экран ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-h) + 80px) 0 100px;
  background: var(--c-dark);
  color: #fff;
}
.hero__bg { position: absolute; inset: 0; pointer-events: none; }
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 70% 40%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at 70% 40%, #000 20%, transparent 75%);
}
.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: .55;
}
.hero__glow--1 { width: 480px; height: 480px; background: var(--c-primary); top: -120px; right: -80px; }
.hero__glow--2 { width: 360px; height: 360px; background: var(--c-accent); bottom: -160px; left: 10%; opacity: .3; }

.hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
  gap: 48px;
}

.badge {
  display: inline-block;
  padding: 6px 14px;
  margin-bottom: 24px;
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: rgba(255, 255, 255, .85);
  background: rgba(255, 255, 255, .06);
}

.hero__title { font-size: clamp(34px, 5vw, 58px); letter-spacing: -.02em; }
.hero__text {
  max-width: 540px;
  margin-top: 24px;
  font-size: 18px;
  color: rgba(255, 255, 255, .72);
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 40px; }
.hero .btn--ghost { color: #fff; border-color: rgba(255, 255, 255, .35); }
.hero .btn--ghost:hover { background: #fff; color: var(--c-dark); border-color: #fff; }

/* Схема-визуал */
.hero__visual {
  position: relative;
  aspect-ratio: 1;
  max-width: 440px;
  width: 100%;
  margin-left: auto;
}
.hero__lines { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero__lines line {
  stroke: rgba(255, 255, 255, .25);
  stroke-width: 1.5;
  stroke-dasharray: 6 6;
  animation: dash 3s linear infinite;
}
@keyframes dash { to { stroke-dashoffset: -24; } }

.node {
  position: absolute;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 76px; height: 76px;
  margin: -38px 0 0 -38px;
  border-radius: 20px;
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .18);
  backdrop-filter: blur(6px);
  font-weight: 800;
  font-size: 15px;
  animation: float 6s ease-in-out infinite;
}
.node--center {
  width: 110px; height: 110px;
  margin: -55px 0 0 -55px;
  left: 50%; top: 50%;
  border-radius: 28px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  border: 0;
  box-shadow: 0 20px 60px rgba(47, 107, 255, .5);
  animation: pulse 4s ease-in-out infinite;
}
.node--center svg {
  width: 48px; height: 48px;
  fill: none; stroke: #fff; stroke-width: 1.8; stroke-linejoin: round; stroke-linecap: round;
}
.node--1 { left: 17.5%; top: 20%; }
.node--2 { left: 82.5%; top: 20%; animation-delay: -1.2s; }
.node--3 { left: 90%;   top: 62.5%; animation-delay: -2.4s; }
.node--4 { left: 50%;   top: 90%; animation-delay: -3.6s; }
.node--5 { left: 10%;   top: 62.5%; animation-delay: -4.8s; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-10px); }
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 20px 60px rgba(47, 107, 255, .45); }
  50%      { box-shadow: 0 20px 80px rgba(25, 211, 197, .6); }
}

/* ---------- Секции ---------- */
.section { padding: 100px 0; }
.section--alt { background: var(--c-bg-alt); }

.section__head { max-width: 720px; margin-bottom: 56px; }
.section__label {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-primary);
}
.section__title { font-size: clamp(28px, 3.4vw, 42px); letter-spacing: -.015em; }
.section__text { margin-top: 16px; font-size: 17px; color: var(--c-muted); }

/* ---------- Карточки услуг ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.card {
  padding: 32px;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}
.card__icon {
  display: grid;
  place-items: center;
  width: 56px; height: 56px;
  margin-bottom: 24px;
  border-radius: 14px;
  background: rgba(47, 107, 255, .1);
  transition: background var(--t);
}
.card__icon svg {
  width: 28px; height: 28px;
  fill: none; stroke: var(--c-primary); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round;
  transition: stroke var(--t);
}
.card:hover .card__icon { background: var(--c-primary); }
.card:hover .card__icon svg { stroke: #fff; }
.card__title { font-size: 20px; margin-bottom: 12px; }
.card__text { color: var(--c-muted); }

/* ---------- Этапы ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  counter-reset: step;
}
.step {
  position: relative;
  padding: 28px 24px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.step__num {
  display: block;
  margin-bottom: 16px;
  font-size: 36px;
  font-weight: 800;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--c-primary);
}
.step__title { font-size: 18px; margin-bottom: 8px; }
.step__text { font-size: 15px; color: var(--c-muted); }

/* ---------- Преимущества ---------- */
.advantages {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.advantages__text .btn { margin-top: 32px; }

.features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.feature {
  padding: 28px;
  border-radius: var(--radius);
  background: var(--c-dark);
  color: #fff;
}
.feature:nth-child(2),
.feature:nth-child(3) { background: linear-gradient(135deg, var(--c-primary), #4d84ff); }
.feature__value {
  display: block;
  font-size: 40px;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 12px;
}
.feature__label { font-size: 15px; color: rgba(255, 255, 255, .75); }

/* ---------- Реквизиты ---------- */
.requisites {
  padding: 16px 40px 40px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.requisites__list { margin: 0; }
.requisites__row {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 24px;
  padding: 20px 0;
  border-bottom: 1px solid var(--c-border);
}
.requisites__row dt { font-weight: 600; color: var(--c-muted); }
.requisites__row dd { margin: 0; font-weight: 600; }
.requisites__row a { color: var(--c-primary); }
.requisites__copy { margin-top: 32px; }

.copyable {
  position: relative;
  cursor: pointer;
  border-bottom: 1px dashed var(--c-primary);
  transition: color var(--t);
}
.copyable:hover { color: var(--c-primary); }
.copyable::after {
  content: "копировать";
  position: absolute;
  left: 100%;
  top: 50%;
  transform: translateY(-50%);
  white-space: nowrap;
  margin-left: 10px;
  font-size: 12px;
  font-weight: 500;
  color: var(--c-muted);
  opacity: 0;
  transition: opacity var(--t);
}
.copyable:hover::after { opacity: 1; }

/* ---------- Контакты и форма ---------- */
.contacts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}
.contacts__list { margin-top: 40px; display: grid; gap: 24px; }
.contacts__list li { display: flex; gap: 16px; align-items: center; }
.contacts__list small { display: block; color: var(--c-muted); font-size: 13px; }
.contacts__list a,
.contacts__list span { font-weight: 700; font-size: 17px; }
.contacts__list a:hover { color: var(--c-primary); }
.contacts__icon {
  flex-shrink: 0;
  display: grid;
  place-items: center;
  width: 52px; height: 52px;
  border-radius: 14px;
  background: rgba(47, 107, 255, .1);
}
.contacts__icon svg {
  width: 24px; height: 24px;
  fill: none; stroke: var(--c-primary); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round;
}

.form {
  padding: 40px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--c-border);
  box-shadow: var(--shadow-lg);
}
.form__title { font-size: 24px; margin-bottom: 24px; }

.field { display: block; margin-bottom: 18px; }
.field__label { display: block; margin-bottom: 6px; font-size: 14px; font-weight: 600; }
.field__input {
  width: 100%;
  padding: 14px 16px;
  font: inherit;
  font-size: 15px;
  color: var(--c-text);
  background: var(--c-bg-alt);
  border: 1.5px solid transparent;
  border-radius: var(--radius-sm);
  outline: none;
  resize: vertical;
  transition: border-color var(--t), background var(--t);
}
.field__input:focus { border-color: var(--c-primary); background: #fff; }
.field__error {
  display: none;
  margin-top: 6px;
  font-size: 13px;
  color: var(--c-error);
}
.field.is-invalid .field__input { border-color: var(--c-error); }
.field.is-invalid .field__error { display: block; }

.checkbox {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin: 8px 0 24px;
  font-size: 14px;
  color: var(--c-muted);
  cursor: pointer;
}
.checkbox input { margin-top: 4px; accent-color: var(--c-primary); width: 16px; height: 16px; }
.checkbox.is-invalid span { color: var(--c-error); }

.form__success {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: rgba(25, 211, 197, .12);
  color: #0d7f76;
  font-weight: 600;
}

/* ---------- Подвал ---------- */
.footer {
  padding: 56px 0 24px;
  background: var(--c-dark);
  color: rgba(255, 255, 255, .7);
  font-size: 14px;
}
.footer__inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}
.footer__brand p { margin-top: 16px; }
.footer__contacts { display: flex; flex-direction: column; gap: 8px; text-align: right; }
.footer__contacts a { color: #fff; font-weight: 700; font-size: 18px; }
.footer__bottom { padding-top: 24px; font-size: 13px; color: rgba(255, 255, 255, .45); }

/* ---------- Уведомление ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  z-index: 200;
  padding: 12px 22px;
  border-radius: 999px;
  background: var(--c-dark);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  box-shadow: var(--shadow-lg);
  transform: translate(-50%, 20px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t), transform var(--t);
}
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Анимация появления ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .6s ease, transform .6s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}

/* =========================================================
   Адаптив
   ========================================================= */
@media (max-width: 1100px) {
  .steps { grid-template-columns: repeat(3, 1fr); }
  .header__phone { display: none; }
}

@media (max-width: 960px) {
  .hero__inner,
  .advantages,
  .contacts { grid-template-columns: 1fr; }
  .hero__visual { margin: 0 auto; max-width: 360px; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .requisites__row { grid-template-columns: 220px 1fr; }

  .burger { display: block; }
  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    padding: 8px 24px 24px;
    background: #fff;
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--shadow);
    transform: translateY(-120%);
    transition: transform var(--t);
  }
  .nav.is-open { transform: none; }
  .nav__link { padding: 14px 0; border-bottom: 1px solid var(--c-border); font-size: 17px; }
  .nav__link::after { display: none; }
}

@media (max-width: 640px) {
  :root { --header-h: 66px; }
  .container { padding: 0 16px; }
  .section { padding: 72px 0; }
  .hero { padding: calc(var(--header-h) + 48px) 0 72px; }
  .hero__text { font-size: 16px; }
  .hero__actions .btn { flex: 1 1 100%; }
  .node { width: 60px; height: 60px; margin: -30px 0 0 -30px; font-size: 13px; border-radius: 16px; }
  .node--center { width: 88px; height: 88px; margin: -44px 0 0 -44px; }

  .cards,
  .steps,
  .features { grid-template-columns: 1fr; }

  .requisites { padding: 8px 20px 24px; }
  .requisites__row { grid-template-columns: 1fr; gap: 4px; padding: 16px 0; }
  .requisites__copy { width: 100%; }
  .copyable::after { display: none; }

  .form { padding: 28px 20px; }
  .footer__contacts { text-align: left; }
}