/* Underdot landing — статическая страница для корня домена */

:root {
  --bg-deep: #070b14;
  --bg: #0c1222;
  --surface: rgba(255, 255, 255, 0.045);
  --surface2: rgba(255, 255, 255, 0.08);
  --border: rgba(255, 255, 255, 0.08);
  --text: #e8edf5;
  --muted: #8b9bb4;
  --accent: #818cf8;
  --accent2: #6366f1;
  --accent-glow: rgba(99, 102, 241, 0.35);
  --radius: 14px;
  --radius-sm: 10px;
  --font: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --max: 1080px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1.05rem;
  line-height: 1.55;
  color: var(--text);
  background: var(--bg-deep);
  min-height: 100vh;
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 102, 241, 0.22), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(56, 189, 248, 0.08), transparent 50%),
    linear-gradient(180deg, var(--bg-deep) 0%, var(--bg) 40%, #0a0f1a 100%);
  opacity: 1;
}

.bg-grid::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black, transparent);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.container {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
  position: relative;
  z-index: 1;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(7, 11, 20, 0.75);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  gap: 1rem;
  min-height: 4rem;
}

.header__cluster {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  padding: 3px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  flex-shrink: 0;
}

.lang-switch__btn {
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.4rem 0.7rem;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  line-height: 1;
  transition: color 0.15s ease, background 0.15s ease;
}

.lang-switch__btn:hover {
  color: var(--text);
}

.lang-switch__btn--active {
  background: rgba(99, 102, 241, 0.28);
  color: var(--text);
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
}

.logo:hover {
  color: var(--accent);
  text-decoration: none;
}

.logo--brand {
  display: flex;
  align-items: center;
  line-height: 0;
}

.logo--brand:hover .logo__img {
  opacity: 0.92;
}

.logo__img {
  height: 90px;
  width: auto;
  max-width: min(280px, 58vw);
  object-fit: contain;
  display: block;
}

.logo__img--footer {
  height: clamp(32px, 4vw, 40px);
  max-width: 200px;
  opacity: 0.85;
}

.logo--muted {
  color: var(--muted);
  font-size: 1rem;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav__link {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
}

.nav__link:hover {
  color: var(--text);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background: var(--text);
  border-radius: 1px;
}

.nav-mobile {
  display: none;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1rem 1.25rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background: rgba(7, 11, 20, 0.95);
}

.nav-mobile:not([hidden]) {
  display: flex;
}

@media (min-width: 769px) {
  .nav-mobile {
    display: none !important;
  }
}

.nav-mobile a {
  color: var(--text);
  padding: 0.5rem 0;
  font-weight: 500;
}

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn--sm {
  padding: 0.45rem 1rem;
  font-size: 0.875rem;
}

.btn--lg {
  padding: 0.85rem 1.75rem;
  font-size: 1rem;
}

.btn--primary {
  background: linear-gradient(135deg, var(--accent2), #4f46e5);
  color: #fff;
  box-shadow: 0 4px 24px var(--accent-glow);
}

.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 32px rgba(99, 102, 241, 0.45);
}

.btn--secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn--secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

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

.btn--ghost:hover {
  background: var(--surface);
}

/* Hero */
.hero {
  position: relative;
  z-index: 1;
  padding: 3.5rem 0 4rem;
}

@media (min-width: 900px) {
  .hero {
    padding: 5rem 0 5.5rem;
  }
}

.hero__grid {
  display: grid;
  gap: 3rem;
  align-items: center;
}

@media (min-width: 900px) {
  .hero__grid {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }
}

.eyebrow {
  display: inline-block;
  margin: 0 0 1rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.25);
  border-radius: 999px;
}

.hero h1 {
  margin: 0 0 1.25rem;
  font-size: clamp(1.85rem, 4vw, 2.65rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.lead {
  margin: 0 0 1.75rem;
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 38ch;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.hero__bullets {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.hero__bullets li {
  position: relative;
  padding-left: 1.35rem;
  font-size: 0.95rem;
  color: var(--muted);
}

.hero__bullets li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent2);
  box-shadow: 0 0 10px var(--accent-glow);
}

/* Mock phone */
.hero__visual {
  display: flex;
  justify-content: center;
}

.mock-phone {
  width: min(100%, 280px);
  aspect-ratio: 9 / 18;
  border-radius: 28px;
  background: linear-gradient(165deg, #1a2135 0%, #0f1424 100%);
  border: 1px solid var(--border);
  box-shadow:
    0 24px 80px rgba(0, 0, 0, 0.45),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
  padding: 10px 12px 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.mock-phone__bar {
  height: 5px;
  width: 36%;
  margin: 4px auto 0;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.12);
}

.mock-phone__chat {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 8px 4px;
  min-height: 0;
}

.bubble {
  max-width: 92%;
  padding: 8px 11px;
  border-radius: 12px;
  font-size: 0.78rem;
  line-height: 1.35;
}

.bubble--bot {
  align-self: flex-start;
  background: rgba(99, 102, 241, 0.2);
  border: 1px solid rgba(99, 102, 241, 0.25);
  color: #e0e4ff;
}

.bubble--user {
  align-self: flex-end;
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
}

.mock-phone__rail {
  width: 28px;
  align-self: flex-end;
  flex: 0 0 auto;
  height: 42%;
  min-height: 80px;
  border-radius: 10px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.02));
  border: 1px solid var(--border);
}

/* Sections */
.section {
  position: relative;
  z-index: 1;
  padding: 4rem 0;
}

.section--alt {
  background: rgba(0, 0, 0, 0.2);
  border-block: 1px solid var(--border);
}

.section__title {
  margin: 0 0 0.75rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
}

.section__title--left {
  text-align: left;
}

.section__subtitle {
  margin: 0 auto 2.5rem;
  max-width: 52ch;
  text-align: center;
  color: var(--muted);
  font-size: 1.05rem;
}

.section__subtitle--left {
  margin-left: 0;
  text-align: left;
}

/* Cards */
.cards {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 600px) {
  .cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .cards {
    grid-template-columns: repeat(4, 1fr);
  }
}

.card {
  padding: 1.5rem;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
  border-color: rgba(99, 102, 241, 0.35);
  transform: translateY(-2px);
}

.card__icon {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  opacity: 0.9;
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.card p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 1.5;
}

/* Steps */
.steps {
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: 640px;
  margin-inline: auto;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.steps__item {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
}

.steps__num {
  flex-shrink: 0;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  color: #fff;
  background: linear-gradient(135deg, var(--accent2), #4338ca);
  border-radius: 50%;
  box-shadow: 0 4px 16px var(--accent-glow);
}

.steps__item h3 {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
}

.steps__item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

/* Demo */
.demo {
  padding-bottom: 4.5rem;
}

.demo__inner {
  padding: 2.5rem;
  border-radius: calc(var(--radius) + 4px);
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.12), rgba(15, 23, 42, 0.6));
  border: 1px solid rgba(99, 102, 241, 0.2);
}

.demo__text {
  max-width: 560px;
}

.demo__hint {
  margin: 1.25rem 0 0;
  font-size: 0.88rem;
  color: var(--muted);
}

/* CTA */
.section--cta {
  padding: 4.5rem 0;
}

.cta {
  text-align: center;
  max-width: 560px;
  margin-inline: auto;
}

.cta--form {
  max-width: 420px;
}

.cta h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.45rem, 3vw, 1.85rem);
}

.cta > p {
  margin: 0 0 1.5rem;
  color: var(--muted);
}

.landing-form {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.landing-form__field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.landing-form__label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
}

.landing-form input {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  font-size: 1rem;
  font-family: inherit;
}

.landing-form input::placeholder {
  color: var(--muted);
  opacity: 0.7;
}

.landing-form input:focus {
  outline: none;
  border-color: rgba(99, 102, 241, 0.55);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.landing-form__submit {
  margin-top: 0.25rem;
  width: 100%;
  justify-content: center;
}

.landing-form__msg {
  margin: 0;
  font-size: 0.92rem;
  text-align: center;
}

.landing-form__msg--ok {
  color: #86efac;
}

.landing-form__msg--err {
  color: #fca5a5;
}

.muted {
  color: var(--muted);
}

/* Footer */
.footer {
  position: relative;
  z-index: 1;
  padding: 2rem 0 2.5rem;
  border-top: 1px solid var(--border);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.footer__copy {
  font-size: 0.88rem;
  color: var(--muted);
}