/* ========== Base ========== */

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #e3e6ec;
  color: #111827;
}

a {
  color: #1f4f9a;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ========== Layout ========== */

.layout {
  display: flex;
  min-height: 100vh;
}

/* ========== Sidebar ========== */

.sidebar {
  width: 260px;
  background: #dde2ea;
  border-right: 1px solid #c5ccd8;
  padding: 16px 14px 24px;
  position: sticky;
  top: 0;
  align-self: flex-start;
}

.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.nav-header {
  margin-top: 16px;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #4b5563;
}

.nav-section {
  list-style: none;
  padding-left: 0;
  margin: 4px 0 0 0;
}

.nav-section li {
  margin: 2px 0;
}

.nav-section a {
  display: block;
  padding: 4px 8px;
  border-radius: 5px;
  text-decoration: none;
  color: #111827;
  font-size: 0.93rem;
}

.nav-section a:hover {
  background: #cfd6e4;
}

.nav-section a.active {
  background: #b7c4dd;
  font-weight: 600;
}

/* ========== Main content ========== */

.content {
  flex: 1;
  padding: 22px 28px 32px;
  background: #ffffff;
}

.content h1 {
  margin-top: 0;
  margin-bottom: 10px;
  font-size: 1.6rem;
}

.content h2 {
  margin-top: 22px;
  margin-bottom: 8px;
  font-size: 1.25rem;
}

.content h3 {
  margin-top: 14px;
  margin-bottom: 6px;
  font-size: 1.05rem;
}

.content p {
  line-height: 1.5;
  margin: 0 0 10px 0;
}

.content ul {
  padding-left: 20px;
  margin-top: 6px;
  margin-bottom: 10px;
}

.content li {
  margin-bottom: 4px;
}

/* ========== Callouts ========== */

.callout {
  border-radius: 6px;
  padding: 10px 12px;
  margin: 16px 0;
  font-size: 0.95rem;
  border-left: 4px solid transparent;
}

.callout h2 {
  margin-top: 0;
  margin-bottom: 4px;
  font-size: 1.05rem;
}

.callout.info {
  background: #e5f1ff;
  border-left-color: #4c7bd9;
}

/* ========== Card grid (Quick Start) ========== */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 12px;
  margin-top: 8px;
}

.card {
  background: #f5f6fa;
  border-radius: 6px;
  padding: 10px 12px;
  border: 1px solid #d3d7e3;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
  font-size: 0.95rem;
}

.card h3 {
  margin-top: 0;
  margin-bottom: 4px;
  font-size: 1rem;
}

.card h3 a {
  text-decoration: none;
}

.card h3 a:hover {
  text-decoration: underline;
}

/* ========== Images (for later pages) ========== */

img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  border: 1px solid #d1d5db;
}

/* ========== Responsive tweaks ========== */

@media (max-width: 800px) {
  .layout {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    position: relative;
    border-right: none;
    border-bottom: 1px solid #c5ccd8;
  }

  .content {
    padding: 16px 16px 24px;
  }
}