/* ============================================
   "IN THIS FILE" — case-study contents (built by js/case-toc.js)
   Wide screens: always-open sidebar down the left. Narrower: a small
   "In this file" button that opens the same list on demand, so nothing
   ever sits on top of the page content uninvited.
============================================ */
.cs-toc-toggle,
.cs-toc {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
}
.cs-toc-on .cs-toc-toggle,
.cs-toc-on .cs-toc.is-open { opacity: 1; visibility: visible; pointer-events: auto; }

.cs-toc-toggle {
  position: fixed;
  left: 16px;
  bottom: 16px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px;
  border: none;
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 0 0 2px var(--navy), 0 10px 24px rgba(10, 0, 84, 0.18);
  color: var(--navy);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  cursor: pointer;
}
.cs-toc-toggle svg { width: 14px; height: 14px; }

.cs-toc {
  position: fixed;
  left: 16px;
  bottom: 66px;
  z-index: 90;
  width: max-content;
  max-width: min(250px, calc(100vw - 32px));
  max-height: calc(100vh - 160px);
  overflow-y: auto;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 16px 14px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: 0 0 0 2px var(--navy), 0 18px 40px rgba(10, 0, 84, 0.2);
  transform: translateY(8px);
}
.cs-toc.is-open { transform: none; }

.cs-toc-back {
  display: inline-flex;
  align-items: center;
  align-self: flex-start;
  gap: 8px;
  padding: 7px 14px 7px 10px;
  border-radius: 999px;
  box-shadow: 0 0 0 2px var(--navy);
  background: #fff;
  color: var(--navy);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  transition: transform 0.2s ease;
}
.cs-toc-back svg { width: 14px; height: 14px; transition: transform 0.2s ease; }
.cs-toc-back:hover { transform: translateY(-1px); }
.cs-toc-back:hover svg { transform: translateX(-2px); }

.cs-toc-label {
  display: block;
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: rgba(12, 0, 84, 0.6);
}
.cs-toc-list { display: flex; flex-direction: column; align-items: flex-start; gap: 3px; margin: 0; padding: 0; list-style: none; }
.cs-toc-link {
  display: block;
  padding: 6px 10px;
  border: none;
  border-radius: 8px;
  background: transparent;
  color: rgba(12, 0, 84, 0.65);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.875rem;
  line-height: 1.4;
  text-align: left;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
}
.cs-toc-link:hover { color: var(--navy); background: rgba(191, 212, 255, 0.45); }
.cs-toc-link.is-active { background: var(--blue); color: #fff; }

/* Anchored sections stop clear of the fixed nav. */
[data-toc] { scroll-margin-top: 90px; }

/* Desktop and laptop (1280px and up): a slim rail of ticks down the left edge, one per section.
   The current section is the blue tick. Hovering or focusing a tick shows its name beside it, so
   the rail never sits over the page content. */
@media (min-width: 1280px) {
  .cs-toc-toggle { display: none; }
  .cs-toc {
    left: 14px;
    top: 50%;
    bottom: auto;
    width: auto;
    max-width: none;
    max-height: none;
    padding: 0;
    gap: 0;
    background: transparent;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    box-shadow: none;
    transform: translateY(-50%);
  }
  .cs-toc-on .cs-toc { opacity: 1; visibility: visible; pointer-events: auto; }
  .cs-toc-back, .cs-toc-label { display: none; }
  .cs-toc-list { gap: 12px; }
  .cs-toc-link {
    position: relative;
    width: 22px;
    height: 6px;
    padding: 0;
    border-radius: 3px;
    background: rgba(12, 0, 84, 0.22);
    color: transparent;
    font-size: 0;
  }
  .cs-toc-link:hover,
  .cs-toc-link:focus-visible { background: rgba(12, 0, 84, 0.45); }
  .cs-toc-link.is-active { width: 30px; background: var(--blue); }
  .cs-toc-link::after {
    content: attr(data-label);
    position: absolute;
    left: 40px;
    top: 50%;
    transform: translateY(-50%);
    padding: 6px 12px;
    border-radius: 999px;
    background: #fff;
    box-shadow: 0 0 0 1.5px var(--navy);
    color: var(--navy);
    font-family: var(--font-body);
    font-size: 0.8125rem;
    font-weight: 600;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
  }
  .cs-toc-link:hover::after,
  .cs-toc-link:focus-visible::after { opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .cs-toc-toggle, .cs-toc, .cs-toc-back, .cs-toc-back svg { transition: none; }
}