:root {
  --bg: #f5f6f7;
  --panel: #ffffff;
  --text: #1e2428;
  --muted: #4a555d;
  --line: #d3d9de;
  --accent: #1b4a6b;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
  line-height: 1.62;
}

.container {
  width: min(920px, 92vw);
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid var(--line);
  padding: 3.3rem 0 2.4rem;
  background: linear-gradient(180deg, #f9fbfc 0%, #f0f4f7 100%);
}

h1,
h2 {
  font-family: "IBM Plex Serif", Georgia, serif;
  line-height: 1.3;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 5.2vw, 3rem);
}

h2 {
  margin: 0 0 0.8rem;
  font-size: clamp(1.2rem, 3vw, 1.8rem);
}

h3 {
  margin: 1.25rem 0 0.4rem;
  font-size: 1.02rem;
}

.lead {
  margin: 0.8rem 0 0;
  font-size: clamp(1.02rem, 2.2vw, 1.22rem);
}

.subtext {
  margin: 0.75rem 0 0;
  color: var(--muted);
  max-width: 74ch;
}

.version-note {
  margin: 1rem 0 0;
  color: var(--accent);
  font-size: 0.95rem;
}

section {
  margin-top: 1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.2rem 1.1rem;
}

ul,
ol {
  padding-left: 1.2rem;
  margin: 0.55rem 0 0;
}

code {
  font-family: "JetBrains Mono", Consolas, monospace;
  background: #eef3f8;
  border-radius: 4px;
  padding: 0.06rem 0.34rem;
}

pre {
  margin: 1rem 0 0;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f7f9fb;
  padding: 1rem;
}

pre code {
  display: block;
  padding: 0;
  background: transparent;
  white-space: pre;
}

.flow-diagram {
  color: #26343d;
}

.json-example {
  font-size: 0.9rem;
}

.verification-flow {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 0.45rem;
  margin-top: 1rem;
}

.verification-flow span {
  min-height: 4rem;
  border: 1px solid var(--line);
  background: #f7f9fb;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.6rem;
  text-align: center;
  font-size: 0.88rem;
}

a {
  color: var(--accent);
}

.quote {
  margin: 0;
  border-left: 4px solid #8098ac;
  padding-left: 0.8rem;
}

@media (min-width: 860px) {
  main {
    padding-bottom: 2rem;
  }

  section {
    padding: 1.4rem;
  }
}

@media (max-width: 540px) {
  .site-header {
    padding-top: 2.5rem;
  }

  section {
    padding: 1rem 0.9rem;
  }

  .verification-flow {
    grid-template-columns: 1fr 1fr;
  }
}