:root {
  --bg: #0b0c0f;
  --panel: #15171c;
  --border: #262a33;
  --text: #e8e9ec;
  --muted: #9298a4;
  --accent: #5eead4;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Segoe UI", sans-serif;
  line-height: 1.75;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}
main {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}
a { color: var(--accent); }
header h1 {
  font-size: clamp(1.3rem, 5vw, 1.6rem);
  margin: 0 0 6px;
  letter-spacing: -0.02em;
}
header p {
  color: var(--muted);
  margin: 0 0 32px;
  font-size: 0.95rem;
}
.breadcrumb {
  font-size: 0.85rem;
  margin: 0 0 20px;
}
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
section { margin-bottom: 40px; }
h2 {
  font-size: 1.05rem;
  margin: 0 0 4px;
}
h3 {
  font-size: 0.95rem;
  margin: 24px 0 8px;
}
p { margin: 0 0 12px; }
.lead {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 16px;
}
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 16px;
}
.sketch {
  width: 100%;
  display: block;
  border-radius: 10px;
  overflow: hidden;
}
.sketch canvas {
  display: block;
  width: 100% !important;
  height: auto !important;
  touch-action: none;
}
.caption {
  color: var(--muted);
  font-size: 0.8rem;
  margin-top: 12px;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
th, td {
  text-align: left;
  padding: 8px 6px;
  border-bottom: 1px solid var(--border);
}
th { color: var(--muted); font-weight: 500; }
pre {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  overflow-x: auto;
  font-size: 0.8rem;
  line-height: 1.5;
}
code {
  font-family: "SF Mono", Menlo, Consolas, monospace;
}
.roadmap {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.roadmap li {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
}
.roadmap a { text-decoration: none; color: inherit; display: block; }
.roadmap .num {
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
}
.roadmap .title {
  font-size: 0.95rem;
  margin: 4px 0 2px;
  color: var(--text);
}
.roadmap .desc {
  color: var(--muted);
  font-size: 0.85rem;
  margin: 0;
}
.roadmap li.done {
  border-color: var(--accent);
}
footer {
  color: var(--muted);
  font-size: 0.8rem;
  text-align: center;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}