:root {
  color-scheme: light dark;
  --ink: #1c1916;
  --ink2: #5a544d;
  --ink3: #8a837a;
  --line: #e6e1da;
  --bg: #fbfaf8;
  --accent: #bba58a;
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #f2eee8; --ink2: #bdb5aa; --ink3: #8a837a; --line: #2c2823; --bg: #17140f; }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", "Noto Sans CJK SC", sans-serif;
}
a { color: inherit; text-decoration: underline; text-decoration-color: var(--accent); text-underline-offset: 3px; }
header.site, footer.site, main { max-width: 720px; margin: 0 auto; padding: 0 20px; }
header.site {
  display: flex; align-items: baseline; justify-content: space-between; gap: 16px;
  padding-top: 28px; padding-bottom: 20px; border-bottom: 1px solid var(--line);
}
header.site .brand { font-weight: 600; text-decoration: none; letter-spacing: .01em; }
header.site nav { display: flex; gap: 18px; font-size: 14px; color: var(--ink2); }
header.site nav a { text-decoration: none; }
main { padding-top: 32px; padding-bottom: 56px; }
main.hero { min-height: 60vh; display: flex; flex-direction: column; justify-content: center; }
.hero h1 { font-size: 34px; line-height: 1.2; margin: 0 0 12px; font-weight: 600; letter-spacing: -.01em; }
.hero p { font-size: 18px; color: var(--ink2); margin: 0 0 8px; max-width: 34em; }
.hero .cat { color: var(--ink3); font-size: 15px; }
.doc h1 { font-size: 28px; line-height: 1.25; margin: 0 0 12px; }
.doc h2 { font-size: 22px; margin: 44px 0 12px; padding-top: 28px; border-top: 1px solid var(--line); }
.doc h3 { font-size: 17px; margin: 28px 0 8px; }
.doc p, .doc li { color: var(--ink); }
.doc blockquote { margin: 0 0 24px; padding: 12px 16px; border-left: 3px solid var(--accent); color: var(--ink2); font-size: 14px; }
.doc table { border-collapse: collapse; width: 100%; font-size: 15px; margin: 12px 0 20px; }
.doc th, .doc td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
.doc th { color: var(--ink2); font-weight: 500; }
.doc hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
.doc code { font: 14px ui-monospace, "SF Mono", Menlo, monospace; background: color-mix(in srgb, var(--line) 60%, transparent); padding: 1px 5px; border-radius: 4px; }
/* Signal Page(apps/landing/README.md):市场学习用,不是 Phase L 落地页。 */
.btn { display: inline-block; padding: 8px 14px; border: 1px solid var(--ink); border-radius: 10px; text-decoration: none; font-size: 14px; font-weight: 500; color: var(--ink); background: transparent; white-space: nowrap; }
.btn.primary { background: var(--ink); color: var(--bg); }
header.site nav .btn { padding: 6px 12px; }
header.site .brand { white-space: nowrap; }
@media (max-width: 639px) { header.site nav .btn { display: none; } }
main.signal { padding-top: 40px; }
main.signal section { padding: 40px 0; border-top: 1px solid var(--line); }
main.signal section.hero { border-top: 0; padding-top: 24px; padding-bottom: 48px; }
main.signal .eyebrow { margin: 0 0 20px; font-size: 14px; color: var(--ink3); letter-spacing: .01em; }
main.signal h1 { font-size: 40px; line-height: 1.15; margin: 0 0 20px; font-weight: 600; letter-spacing: -.015em; }
main.signal .lede { font-size: 19px; line-height: 1.6; color: var(--ink2); margin: 0 0 28px; max-width: 32em; }
main.signal h2 { font-size: 26px; line-height: 1.3; margin: 0 0 16px; font-weight: 600; letter-spacing: -.01em; }
main.signal h3 { font-size: 16px; margin: 0 0 6px; font-weight: 600; }
main.signal h3 small { font-weight: 500; font-size: 12px; color: var(--ink3); margin-left: 6px; }
main.signal p { margin: 0 0 12px; max-width: 36em; }
main.signal .label { font: 500 12px/1 ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: .08em; color: var(--ink3); margin-bottom: 14px; }
main.signal .cta-row { margin: 0 0 16px; display: flex; gap: 10px; flex-wrap: wrap; }
main.signal .micro { font-size: 14px; color: var(--ink3); margin: 0 0 6px; }
main.signal .micro a { text-decoration-color: var(--accent); }
main.signal .proof, main.signal .truth { border-left: 3px solid var(--accent); padding-left: 14px; color: var(--ink2); }
main.signal .scenes { list-style: none; padding: 0; margin: 20px 0; display: grid; gap: 14px; }
main.signal .scenes li { border: 1px solid var(--line); border-radius: 14px; padding: 16px 18px; }
main.signal .scenes p { margin: 0; }
main.signal .scenes span { display: block; font-size: 14px; color: var(--ink2); margin-top: 4px; }
main.signal .trust { margin: 16px 0; display: grid; gap: 14px; }
main.signal .trust dt { font-weight: 600; margin-bottom: 4px; }
main.signal .trust dd { margin: 0; color: var(--ink2); font-size: 15px; }
main.signal section.final { padding-bottom: 8px; }
main.join .answers { display: grid; gap: 12px; }
main.join .answer { display: block; border: 1px solid var(--line); border-radius: 14px; padding: 18px 20px; text-decoration: none; color: var(--ink); }
main.join .answer strong { display: block; font-size: 17px; font-weight: 600; margin-bottom: 4px; }
main.join .answer span { display: block; font-size: 14px; color: var(--ink2); }
main.join .answer:hover { border-color: var(--ink3); }
@media (min-width: 640px) { main.signal .scenes { grid-template-columns: repeat(3, 1fr); } main.signal .trust { grid-template-columns: repeat(2, 1fr); } }
footer.site { border-top: 1px solid var(--line); padding-top: 20px; padding-bottom: 40px; font-size: 13px; color: var(--ink3); }
footer.site p { margin: 4px 0; }
footer.site a { text-decoration: none; }