/* === GLOBAL RESET & BASE === */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Segoe UI', 'Helvetica Neue', 'Open Sans', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  background: #ffffff;
  color: #2c3e50;
}

/* === CONTAINER === */
.container {
  display: flex;
  flex-direction: row;
}

/* === SIDEBAR TOC === */
#TOC {
  width: 260px;
  background-color: #2e2e2e;
  color: #f0f0f0;
  padding: 2rem 1.2rem;
  height: 100vh;
  position: fixed;
  left: 0;
  top: 0;
  overflow-y: auto;
  border-right: 1px solid #1c1c1c;
  font-size: 0.95rem;
}

#TOC h2 {
  font-size: 1rem;
  color: #9ae1ff;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

#TOC ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

#TOC li {
  margin: 0.3rem 0;
}

#TOC li ul {
  padding-left: 1rem;
  margin-top: 0.2rem;
  border-left: 1px solid #444;
}

#TOC a {
  display: block;
  padding: 6px 10px;
  border-radius: 4px;
  color: #d3d3d3;
  text-decoration: none;
  transition: background 0.2s, color 0.2s;
}

#TOC a:hover {
  background-color: #3d3d3d;
  color: #fff;
}

/* === MAIN CONTENT === */
.content {
  margin-left: 260px;
  padding: 2.5rem 3rem;
  max-width: 960px;
  background: #ffffff;
}

/* === HEADINGS === */
h1, h2, h3, h4 {
  color: #222;
  margin-top: 2rem;
  scroll-margin-top: 80px;
}

h1 {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.6rem;
  border-bottom: 1px solid #eee;
  padding-bottom: 0.4rem;
  margin-top: 2rem;
}

h3 {
  font-size: 1.3rem;
}

h4 {
  font-size: 1.1rem;
  color: #444;
}

/* === PARAGRAPH & LINKS === */
p {
  margin: 1rem 0;
}

a {
  color: #2ba8db;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* === CODE & PRE === */
code {
  background: #f4f4f4;
  padding: 2px 5px;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
}

pre {
  background: #f4f4f4;
  padding: 1rem;
  overflow-x: auto;
  border-radius: 6px;
  border: 1px solid #ddd;
  font-size: 0.95rem;
}

/* === MATH === */
mjx-container {
  font-size: 1.05em;
}

/* === IMAGES === */
img {
  display: block;
  margin: 2rem auto;
  height: auto;
  max-width: 100%;
  border-radius: 4px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  object-fit: contain;
}

/* Let style="width:50%" work */
img[style] {
  max-width: none !important;
  height: auto !important;
  object-fit: contain;
}

/* === FIGURES === */
figure {
  text-align: center;
  margin: 2rem 0;
}

figcaption {
  font-size: 0.9rem;
  color: #666;
  margin-top: 0.5rem;
}

/* === BLOCKQUOTES === */
blockquote {
  border-left: 4px solid #9ae1ff;
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: #555;
  background: #f9f9f9;
  font-style: italic;
}

/* === TABLES === */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid #ccc;
  padding: 0.6rem;
  text-align: left;
}

th {
  background: #f2f2f2;
}

/* === INFO BOX / NOTE === */
.note {
  background: #e3f2fd;
  border-left: 4px solid #2196f3;
  padding: 1rem;
  margin: 2rem 0;
  color: #0d47a1;
  border-radius: 5px;
  box-shadow: 0 0 6px rgba(33, 150, 243, 0.1);
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
  #TOC {
    display: none;
  }

  .content {
    margin-left: 0;
    padding: 2rem 1.5rem;
  }
}