:root {
  --bg: #f6f8fb; --paper: #fff; --text: #1f2a37; --muted: #5c6b7f; --line: #e3e8ef;
  --accent: #1a73e8; --dark: #2a3a4b; --ok: #1f8a4c; --danger: #d33a42; --warn-bg: #fff6e5; --warn-line: #f0c070; --note-bg: #eef4fd;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #141c25; --paper: #1e2a37; --text: #e9eef3; --muted: #9fb0c0; --line: #2f3f52; --warn-bg: #4a3512; --warn-line: #9a6b1c; --note-bg: #1d3350; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: "Segoe UI", "Malgun Gothic", "Apple SD Gothic Neo", system-ui, sans-serif; line-height: 1.65; }
a { color: var(--accent); }
.wrap { max-width: 1100px; margin: 0 auto; padding: 0 16px; }
.top { background: var(--dark); color: #fff; }
.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 56px; gap: 12px; flex-wrap: wrap; }
.brand { color: #fff; text-decoration: none; font-weight: 700; font-size: 18px; display: flex; align-items: center; gap: 8px; }
.logo { color: #3f8ff7; font-size: 13px; }
.tag { font-size: 11px; background: var(--accent); border-radius: 6px; padding: 2px 8px; }
.top nav a { color: #cfd8e3; text-decoration: none; margin-left: 16px; font-size: 14px; }
.top nav a.cur, .top nav a:hover { color: #fff; border-bottom: 2px solid #3f8ff7; }

.layout { display: grid; grid-template-columns: 220px 1fr; gap: 24px; padding: 24px 16px 60px; }
.toc { position: sticky; top: 16px; align-self: start; background: var(--paper); border: 1px solid var(--line); border-radius: 10px; padding: 12px; font-size: 14px; }
.toc-title { font-weight: 700; color: var(--muted); font-size: 12px; margin-bottom: 6px; }
.toc a { display: block; color: var(--text); text-decoration: none; padding: 5px 6px; border-radius: 6px; }
.toc a:hover { background: var(--note-bg); }

.doc { background: var(--paper); border: 1px solid var(--line); border-radius: 10px; padding: 28px 32px; }
.doc h1 { margin: 0 0 8px; font-size: 28px; }
.lead { color: var(--muted); margin: 0 0 24px; font-size: 15px; }
.doc h2 { font-size: 20px; margin: 36px 0 12px; padding-bottom: 6px; border-bottom: 2px solid var(--line); scroll-margin-top: 16px; }
.doc p, .doc ul, .doc ol { margin: 8px 0 12px; }
.doc li { margin: 4px 0; }
code { background: var(--note-bg); border-radius: 4px; padding: 1px 6px; font-family: Consolas, "D2Coding", monospace; font-size: 13px; }
code.fail { color: var(--danger); }
pre { background: #0f1620; color: #dfe7f1; padding: 14px 16px; border-radius: 8px; overflow-x: auto; font-size: 13px; line-height: 1.5; }
kbd { background: #eef1f5; color: #222; border: 1px solid #c8ced8; border-bottom-width: 2px; border-radius: 5px; padding: 2px 8px; font-family: inherit; font-weight: 600; font-size: 13px; }
table { width: 100%; border-collapse: collapse; margin: 10px 0 16px; font-size: 14px; }
th, td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; vertical-align: top; }
th { background: var(--note-bg); font-weight: 600; white-space: nowrap; }
table.keys td:first-child { width: 80px; }
.steps { padding-left: 22px; }
.steps > li { margin: 8px 0; }
.note, .warn { border-radius: 8px; padding: 10px 14px; margin: 10px 0; font-size: 14px; }
.note { background: var(--note-bg); border-left: 4px solid var(--accent); }
.warn { background: var(--warn-bg); border-left: 4px solid var(--warn-line); }
.hint { color: var(--muted); font-size: 13px; }
.on { color: var(--ok); font-weight: 700; } .off { color: var(--danger); font-weight: 700; }
.faq dt { font-weight: 700; margin-top: 14px; }
.faq dd { margin: 4px 0 0 0; color: var(--text); }
.foot { margin-top: 40px; padding-top: 14px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; text-align: center; }

/* 화면 구성 모형 */
.figure { margin: 12px 0 16px; }
.mock { border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: #141c25; color: #cfd8e3; font-size: 12px; }
.mock-head, .mock-bar { display: flex; justify-content: space-between; padding: 8px 12px; background: #1e2a37; }
.mock-bar { justify-content: center; }
.mock-body { display: flex; gap: 8px; padding: 10px; }
.mock-tile { flex: 1; aspect-ratio: 16/9; background: #2a3a4b; border-radius: 8px; display: flex; align-items: center; justify-content: center; }

@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; }
  .toc { position: static; }
  .doc { padding: 20px 16px; }
  .top nav a { margin-left: 10px; }
}
@media print {
  .top, .toc { display: none; }
  .layout { display: block; padding: 0; }
  .doc { border: 0; padding: 0; }
}