/*
 * Glossary & formulae - /revision-notes/glossary/
 *
 * Every rule is nested under .glossary-page, the wrapper class on this page's
 * <section id="main">, per the house convention. Bare class names have already
 * collided across two stylesheets here.
 *
 * Colours are hex, not the :root tokens in revision-notes-textbook.css - those
 * are for the notes pages only. The brand accent is #d52349. Body and muted
 * greys are borrowed from css/pages/practice-questions.css so the section reads
 * as part of the site.
 */

.glossary-page {
  --gl-accent: #d52349;
  --gl-body: #5d5d5d;
  --gl-muted: #6b6b6b; /* 5.7:1 on #f7f7f7 - the inherited #7f888f is 3.4:1 */
  --gl-border: #e0e0e0;
  --gl-rule: #d3d9df;
  --gl-card: #ffffff;
}

/*
 * The UA rule for [hidden] is display:none, but any author display rule beats
 * it. The filter toggles entries with .hidden = true, so without this they
 * would stay on screen. css/pages/past-paper-questions.css documents the same
 * trap.
 */
.glossary-page [hidden] {
  display: none !important;
}

/* ---------------------------------------------------------------- breadcrumb
 * Restated because the inherited #7f888f fails AA on #main's #f7f7f7.
 */
.glossary-page .breadcrumb {
  margin-bottom: 2em;
  font-size: 0.9em;
  color: var(--gl-muted);
}

.glossary-page .breadcrumb a {
  color: #b91d3c;
  text-decoration: underline;
}

.glossary-page .breadcrumb a:hover {
  color: var(--gl-accent);
}

.glossary-page .breadcrumb .separator {
  color: #9aa3aa;
}

/* Long words in a definition, and the KaTeX boxes, must never widen the page.
 * The body scrolling sideways on a phone is the failure this prevents. */
.glossary-page .gl-entry,
.glossary-page .gl-text,
.glossary-page .gl-def-list,
.glossary-page .gl-source,
.glossary-page .gl-also {
  min-width: 0;
  overflow-wrap: break-word;
}

/* ---------------------------------------------------------------- hero */

.glossary-page .gl-hero {
  margin-bottom: 2.5em;
}

/* main.css leaves an <h1> inside #main at body size; the notes hub sizes its
 * own with .notes-h1. Same treatment here rather than borrowing that class,
 * which belongs to a different stylesheet. */
.glossary-page .gl-hero h1 {
  margin-bottom: 0.4em;
  font-size: 2.4em;
  line-height: 1.2;
}

.glossary-page .gl-intro {
  max-width: 46em;
  color: var(--gl-body);
  line-height: 1.7;
}

.glossary-page .gl-stats {
  margin-top: 1em;
  font-size: 0.95em;
  color: var(--gl-muted);
}

.glossary-page .gl-stats strong {
  color: var(--gl-accent);
}

.glossary-page .gl-stats a {
  margin-left: 0.6em;
  color: #b91d3c;
  text-decoration: underline;
}

/* ---------------------------------------------------------------- controls */

.glossary-page .gl-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 1em;
  align-items: flex-end;
  padding: 1.25em;
  margin-bottom: 1em;
  background: var(--gl-card);
  border: 1px solid var(--gl-border);
  border-radius: 4px;
}

.glossary-page .gl-field {
  display: flex;
  flex: 1 1 16em;
  flex-direction: column;
  gap: 0.35em;
}

.glossary-page .gl-field label {
  font-size: 0.85em;
  font-weight: 700;
  color: var(--gl-body);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.glossary-page .gl-field input,
.glossary-page .gl-field select {
  width: 100%;
  height: 2.75em;
  padding: 0 0.75em;
  font-size: 1em;
  color: #333;
  background: #fff;
  border: 1px solid #c9c9c9;
  border-radius: 3px;
}

.glossary-page .gl-field input:focus,
.glossary-page .gl-field select:focus,
.glossary-page .gl-clear:focus,
.glossary-page .gl-atoz a:focus,
.glossary-page .gl-clear-inline:focus {
  outline: 3px solid var(--gl-accent);
  outline-offset: 2px;
}

.glossary-page .gl-clear {
  height: 2.75em;
  padding: 0 1.25em;
  font-size: 0.9em;
  font-weight: 700;
  color: #3f3f3f; /* 9.6:1 on #ececec - grey-on-white read as disabled */
  cursor: pointer;
  background: #ececec;
  border: 1px solid #b5b5b5;
  border-radius: 3px;
}

.glossary-page .gl-clear:hover {
  color: #fff;
  background: var(--gl-accent);
  border-color: var(--gl-accent);
}

.glossary-page .gl-count {
  margin-bottom: 1.5em;
  font-size: 0.9em;
  color: var(--gl-muted);
}

.glossary-page .gl-noscript p,
.glossary-page .gl-empty {
  padding: 1em 1.25em;
  margin-bottom: 1.5em;
  font-size: 0.95em;
  color: var(--gl-body);
  background: #fff8e6;
  border-left: 4px solid #e0a800;
}

.glossary-page .gl-clear-inline {
  padding: 0;
  font: inherit;
  color: #b91d3c;
  text-decoration: underline;
  cursor: pointer;
  background: none;
  border: 0;
}

/* ---------------------------------------------------------------- A to Z */

.glossary-page .gl-atoz {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3em;
  padding-bottom: 1.5em;
  margin-bottom: 2em;
  border-bottom: 1px solid var(--gl-rule);
}

.glossary-page .gl-atoz a,
.glossary-page .gl-atoz span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.2em;
  height: 2.2em;
  font-size: 0.95em;
  font-weight: 700;
  border-radius: 3px;
}

.glossary-page .gl-atoz a {
  color: #fff;
  text-decoration: none;
  background: var(--gl-accent);
}

.glossary-page .gl-atoz a:hover {
  background: #a81b39;
}

/* Letters with no entries stay in place, greyed, so the strip does not reflow
 * between the two boards. */
.glossary-page .gl-atoz span {
  color: #9aa3aa;
  background: #ececec;
}

/* ---------------------------------------------------------------- formulae */

.glossary-page .gl-formulae {
  margin-bottom: 3em;
}

.glossary-page .gl-formulae-intro {
  max-width: 46em;
  color: var(--gl-body);
}

/* A formula is as wide as it is; 20em columns clipped the longer ones. These
 * columns fit two per row on a desktop and one below 980px. min-width: 0 is
 * load-bearing - a grid item defaults to min-width: auto, so without it a wide
 * formula pushes the column out and the whole page scrolls sideways. */
.glossary-page .gl-formula-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 28em), 1fr));
  gap: 1.25em;
}

.glossary-page .gl-formula {
  min-width: 0;
  padding: 1.25em;
  background: var(--gl-card);
  border: 1px solid var(--gl-border);
  border-top: 3px solid var(--gl-accent);
  border-radius: 4px;
}

.glossary-page .gl-formula-name {
  margin-bottom: 0.6em;
  font-size: 1em;
  letter-spacing: 0.03em;
}

/* KaTeX sets its own font size; hold it to the page's scale and let a long
 * formula scroll inside its own box rather than widening the page. */
.glossary-page .gl-math {
  max-width: 100%;
  padding: 0.5em 0;
  overflow-x: auto;
  overflow-y: hidden;
}

.glossary-page .gl-math .katex-display {
  margin: 0;
}

.glossary-page .gl-math .katex {
  font-size: 1em;
}

/* ---------------------------------------------------------------- entries */

.glossary-page .gl-letter {
  margin-bottom: 2.5em;
  scroll-margin-top: 1em;
}

.glossary-page .gl-letter-head {
  padding-bottom: 0.2em;
  margin-bottom: 1em;
  font-size: 1.6em;
  color: var(--gl-accent);
  border-bottom: 2px solid var(--gl-rule);
}

.glossary-page .gl-list {
  margin: 0;
}

/* dl > div > dt + dd is valid HTML5 and gives the filter a single node to
 * toggle per entry. */
.glossary-page .gl-entry {
  padding: 1.1em 1.25em;
  margin-bottom: 0.75em;
  background: var(--gl-card);
  border: 1px solid var(--gl-border);
  border-left: 3px solid var(--gl-accent);
  border-radius: 3px;
  scroll-margin-top: 1em;
}

.glossary-page .gl-entry:target {
  border-left-width: 6px;
  box-shadow: 0 0 0 3px rgba(213, 35, 73, 0.18);
}

.glossary-page .gl-term {
  margin-bottom: 0.35em;
  font-size: 1.05em;
  font-weight: 700;
  color: #2f2f2f;
}

.glossary-page .gl-def {
  margin: 0;
  margin-left: 0;
}

.glossary-page .gl-text {
  margin-bottom: 0.5em;
  color: var(--gl-body);
  line-height: 1.65;
}

/* The list that completes a definition which ends on a colon in the notes. It
 * cannot live inside the <p>, so it sits after it inside the <dd>. */
.glossary-page .gl-def-list {
  margin: 0 0 0.6em 0;
}

.glossary-page .gl-def-list ul {
  margin: 0;
  padding-left: 1.3em;
  list-style: disc;
}

.glossary-page .gl-def-list li {
  padding-left: 0.2em;
  color: var(--gl-body);
  line-height: 1.6;
}

/* The list that completes a definition which ends on a colon in the notes. */
.glossary-page .gl-def-list {
  margin: 0 0 0.6em 0;
}

.glossary-page .gl-def-list ul {
  margin: 0;
  padding-left: 1.3em;
  list-style: disc;
}

.glossary-page .gl-def-list li {
  padding-left: 0.2em;
  color: var(--gl-body);
  line-height: 1.6;
}

.glossary-page .gl-source,
.glossary-page .gl-also {
  margin-bottom: 0;
  font-size: 0.85em;
  color: var(--gl-muted);
}

.glossary-page .gl-source a,
.glossary-page .gl-also a {
  color: #b91d3c;
  text-decoration: underline;
}

/* Shown instead of a source link on the handful of entries whose concept the
 * specification requires but no notes page covers yet. */
.glossary-page .gl-nopage {
  font-style: italic;
  color: #8a6d00;
}

.glossary-page .gl-group {
  display: inline-block;
  padding: 0.15em 0.55em;
  margin-right: 0.5em;
  font-size: 0.9em;
  font-weight: 700;
  color: #fff;
  background: #7a7a7a;
  border-radius: 2px;
}

.glossary-page .gl-mark {
  padding: 0 0.1em;
  font-weight: 700;
  color: inherit;
  background: #ffe9b3;
}

/* ---------------------------------------------------------------- landing */

.glossary-page .gl-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(19em, 1fr));
  gap: 1.5em;
  margin-bottom: 3em;
}

.glossary-page .gl-card {
  display: flex;
  flex-direction: column;
  padding: 1.75em;
  background: var(--gl-card);
  border: 1px solid var(--gl-border);
  border-top: 4px solid var(--gl-accent);
  border-radius: 4px;
}

.glossary-page .gl-card h2 {
  margin-bottom: 0.3em;
  font-size: 1.3em;
}

.glossary-page .gl-card h2 a {
  color: #2f2f2f;
  text-decoration: none;
  border: 0;
}

.glossary-page .gl-card h2 a:hover {
  color: var(--gl-accent);
}

.glossary-page .gl-card-count {
  margin-bottom: 0.8em;
  font-size: 0.9em;
  color: var(--gl-muted);
}

.glossary-page .gl-card-count strong {
  color: var(--gl-accent);
}

.glossary-page .gl-card p {
  color: var(--gl-body);
  line-height: 1.65;
}

.glossary-page .gl-card-button {
  margin-top: auto;
}

.glossary-page .gl-more-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75em;
}

/* ---------------------------------------------------------------- mobile */

@media screen and (max-width: 736px) {
  .glossary-page .gl-controls {
    padding: 1em;
  }

  .glossary-page .gl-field {
    flex-basis: 100%;
  }

  .glossary-page .gl-clear {
    width: 100%;
  }

  /* The strip scrolls sideways rather than wrapping to four rows. */
  .glossary-page .gl-atoz {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .glossary-page .gl-atoz a,
  .glossary-page .gl-atoz span {
    flex: 0 0 auto;
  }

  .glossary-page .gl-formula-grid {
    grid-template-columns: 1fr;
  }

  .glossary-page .gl-entry {
    padding: 0.9em 1em;
  }
}

/* ---------------------------------------------------------------- print
 *
 * A glossary is the one page on this site a student actually prints. Drop
 * everything that is not a definition, and keep entries off page breaks.
 */

@media print {
  .glossary-page .gl-controls,
  .glossary-page .gl-count,
  .glossary-page .gl-atoz,
  .glossary-page .gl-empty,
  .glossary-page .gl-noscript,
  .glossary-page .gl-stats a,
  .glossary-page .breadcrumb,
  .glossary-page .gl-more {
    display: none !important;
  }

  .glossary-page .gl-entry,
  .glossary-page .gl-formula {
    padding: 0.4em 0;
    margin-bottom: 0.35em;
    background: none;
    border: 0;
    border-bottom: 1px solid #ddd;
    border-radius: 0;
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .glossary-page .gl-letter,
  .glossary-page .gl-formula-grid {
    break-inside: auto;
  }

  .glossary-page .gl-letter-head {
    break-after: avoid;
    page-break-after: avoid;
  }

  .glossary-page .gl-formula-grid {
    display: block;
  }

  /* The spec code is the useful part on paper; the link target is not. */
  .glossary-page .gl-source a,
  .glossary-page .gl-also a {
    color: #000;
    text-decoration: none;
  }

  .glossary-page .gl-group {
    color: #000;
    background: none;
    border: 1px solid #999;
  }

  .glossary-page .gl-text,
  .glossary-page .gl-source {
    color: #000;
  }
}