:root {
  --blue: #1b4f8a;
  --blue-dark: #143a66;
  --blue-soft: #e8f0fa;
  --ink: #1c2430;
  --muted: #5c6570;
  --line: #d8dee6;
  --bg: #f3f5f8;
  --card: #ffffff;
  --max: 1080px;
  --radius: 16px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--blue);
}

a:hover {
  color: var(--blue-dark);
}

.skip {
  position: absolute;
  left: -999px;
  top: 8px;
}

.skip:focus {
  left: 8px;
  z-index: 20;
  background: #fff;
  padding: 8px 12px;
}

.wrap {
  width: min(var(--max), calc(100% - 32px));
  margin-inline: auto;
}

header {
  background: #fff;
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
}

.nav-toggle {
  display: none;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 12px;
  font: inherit;
  cursor: pointer;
}

header nav {
  display: flex;
  gap: 8px;
}

header nav a {
  text-decoration: none;
  color: var(--muted);
  padding: 8px 12px;
  border-radius: 8px;
}

header nav a:hover,
header nav a[aria-current="page"] {
  color: var(--blue);
  background: var(--blue-soft);
}

.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
  padding: 48px 0 24px;
}

.hero > * {
  min-width: 0;
}

h1,
.lead,
.prose p,
.prose li {
  overflow-wrap: break-word;
}

main > .kicker + h1,
.section > h1 {
  margin: 0 0 12px;
  font-size: clamp(1.8rem, 3.4vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.hero h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 4vw, 2.8rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.hero .lead {
  font-size: 1.12rem;
  color: var(--muted);
  margin: 0 0 24px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-block;
  background: var(--blue);
  color: #fff;
  text-decoration: none;
  padding: 12px 18px;
  border-radius: 10px;
  font-weight: 600;
}

.btn:hover {
  background: var(--blue-dark);
  color: #fff;
}

.btn-ghost {
  background: #fff;
  color: var(--blue);
  border: 1px solid var(--line);
}

.btn-ghost:hover {
  background: var(--blue-soft);
  color: var(--blue-dark);
}

.note {
  font-size: 0.9rem;
  color: var(--muted);
  margin-top: 16px;
}

.section {
  padding: 28px 0 48px;
}

.section h2 {
  margin: 0 0 8px;
  font-size: 1.6rem;
  letter-spacing: -0.02em;
}

.section > p {
  color: var(--muted);
}

.prose p,
.prose li {
  color: var(--ink);
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 24px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

.card img {
  width: 64px;
  height: 64px;
  object-fit: cover;
  border-radius: 14px;
  display: block;
  margin-bottom: 12px;
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.demo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
  margin-top: 24px;
}

.demo-copy h3 {
  margin-top: 0;
}

.phones {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
}

.phone {
  width: 260px;
  background: #1a1f26;
  border-radius: 28px;
  padding: 10px;
  box-shadow: 0 18px 40px rgba(20, 58, 102, 0.28);
}

.phone-screen {
  background: #fff;
  border-radius: 20px;
  overflow: hidden;
  min-height: 470px;
}

.phone-status {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  padding: 8px 12px 4px;
  color: #444;
}

.phone-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px;
  background: #fff;
  border-bottom: 1px solid var(--line);
  font-weight: 650;
  font-size: 14px;
}

.phone-bar span {
  color: var(--blue);
  font-weight: 600;
  font-size: 13px;
}

.phone-chips {
  display: flex;
  gap: 6px;
  padding: 8px 12px;
}

.chip {
  font-size: 11px;
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--bg);
  color: var(--muted);
}

.chip.on {
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 600;
}

.row {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
}

.row.unread {
  background: var(--blue-soft);
}

.row strong {
  display: block;
  font-size: 13px;
}

.row small {
  display: block;
  color: var(--muted);
  font-size: 11px;
  margin-top: 2px;
}

.msg {
  padding: 12px;
}

.msg h4 {
  margin: 0 0 6px;
  font-size: 14px;
}

.msg p {
  margin: 0 0 10px;
  font-size: 13px;
  color: #333;
}

.msg .meta {
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 8px;
}

.linkish {
  color: var(--blue);
  font-size: 13px;
  font-weight: 600;
}

.lock-demo {
  text-align: center;
  padding: 40px 16px;
}

.lock-demo .dots {
  letter-spacing: 8px;
  font-size: 22px;
  color: var(--blue);
  margin: 12px 0 18px;
}

.lock-keys {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  max-width: 180px;
  margin: 0 auto;
  font-size: 16px;
  color: var(--ink);
}

.lock-keys span {
  background: var(--bg);
  border-radius: 50%;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
}

.toc {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 20px 0 28px;
}

.toc ol {
  margin: 8px 0 0;
  padding-left: 20px;
}

.prose {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px 28px 28px;
}

.prose h2 {
  margin-top: 32px;
  padding-top: 8px;
}

.prose h3 {
  margin-top: 22px;
}

.prose ul,
.prose ol {
  color: var(--ink);
}

.prose li + li {
  margin-top: 6px;
}

.prose code {
  font-size: 0.92em;
  background: var(--bg);
  padding: 1px 6px;
  border-radius: 4px;
}

.kicker {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue);
  font-weight: 700;
  margin: 0 0 6px;
}

.callout {
  background: var(--blue-soft);
  border-left: 4px solid var(--blue);
  padding: 12px 16px;
  border-radius: 0 10px 10px 0;
  margin: 16px 0;
}

footer {
  border-top: 1px solid var(--line);
  background: #fff;
  padding: 28px 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

footer a {
  color: var(--muted);
}

@media (max-width: 880px) {
  .hero,
  .demo,
  .grid {
    grid-template-columns: 1fr;
  }

  .grid {
    grid-template-columns: 1fr 1fr;
  }

  .nav-toggle {
    display: inline-block;
  }

  header nav {
    display: none;
    position: absolute;
    right: 16px;
    top: 64px;
    flex-direction: column;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 8px;
    min-width: 180px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
  }

  header nav.open {
    display: flex;
  }
}

@media (max-width: 560px) {
  .grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 28px;
  }

  .prose {
    padding-inline: 18px;
  }
}