:root {
  --ink: #1a1a1a;
  --soft-ink: #555;
  --muted: #767676;
  --accent: #4b2e83;
  --accent-soft: #f1eef7;
  --line: #e8e8e8;
  --paper: #f5f4f1;
  --white: #ffffff;
  --font-heading: "Instrument Serif", serif;
  --grain-svg: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.55'/%3E%3C/svg%3E");
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, "PingFang TC", "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.7;
  mix-blend-mode: multiply;
  background-image: var(--grain-svg);
  background-size: 180px 180px;
}

.toc-main {
  position: relative;
  z-index: 0;
  width: min(72rem, 94vw);
  margin: 0 auto;
  padding: 3rem 0 3.5rem;
}

.toc-back {
  display: inline-block;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.toc-back:hover,
.toc-back:focus-visible {
  color: var(--accent);
  border-bottom-color: color-mix(in srgb, var(--accent) 35%, transparent);
}

.toc-header {
  margin-bottom: 1.5rem;
}

.toc-header-row {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
}

.toc-title {
  margin: 0 0 0.75rem;
  font-family: var(--font-heading);
  font-size: clamp(1.55rem, 2.6vw, 2rem);
  font-weight: 400;
}

.toc-lead {
  margin: 0;
  max-width: 40rem;
  color: var(--soft-ink);
  line-height: 1.7;
}

.toc-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

@media (min-width: 960px) {
  .toc-layout {
    grid-template-columns: 1fr 1fr;
    align-items: stretch;
  }
}

.toc-col {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-height: 0;
}

.toc-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  padding: 1rem 1.1rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.toc-card-grow {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 22rem;
}

.toc-card-title {
  margin: 0 0 0.85rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--soft-ink);
}

.toc-card-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.toc-card-toolbar .toc-card-title {
  margin: 0;
}

.toc-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 560px) {
  .toc-options {
    grid-template-columns: 1fr 1fr;
  }
}

.toc-field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  font-size: 0.875rem;
}

.toc-field-inline {
  justify-content: center;
}

.toc-label {
  font-weight: 500;
  color: var(--ink);
}

.toc-level-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.toc-check {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  color: var(--soft-ink);
}

.toc-check input {
  accent-color: var(--accent);
}

.toc-input {
  width: 100%;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  font: inherit;
  font-size: 0.875rem;
  background: var(--paper);
  color: var(--ink);
}

.toc-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 25%, transparent);
}

.toc-textarea {
  flex: 1;
  width: 100%;
  min-height: 16rem;
  padding: 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  font-family: "IBM Plex Mono", "SFMono-Regular", Menlo, Monaco, Consolas, monospace;
  font-size: 0.75rem;
  line-height: 1.55;
  resize: vertical;
  background: var(--paper);
  color: var(--ink);
}

.toc-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 25%, transparent);
}

.toc-tabs-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-bottom: 0.75rem;
  margin-bottom: 0.85rem;
  border-bottom: 1px solid var(--line);
}

.toc-tabs {
  display: flex;
  gap: 0.25rem;
}

.toc-tab {
  appearance: none;
  border: none;
  background: transparent;
  padding: 0.4rem 0.7rem;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
}

.toc-tab:hover,
.toc-tab:focus-visible {
  color: var(--ink);
}

.toc-tab.is-active {
  color: var(--accent);
  font-weight: 600;
  border-bottom-color: var(--accent);
}

.toc-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.toc-btn {
  appearance: none;
  border: none;
  border-radius: 0.5rem;
  padding: 0.45rem 0.8rem;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.toc-btn-primary {
  background: var(--accent);
  color: #fff;
}

.toc-btn-primary:hover,
.toc-btn-primary:focus-visible {
  background: color-mix(in srgb, var(--accent) 85%, #000);
}

.toc-btn-secondary {
  background: var(--ink);
  color: #fff;
}

.toc-btn-secondary:hover,
.toc-btn-secondary:focus-visible {
  background: color-mix(in srgb, var(--ink) 85%, #000);
}

.toc-btn-text {
  appearance: none;
  border: none;
  background: transparent;
  padding: 0;
  font: inherit;
  font-size: 0.75rem;
  color: var(--muted);
  cursor: pointer;
}

.toc-btn-text:hover,
.toc-btn-text:focus-visible {
  color: #b91c1c;
}

.toc-preview {
  flex: 1;
  min-height: 16rem;
  max-height: 38rem;
  overflow: auto;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: var(--white);
  line-height: 1.65;
}

.toc-preview.is-hidden,
.toc-code.is-hidden {
  display: none;
}

.toc-code {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 16rem;
}

.toc-output {
  flex: 1;
  width: 100%;
  min-height: 16rem;
  max-height: 38rem;
  padding: 0.85rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  font-family: "IBM Plex Mono", "SFMono-Regular", Menlo, Monaco, Consolas, monospace;
  font-size: 0.75rem;
  line-height: 1.55;
  resize: vertical;
  background: #1a1a1a;
  color: #86efac;
}

.toc-output:focus {
  outline: none;
}

.toc-empty {
  margin: 3rem 0;
  text-align: center;
  color: var(--muted);
  font-style: italic;
}

.toc-preview .table-of-contents summary.toc-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0;
  padding: 0.35rem 0 0.65rem;
  border-bottom: 2px solid var(--line);
  cursor: pointer;
  list-style: none;
}

.toc-preview .table-of-contents summary.toc-title::-webkit-details-marker {
  display: none;
}

.toc-preview .table-of-contents summary.toc-title::before {
  content: "▾";
  display: inline-block;
  margin-right: 0.45rem;
  color: var(--accent);
  transition: transform 0.15s ease;
}

.toc-preview .table-of-contents details:not([open]) summary.toc-title::before {
  transform: rotate(-90deg);
}

.toc-preview .table-of-contents details:not([open]) summary.toc-title {
  border-bottom-color: transparent;
  padding-bottom: 0.2rem;
}

.toc-preview h1,
.toc-preview h2,
.toc-preview h3,
.toc-preview h4 {
  margin: 1.1em 0 0.45em;
  line-height: 1.3;
}

.toc-preview h1:first-child,
.toc-preview h2:first-child,
.toc-preview h3:first-child,
.toc-preview h4:first-child,
.toc-preview nav:first-child {
  margin-top: 0;
}

.toc-preview p,
.toc-preview ol,
.toc-preview ul {
  margin: 0 0 0.85em;
}

.toc-preview a {
  color: var(--accent);
}

.toc-toast {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  z-index: 10000;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1rem;
  border-radius: 0.6rem;
  background: #1a1a1a;
  color: #fff;
  font-size: 0.875rem;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
  opacity: 0;
  pointer-events: none;
  transform: translateY(0.5rem);
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.toc-toast.is-visible {
  opacity: 1;
  transform: translateY(0);
}