:root {
  color-scheme: light;
  --bg: #f7f7f5;
  --panel: #ffffff;
  --text: #1d1f23;
  --muted: #646a73;
  --faint: #8b9099;
  --border: #e3e3df;
  --hover: #f0f0ec;
  --accent: #0e7468;
  --accent-text: #ffffff;
  --accent-soft: #e2f3f0;
  --code-bg: #f2f2ee;
  --danger: #b42318;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 8px 24px rgb(0 0 0 / 0.06);
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #15171a;
    --panel: #1c1f23;
    --text: #e6e7e9;
    --muted: #a0a5ad;
    --faint: #7c818a;
    --border: #2c3036;
    --hover: #24282d;
    --accent: #3cc2b0;
    --accent-text: #0b1513;
    --accent-soft: #17312d;
    --code-bg: #24272c;
    --danger: #f97066;
    --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 8px 24px rgb(0 0 0 / 0.3);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100dvh;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 var(--sans);
  -webkit-font-smoothing: antialiased;
}

[hidden] {
  display: none !important;
}

button {
  font: inherit;
  color: inherit;
}

code,
pre {
  font-family: var(--mono);
  font-size: 0.9em;
}

svg.icon {
  width: 16px;
  height: 16px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Header ------------------------------------------------------------------ */

.bar {
  display: flex;
  align-items: center;
  gap: 16px;
  min-width: 0;
  padding: 10px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  font-weight: 650;
  font-size: 16px;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.source {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  color: var(--muted);
  white-space: nowrap;
  text-overflow: ellipsis;
}

.bar-actions {
  display: flex;
  gap: 8px;
  margin-left: auto;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 34px;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel);
  cursor: pointer;
  white-space: nowrap;
}

.button:hover {
  background: var(--hover);
}

.button:disabled {
  opacity: 0.6;
  cursor: progress;
}

.button.primary {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 550;
}

.button.primary:hover {
  filter: brightness(1.08);
}

.button.large {
  min-height: 44px;
  padding: 10px 22px;
  font-size: 16px;
}

.button.icon-only {
  padding: 6px 8px;
}

.button.icon-only svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Layout ------------------------------------------------------------------ */

.main {
  position: relative;
  display: grid;
  grid-template-columns: minmax(240px, 320px) minmax(0, 1fr);
  min-height: 0;
}

.main:not([data-state="files"]) {
  grid-template-columns: minmax(0, 1fr);
}

.welcome,
.busy,
.failure {
  display: grid;
  place-items: center;
  padding: 24px 16px;
  overflow: auto;
}

.welcome-card {
  max-width: 620px;
  padding: 40px;
  border: 1.5px dashed var(--border);
  border-radius: 16px;
  background: var(--panel);
  text-align: center;
}

.welcome-card h1 {
  margin: 0 0 12px;
  font-size: 26px;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.welcome-card h2 {
  margin: 0 0 12px;
  font-size: 20px;
}

.lede {
  margin: 0 0 24px;
  color: var(--muted);
}

.formats {
  margin: 24px 0 0;
  color: var(--faint);
  font-size: 13px;
  line-height: 1.9;
}

.formats code {
  padding: 1px 5px;
  border-radius: 4px;
  background: var(--code-bg);
  font-size: 12px;
}

.engine {
  margin: 12px 0 0;
  color: var(--faint);
  font-size: 13px;
}

.links {
  margin: 6px 0 0;
  color: var(--faint);
  font-size: 13px;
}

.links a {
  color: var(--muted);
}

.engine.error,
#failure-text {
  color: var(--danger);
}

#failure-text {
  margin: 0 0 24px;
  overflow-wrap: anywhere;
}

.busy {
  gap: 16px;
  align-content: center;
  color: var(--muted);
}

.busy p {
  margin: 0;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(1turn);
  }
}

/* File tree --------------------------------------------------------------- */

.tree {
  display: flex;
  flex-direction: column;
  min-height: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
}

.tree-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  padding: 12px 16px 8px;
  font-weight: 600;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.tree-count {
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  color: var(--faint);
}

.tree ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.tree-root {
  flex: 1;
  min-height: 0;
  overflow: auto;
  padding: 0 8px 12px;
}

.tree li[aria-expanded="false"] > ul {
  display: none;
}

.row {
  display: flex;
  align-items: center;
  border-radius: 6px;
}

.row:hover {
  background: var(--hover);
}

li[aria-selected="true"] > .row {
  background: var(--accent-soft);
}

li[aria-selected="true"] > .row .row-name {
  color: var(--accent);
  font-weight: 600;
}

.row-main {
  display: flex;
  flex: 1;
  align-items: center;
  gap: 7px;
  min-width: 0;
  padding: 5px 6px 5px calc(6px + var(--depth, 0) * 16px);
  border: 0;
  background: none;
  text-align: left;
  cursor: pointer;
}

.row-main .icon {
  color: var(--faint);
}

.chevron {
  transition: transform 0.12s;
}

li[aria-expanded="true"] > .row .chevron {
  transform: rotate(90deg);
}

li.dir > .row .row-main {
  padding-left: calc(6px + var(--depth, 0) * 16px - 2px);
}

li:not(.dir) > .row .row-main {
  padding-left: calc(6px + var(--depth, 0) * 16px + 21px);
}

.row-name {
  min-width: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.row-hint {
  flex: none;
  max-width: 45%;
  margin-left: auto;
  overflow: hidden;
  color: var(--faint);
  font-size: 12px;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.row-save {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  margin-right: 2px;
  border: 0;
  border-radius: 6px;
  background: none;
  color: var(--muted);
  cursor: pointer;
  opacity: 0;
}

.row:hover .row-save,
.row-save:focus-visible,
li[aria-selected="true"] > .row .row-save {
  opacity: 1;
}

.row-save:hover {
  background: var(--border);
  color: var(--text);
}

@media (hover: none) {
  .row-save {
    opacity: 1;
  }
}

.tree-foot {
  padding: 0 16px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 13px;
}

.tree-foot:empty {
  display: none;
}

.tree-foot p,
.tree-foot details {
  margin: 10px 0;
}

.tree-foot summary {
  cursor: pointer;
}

.tree-foot ul {
  max-height: 160px;
  margin-top: 6px;
  overflow: auto;
  overflow-wrap: anywhere;
}

/* Viewer ------------------------------------------------------------------ */

.viewer {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.viewer-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 24px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.crumbs {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  color: var(--muted);
  font-size: 14px;
}

.crumb.current {
  color: var(--text);
  font-weight: 600;
}

.crumb-sep {
  margin: 0 5px;
  color: var(--faint);
}

.viewer-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.segmented {
  display: inline-flex;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
}

.segmented button {
  padding: 4px 12px;
  border: 0;
  border-radius: 6px;
  background: none;
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
}

.segmented button[aria-pressed="true"] {
  background: var(--panel);
  color: var(--text);
  box-shadow: var(--shadow);
}

.viewer-meta {
  padding: 6px 24px;
  border-bottom: 1px solid var(--border);
  color: var(--faint);
  font-size: 12.5px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.viewer-scroll {
  flex: 1;
  min-height: 0;
  overflow: auto;
}

.only-narrow {
  display: none;
}

/* Rendered content -------------------------------------------------------- */

.content {
  max-width: 880px;
  margin: 0 auto;
  padding: 28px 32px 64px;
  overflow-wrap: break-word;
}

.content.markdown > :first-child {
  margin-top: 0;
}

.content h1,
.content h2,
.content h3,
.content h4,
.content h5,
.content h6 {
  margin: 1.6em 0 0.6em;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.content h1 {
  font-size: 1.75em;
}

.content h2 {
  padding-bottom: 0.25em;
  border-bottom: 1px solid var(--border);
  font-size: 1.4em;
}

.content h3 {
  font-size: 1.2em;
}

.content a {
  color: var(--accent);
  text-underline-offset: 2px;
}

.content a[data-path] {
  text-decoration-style: dotted;
}

.content .elsewhere {
  color: var(--muted);
  text-decoration: underline dotted var(--faint);
  cursor: help;
}

.content .picture-file {
  display: inline-block;
  padding: 2px 8px;
  border: 1px dashed var(--border);
  border-radius: 6px;
  font-size: 0.92em;
  text-decoration: none;
}

.content .remote-image::before {
  content: "Picture on the web: ";
  color: var(--muted);
}

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

.content img[data-path] {
  border-radius: 4px;
}

.content code {
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: var(--code-bg);
}

.content pre {
  padding: 14px 16px;
  overflow: auto;
  border-radius: 8px;
  background: var(--code-bg);
  line-height: 1.45;
}

.content pre code {
  padding: 0;
  background: none;
}

.content blockquote {
  margin: 1em 0;
  padding: 0 1em;
  border-left: 3px solid var(--border);
  color: var(--muted);
}

.content table {
  display: block;
  max-width: 100%;
  margin: 1em 0;
  overflow: auto;
  border-collapse: collapse;
  font-size: 0.93em;
}

.content th,
.content td {
  padding: 6px 10px;
  border: 1px solid var(--border);
  vertical-align: top;
}

.content th {
  background: var(--code-bg);
  text-align: left;
}

.content hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2em 0;
}

.content .footnote-definition {
  display: flex;
  gap: 6px;
  color: var(--muted);
  font-size: 0.92em;
}

.content .footnote-definition p {
  margin: 0;
}

.front-matter {
  margin: 0 0 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 13px;
}

.front-matter summary {
  padding: 8px 12px;
  color: var(--muted);
  cursor: pointer;
}

.front-matter pre {
  margin: 0;
  border-top: 1px solid var(--border);
  border-radius: 0 0 8px 8px;
}

.content pre.mermaid {
  background: none;
  border: 1px solid var(--border);
  text-align: center;
}

.content pre.mermaid:not([data-processed]) {
  color: var(--muted);
  text-align: left;
  white-space: pre;
}

.content pre.mermaid:not([data-processed]):not(.not-drawn)::before {
  content: "Drawing diagram…";
  display: block;
  margin-bottom: 8px;
  font-family: var(--sans);
  color: var(--faint);
}

.content pre.mermaid.not-drawn::before {
  content: "Mermaid diagram (not drawn: " attr(title) ")";
  display: block;
  margin-bottom: 8px;
  font-family: var(--sans);
  color: var(--faint);
}

.content.source {
  max-width: none;
}

.content.source pre {
  margin: 0;
  padding: 0;
  background: none;
  white-space: pre-wrap;
  font-size: 13px;
}

.content.picture {
  display: grid;
  place-items: center;
  max-width: none;
  min-height: 100%;
  background-image: conic-gradient(var(--hover) 25%, transparent 0 50%, var(--hover) 0 75%, transparent 0);
  background-size: 20px 20px;
}

.content.picture img {
  box-shadow: var(--shadow);
}

.content.card {
  margin-top: 48px;
  max-width: 520px;
  padding: 32px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--panel);
  text-align: center;
}

.content.card h2 {
  margin: 0 0 8px;
  overflow-wrap: anywhere;
}

.content.card p {
  margin: 0 0 20px;
  color: var(--muted);
}

/* Drop zone and messages -------------------------------------------------- */

.dropzone {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 16px;
  background: rgb(0 0 0 / 0.35);
  pointer-events: none;
}

.dropzone-inner {
  padding: 48px 64px;
  border: 2px dashed var(--accent);
  border-radius: 16px;
  background: var(--panel);
  color: var(--accent);
  font-size: 18px;
  font-weight: 600;
  text-align: center;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 30;
  max-width: calc(100vw - 32px);
  padding: 10px 16px;
  border-radius: 8px;
  background: var(--text);
  color: var(--bg);
  box-shadow: var(--shadow);
  transform: translateX(-50%);
}

/* Narrow screens: the file list becomes a drawer -------------------------- */

@media (max-width: 760px) {
  .bar {
    gap: 10px;
  }

  .source {
    display: none;
  }

  #download-all {
    padding: 6px 10px;
  }

  .main[data-state="files"] {
    grid-template-columns: minmax(0, 1fr);
  }

  .tree {
    position: absolute;
    inset: 0 auto 0 0;
    z-index: 10;
    width: min(320px, 86vw);
    box-shadow: var(--shadow);
    transform: translateX(-105%);
    transition: transform 0.18s ease;
  }

  .main.drawer-open .tree {
    transform: none;
  }

  .only-narrow {
    display: inline-flex;
  }

  .only-wide {
    display: none;
  }

  .viewer-bar,
  .viewer-meta {
    padding-left: 16px;
    padding-right: 16px;
  }

  .viewer-bar {
    flex-wrap: wrap;
    row-gap: 8px;
  }

  .crumbs {
    flex-basis: calc(100% - 56px);
  }

  .viewer-actions {
    flex: 1;
    justify-content: flex-end;
  }

  .content {
    padding: 20px 16px 48px;
  }

  .welcome-card {
    padding: 28px 20px;
  }

  .welcome-card h1 {
    font-size: 22px;
  }
}