:root {
  color-scheme: light;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --blue: #0071e3;
  --paper: #f5f5f7;
  --line: #e5e5e8;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: #fff;
  font-synthesis: none;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
a {
  color: var(--blue);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
a:focus-visible,
summary:focus-visible {
  outline: 3px solid #0071e3;
  outline-offset: 5px;
  border-radius: 4px;
}
header {
  position: sticky;
  top: 0;
  z-index: 2;
  background: #ffffffeb;
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(20px);
}
nav {
  max-width: 1080px;
  min-height: 68px;
  margin: auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  gap: 28px;
}
.brand {
  font-size: 22px;
  letter-spacing: -1px;
  font-weight: 650;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 9px;
}
.brand img {
  width: 24px;
  height: 24px;
}
.spacer {
  flex: 1;
}
nav > a:not(.brand) {
  font-size: 13px;
  color: var(--muted);
}
main {
  overflow: hidden;
}
.hero {
  text-align: center;
  padding: 90px 24px 0;
  background: linear-gradient(#fff, var(--paper));
}
.eyebrow {
  font-size: 11px;
  letter-spacing: 2.8px;
  font-weight: 600;
  color: var(--muted);
}
h1 {
  font-size: clamp(38px, 6vw, 72px);
  line-height: 1.12;
  letter-spacing: -2.7px;
  font-weight: 650;
  margin: 25px auto 24px;
  max-width: 900px;
}
h1 span {
  color: #86868b;
}
.lede {
  font-size: clamp(16px, 2vw, 21px);
  line-height: 1.75;
  max-width: 680px;
  margin: auto;
  color: var(--muted);
}
.actions {
  display: flex;
  justify-content: center;
  gap: 24px;
  align-items: center;
  margin: 30px 0 18px;
  flex-wrap: wrap;
}
.button {
  display: inline-flex;
  background: var(--blue);
  color: #fff;
  padding: 13px 24px;
  border-radius: 24px;
  font-size: 15px;
}
.button:hover {
  background: #0077ed;
  text-decoration: none;
}
.note {
  font-size: 12px;
  line-height: 1.8;
  color: var(--muted);
}
.window {
  max-width: 1020px;
  margin: 46px auto 0;
  border: 1px solid #dddde2;
  border-radius: 19px 19px 0 0;
  background: #fff;
  box-shadow: 0 14px 60px #0000000b;
  overflow: hidden;
}
.chrome {
  height: 35px;
  background: #fafafa;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 14px;
  border-bottom: 1px solid var(--line);
}
.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #dfdfe3;
}
.address {
  font-size: 10px;
  color: #86868b;
  flex: 1;
  letter-spacing: 0.2px;
  padding-right: 40px;
}
.window img {
  width: 100%;
  height: auto;
  display: block;
}
.section {
  max-width: 1080px;
  margin: auto;
  padding: 86px 28px;
}
.section h2 {
  font-size: clamp(28px, 4vw, 42px);
  letter-spacing: -1.3px;
  font-weight: 650;
  line-height: 1.25;
  margin: 0 0 16px;
}
.section-intro {
  font-size: 17px;
  color: var(--muted);
  line-height: 1.8;
  max-width: 700px;
  margin: 0 0 36px;
}
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 38px;
}
.feature {
  border-top: 1px solid var(--line);
  padding-top: 22px;
}
.number {
  font-size: 12px;
  color: var(--blue);
  font-variant-numeric: tabular-nums;
}
.feature h3 {
  font-size: 21px;
  letter-spacing: -0.5px;
  margin: 17px 0 12px;
}
.feature p {
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}
.soft {
  background: var(--paper);
}
.lengths {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 30px;
}
.length {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 25px 20px;
}
.length b {
  display: block;
  font-size: 21px;
  letter-spacing: -0.5px;
  margin-bottom: 10px;
}
.length small {
  color: var(--muted);
  line-height: 1.8;
  font-size: 13px;
}
.reading {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 56px;
  align-items: center;
}
.reading img {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 16px 40px #00000006;
}
.reading p {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.9;
}
.steps {
  counter-reset: step;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 35px;
  margin: 36px 0;
  list-style: none;
  padding: 0;
}
.steps li {
  counter-increment: step;
  font-size: 15px;
  line-height: 1.8;
}
.steps li:before {
  content: "0" counter(step);
  display: block;
  color: var(--blue);
  font-size: 13px;
  margin-bottom: 13px;
}
.steps b {
  display: block;
  margin-bottom: 8px;
}
.steps p {
  color: var(--muted);
  font-size: 14px;
  margin: 0;
}
.command {
  background: #f5f5f7;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
  overflow: auto;
  font-size: 13px;
  line-height: 1.8;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
}
.faq {
  max-width: 780px;
}
details {
  border-bottom: 1px solid var(--line);
  padding: 22px 0;
}
summary {
  font-size: 16px;
  cursor: pointer;
  line-height: 1.6;
}
details p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.9;
}
footer {
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--muted);
  line-height: 1.8;
  padding: 28px;
  text-align: center;
}
footer a {
  margin: 0 9px;
}
@media (max-width: 700px) {
  nav {
    gap: 18px;
    padding: 0 20px;
  }
  .hero {
    padding-top: 62px;
  }
  h1 {
    letter-spacing: -1.4px;
  }
  .window {
    margin-top: 36px;
    border-radius: 12px 12px 0 0;
  }
  .section {
    padding: 58px 24px;
  }
  .features,
  .steps,
  .reading {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .lengths {
    grid-template-columns: 1fr 1fr;
  }
  .length {
    padding: 20px 16px;
  }
  .section-intro {
    font-size: 15px;
  }
  .reading {
    gap: 30px;
  }
  nav > a:not(.brand) {
    font-size: 12px;
  }
  .actions {
    gap: 20px;
  }
  .brand {
    font-size: 20px;
  }
}
@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}