:root {
  --bg: #f3f5fb;
  --card: #ffffff;
  --text: #1f2430;
  --muted: #80869a;
  --line: #e7eaf2;
  --accent: #2f72ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: radial-gradient(circle at 20% -10%, #ffffff, var(--bg));
  color: var(--text);
}

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

.shell {
  max-width: 860px;
  margin: 0 auto;
  min-height: 100vh;
  background: #fff;
  border-left: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(5px);
  border-bottom: 1px solid var(--line);
  padding: 14px 16px;
  display: grid;
  grid-template-columns: 32px 1fr 32px;
  gap: 10px;
  align-items: center;
}

.icon-btn {
  border: 0;
  background: transparent;
  color: #56607a;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
}

.icon-btn svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.brand-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  overflow: hidden;
  flex-shrink: 0;
}

.brand-logo img {
  width: 100%;
  height: 100%;
  display: block;
}

.brand-wrap h1 {
  margin: 0;
  font-size: 19px;
}

.brand-wrap p {
  margin: 1px 0 0;
  font-size: 11px;
  color: var(--muted);
}

.content {
  padding: 20px 16px 30px;
}

.crumb {
  margin: 4px 0 12px;
  color: #8390a8;
  font-size: 15px;
}

.page-card {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #fff;
  padding: 20px;
}

.page-card h2 {
  margin: 0 0 10px;
  font-size: 34px;
  line-height: 1.08;
}

.lead {
  margin: 0 0 18px;
  color: #556178;
  font-size: 15px;
  line-height: 1.65;
}

.section + .section {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.section h3 {
  margin: 0 0 8px;
  font-size: 19px;
}

.section p,
.section li {
  color: #4f5b75;
  font-size: 14px;
  line-height: 1.7;
}

.section ul {
  margin: 0;
  padding-left: 18px;
}

.section p {
  margin: 0;
}

.quick-links {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.quick-links a {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 12px;
  font-size: 13px;
  background: #fafbff;
}

@media (max-width: 640px) {
  .page-card h2 {
    font-size: 28px;
  }

  .section h3 {
    font-size: 17px;
  }
}