:root {
  --bg: #f6f7fb;
  --panel: #ffffff;
  --ink: #162238;
  --muted: #5d6b82;
  --line: #dbe2ec;
  --accent: #0d6e66;
  --accent-soft: #e5f6f4;
  --code-bg: #0e1726;
  --code-ink: #dce7ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", "Helvetica Neue", sans-serif;
  background: radial-gradient(circle at 0 0, #edf4ff, var(--bg) 40%);
  color: var(--ink);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 24px;
  background: linear-gradient(90deg, #0f2538, #1c3047);
  color: #eef4ff;
  border-bottom: 1px solid #22354f;
}

.brand {
  font-weight: 700;
  letter-spacing: 0.2px;
}

.contract-link {
  color: #c7f3ef;
  text-decoration: none;
  font-size: 14px;
}

.top-links {
  display: flex;
  gap: 14px;
}

.layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - 56px);
}

.sidebar {
  border-right: 1px solid var(--line);
  background: #f9fbfe;
  padding: 24px 16px;
  position: sticky;
  top: 56px;
  height: calc(100vh - 56px);
  overflow: auto;
}

.sidebar a {
  display: block;
  color: #28415f;
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 8px;
  margin-bottom: 4px;
}

.sidebar a:hover {
  background: #e8f0fb;
}

.content {
  padding: 28px;
  max-width: 980px;
}

section {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 18px;
}

h1, h2, h3 {
  margin-top: 0;
  color: #11243b;
}

p, li {
  color: var(--muted);
  line-height: 1.55;
}

.callout {
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  padding: 12px 14px;
  border-radius: 8px;
}

pre {
  margin: 10px 0 0;
  padding: 14px;
  border-radius: 10px;
  background: var(--code-bg);
  color: var(--code-ink);
  overflow: auto;
}

.tabs {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.tab {
  border: 1px solid #c5d2e5;
  background: #f3f8ff;
  color: #2a4668;
  border-radius: 8px;
  padding: 7px 12px;
  cursor: pointer;
  font-size: 13px;
  text-transform: lowercase;
}

.tab.active {
  background: #0d6e66;
  border-color: #0d6e66;
  color: #ffffff;
}

.panel {
  display: none;
}

.panel.active {
  display: block;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .content {
    padding: 16px;
  }
}