:root {
  --bg: #0A111C;
  --panel: #0E1626;
  --line: #1C2942;
  --text: #C9D6E4;
  --dim: #7B8CA3;
  --accent: #7FC9F3;
  --good: #7FE3A8;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
          Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
}

/* ---- header ---- */
header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(10, 17, 28, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
nav {
  max-width: 1040px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand {
  font-family: var(--mono);
  font-size: 19px;
  text-decoration: none;
  color: var(--text);
  display: flex;
  align-items: baseline;
  gap: 1px;
}
.brand .mark { color: var(--accent); font-weight: 700; }
.brand .slash { color: var(--dim); margin: 0 2px; }
.brand .word { margin-left: 8px; letter-spacing: 0.04em; }
.links { display: flex; gap: 24px; }
.links a {
  color: var(--dim);
  text-decoration: none;
  font-size: 15px;
}
.links a:hover { color: var(--accent); }

/* ---- layout ---- */
main { max-width: 1040px; margin: 0 auto; padding: 0 24px 80px; }
section { padding: 64px 0; border-bottom: 1px solid var(--line); }
section:last-of-type { border-bottom: none; }

h1 {
  font-size: clamp(34px, 6vw, 56px);
  line-height: 1.1;
  margin: 0 0 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
h2 { font-size: 30px; margin: 0 0 24px; letter-spacing: -0.01em; }
h3 { font-size: 19px; margin: 0 0 8px; }
h3.sub { margin-top: 40px; }
h4 { color: var(--accent); margin: 0 0 6px; font-size: 16px; }
h5 { color: var(--dim); margin: 0 0 6px; font-size: 13px;
     text-transform: uppercase; letter-spacing: 0.08em; }

.lede { font-size: 19px; color: var(--dim); max-width: 62ch; margin: 0 0 32px; }
p { max-width: 68ch; }
a { color: var(--accent); }

code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: #101B2C;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 5px;
  color: #CFE3F5;
}
kbd {
  font-family: var(--mono);
  font-size: 12px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 1px 6px;
  background: var(--panel);
}

/* ---- code blocks ---- */
pre.sample {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px 22px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  margin: 0 0 0;
}
pre.sample code { background: none; border: none; padding: 0; color: var(--text); }

.out {
  font-family: var(--mono);
  font-size: 14px;
  background: #07111C;
  border: 1px solid var(--line);
  border-top: none;
  border-radius: 0 0 10px 10px;
  margin: 0 0 28px;
  padding: 12px 22px;
  color: var(--dim);
}
.out .good { color: var(--good); }

/* ---- buttons ---- */
.cta { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 8px; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #06101C;
  font-weight: 650;
  font-size: 16px;
  text-decoration: none;
  padding: 11px 24px;
  border-radius: 8px;
  border: 1px solid var(--accent);
}
.btn:hover { filter: brightness(1.08); }
.btn.ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line);
}
.btn.small { font-size: 14px; padding: 9px 16px; font-weight: 550; }
.btn code { background: none; border: none; color: inherit; padding: 0; }

/* ---- command rows ---- */
.cmdrow {
  display: flex;
  align-items: stretch;
  gap: 8px;
  margin: 14px 0 10px;
  flex-wrap: wrap;
}
.cmd {
  flex: 1 1 320px;
  display: block;
  background: #07111C;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  overflow-x: auto;
  white-space: pre;
  line-height: 1.5;
}
button.copy {
  background: var(--panel);
  color: var(--dim);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 18px;
  font-size: 13px;
  cursor: pointer;
  font-family: var(--sans);
}
button.copy:hover { color: var(--accent); border-color: var(--accent); }
.fine { font-size: 14px; color: var(--dim); margin-top: 8px; }

/* ---- cards ---- */
.cards { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px;
}
.card p { font-size: 15px; color: var(--dim); margin: 0; }
.card .cmdrow { margin-top: 16px; }

/* ---- learn ---- */
.cols { display: grid; gap: 26px; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.cols p { font-size: 15px; color: var(--dim); margin: 0; }

.grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  margin-top: 16px;
}
.grid > div {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
}
.grid code {
  display: block;
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
  font-size: 13px;
  line-height: 1.7;
}

/* ---- ticks ---- */
.ticks { list-style: none; padding: 0; margin: 18px 0 0; }
.ticks li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 10px;
  color: var(--dim);
  font-size: 16px;
}
.ticks li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--good);
  font-weight: 700;
}

footer {
  border-top: 1px solid var(--line);
  padding: 28px 24px;
  text-align: center;
  color: var(--dim);
  font-size: 14px;
}
footer p { margin: 0; }

@media (max-width: 620px) {
  .links { display: none; }
  section { padding: 44px 0; }
}