/* Flanagan Math - one simple style for every page */

* { box-sizing: border-box; }

body {
  margin: 0;
  background: #fff;
  color: #111;
  font-family: Aptos, "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.6;
}

.page {
  max-width: 54rem;
  margin: 0 auto;
  padding: 1rem 1.5rem 3rem;
}

a { color: #111; text-underline-offset: 0.15em; }
:focus-visible { outline: 3px solid #111; outline-offset: 2px; }

img { max-width: 100%; height: auto; }

/* Equations never get their own scroll bar; displayed equations are indented a little, like the notes */
mjx-container { overflow: visible !important; }
mjx-container[display="true"] { margin-left: 1.5em !important; }

/* Top line: where you are */
.top {
  font-size: 0.95rem;
  color: #444;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid #ccc;
}
.top a { color: #444; }

/* Headings, like the notes */
h1 { font-size: 1.7rem; line-height: 1.25; margin: 1.5rem 0 1.5rem; }
h2 { font-size: 1.15rem; margin: 0; }

/* Each section: a title row that opens and closes the section below it */
.topic-section { border-top: 1px solid #bbb; }
.topic-section:last-of-type { border-bottom: 1px solid #bbb; }

button.section-toggle {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  width: 100%;
  margin: 0;
  padding: 0.9rem 0;
  border: 0;
  background: none;
  color: inherit;
  font: inherit;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
}
.chevron::before {
  content: "\25B8";                 /* small right-pointing triangle */
  display: inline-block;
  width: 0.8em;
  transition: transform 0.15s;
}
button.section-toggle[aria-expanded="true"] .chevron::before { transform: rotate(90deg); }

.section-body { padding: 0 0 1.5rem; }

/* Closed sections keep their width (so equations lay out correctly) but take no space */
.js .section-body:not(.open) {
  height: 0;
  padding: 0;
  overflow: hidden;
  visibility: hidden;
}

h3 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; }

p { margin: 0 0 0.9rem; }
ul { margin: 0 0 0.9rem; }

/* Text with a figure to the right, like the notes; stacked on phones */
.row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 18rem);
  gap: 2rem;
  align-items: start;
}
.row > * { min-width: 0; }
.row > img { max-width: 100%; }

@media (max-width: 760px) {
  .row { grid-template-columns: minmax(0, 1fr); gap: 0.5rem; }
  .row.fig-first > img { order: -1; }
}

img.wide { display: block; max-width: min(36rem, 100%); margin: 0.5rem 0 1rem; }

/* Worked solutions: hidden until the button is pressed */
button.toggle {
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: #111;
  background: #fff;
  padding: 0.25rem 0.8rem;
  border: 1px solid #111;
  border-radius: 4px;
  cursor: pointer;
}
button.toggle { display: block; margin: 0.25rem 0 0.75rem; }
button.toggle[hidden] { display: none; }

.example {                         /* an example, start to finish */
  background: #f3f3f3;
  border-radius: 6px;
  padding: 0.9rem 1.1rem 0.3rem;
  margin: 1rem 0 1.5rem;
}
.example h3 { margin-top: 0; }
.example .work { border-left-color: #bbb; }

.formula {                         /* a key formula, with its name */
  border: 1px solid #c8c8c8;
  padding: 0.6rem 1rem 0.2rem;
  margin: 0.5rem 0 1.25rem;
  background: #fff;
}
.formula-name { font-weight: 700; font-size: 0.95rem; margin: 0; }
.formula mjx-container[display="true"] { margin: 0.4em 0 0.5em 0.75em !important; }

.work {
  margin: 0 0 0.75rem;
  padding-left: 1rem;
  border-left: 2px solid #ccc;
}
.work.collapsed {
  height: 0;
  margin: 0;
  overflow: hidden;
  visibility: hidden;
}

/* Lists of properties */
dl.properties { margin: 0 0 1rem; }
dl.properties dt { margin-top: 0.5rem; }
dl.properties dd { margin: 0; }

/* Small grid, such as the standard basis cross products */
table.grid { border-collapse: collapse; margin: 0.5rem 0 1rem; }
table.grid td { border: 1px solid #ccc; padding: 0.35rem 0.9rem; text-align: center; }

/* Course and topic lists */
ul.links { list-style: none; padding: 0; }
ul.links li { margin: 0.5rem 0; font-size: 1.1rem; }

/* Previous / next topic */
.next-prev {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid #ccc;
  font-size: 0.95rem;
}
.next-prev .next { margin-left: auto; text-align: right; }

/* Text for screen readers only */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

@media (max-width: 600px) {
  body { font-size: 1rem; }
  mjx-container[display="true"] { margin-left: 0.25em !important; }
  .page { padding: 0.75rem 1rem 2.5rem; }
  .example { padding: 0.75rem 0.75rem 0.2rem; }
  .example .work { padding-left: 0.6rem; }
  h1 { font-size: 1.45rem; }
}

@media (max-width: 400px) {
  table.grid { width: 100%; table-layout: fixed; }
  table.grid td { padding: 0.35rem 0.1rem; font-size: 0.9rem; }
}

/* Printing gives the notes without the solutions, like a guided-notes handout */
@media print {
  .section-body, .js .section-body:not(.open) { height: auto !important; visibility: visible !important; overflow: visible !important; padding-bottom: 1rem !important; }
  .section-body[hidden] { display: block !important; content-visibility: visible !important; }
  .chevron { display: none; }
  .top, .next-prev { display: none; }
  .page { max-width: none; padding: 0; }
  body { font-size: 11pt; }
  .work, button.toggle { display: none !important; }
}