/* Two-tone color system: Whitish and Greyish */
:root {
  --whitish: #fafafa;
  --greyish: #555555;
  --container-bg: #f0f0f0;
}

[data-theme="dark"] {
  --whitish: #222222;
  --greyish: #cccccc;
  --container-bg: #262626;
}

body {
  max-width: 600px;
  margin: 60px auto;
  padding: 0 20px;
  font: 16px/1.45 georgia, serif;
  color: var(--greyish);
  background-color: var(--whitish);
}

h1,
h2,
h3 {
  color: var(--greyish);
  font-weight: normal;
  margin-bottom: 0.5em;
}

h2 {
  margin-top: 40px;
  border-bottom: 1px dashed var(--greyish);
  padding-bottom: 5px;
  font-size: 20px;
}

a {
  color: var(--greyish);
  text-decoration: underline;
}

a:hover {
  color: var(--greyish);
  opacity: 0.7;
}

header {
  margin-bottom: 40px;
}

.theme-toggle {
  background: none;
  border: none;
  color: var(--greyish);
  cursor: pointer;
  font-family: inherit;
  font-size: 14px;
  text-decoration: underline;
  padding: 0;
  margin-top: 10px;
  /* float: right; */
}

/* Minimalist Search Styling */
.search-container {
  margin-bottom: 20px;
}

.search-input {
  width: 100%;
  padding: 10px 0;
  font-family: inherit;
  font-size: 16px;
  color: var(--greyish);
  background-color: transparent;
  border: none;
  border-bottom: 1px solid var(--greyish);
  outline: none;
}

.search-input::placeholder {
  color: var(--greyish);
  opacity: 0.5;
}

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

li {
  margin-bottom: 25px;
}

p {
  margin: 5px 0 0 0;
}

footer {
  margin-top: 100px;
  font-size: 13px;
  border-top: 1px dashed var(--greyish);
  padding-top: 20px;
  opacity: 0.6;
}

/* ------------------------------------------------------------- */
/* Chapter Specific Styles (Recycled Across All Subdomain Files) */
/* ------------------------------------------------------------- */

header nav {
  font-size: 14px;
  margin-bottom: 30px;
  border-bottom: 1px dashed var(--greyish);
  padding-bottom: 10px;
}

.phase-indicator {
  font-family: monospace;
  font-size: 12px;
  opacity: 0.6;
  text-transform: uppercase;
  margin-bottom: 5px;
}

pre {
  background-color: var(--container-bg);
  padding: 15px;
  overflow-x: auto;
  font-family: monospace;
  font-size: 14px;
  border-left: 2px solid var(--greyish);
  margin: 20px 0;
}

code {
  font-family: monospace;
  background-color: var(--container-bg);
  padding: 2px 4px;
  font-size: 14px;
}

.chapter-nav {
  margin-top: 60px;
  padding-top: 20px;
  border-top: 1px dashed var(--greyish);
  display: flex;
  justify-content: space-between;
}

/* Specific internal adjustments for reading a textbook syllabus index */
.chapter-list {
  list-style: none;
  padding-left: 0;
}

.chapter-list li {
  margin-bottom: 15px;
  line-height: 1.4;
}

.chapter-num {
  font-family: monospace;
  margin-right: 10px;
  opacity: 0.6;
}