html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  color: #222;
  background: #fff;
}
#Main {
  display: grid;
  grid-template-columns: minmax(220px, 300px) 1fr;
  grid-template-rows: auto 1fr;
  grid-template-areas:
    "banner banner"
    "menu content";
  height: 100vh;
  width: 100vw;
  max-height: 100vh;
  max-width: 100vw;
  overflow: hidden;
  box-sizing: border-box;
}
#Banner {
  grid-area: banner;
  overflow: hidden;
  background: #0b57d0;
  color: #fff;
  padding: 14px 20px;
  border-bottom: 1px solid #0842a0;
}
#Banner h1 { margin: 0; font-size: 1.25rem; font-weight: 600; line-height: 1.3; }
#Banner .subtitle { margin: 4px 0 0; font-size: 0.85rem; opacity: 0.9; }
#Menu {
  grid-area: menu;
  overflow: auto;
  background: #f7f7f7;
  border-right: 1px solid #ddd;
  padding: 12px 10px 24px;
  box-sizing: border-box;
}
#Content {
  grid-area: content;
  overflow: auto;
  background: #fff;
  box-sizing: border-box;
  min-width: 0;
  min-height: 0;
}
#Content iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}

/* Menu: bold section headers; indent topics under each section */
#Menu .menu-title {
  font-size: 1rem;
  margin: 0 0 10px;
  padding: 0 6px;
  font-weight: 700;
}
#Menu .sec {
  margin-bottom: 12px;
}
#Menu .sec-t {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: #333;
  padding: 4px 6px;
}
#Menu ul {
  list-style: none;
  margin: 0;
  padding: 2px 0 4px 18px;
}
#Menu li a {
  display: block;
  padding: 5px 8px 5px 10px;
  border-radius: 4px;
  color: #0b57d0;
  text-decoration: none;
  font-size: 0.86rem;
}
#Menu li a:hover,
#Menu li a:focus {
  background: #e8f0fe;
}
#Menu li a.active {
  background: #d3e3fd;
  font-weight: 600;
}
#Menu .note {
  font-size: 0.75rem;
  color: #666;
  padding: 8px 6px 0;
  line-height: 1.35;
}

body.topic {
  overflow: auto; height: auto; min-height: 100%;
  padding: 16px 24px 40px; box-sizing: border-box;
  line-height: 1.45; max-width: 960px;
}
body.topic h1 { font-size: 1.6rem; margin: 0 0 0.6rem; border-bottom: 1px solid #ddd; padding-bottom: 0.35rem; }
body.topic h2 { font-size: 1.25rem; margin: 1.4rem 0 0.5rem; }
body.topic h3 { font-size: 1.05rem; margin: 1.1rem 0 0.4rem; }
body.topic p, body.topic li { font-size: 0.95rem; }
body.topic code {
  font-family: Consolas, Menlo, monospace; background: #f4f4f4;
  padding: 0.1em 0.35em; border-radius: 3px; font-size: 0.9em;
}
body.topic pre { background: #f4f4f4; padding: 12px; overflow: auto; border-radius: 6px; }
body.topic pre code { background: none; padding: 0; }
body.topic table { border-collapse: collapse; width: 100%; margin: 0.8rem 0; font-size: 0.9rem; }
body.topic th, body.topic td { border: 1px solid #ccc; padding: 6px 8px; text-align: left; vertical-align: top; }
body.topic th { background: #f0f0f0; }
body.topic blockquote { margin: 0; padding-left: 12px; border-left: 3px solid #999; color: #444; }
body.topic a { color: #0b57d0; }
body.topic .meta { color: #555; font-size: 0.9rem; }