:root {
  color-scheme: light;
  --paper: #fafafa;
  --ink: #18181b;
  --soft: #626269;
  --line: #dedee3;
  --accent: #3559b8;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
a, summary { -webkit-tap-highlight-color: transparent; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 6px; border-radius: 3px; }
::selection { background: #efd5c8; color: var(--ink); }
.shell { width: min(1040px, calc(100% - 80px)); margin-inline: auto; }
.skip-link { position: absolute; top: 10px; left: 16px; padding: 12px 18px; background: var(--ink); color: white; transform: translateY(-160%); z-index: 2; }
.skip-link:focus { transform: translateY(0); }
.top { display: flex; align-items: center; justify-content: space-between; height: 100px; }
.wordmark { font-size: 29px; font-weight: 700; letter-spacing: -1.5px; line-height: 1; }
.wordmark span { color: #696a62; font-weight: 400; }
.top nav { display: flex; align-items: center; gap: 32px; font-size: 13px; }
.top nav a { padding-block: 12px; }
.vault-link { color: var(--soft); }
.signin span { margin-left: 9px; color: var(--accent); }
.top nav a:hover, .text-link:hover, .foot > a:last-child:hover, .invite-note a:hover { color: var(--accent); }
.hero { text-align: center; padding-top: 38px; padding-bottom: 42px; }
.eyebrow { display: flex; align-items: center; justify-content: center; gap: 10px; margin: 0 0 26px; font-family: var(--mono); font-size: 11px; letter-spacing: .045em; color: var(--soft); }
.small-envelope { display: inline-block; flex-shrink: 0; width: 16px; height: 12px; border: 1.3px solid currentColor; border-radius: 2px; position: relative; color: var(--accent); overflow: hidden; }
.small-envelope::after { content: ""; position: absolute; width: 10px; height: 10px; border-right: 1px solid currentColor; border-bottom: 1px solid currentColor; top: -6px; left: 1.6px; transform: rotate(45deg); }
h1 { margin: 0; font-size: clamp(52px, 6vw, 76px); font-weight: 600; line-height: 1.07; letter-spacing: -.05em; }
h1 > span { color: var(--ink); }
.lede { margin: 25px 0 28px; font-size: 18px; line-height: 1.65; color: var(--soft); letter-spacing: -.02em; }
.hero-actions { display: flex; justify-content: center; align-items: center; gap: 25px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 24px; background: var(--ink); color: #fff; font-size: 14px; font-weight: 500; padding: 16px 21px; border-radius: 7px; transition: background .15s ease, transform .15s ease; }
.button:hover { background: #414239; transform: translateY(-2px); }
.button:active { transform: translateY(0); }
.text-link { font-size: 13px; padding-block: 16px; }
.text-link span { margin-left: 8px; color: var(--accent); }
.availability { margin: 14px 0 0; font-size: 11px; color: var(--soft); }
.compatibility { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 14px; margin: 38px 0 0; font-size: 11px; color: var(--soft); }
.compatibility strong { font-weight: 600; color: var(--ink); }
.compatibility > span[aria-hidden] { color: #a3a399; }
.section-label { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
.section-label h2 { font-size: 13px; font-weight: 500; margin: 0; }
.example-label { font-family: var(--mono); font-size: 10px; color: var(--soft); }
.exchange { display: grid; grid-template-columns: minmax(0, 1fr) 72px minmax(0, 1fr); align-items: start; }
.endpoint { min-width: 0; border: 1px solid var(--line); border-radius: 11px; overflow: hidden; }
.endpoint-header { display: flex; align-items: center; gap: 9px; padding: 15px 19px; border-bottom: 1px solid var(--line); }
.person-dot { display: grid; place-items: center; width: 23px; height: 23px; background: #e7e4db; color: #55564d; border-radius: 50%; font-family: var(--mono); font-size: 10px; }
.endpoint-header h3 { font-size: 12px; font-weight: 600; margin: 0; }
.endpoint-header h3 > span { color: var(--soft); font-weight: 400; }
.endpoint-side { margin-left: auto; font-size: 10px; color: var(--soft); }
.sender { background: #fff; }
.sender-body, .recipient-body { padding: 24px; }
.terminal-prompt { position: relative; margin: 1px 0 25px; padding-left: 20px; font-family: var(--mono); font-size: 14px; line-height: 1.65; letter-spacing: -.03em; }
.terminal-prompt > span { position: absolute; left: 0; color: var(--accent); }
.outgoing-message { padding: 16px 19px; border-left: 2px solid #acb5ce; background: #f5f5f7; }
.mono-label { font-family: var(--mono); font-size: 9px; letter-spacing: .055em; color: var(--soft); margin: 0 0 9px; }
.outgoing-message h4 { font-size: 14px; font-weight: 600; margin: 0 0 8px; }
.outgoing-message > p:last-child { color: var(--soft); font-size: 12px; line-height: 1.7; margin: 0; }
.receipt { margin: 19px 0 0; font-family: var(--mono); font-size: 10px; color: var(--soft); }
.receipt > span { color: #4d6950; margin-right: 5px; }
.connection { position: relative; display: grid; place-items: center; height: 342px; }
.connection-line { position: absolute; width: 100%; border-top: 1px solid #acb5ce; }
.connection-letter { width: 33px; height: 33px; border-radius: 50%; display: grid; place-items: center; background: var(--paper); color: var(--accent); z-index: 1; }
.connection-letter svg { width: 20px; stroke: currentColor; stroke-width: 1.25; }
.recipient { background: #202124; border-color: #202124; color: #f2f2ea; }
.recipient .endpoint-header { border-color: #41443c; }
.recipient .person-dot { background: #40443a; color: #dedfd6; }
.recipient .endpoint-header h3 > span, .recipient .endpoint-side { color: #b7baad; }
.inbox-label { display: flex; align-items: center; gap: 7px; margin: 0 0 26px; font-family: var(--mono); color: #c0c8b7; font-size: 10px; }
.unread-dot { width: 5px; height: 5px; border-radius: 50%; background: #c7d7b8; }
.from { color: #b7baad; font-family: var(--mono); font-size: 11px; margin: 0 0 10px; }
.recipient h4 { font-size: 21px; font-weight: 400; letter-spacing: -.025em; margin: 0 0 22px; }
.letter summary { display: inline-flex; align-items: center; min-height: 44px; list-style: none; cursor: pointer; border: 1px solid #72796a; border-radius: 5px; padding: 10px 13px; font-family: var(--mono); font-size: 11px; color: #e1e7d6; transition: background .15s ease; }
.letter summary::-webkit-details-marker { display: none; }
.letter summary:hover { background: #3c4136; }
.letter summary:focus-visible { outline-color: #dbe2cd; }
.letter summary span span { margin-left: 18px; }
.letter .close-label { display: none; }
.letter[open] .close-label { display: inline; }
.letter[open] .open-label { display: none; }
.letter-content { border-top: 1px solid #495043; margin-top: 19px; padding-top: 1px; font-size: 12px; line-height: 1.75; color: #e0e2d9; }
.letter-content code { color: #d0dbbf; overflow-wrap: anywhere; }
.letter-content .letter-note { color: #bac7a7; margin-bottom: 0; }
.recipient-note { font-size: 10px; color: #b7baad; margin: 24px 0 0; line-height: 1.6; }
.recipient-body:has(.letter[open]) .recipient-note { display: none; }
.handoff-caption { text-align: center; font-size: 12px; color: var(--soft); margin: 23px 0 0; }
.handoff-caption span { color: var(--ink); }
.ownership { display: flex; align-items: flex-start; gap: 23px; max-width: 730px; padding-block: 58px 68px; }
.ownership-symbol { color: var(--accent); font-size: 35px; line-height: 1; }
.ownership h2 { margin: 0 0 10px; font-size: 19px; letter-spacing: -.03em; font-weight: 500; }
.ownership p { margin: 0; font-size: 13px; line-height: 1.8; color: var(--soft); }
.connect { padding-block: 62px 58px; border-top: 1px solid var(--line); }
.connect-heading { text-align: center; }
.connect .eyebrow { margin-bottom: 17px; font-size: 10px; }
.connect h2 { font-size: 39px; font-weight: 500; letter-spacing: -.045em; margin: 0 0 12px; }
.connect-heading > p:last-child { font-size: 14px; color: var(--soft); margin: 0; }
.steps { list-style: none; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 45px; padding: 0; margin: 43px 0 32px; }
.step-number { font-family: var(--mono); color: var(--accent); font-size: 11px; }
.steps h3 { font-size: 16px; font-weight: 500; letter-spacing: -.015em; margin: 16px 0 10px; }
.steps p { color: var(--soft); font-size: 13px; line-height: 1.8; margin: 0; max-width: 270px; }
.invite-note { display: flex; align-items: center; gap: 13px; padding: 17px 20px; border: 1px solid var(--line); border-radius: 6px; font-size: 11px; }
.invite-note p { margin: 0; color: var(--soft); line-height: 1.7; }
.invite-note strong { color: var(--ink); font-weight: 600; }
.invite-note a { margin-left: auto; flex-shrink: 0; padding-block: 6px; }
.invite-note a span { color: var(--accent); margin-left: 8px; }
.vault { border-top: 1px solid var(--line); padding-block: 49px 52px; display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.vault .eyebrow { justify-content: flex-start; margin-bottom: 15px; color: var(--accent); font-size: 10px; }
.vault h2 { margin: 0 0 14px; font-size: 29px; font-weight: 500; line-height: 1.2; letter-spacing: -.035em; }
.vault p:last-child { margin: 0; color: var(--soft); font-size: 13px; line-height: 1.8; }
.vault-address { display: flex; flex-direction: column; align-items: flex-start; font-family: var(--mono); font-size: 16px; color: var(--soft); padding: 0 65px 0 0; }
.vault-address strong { font-weight: 500; color: var(--ink); }
.address-slash { color: var(--accent); padding: 0 3px; }
.address-connector { font-size: 17px; color: #828576; margin: 9px 0 9px 6px; }
.vault-caption { font-family: var(--sans); font-size: 11px; margin-top: 19px; }
.foot { border-top: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; gap: 20px; padding-block: 28px 36px; }
.foot .wordmark { font-size: 23px; }
.foot p, .foot > a:last-child { margin: 0; font-size: 11px; color: var(--soft); }
.foot > a:last-child span { color: var(--accent); margin-left: 8px; }
@media (max-width: 900px) {
  .shell { width: calc(100% - 48px); }
  .exchange { grid-template-columns: minmax(0, 1fr) 40px minmax(0, 1fr); }
  .sender-body, .recipient-body { padding: 20px; }
  .terminal-prompt { font-size: 13px; }
  .endpoint-side { display: none; }
  .steps { gap: 25px; }
  .invite-note { flex-wrap: wrap; }
  .invite-note a { margin-left: 29px; }
  .vault-address { padding-right: 0; font-size: 14px; }
}
@media (max-width: 600px) {
  .shell { width: calc(100% - 40px); }
  .top { height: 80px; }
  .wordmark { font-size: 25px; }
  .top nav { gap: 18px; font-size: 11px; }
  .hero { padding-top: 44px; padding-bottom: 43px; }
  .hero .eyebrow { font-size: 9px; gap: 7px; margin-bottom: 25px; }
  h1 { font-size: clamp(39px, 10.2vw, 61px); }
  .lede { font-size: 14px; margin-top: 21px; margin-bottom: 24px; }
  .hero-actions { gap: 20px; }
  .button { font-size: 12px; padding: 15px 17px; gap: 18px; }
  .text-link { font-size: 12px; }
  .availability { font-size: 10px; }
  .compatibility { gap: 9px; font-size: 10px; margin-top: 31px; }
  .compatibility > span:last-child { flex-basis: 100%; }
  .compatibility > span:nth-last-child(2) { display: none; }
  .section-label h2 { font-size: 11px; }
  .example-label { font-size: 9px; }
  .exchange { grid-template-columns: minmax(0, 1fr); }
  .endpoint-header { padding: 14px 20px; }
  .endpoint-side { display: inline; }
  .sender-body, .recipient-body { padding: 23px; }
  .terminal-prompt { font-size: 14px; }
  .connection { height: 46px; }
  .connection-line { height: 100%; width: 0; border-top: 0; border-left: 1px solid #acb5ce; }
  .connection-letter { height: 28px; }
  .handoff-caption { font-size: 11px; line-height: 1.8; margin-top: 18px; }
  .handoff-caption span { display: block; }
  .ownership { padding-block: 39px 44px; gap: 14px; }
  .ownership-symbol { font-size: 29px; }
  .ownership h2 { font-size: 18px; }
  .ownership p { font-size: 12px; }
  .ownership p br { display: none; }
  .connect { padding-block: 43px 39px; }
  .connect h2 { font-size: 30px; }
  .connect-heading > p:last-child { font-size: 12px; }
  .steps { grid-template-columns: minmax(0, 1fr); gap: 26px; margin: 32px 0; }
  .steps li { display: grid; grid-template-columns: 30px 1fr; column-gap: 10px; }
  .step-number { grid-row: span 2; padding-top: 4px; }
  .steps h3 { margin: 0 0 7px; font-size: 15px; }
  .steps p { font-size: 12px; max-width: none; }
  .invite-note { align-items: flex-start; gap: 10px; padding: 16px; }
  .invite-note .small-envelope { margin-top: 4px; }
  .invite-note p { flex: 1 1 calc(100% - 26px); }
  .invite-note a { margin-left: 26px; flex-basis: calc(100% - 26px); }
  .vault { align-items: flex-start; flex-direction: column; gap: 28px; padding-block: 37px; }
  .vault h2 { font-size: 28px; }
  .vault p:last-child { font-size: 12px; }
  .vault-address { font-size: 14px; border-left: 1px solid var(--line); padding-left: 20px; }
  .foot { flex-wrap: wrap; gap: 22px; padding-block: 26px 30px; }
  .foot p { order: 3; width: 100%; font-size: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button, .letter summary { transition: none; }
  .button:hover { transform: none; }
}