:root {
  --paper: #f4efe5;
  --paper-soft: #faf6ee;
  --ink: #24201b;
  --muted: #716d65;
  --line: rgba(77, 70, 60, 0.17);
  --accent: #7f99af;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--paper);
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  font-family: Inter, "Noto Serif SC", "Microsoft YaHei", sans-serif;
  background:
    url("textures/paper-warm.webp") center / 580px 580px repeat,
    radial-gradient(circle at 22% 20%, rgba(255, 255, 255, 0.55), transparent 34%),
    radial-gradient(circle at 80% 76%, rgba(188, 164, 128, 0.13), transparent 32%),
    linear-gradient(135deg, #f8f3ea 0%, #f0e9de 100%);
}

body[data-topic="product"] {
  --accent: #aeb7a4;
}

body[data-topic="ai"] {
  --accent: #7f99af;
}

body[data-topic="business"] {
  --accent: #c8a083;
}

body[data-topic="system"] {
  --accent: #cfc3a8;
}

body[data-topic="observe"] {
  --accent: #aeb9ac;
}

a {
  color: inherit;
  text-decoration: none;
}

main {
  width: min(920px, calc(100vw - 44px));
  margin: 0 auto;
  padding: 64px 0 88px;
}

nav.crumbs {
  margin-bottom: 48px;
  color: var(--muted);
  font-size: 14px;
}

nav.crumbs a {
  border-bottom: 1px solid rgba(36, 32, 27, 0.3);
}

h1 {
  margin: 0 0 18px;
  font-family: "Noto Serif SC", "Microsoft YaHei", serif;
  font-size: clamp(36px, 6vw, 52px);
  font-weight: 700;
  line-height: 1.1;
}

.lead {
  margin: 0 0 44px;
  max-width: 40rem;
  color: var(--muted);
  font-family: "Noto Serif SC", "Microsoft YaHei", serif;
  font-size: 17px;
  line-height: 1.9;
}

.section-label {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
}

.grid,
.note-list {
  display: grid;
  gap: 18px;
}

.grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card,
.note-card {
  display: grid;
  gap: 10px;
  align-content: start;
  padding: 24px 26px;
  color: inherit;
  border: 1px solid rgba(77, 70, 60, 0.16);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.28);
  transition: border-color 160ms ease;
}

.card:hover,
.note-card:hover {
  border-color: rgba(77, 70, 60, 0.34);
}

.card strong,
.note-card strong {
  font-family: "Noto Serif SC", "Microsoft YaHei", serif;
  font-size: 23px;
  font-weight: 700;
  line-height: 1.35;
}

.card span,
.note-card span {
  color: var(--muted);
  line-height: 1.8;
}

.status {
  width: fit-content;
  padding: 4px 11px;
  color: #6b6760;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.4);
  font-size: 13px;
}

.status.accent {
  color: #514d45;
  border-color: transparent;
  background: rgba(219, 211, 191, 0.58);
}

.dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
}

.card-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 2px;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 720px) {
  main {
    width: min(100% - 36px, 920px);
    padding: 40px 0 64px;
  }

  nav.crumbs {
    margin-bottom: 34px;
  }

  .card strong,
  .note-card strong {
    font-size: 20px;
  }
}