/* Sticky thinker TOC + back-to-top for long philosophy essays */

.essay-layout {
  position: relative;
}

.essay-toc-toggle {
  display: none;
  position: fixed;
  z-index: 40;
  left: max(12px, env(safe-area-inset-left));
  bottom: max(20px, env(safe-area-inset-bottom));
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.65rem 1rem;
  box-shadow: var(--shadow);
  cursor: pointer;
}

.essay-toc {
  font-family: var(--sans);
  font-size: 0.78rem;
  line-height: 1.35;
}

.essay-toc-label {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--faint);
  margin: 0 0 0.75rem;
}

.essay-toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
}

.essay-toc li + li {
  margin-top: 0.35rem;
}

.essay-toc a {
  display: block;
  color: var(--muted);
  text-decoration: none;
  border-bottom: none;
  padding: 0.2rem 0.55rem 0.2rem 0.65rem;
  border-left: 2px solid transparent;
  border-radius: 0 4px 4px 0;
}

.essay-toc a:hover {
  color: var(--ink);
  border-bottom: none;
}

.essay-toc a.is-active {
  color: var(--ink);
  border-left-color: var(--cyan);
  background: var(--cyan-soft);
}

.essay-toc-more {
  margin: 0 0 1rem;
  padding: 0 0 0.9rem;
  border-bottom: 1px solid var(--line);
}

.essay-toc-more ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.essay-toc-more li + li {
  margin-top: 0.35rem;
}

.essay-toc-close {
  display: none;
}

.back-to-top {
  position: fixed;
  z-index: 40;
  right: max(16px, env(safe-area-inset-right));
  bottom: max(20px, env(safe-area-inset-bottom));
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  box-shadow: var(--shadow);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  font-size: 1.1rem;
  line-height: 1;
  padding: 0;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

@media (min-width: 1100px) {
  .essay-layout {
    display: grid;
    grid-template-columns: minmax(160px, 200px) minmax(0, 960px);
    gap: clamp(1.5rem, 3vw, 2.5rem);
    align-items: start;
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 clamp(16px, 3vw, 40px);
  }

  .essay-layout > .wrap.essay {
    max-width: none;
    margin: 0;
    padding-left: 0;
    padding-right: 0;
  }

  .essay-toc {
    position: sticky;
    top: 1.25rem;
    align-self: start;
    max-height: calc(100vh - 2.5rem);
    overflow-y: auto;
    padding: 0.4rem 0 1rem;
    scrollbar-width: thin;
  }
}

@media (max-width: 1099px) {
  .essay-toc-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
  }

  .essay-toc {
    position: fixed;
    z-index: 50;
    left: 0;
    top: 0;
    bottom: 0;
    width: min(300px, 86vw);
    padding: 1.25rem 1rem 1.5rem;
    background: var(--panel);
    border-right: 1px solid var(--line);
    box-shadow: var(--shadow);
    overflow-y: auto;
    transform: translateX(-105%);
    transition: transform 0.22s ease;
  }

  .essay-toc.is-open {
    transform: translateX(0);
  }

  .essay-toc-close {
    display: block;
    float: right;
    margin: -0.2rem 0 0.6rem;
    border: none;
    background: transparent;
    color: var(--muted);
    font-size: 1.4rem;
    line-height: 1;
    cursor: pointer;
    padding: 0.2rem 0.4rem;
  }

  .essay-toc-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 45;
    background: rgba(10, 14, 24, 0.45);
  }

  .essay-toc-backdrop.is-open {
    display: block;
  }

  .back-to-top {
    bottom: max(72px, calc(env(safe-area-inset-bottom) + 64px));
  }
}

@media (prefers-reduced-motion: reduce) {
  .essay-toc,
  .back-to-top {
    transition: none;
  }
}