:root {
  --background: #ffffff;
  --text: #080b11;
  --muted: #5e6673;
  --subtle: #f6f8fb;
  --line: #e6eaf0;
  --line-strong: #d8dee8;
  --accent: #075cff;
  --accent-dark: #0346cb;
  --shadow: 0 24px 70px rgba(8, 18, 36, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  letter-spacing: 0;
}

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

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 86px;
  padding: 0 clamp(24px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-size: clamp(28px, 3vw, 36px);
  line-height: 1;
  font-weight: 760;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 3vw, 42px);
  font-size: 16px;
  font-weight: 520;
}

.nav a {
  color: #11151d;
}

.nav a:hover,
.nav a:focus-visible {
  color: var(--accent);
}

.login-link {
  color: var(--accent) !important;
  padding-left: clamp(12px, 2vw, 28px);
  border-left: 1px solid var(--line-strong);
}

.hero {
  min-height: calc(100vh - 86px);
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
  align-items: center;
  gap: clamp(42px, 7vw, 96px);
  padding: clamp(64px, 10vw, 132px) clamp(24px, 5vw, 72px) clamp(58px, 8vw, 96px);
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  max-width: 640px;
}

.hero h1 {
  margin: 0;
  max-width: 620px;
  font-size: clamp(48px, 7vw, 78px);
  line-height: 0.98;
  font-weight: 800;
  letter-spacing: 0;
}

.hero p {
  margin: 34px 0 0;
  max-width: 460px;
  color: var(--muted);
  font-size: clamp(20px, 2vw, 24px);
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-top: 46px;
}

.button-primary,
.button-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 60px;
  border-radius: 8px;
  font-size: 20px;
  font-weight: 720;
}

.button-primary {
  min-width: 138px;
  color: #fff;
  background: var(--accent);
  box-shadow: 0 16px 38px rgba(7, 92, 255, 0.22);
}

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--accent-dark);
}

.button-secondary {
  color: var(--accent);
  gap: 10px;
}

.button-secondary::after {
  content: "";
  width: 8px;
  height: 8px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
}

.product-preview {
  min-height: 438px;
  display: grid;
  grid-template-columns: 72px 230px minmax(280px, 1fr);
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: 14px;
  background: #fff;
  box-shadow: var(--shadow);
}

.preview-rail {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  padding-top: 25px;
  background: linear-gradient(180deg, #111318, #06070a);
  color: #fff;
  position: relative;
}

.preview-mark {
  font-size: 24px;
  font-weight: 800;
}

.preview-mark::after {
  content: "";
  display: inline-block;
  width: 5px;
  height: 18px;
  margin-left: -6px;
  background: var(--accent);
  transform: skew(-13deg);
}

.preview-rail span:not(.preview-mark) {
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255, 255, 255, 0.78);
  border-radius: 5px;
}

.preview-rail .rail-active {
  border-color: #fff;
  box-shadow: -24px 0 0 -21px var(--accent);
}

.preview-list,
.preview-chat {
  min-width: 0;
}

.preview-list {
  border-right: 1px solid var(--line);
  background: #fbfcfe;
}

.preview-heading {
  min-height: 70px;
  display: flex;
  align-items: center;
  padding: 0 22px;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
  font-weight: 760;
}

.preview-filter {
  padding: 18px 22px 12px;
  color: #3d4654;
  font-size: 13px;
}

.conversation {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 14px 18px;
}

.conversation.active {
  background: #eef4ff;
}

.conversation span {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: #d8e5fa;
  color: #1f5dbd;
  font-size: 12px;
  font-weight: 760;
}

.conversation strong,
.conversation small {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.conversation strong {
  font-size: 13px;
  font-weight: 700;
}

.conversation small {
  margin-top: 4px;
  color: #697386;
  font-size: 12px;
}

.preview-chat {
  display: flex;
  flex-direction: column;
}

.chat-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: 34px 24px 24px;
}

.bubble {
  max-width: 235px;
  margin: 0;
  padding: 17px 18px;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.45;
}

.bubble.inbound {
  align-self: flex-start;
  background: #f0f2f5;
}

.bubble.outbound {
  align-self: flex-end;
  color: #fff;
  background: var(--accent);
}

.bubble.short {
  max-width: 175px;
}

.message-input {
  height: 45px;
  display: flex;
  align-items: center;
  margin: 0 24px 20px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: #9aa3b2;
  font-size: 13px;
}

.capabilities {
  padding: clamp(38px, 6vw, 76px) clamp(24px, 5vw, 72px);
}

.capability {
  display: grid;
  grid-template-columns: 112px minmax(220px, 0.62fr) minmax(280px, 0.8fr);
  align-items: center;
  gap: clamp(28px, 5vw, 64px);
  max-width: 1060px;
  margin: 0 auto;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.capability:last-child {
  border-bottom: 0;
}

.capability-icon {
  width: 82px;
  height: 82px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  color: var(--accent);
}

.capability-icon svg {
  width: 38px;
  height: 38px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.capability h2 {
  margin: 0;
  font-size: clamp(30px, 3vw, 40px);
  line-height: 1.1;
}

.capability p {
  margin: 0;
  color: var(--muted);
  font-size: 19px;
  line-height: 1.5;
}

.about {
  display: flex;
  justify-content: center;
  padding: 12px 24px 72px;
}

.about p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  text-align: center;
  font-size: 17px;
  line-height: 1.55;
}

.footer {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 96px;
  border-top: 1px solid var(--line);
  color: #6c7480;
  font-size: 16px;
}

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .product-preview {
    grid-template-columns: 62px minmax(180px, 0.48fr) minmax(260px, 0.72fr);
  }

  .capability {
    grid-template-columns: 86px 1fr;
  }

  .capability p {
    grid-column: 2;
  }
}

@media (max-width: 720px) {
  .site-header {
    min-height: 72px;
    padding: 0 20px;
  }

  .nav a:not(.login-link) {
    display: none;
  }

  .login-link {
    padding-left: 0;
    border-left: 0;
  }

  .hero {
    padding: 52px 20px 44px;
  }

  .hero h1 {
    font-size: 44px;
  }

  .hero p {
    margin-top: 24px;
    font-size: 18px;
  }

  .hero-actions {
    align-items: stretch;
    gap: 16px;
    margin-top: 34px;
  }

  .button-primary,
  .button-secondary {
    min-height: 52px;
    font-size: 17px;
  }

  .product-preview {
    grid-template-columns: 1fr;
    min-height: 0;
  }

  .preview-rail {
    display: none;
  }

  .preview-list {
    display: none;
  }

  .preview-chat {
    min-height: 390px;
  }

  .capabilities {
    padding: 22px 20px 54px;
  }

  .capability {
    grid-template-columns: 1fr;
    gap: 18px;
    padding: 30px 0;
  }

  .capability p {
    grid-column: auto;
    font-size: 17px;
  }

  .about {
    padding-bottom: 56px;
  }
}