/* =========================
   Reset
========================= */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont,
               "Segoe UI", Roboto, sans-serif;
  background: #f5f5f7;
  color: #1d1d1f;
}

/* =========================
   Layout
========================= */
.layout {
  display: flex;
  min-height: 100vh;
  gap: 24px;
  padding: 24px;
  justify-content: center;
}

/* =========================
   Sidebar
========================= */
.sidebar {
  width: 220px;
  background: #ffffff;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}

.sidebar h1 {
  font-size: 18px;
  margin: 0 0 16px;
}

.sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar a {
  display: block;
  padding: 8px 12px;
  border-radius: 10px;
  text-decoration: none;
  color: #1d1d1f;
}

.sidebar a:hover {
  background: #f2f2f2;
}

/* =========================
   Content Grid
========================= */
.content {
  width: 100%;
}

.content.with-toc {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 32px;
  max-width: 1200px;
}

/* =========================
   Page
========================= */
.page {
  background: #ffffff;
  border-radius: 20px;
  padding: 32px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.06);
}

.page h2 {
  margin-top: 0;
  font-size: 26px;
}

.page h3 {
  margin-top: 36px;
  font-size: 18px;
}

.page ul {
  padding-left: 20px;
}

/* =========================
   TOC
========================= */
.toc {
  position: sticky;
  top: 24px;
  background: #ffffff;
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.05);
  font-size: 14px;
}

.toc strong {
  display: block;
  margin-bottom: 12px;
}

.toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc a {
  display: block;
  padding: 6px 10px;
  border-radius: 8px;
  text-decoration: none;
  color: #555;
}

.toc a:hover {
  background: #f2f2f2;
  color: #000;
}

/* =========================
   Tablet
========================= */
@media (max-width: 1100px) {
  .sidebar {
    display: none;
  }
}

/* =========================
   Mobile
========================= */
@media (max-width: 768px) {
  .layout {
    padding: 12px;
  }

  .sidebar {
    display: none;
  }

  /* Grid 해제 */
  .content.with-toc {
    display: block;
  }

  /* TOC를 본문 흐름으로 끌어오기 */
  .toc {
    position: static;
    margin: 16px 0 24px;
    background: #f6f6f6;
    box-shadow: none;
  }

  /* 본문 패딩 축소 */
  .page {
    padding: 20px;
  }
}