@font-face {
  font-family: "Onest";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("/fonts/onest-cyrillic.woff2") format("woff2");
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}

@font-face {
  font-family: "Onest";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("/fonts/onest-latin.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

@font-face {
  font-family: "Unbounded";
  font-style: normal;
  font-weight: 200 900;
  font-display: swap;
  src: url("/fonts/unbounded-cyrillic.woff2") format("woff2");
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}

@font-face {
  font-family: "Unbounded";
  font-style: normal;
  font-weight: 200 900;
  font-display: swap;
  src: url("/fonts/unbounded-latin.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, "Apple Color Emoji", Arial, sans-serif, "Segoe UI Emoji", "Segoe UI Symbol";
  font-size: 16px;
  line-height: 1.6;
  color: rgb(55, 53, 47);
  background: #fff;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
}

/* Smooth scroll for anchor links */
html {
  scroll-behavior: smooth;
}

/* Highlight target heading briefly after anchor jump */
:target {
  animation: anchor-flash 1.5s ease;
}
@keyframes anchor-flash {
  0% { background: rgba(255, 212, 0, 0.25); }
  100% { background: transparent; }
}

.page {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* Title */
.page-title {
  font-size: 40px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 4px;
  padding: 3px 2px;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.page-icon {
  font-size: 48px;
  line-height: 1;
  margin: 72px 0 18px;
  padding: 3px 2px;
}

.page-landing > h1:first-of-type {
  font-size: 40px;
  font-weight: 700;
  line-height: 1.2;
  margin-top: 72px;
  margin-bottom: 4px;
  padding: 3px 2px;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.page-landing > .page-icon + h1:first-of-type {
  margin-top: 0;
}

/* Headings */
h1 {
  font-size: 30px;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 4px;
  padding: 3px 2px;
  line-height: 1.3;
  overflow-wrap: anywhere;
  word-break: break-word;
}

h2 {
  font-size: 24px;
  font-weight: 600;
  margin-top: 22px;
  margin-bottom: 4px;
  padding: 3px 2px;
  line-height: 1.3;
  overflow-wrap: anywhere;
  word-break: break-word;
}

h3 {
  font-size: 20px;
  font-weight: 600;
  margin-top: 16px;
  margin-bottom: 4px;
  padding: 3px 2px;
  line-height: 1.3;
  overflow-wrap: anywhere;
  word-break: break-word;
}

h4 {
  font-size: 17px;
  font-weight: 600;
  margin-top: 14px;
  margin-bottom: 4px;
  padding: 3px 2px;
  line-height: 1.3;
  overflow-wrap: anywhere;
  word-break: break-word;
}

/* Strikethrough */
del, s {
  text-decoration: line-through;
  color: rgba(55, 53, 47, 0.5);
}

/* Paragraph */
p {
  margin-top: 2px;
  margin-bottom: 2px;
  padding: 3px 2px;
  min-height: 1.6em;
}

/* Links */
a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: rgba(55, 53, 47, 0.4);
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-color: rgb(55, 53, 47);
}

/* Bold / Italic */
strong {
  font-weight: 600;
}

em {
  font-style: italic;
}

/* Underline */
u {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(55, 53, 47, 0.4);
}

/* Highlight — color variants */
mark { padding: 0 2px; border-radius: 2px; color: inherit; }
mark, mark.bg-yellow { background: rgba(255, 212, 0, 0.14); }
mark.bg-gray { background: rgba(155, 154, 151, 0.15); }
mark.bg-brown { background: rgba(140, 46, 0, 0.10); }
mark.bg-orange { background: rgba(245, 93, 0, 0.10); }
mark.bg-green { background: rgba(0, 135, 107, 0.10); }
mark.bg-blue { background: rgba(0, 120, 223, 0.10); }
mark.bg-purple { background: rgba(103, 36, 222, 0.10); }
mark.bg-pink { background: rgba(221, 0, 129, 0.10); }
mark.bg-red { background: rgba(255, 0, 26, 0.10); }

/* Lists */
ul, ol {
  padding-left: 1.7em;
  margin-top: 2px;
  margin-bottom: 2px;
}

li {
  padding: 3px 0;
}

li > ul, li > ol {
  margin-top: 0;
  margin-bottom: 0;
}

/* Compact list items — remove extra spacing when markdown wraps li content in <p> */
li > p {
  margin: 0;
  padding: 0;
  min-height: auto;
}

/* Checkboxes */
li.task-list-item {
  list-style-type: none;
  margin-left: -1.5em;
}

li.task-list-item input[type="checkbox"] {
  margin-right: 6px;
  vertical-align: middle;
}

/* Table of Contents — clean navigation style */
.toc {
  margin: 4px 0;
  padding: 0;
}
.toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.toc li {
  padding: 5px 2px;
  line-height: 1.4;
}
.toc li a {
  color: rgb(120, 119, 116);
  text-decoration: none;
  font-size: 15px;
  transition: color 0.15s;
}
.toc li a:hover {
  color: rgb(55, 53, 47);
}
/* Nested TOC — sub-sections (H2 under H1) */
.toc ul ul {
  padding-left: 20px;
  margin-top: 2px;
  margin-bottom: 2px;
  border-left: 1px solid rgba(55, 53, 47, 0.09);
}
.toc ul ul li {
  padding: 3px 2px 3px 8px;
}
.toc ul ul li a {
  color: rgb(145, 144, 142);
  font-size: 15px;
}
.toc ul ul li a:hover {
  color: rgb(100, 99, 97);
}

/* Blockquote — legacy markdown (>) fallback: callout style */
blockquote {
  margin: 4px 0;
  padding: 16px 16px 16px 12px;
  background: rgb(241, 241, 239);
  border-radius: 4px;
  border: none;
  font-size: 16px;
}
blockquote p {
  margin: 0;
  padding: 0;
}

/* Notion Quote — left border, no background */
.notion-quote {
  margin: 8px 0;
  padding: 12px 0 12px 16px;
  border-left: 3px solid rgb(55, 53, 47);
  background: none;
  border-radius: 0;
  font-size: 16px;
  font-style: italic;
}

/* Notion Callout — colored background with inline emoji icon */
.notion-callout {
  margin: 8px 0;
  padding: 16px;
  border-radius: 4px;
  font-size: 16px;
}
.notion-callout > p:first-child { margin-top: 0; }
.notion-callout > p:last-child { margin-bottom: 0; }
/* Callout color variants */
.callout-gray { background: rgb(241, 241, 239); }
.callout-brown { background: rgba(140, 46, 0, 0.06); }
.callout-orange { background: rgba(245, 93, 0, 0.06); }
.callout-yellow { background: rgba(255, 212, 0, 0.06); }
.callout-green { background: rgba(0, 135, 107, 0.06); }
.callout-blue { background: rgba(0, 120, 223, 0.06); }
.callout-purple { background: rgba(103, 36, 222, 0.06); }
.callout-pink { background: rgba(221, 0, 129, 0.06); }
.callout-red { background: rgba(255, 0, 26, 0.06); }
.callout-gray_background, .callout-default { background: rgb(241, 241, 239); }

/* Inline math */
.math { font-family: "KaTeX_Main", "Times New Roman", serif; font-style: italic; }
.math-block { font-family: "KaTeX_Main", "Times New Roman", serif; text-align: center; margin: 16px 0; font-size: 1.2em; }

/* Notion columns — side-by-side layout */
.notion-columns {
  display: flex;
  gap: 16px;
  margin: 8px 0;
}
.notion-column {
  flex: 1;
  min-width: 0;
}
.notion-column img {
  width: 100%;
}
@media (max-width: 600px) {
  .notion-columns {
    flex-direction: column;
    gap: 8px;
  }
}

/* Divider — extra space before next heading */
hr {
  border: none;
  border-top: 1px solid rgba(55, 53, 47, 0.16);
  margin: 24px 0 8px;
}

/* Code inline */
code {
  font-family: "SFMono-Regular", Menlo, Consolas, "PT Mono", "Liberation Mono", Courier, monospace;
  font-size: 85%;
  background: rgba(135, 131, 120, 0.15);
  border-radius: 4px;
  padding: 0.2em 0.4em;
  color: #eb5757;
}

/* Code block — wrap lines, copy button */
.code-wrapper {
  position: relative;
  margin: 8px 0;
}

.code-wrapper .copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 8px;
  font-size: 12px;
  background: rgba(255,255,255,0.8);
  border: 1px solid rgba(55,53,47,0.16);
  border-radius: 4px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s;
  color: rgb(55,53,47);
  font-family: inherit;
}
.code-wrapper:hover .copy-btn {
  opacity: 1;
}
.code-wrapper .copy-btn.copied {
  background: rgb(0,135,107);
  color: #fff;
  border-color: transparent;
}

.copy-status {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

pre {
  margin: 0;
  padding: 24px 20px;
  background: rgb(247, 246, 243);
  border-radius: 4px;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow-wrap: anywhere;
  font-size: 85%;
  line-height: 1.5;
  tab-size: 2;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
  font-size: inherit;
}

/* Images — progressive loading */
img {
  max-width: 100%;
  height: auto;
  border-radius: 2px;
  margin: 4px 0;
  display: block;
}
img[loading="lazy"] {
  opacity: 0;
  transition: opacity 0.3s ease;
}
img.loaded {
  opacity: 1;
}

.image-figure {
  margin: 18px 0 24px;
}
.image-figure img {
  margin: 0;
  width: 100%;
}
.image-figure figcaption {
  margin-top: 8px;
  color: rgb(95, 99, 104);
  font-size: 14px;
  line-height: 1.45;
  text-align: center;
}
/* HARD RULE (operator 2026-06-02): lesson images stay at TEXT-COLUMN width.
   NEVER break .image-figure out wider than the .page content (no width:min(...),
   no margin-left:50%, no transform breakout). Larger viewing is via click-to-zoom
   (lightbox), not inline width. A prior wide treatment was reverted twice
   (lesson 20, and 2026-06-02) — do not reintroduce. Guarded by
   tests/test_lesson_page_css.py::test_image_figure_no_breakout. */

/* Blur placeholder wrapper — injected by _image_refs_rewrite.inject_blur_placeholders.
   Scoped to <figure class="image-figure"> only (block-level lesson images);
   inline icons / small images outside figures stay un-wrapped so we don't
   inflate them to full content width.
   Holds a 20×20 base64-blurred preview as background-image. The real <img>
   above starts at opacity 0 (img[loading="lazy"] rule) and fades to 1 once
   loaded, covering the blur. No filter:blur() on this element — the thumb
   is already blurry by virtue of being 20px stretched to ~700px+. */
.img-placeholder {
  position: relative;
  background-size: cover;
  background-position: center;
  border-radius: 2px;
  overflow: hidden;
  line-height: 0; /* no whitespace gap below inline <img> */
}
.img-placeholder img {
  display: block;
  width: 100%;
  position: relative; /* sits above background */
}

/* Image grid — consecutive images auto-layout side by side */
.img-grid {
  display: grid;
  gap: 8px;
  margin: 8px 0;
}
.img-grid.cols-2 { grid-template-columns: 1fr 1fr; }
.img-grid.cols-3 { grid-template-columns: 1fr 1fr 1fr; }
.img-grid img {
  margin: 0;
  width: 100%;
  object-fit: cover;
  border-radius: 4px;
}
@media (max-width: 600px) {
  .img-grid.cols-2, .img-grid.cols-3 { grid-template-columns: 1fr; }
}

/* Video embed (YouTube, etc.) */
.video-embed {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
  margin: 8px 0;
  border-radius: 4px;
  overflow: hidden;
  background: rgb(247, 246, 243);
}

.video-embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.video-placeholder {
  display: flex;
  min-height: 180px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 24px;
  text-align: center;
}

.video-placeholder .video-load-button,
.video-placeholder .video-fallback {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 14px;
  line-height: 1.25;
}

.video-placeholder .video-load-button {
  border: 1px solid rgba(55, 53, 47, 0.18);
  color: rgb(55, 53, 47);
  background: #fff;
  cursor: pointer;
}

.video-placeholder .video-load-button:hover {
  background: rgba(255, 90, 52, 0.10);
}

.video-placeholder .video-fallback {
  color: rgb(55, 53, 47);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.video-placeholder.video-loaded {
  display: block;
  min-height: 0;
  padding: 0 0 56.25%;
}

.video-placeholder.video-loaded .video-fallback {
  display: none;
}

/* Tables */
table {
  border-collapse: collapse;
  width: 100%;
  margin: 4px 0;
  font-size: 15px;
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

th, td {
  border: 1px solid rgb(233, 233, 231);
  padding: 7px 9px;
  text-align: left;
  vertical-align: top;
  min-width: 100px;
}

th {
  background: rgb(247, 246, 243);
  font-weight: 600;
}

/* Bare URLs — make them clickable */
.bare-url {
  word-break: break-all;
  color: rgb(55, 53, 47);
  text-decoration: underline;
  text-decoration-color: rgba(55, 53, 47, 0.4);
}

/* Toggle / Accordion (<details>) */
details {
  margin: 4px 0;
  padding: 3px 2px;
}

details summary {
  cursor: pointer;
  font-weight: 600;
  padding: 3px 2px;
  list-style: none;
}

details summary::-webkit-details-marker {
  display: none;
}

details summary::before {
  content: "▶";
  display: inline-block;
  margin-right: 6px;
  font-size: 12px;
  transition: transform 0.15s ease;
}

details[open] summary::before {
  transform: rotate(90deg);
}

details > *:not(summary) {
  margin-left: 22px;
}

details.landing-toggle {
  margin: 6px 0;
}

details.landing-toggle > summary {
  color: rgb(55, 53, 47);
}

details.landing-toggle > ul,
details.landing-toggle > ol,
details.landing-toggle > p,
details.landing-toggle > .notion-callout,
details.landing-toggle > .img-grid,
details.landing-toggle > figure,
details.landing-toggle > table {
  margin-left: 22px;
}

/* Mobile */
@media (max-width: 600px) {
  .page {
    padding: 24px 16px 60px;
  }

  .page-title {
    font-size: 30px;
  }

  .page-icon {
    font-size: 42px;
    margin-top: 40px;
  }

  .page-landing > h1:first-of-type {
    font-size: 30px;
    margin-top: 40px;
  }

  h1 {
    font-size: 24px;
  }

  h2 {
    font-size: 20px;
  }

  h3 {
    font-size: 18px;
  }

  pre {
    padding: 16px 12px 16px 16px;
    font-size: 13px;
  }

  table {
    font-size: 14px;
  }

  th, td {
    padding: 6px 8px;
    min-width: 80px;
  }
}

/* Lightbox — click-to-zoom overlay for images */
.lightbox-overlay {
  position: fixed;
  inset: 0;
  width: auto;
  height: auto;
  max-width: 100vw;
  overflow: hidden;
  background: rgba(12, 12, 14, 0.92);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
  cursor: zoom-out;
  -webkit-tap-highlight-color: transparent;
}
.lightbox-overlay.active {
  opacity: 1;
  visibility: visible;
}
.lightbox-overlay img {
  max-width: 96vw;
  max-height: 96vh;
  object-fit: contain;
  border-radius: 2px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.3);
  image-rendering: high-quality;
  cursor: zoom-out;
  transform: scale(0.95);
  transition: transform 0.2s ease;
  margin: 0;
  opacity: 1;
}
.lightbox-overlay.active img {
  transform: scale(1);
}
.lightbox-close {
  position: absolute;
  top: 16px;
  right: max(16px, env(safe-area-inset-right));
  width: 32px;
  height: 32px;
  background: rgba(255, 255, 255, 0.9);
  border: none;
  border-radius: 50%;
  font-size: 18px;
  line-height: 32px;
  text-align: center;
  cursor: pointer;
  color: rgb(55, 53, 47);
  z-index: 10000;
  transition: background 0.15s;
}
.lightbox-close:hover {
  background: #fff;
}
/* Clickable images — cursor hint */
article.page img {
  cursor: zoom-in;
}

/* File download buttons */
.file-download {
  display: flex;
  align-items: center;
  padding: 12px 14px;
  border: 1px solid rgba(55, 53, 47, 0.16);
  border-radius: 4px;
  margin: 4px 0;
  text-decoration: none;
  color: rgb(55, 53, 47);
  transition: background 0.1s;
  cursor: pointer;
}
.file-download:hover {
  background: rgba(55, 53, 47, 0.04);
}
.file-download .file-icon {
  margin-right: 8px;
  font-size: 18px;
  flex-shrink: 0;
}
.file-download .file-name {
  flex: 1;
  font-size: 14px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.file-download .download-icon {
  opacity: 0;
  font-size: 14px;
  margin-left: 8px;
  transition: opacity 0.15s;
  flex-shrink: 0;
}
.file-download:hover .download-icon {
  opacity: 1;
}

/* Public report gallery */
.lesson-report-gallery {
  margin: 38px 0 22px;
  padding: 10px 0 4px;
  position: relative;
  transition: width 0.18s ease, margin-left 0.18s ease, transform 0.18s ease;
}

.lesson-report-gallery.is-wide {
  width: min(1120px, calc(100vw - 56px));
  margin-left: 50%;
  transform: translateX(-50%);
}

.lesson-report-gallery-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.lesson-report-gallery-head h1,
.lesson-report-gallery-head h2 {
  margin: 0;
  padding: 3px 2px;
  font-size: 24px;
  line-height: 1.25;
}

.lesson-report-gallery-nav {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
}

.lesson-report-gallery-btn {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(55, 53, 47, 0.18);
  border-radius: 50%;
  background: #fff;
  color: rgb(55, 53, 47);
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, opacity 0.15s;
}

.lesson-report-gallery-wide-btn {
  font-size: 17px;
  font-weight: 650;
}

.lesson-report-gallery-btn:hover:not(:disabled) {
  background: rgba(55, 53, 47, 0.04);
  border-color: rgba(55, 53, 47, 0.32);
}

.lesson-report-gallery-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.lesson-report-gallery-track {
  display: grid;
  grid-auto-flow: column;
  grid-template-rows: max-content;
  grid-auto-columns: minmax(256px, 88%);
  align-items: start;
  gap: 12px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  scroll-padding: 2px;
  padding: 2px 2px 12px;
  scrollbar-width: thin;
  mask-image: linear-gradient(90deg, #000 0, #000 calc(100% - 18px), transparent 100%);
}

.lesson-report-card {
  display: flex;
  flex-direction: column;
  border: 1px solid rgba(55, 53, 47, 0.12);
  border-radius: 8px;
  background: rgb(251, 251, 250);
  overflow: hidden;
  scroll-snap-align: start;
  align-self: start;
  cursor: pointer;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.lesson-report-card:focus-visible,
.lesson-report-card:has(.lesson-report-media:hover),
.lesson-report-card:has(.lesson-report-snippet:hover) {
  border-color: rgba(55, 53, 47, 0.28);
  box-shadow: 0 8px 24px rgba(55, 53, 47, 0.08);
}

.lesson-report-person {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 10px;
  align-items: center;
  padding: 14px 14px 10px;
}

.lesson-report-avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  align-self: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgb(238, 238, 236);
  color: rgb(55, 53, 47);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  overflow: hidden;
  flex-shrink: 0;
  transform: none;
  transition: none;
}

.lesson-report-avatar img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  margin: 0;
  border-radius: 0;
}

.lesson-report-person-copy {
  display: flex;
  min-height: 44px;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}

.lesson-report-author {
  display: inline-block;
  max-width: 100%;
  color: rgb(55, 53, 47);
  font-size: 15px;
  font-weight: 650;
  line-height: 1.25;
  text-decoration: none;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  vertical-align: top;
}

a.lesson-report-author:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.lesson-report-author-desc {
  margin: 2px 0 0;
  padding: 0;
  color: rgba(55, 53, 47, 0.62);
  font-size: 13px;
  line-height: 1.35;
  min-height: 0;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
}

.lesson-report-media {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: rgba(55, 53, 47, 0.055);
  overflow: hidden;
}

.lesson-report-media.is-media-wide {
  aspect-ratio: var(--report-media-ratio, 16 / 9);
  background: rgb(247, 246, 243);
}

.lesson-report-media.is-empty {
  display: none;
}

.lesson-report-media-item {
  width: 100%;
  height: 100%;
  margin: 0;
}

.lesson-report-media.is-slider {
  position: relative;
}

.lesson-report-media-track {
  display: flex;
  height: 100%;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.lesson-report-media-track::-webkit-scrollbar {
  display: none;
}

.lesson-report-media.is-slider .lesson-report-media-item {
  flex: 0 0 100%;
  scroll-snap-align: start;
}

.lesson-report-media-dots {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 8px;
  display: flex;
  justify-content: center;
  gap: 5px;
  pointer-events: none;
}

.lesson-report-media-dot {
  width: 7px;
  height: 7px;
  padding: 0;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 50%;
  background: rgba(55, 53, 47, 0.38);
  box-shadow: 0 1px 3px rgba(55, 53, 47, 0.25);
  cursor: pointer;
  pointer-events: auto;
}

.lesson-report-media-dot.is-active {
  background: #fff;
}

.lesson-report-media img,
.lesson-report-media video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: var(--report-media-position, 50% 50%);
  margin: 0;
  border-radius: 0;
}

.lesson-report-media.is-media-wide img,
.lesson-report-media.is-media-wide video {
  object-fit: contain;
}

.lesson-report-media-item.is-file {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
}

.lesson-report-media-item.is-file a {
  display: inline-flex;
  max-width: 100%;
  min-height: 44px;
  align-items: center;
  padding: 8px 12px;
  border: 1px solid rgba(55, 53, 47, 0.14);
  border-radius: 8px;
  background: #fff;
  color: rgb(55, 53, 47);
  font-size: 14px;
  line-height: 1.25;
  text-decoration: none;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-report-snippet {
  margin: 0;
  padding: 12px 14px 8px;
  color: rgb(55, 53, 47);
  font-size: 15px;
  line-height: 1.48;
  min-height: 0;
  max-height: calc(1.48em * 4 + 20px);
  display: -webkit-box;
  overflow: hidden;
  overflow-wrap: anywhere;
  word-break: break-word;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
}

.lesson-report-card-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 0 14px 14px;
}

.lesson-report-cohort {
  display: inline-flex;
  min-width: 0;
  max-width: 100%;
  align-items: center;
  min-height: 24px;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(55, 53, 47, 0.06);
  color: rgba(55, 53, 47, 0.68);
  font-size: 12px;
  line-height: 1.2;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-report-reactions {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-left: auto;
}

.lesson-report-chip {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 2px 7px;
  border-radius: 999px;
  background: rgba(55, 53, 47, 0.07);
  color: rgba(55, 53, 47, 0.78);
  font-size: 13px;
  line-height: 1.2;
  white-space: nowrap;
}

.lesson-report-lightbox {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: none;
  padding: 18px;
  background: rgba(15, 15, 15, 0.64);
}

.lesson-report-lightbox.is-open {
  display: flex;
  align-items: center;
  justify-content: center;
}

.lesson-report-lightbox-panel {
  position: relative;
  width: min(1120px, calc(100vw - 32px));
  max-height: calc(100vh - 32px);
  overflow: auto;
  border-radius: 12px;
  background: rgb(251, 251, 250);
  box-shadow: 0 24px 80px rgba(15, 15, 15, 0.34);
}

.lesson-report-lightbox-close {
  position: sticky;
  top: 12px;
  left: calc(100% - 48px);
  z-index: 2;
  width: 36px;
  height: 36px;
  margin: 12px 12px -48px auto;
  border: 1px solid rgba(55, 53, 47, 0.14);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  color: rgb(55, 53, 47);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.lesson-report-detail {
  display: flex;
  flex-direction: column;
}

.lesson-report-detail-head {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 18px 22px 14px;
}

.lesson-report-detail-avatar {
  display: inline-flex;
  width: 48px;
  height: 48px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgb(238, 238, 236);
  color: rgb(55, 53, 47);
  font-size: 15px;
  font-weight: 700;
  object-fit: cover;
}

.lesson-report-detail-person {
  min-width: 0;
}

.lesson-report-detail-author {
  display: inline-block;
  max-width: 100%;
  color: rgb(55, 53, 47);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

a.lesson-report-detail-author:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.lesson-report-detail-person p {
  margin: 3px 0 0;
  color: rgba(55, 53, 47, 0.66);
  font-size: 14px;
  line-height: 1.35;
}

.lesson-report-detail-media {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(320px, min(92vw, 980px));
  gap: 12px;
  align-items: start;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  padding: 16px 22px;
  background: rgb(24, 24, 23);
  scrollbar-width: thin;
}

.lesson-report-detail-media-item {
  display: flex;
  width: 100%;
  min-height: 0;
  align-items: flex-start;
  justify-content: center;
  margin: 0;
  scroll-snap-align: center;
}

.lesson-report-detail-media-item img,
.lesson-report-detail-media-item video {
  display: block;
  width: 100%;
  height: auto;
  margin: 0;
  border-radius: 4px;
  background: rgb(24, 24, 23);
}

.lesson-report-detail-media-item.is-file a {
  display: inline-flex;
  max-width: 100%;
  min-height: 44px;
  align-items: center;
  padding: 10px 14px;
  border-radius: 8px;
  background: #fff;
  color: rgb(55, 53, 47);
  text-decoration: none;
}

.lesson-report-detail-text {
  padding: 18px 22px 4px;
}

.lesson-report-detail-text p {
  margin: 0 0 12px;
  color: rgb(55, 53, 47);
  font-size: 16px;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.lesson-report-detail-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 0 22px 22px;
}

@media (min-width: 760px) {
  .lesson-report-gallery-track {
    grid-auto-columns: calc((100% - 12px) / 2);
  }
}

@media (min-width: 1040px) {
  .lesson-report-gallery-track {
    grid-auto-columns: calc((100% - 24px) / 3);
  }

  .lesson-report-gallery.is-wide .lesson-report-gallery-track {
    grid-auto-columns: calc((100% - 24px) / 3);
  }
}

@media (max-width: 560px) {
  .lesson-report-gallery-head {
    align-items: flex-start;
  }
  .lesson-report-gallery-head h1,
  .lesson-report-gallery-head h2 {
    font-size: 22px;
  }
  .lesson-report-gallery-track {
    grid-auto-columns: minmax(248px, 90%);
  }
  .lesson-report-gallery.is-wide {
    width: auto;
    margin-left: 0;
    transform: none;
  }
  .lesson-report-lightbox {
    padding: 0;
  }
  .lesson-report-lightbox-panel {
    width: 100vw;
    max-height: 100vh;
    border-radius: 0;
  }
  .lesson-report-detail-media {
    grid-auto-columns: minmax(260px, 88vw);
    padding: 12px 14px;
  }
  .lesson-report-detail-head,
  .lesson-report-detail-text,
  .lesson-report-detail-meta {
    padding-left: 16px;
    padding-right: 16px;
  }
}

.copy-fallback-field {
  position: fixed;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.broken-image-placeholder {
  padding: 8px 0;
  color: rgba(55, 53, 47, 0.55);
  font-size: 14px;
  font-style: italic;
}

/* ═══════════════════════════════════════════════════════════════════════════
   LESSON DOCUMENT — AI Hero / Vibe Coding Hero shared reading surface

   This scoped layer brings long-form lessons into the current warm/coral
   project system without changing legacy landing pages that share this file.
   ═══════════════════════════════════════════════════════════════════════════ */

body.lesson-document {
  --lesson-ink: #201B17;
  --lesson-muted: #6E655C;
  --lesson-canvas: #FFFDFA;
  --lesson-surface: #FFFFFF;
  --lesson-surface-alt: #FFF4EC;
  --lesson-strip: #FFF0E4;
  --lesson-border: rgba(32, 27, 23, 0.10);
  --lesson-border-strong: rgba(32, 27, 23, 0.18);
  --lesson-coral: #FF5A34;
  --lesson-coral-ink: #B43817;
  --lesson-coral-tint: #FFE7DC;
  --lesson-amber: #FFB020;
  --lesson-teal: #287B78;
  --lesson-teal-tint: #DCEFED;
  --lesson-green: #24613D;
  --lesson-green-tint: #F1F7F0;
  --lesson-red: #C62828;
  --lesson-red-tint: #FFEBEE;
  --lesson-gray-tint: #F5F2EE;
  --lesson-yellow-tint: #FFF8E7;
  --lesson-font-display: "Unbounded", "Onest", system-ui, sans-serif;
  --lesson-font-sans: "Onest", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --lesson-font-mono: "SFMono-Regular", Menlo, Consolas, "PT Mono", monospace;
  width: 100%;
  min-width: 320px;
  max-width: none;
  margin: 0;
  padding: 0;
  color: var(--lesson-ink);
  background: var(--lesson-canvas);
  font-family: var(--lesson-font-sans);
  font-size: 17px;
  line-height: 1.62;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}

.lesson-document .skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 10020;
  min-height: 44px;
  padding: 10px 14px;
  border-radius: 6px;
  color: #FFFFFF;
  background: var(--lesson-ink);
  text-decoration: none;
  transform: translateY(calc(-100% - 24px));
  transition: transform 160ms ease;
}

.lesson-document .skip-link:focus {
  transform: translateY(0);
}

.lesson-document .reading-progress {
  position: fixed;
  inset: 0 0 auto;
  z-index: 10010;
  height: 4px;
  background: var(--lesson-strip);
  pointer-events: none;
}

.lesson-document .reading-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--lesson-coral);
  transform: scaleX(0);
  transform-origin: left center;
  animation: lesson-reading-progress linear both;
  animation-timeline: scroll(root block);
}

@keyframes lesson-reading-progress {
  to { transform: scaleX(1); }
}

@supports not (animation-timeline: scroll()) {
  .lesson-document .reading-progress {
    display: none;
  }
}

.lesson-document .lesson-shell {
  display: grid;
  grid-template-columns: minmax(0, 800px);
  justify-content: center;
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 52px 24px 104px;
}

.lesson-document .page {
  width: 100%;
  min-width: 0;
  max-width: 800px;
  margin: 0;
  padding: 56px 54px 76px;
  border-radius: 14px;
  background: var(--lesson-surface);
  box-shadow: 0 20px 56px rgba(91, 57, 35, 0.09);
}

.lesson-document .page-icon {
  margin: 0 0 18px;
  padding: 0;
  color: var(--lesson-coral);
  font-size: 42px;
  line-height: 1;
}

.lesson-document .page-title {
  max-width: 18ch;
  margin: 0 0 34px;
  padding: 0;
  color: var(--lesson-ink);
  font-family: var(--lesson-font-display);
  font-size: clamp(2rem, 3vw, 2.35rem);
  font-weight: 760;
  line-height: 1.12;
  letter-spacing: -0.02em;
  text-wrap: balance;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.lesson-document .page-title::after {
  display: block;
  width: 52px;
  height: 5px;
  margin-top: 24px;
  border-radius: 999px;
  background: var(--lesson-coral);
  content: "";
}

.lesson-document .page h2,
.lesson-document .page h3,
.lesson-document .page h4,
.lesson-document .page h5,
.lesson-document .page h6 {
  color: var(--lesson-ink);
  font-family: var(--lesson-font-sans);
  letter-spacing: -0.015em;
  text-wrap: balance;
  scroll-margin-top: 28px;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.lesson-document .page h2 {
  margin: 52px 0 14px;
  padding: 0;
  font-size: clamp(1.55rem, 3vw, 1.9rem);
  font-weight: 760;
  line-height: 1.22;
}

.lesson-document .page h3 {
  margin: 34px 0 10px;
  padding: 0;
  font-size: clamp(1.18rem, 2.2vw, 1.35rem);
  font-weight: 720;
  line-height: 1.3;
}

.lesson-document .page h4 {
  margin: 26px 0 8px;
  padding: 0;
  color: var(--lesson-muted);
  font-size: 1.02rem;
  font-weight: 720;
  line-height: 1.38;
}

.lesson-document .page h5,
.lesson-document .page h6 {
  margin: 22px 0 7px;
  padding: 0;
  color: var(--lesson-muted);
  font-size: 0.94rem;
  font-weight: 720;
  line-height: 1.42;
}

.lesson-document .page p {
  min-height: 0;
  margin: 0 0 0.8em;
  padding: 0;
}

.lesson-document .page ul,
.lesson-document .page ol {
  margin: 0.5em 0 1.1em;
  padding-left: 1.45em;
}

.lesson-document .page li {
  padding: 0.22em 0 0.22em 0.12em;
}

.lesson-document .page li::marker {
  color: var(--lesson-coral);
  font-weight: 700;
}

/* Task ticks — the reader can toggle them right on the page. The state is
   page-local: nothing is stored between visits and nothing is sent anywhere. */
.lesson-document .page li.task-list-item {
  cursor: pointer;
  margin-left: 0;
}

.lesson-document .page li.task-list-item input.task-check {
  appearance: none;
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  margin-right: 10px;
  border: 2px solid var(--lesson-border-strong);
  border-radius: 7px;
  background-color: var(--lesson-surface);
  vertical-align: -5px;
  cursor: pointer;
  transition: background-color 120ms ease, border-color 120ms ease;
}

.lesson-document .page li.task-list-item input.task-check:hover {
  border-color: var(--lesson-coral);
  background-color: var(--lesson-coral-tint);
}

.lesson-document .page li.task-list-item input.task-check:checked {
  border-color: var(--lesson-coral);
  background-color: var(--lesson-coral);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='none' stroke='%23FFFFFF' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round' d='M3.2 8.4l3.1 3.1 6.5-6.6'/%3E%3C/svg%3E");
  background-position: center;
  background-repeat: no-repeat;
  background-size: 14px 14px;
  print-color-adjust: exact;
  -webkit-print-color-adjust: exact;
}

.lesson-document .page li.task-list-item input.task-check:focus-visible {
  outline: 3px solid var(--lesson-coral);
  outline-offset: 3px;
}

.lesson-document .page li.task-list-item:has(input.task-check:checked) {
  color: var(--lesson-muted);
}

.lesson-document .page a,
.lesson-document .lesson-rail a {
  color: var(--lesson-coral-ink);
  text-decoration-color: rgba(180, 56, 23, 0.36);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.lesson-document .page a:hover,
.lesson-document .lesson-rail a:hover {
  text-decoration-color: currentColor;
}

.lesson-document :where(a, button, summary, [tabindex]):focus-visible {
  outline: 3px solid var(--lesson-coral);
  outline-offset: 3px;
}

.lesson-document :where(a, button, summary, [tabindex]) {
  touch-action: manipulation;
  -webkit-tap-highlight-color: rgba(255, 90, 52, 0.16);
}

.lesson-document .page hr {
  margin: 42px 0 18px;
  border: 0;
  border-top: 1px solid var(--lesson-border-strong);
}

.lesson-document .toc {
  margin: 26px 0 38px;
  padding: 20px 22px;
  border-radius: 10px;
  background: var(--lesson-surface-alt);
}

.lesson-document .toc-title,
.lesson-document .lesson-rail-title {
  margin: 0 0 10px;
  padding: 0;
  color: var(--lesson-ink);
  font-size: 0.76rem;
  font-weight: 760;
  letter-spacing: 0.08em;
  line-height: 1.25;
  text-transform: uppercase;
}

.lesson-document .toc ul,
.lesson-document .lesson-rail ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.lesson-document .toc ul ul,
.lesson-document .lesson-rail ul ul {
  margin: 3px 0 0 10px;
  padding-left: 12px;
  border-left: 1px solid var(--lesson-border-strong);
}

.lesson-document .toc li,
.lesson-document .lesson-rail li {
  margin: 0;
  padding: 0;
  line-height: 1.35;
}

.lesson-document .toc a,
.lesson-document .lesson-rail a {
  display: flex;
  min-height: 44px;
  align-items: center;
  padding: 7px 8px;
  border-radius: 6px;
  color: var(--lesson-muted);
  font-size: 0.9rem;
  text-decoration: none;
  overflow-wrap: anywhere;
}

.lesson-document .toc a:hover,
.lesson-document .lesson-rail a:hover {
  color: var(--lesson-ink);
  background: rgba(255, 90, 52, 0.08);
}

.lesson-document .toc a[aria-current="location"],
.lesson-document .lesson-rail a[aria-current="location"] {
  color: var(--lesson-coral-ink);
  background: var(--lesson-coral-tint);
  font-weight: 650;
}

.lesson-document .lesson-rail {
  display: none;
}

.lesson-document blockquote,
.lesson-document .notion-callout {
  margin: 22px 0;
  padding: 16px 18px;
  border: 0;
  border-left: 4px solid var(--lesson-amber);
  border-radius: 10px;
  color: var(--lesson-ink);
  background: var(--lesson-yellow-tint);
  font-size: 0.97rem;
}

.lesson-document .notion-callout > :last-child,
.lesson-document blockquote > :last-child {
  margin-bottom: 0;
}

.lesson-document .callout-gray,
.lesson-document .callout-gray_background,
.lesson-document .callout-default {
  border-left-color: var(--lesson-muted);
  background: var(--lesson-gray-tint);
}

.lesson-document .callout-blue {
  border-left-color: var(--lesson-teal);
  background: var(--lesson-teal-tint);
}

.lesson-document .callout-green {
  border-left-color: var(--lesson-green);
  background: var(--lesson-green-tint);
}

.lesson-document .callout-brown,
.lesson-document .callout-orange,
.lesson-document .callout-yellow {
  border-left-color: var(--lesson-amber);
  background: var(--lesson-yellow-tint);
}

.lesson-document .callout-red,
.lesson-document .callout-pink,
.lesson-document .callout-purple {
  border-left-color: var(--lesson-red);
  background: var(--lesson-red-tint);
}

.lesson-document .notion-quote {
  margin: 22px 0;
  padding: 4px 0 4px 18px;
  border-left: 3px solid var(--lesson-coral);
  color: var(--lesson-muted);
  background: transparent;
  font-style: normal;
}

.lesson-document code {
  border-radius: 6px;
  color: var(--lesson-coral-ink);
  background: rgba(110, 101, 92, 0.12);
  font-family: var(--lesson-font-mono);
}

.lesson-document .code-wrapper {
  position: relative;
  margin: 22px 0;
}

.lesson-document pre {
  max-width: 100%;
  margin: 0;
  padding: 22px 118px 22px 20px;
  border: 1px solid var(--lesson-border);
  border-radius: 10px;
  color: var(--lesson-ink);
  background: var(--lesson-gray-tint);
  font-family: var(--lesson-font-mono);
  font-size: 0.84rem;
  line-height: 1.55;
  white-space: pre;
  overflow: auto;
  overflow-wrap: normal;
  word-wrap: normal;
  tab-size: 2;
}

.lesson-document pre:has(code.language-text),
.lesson-document pre:has(code.language-plaintext),
.lesson-document pre:has(code:not([class])) {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.lesson-document pre code {
  padding: 0;
  color: inherit;
  background: transparent;
  font-size: inherit;
}

.lesson-document .copy-btn {
  position: absolute;
  top: 9px;
  right: 9px;
  min-width: 44px;
  min-height: 44px;
  padding: 8px 11px;
  border: 1px solid var(--lesson-border-strong);
  border-radius: 6px;
  color: var(--lesson-ink);
  background: rgba(255, 255, 255, 0.94);
  font-family: var(--lesson-font-sans);
  font-size: 0.76rem;
  font-weight: 650;
  line-height: 1;
  cursor: pointer;
  opacity: 1;
}

.lesson-document .copy-btn:hover {
  background: var(--lesson-coral-tint);
}

.lesson-document .copy-btn.copied {
  border-color: transparent;
  color: #FFFFFF;
  background: var(--lesson-green);
}

.lesson-document .copy-btn.copy-failed {
  border-color: transparent;
  color: #FFFFFF;
  background: var(--lesson-red);
}

.lesson-document img {
  max-width: 100%;
  height: auto;
  border-radius: 10px;
}

.lesson-document .image-figure {
  margin: 28px 0 34px;
}

.lesson-document .image-figure img,
.lesson-document .img-placeholder {
  border-radius: 10px;
}

.lesson-document .image-figure img {
  width: 100%;
  margin: 0;
  box-shadow: 0 10px 28px rgba(91, 57, 35, 0.10);
}

.lesson-document .image-figure figcaption {
  margin-top: 10px;
  color: var(--lesson-muted);
  font-size: 0.82rem;
  line-height: 1.45;
  text-align: left;
}

.lesson-document .image-zoom-trigger {
  cursor: zoom-in;
}

.lesson-document .broken-image-placeholder {
  margin: 18px 0;
  padding: 14px 16px;
  border-radius: 10px;
  color: var(--lesson-muted);
  background: var(--lesson-gray-tint);
  font-size: 0.84rem;
  font-style: italic;
}

.lesson-document table {
  width: 100%;
  margin: 24px 0;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--lesson-border-strong);
  border-radius: 10px;
  font-size: 0.88rem;
  overflow-x: auto;
}

.lesson-document th,
.lesson-document td {
  min-width: 110px;
  padding: 11px 12px;
  border: 0;
  border-right: 1px solid var(--lesson-border);
  border-bottom: 1px solid var(--lesson-border);
}

.lesson-document th {
  color: var(--lesson-ink);
  background: var(--lesson-surface-alt);
  font-weight: 700;
}

.lesson-document tr:last-child td {
  border-bottom: 0;
}

.lesson-document tr > :last-child {
  border-right: 0;
}

.lesson-document details {
  margin: 18px 0;
  padding: 0;
  border: 1px solid var(--lesson-border-strong);
  border-radius: 10px;
  background: var(--lesson-surface);
  overflow: clip;
}

.lesson-document details summary {
  min-height: 48px;
  padding: 12px 42px 12px 16px;
  color: var(--lesson-ink);
  background: var(--lesson-surface-alt);
  position: relative;
}

.lesson-document details summary::before {
  position: absolute;
  top: 17px;
  right: 16px;
  margin: 0;
  color: var(--lesson-coral-ink);
}

.lesson-document details > *:not(summary) {
  margin-right: 16px;
  margin-left: 16px;
}

.lesson-document details > :nth-child(2) {
  margin-top: 14px;
}

.lesson-document details > :last-child {
  margin-bottom: 14px;
}

.lesson-document .file-download {
  min-height: 52px;
  margin: 18px 0;
  padding: 12px 14px;
  border: 1px solid var(--lesson-border-strong);
  border-radius: 10px;
  color: var(--lesson-ink);
  background: var(--lesson-surface-alt);
}

.lesson-document .file-download:hover {
  background: var(--lesson-coral-tint);
}

.lesson-document .file-download .download-icon {
  color: var(--lesson-coral-ink);
  opacity: 1;
}

dialog.lightbox-overlay,
dialog.lesson-report-lightbox {
  width: 100%;
  max-width: none;
  height: 100dvh;
  max-height: none;
  margin: 0;
  padding: max(18px, env(safe-area-inset-top)) max(18px, env(safe-area-inset-right)) max(18px, env(safe-area-inset-bottom)) max(18px, env(safe-area-inset-left));
  border: 0;
  background: transparent;
  overflow: hidden;
  overscroll-behavior: contain;
}

dialog.lightbox-overlay:not([open]),
dialog.lesson-report-lightbox:not([open]) {
  display: none;
}

dialog.lightbox-overlay::backdrop,
dialog.lesson-report-lightbox::backdrop {
  background: rgba(24, 20, 17, 0.90);
}

dialog.lightbox-overlay[open] {
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 1;
  visibility: visible;
}

dialog.lightbox-overlay img {
  max-width: calc(100vw - 36px);
  max-height: calc(100dvh - 36px);
  margin: 0;
  border-radius: 10px;
  object-fit: contain;
  opacity: 1;
  transform: none;
}

dialog.lightbox-overlay .lightbox-close {
  top: max(14px, env(safe-area-inset-top));
  right: max(16px, env(safe-area-inset-right));
  width: 44px;
  height: 44px;
  line-height: 44px;
}

dialog.lesson-report-lightbox[open] {
  display: flex;
  align-items: center;
  justify-content: center;
}

dialog.lesson-report-lightbox .lesson-report-lightbox-panel {
  max-height: calc(100dvh - 36px);
  overscroll-behavior: contain;
}

.lesson-document .lesson-report-lightbox-close {
  left: calc(100% - 60px);
  width: 44px;
  height: 44px;
}

.lesson-document .lesson-report-gallery-btn {
  width: 44px;
  height: 44px;
}

.lesson-document .lesson-report-media-dot {
  position: relative;
  width: 44px;
  height: 44px;
  border: 0;
  background: transparent;
  box-shadow: none;
}

.lesson-document .lesson-report-media-dot::after {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 7px;
  height: 7px;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 50%;
  background: rgba(32, 27, 23, 0.44);
  box-shadow: 0 1px 3px rgba(32, 27, 23, 0.24);
  content: "";
  transform: translate(-50%, -50%);
}

.lesson-document .lesson-report-media-dot.is-active {
  background: transparent;
}

.lesson-document .lesson-report-media-dot.is-active::after {
  background: #FFFFFF;
}

@media (min-width: 1200px) {
  .lesson-document .lesson-shell.has-rail {
    grid-template-columns: 220px minmax(0, 800px);
    gap: 40px;
    align-items: start;
  }

  .lesson-document .lesson-rail {
    position: sticky;
    top: 28px;
    display: block;
    max-height: calc(100dvh - 56px);
    padding: 14px 0 16px;
    overflow-y: auto;
    scrollbar-width: thin;
  }

  .lesson-document .lesson-rail a {
    min-height: 44px;
    padding: 6px 8px;
    font-size: 0.82rem;
  }

  .lesson-document .page > .toc {
    display: none;
  }
}

@media (max-width: 848px) {
  body.lesson-document {
    font-size: 16px;
    background: var(--lesson-surface);
  }

  .lesson-document .lesson-shell {
    grid-template-columns: minmax(0, 1fr);
    padding: 0;
  }

  .lesson-document .page {
    max-width: none;
    padding: 42px max(18px, calc((100vw - 692px) / 2)) 72px;
    border-radius: 0;
    box-shadow: none;
  }

  .lesson-document .page-title {
    margin-bottom: 28px;
    font-size: clamp(1.75rem, 7.6vw, 2rem);
  }

  .lesson-document .page-title::after {
    margin-top: 20px;
  }

  .lesson-document .page h2 {
    margin-top: 42px;
  }

  .lesson-document .toc {
    margin: 22px 0 32px;
    padding: 16px 14px;
  }

  .lesson-document .toc a {
    min-height: 44px;
    padding-right: 4px;
    padding-left: 4px;
  }

  .lesson-document blockquote,
  .lesson-document .notion-callout {
    padding: 14px 14px;
  }

  .lesson-document pre {
    padding: 68px 14px 18px;
    font-size: 0.78rem;
  }

  .lesson-document .copy-btn {
    top: 10px;
    right: 10px;
  }

  .lesson-document .lesson-report-gallery.is-wide {
    width: auto;
    margin-left: 0;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .lesson-document *,
  .lesson-document *::before,
  .lesson-document *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .lesson-document .reading-progress {
    display: none;
  }
}

@media print {
  body.lesson-document {
    color: #000000;
    background: #FFFFFF;
    font-size: 11pt;
  }

  .lesson-document .skip-link,
  .lesson-document .reading-progress,
  .lesson-document .lesson-rail,
  .lesson-document .copy-btn,
  .lesson-document dialog,
  .lesson-document .lesson-report-gallery-nav {
    display: none !important;
  }

  .lesson-document .lesson-shell {
    display: block;
    max-width: none;
    padding: 0;
  }

  .lesson-document .lesson-report-gallery {
    width: auto;
    margin: 28px 0;
    overflow: visible;
  }

  .lesson-document .lesson-report-gallery-track {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-auto-flow: row;
    gap: 16px;
    overflow: visible;
    mask-image: none;
    scroll-snap-type: none;
  }

  .lesson-document .lesson-report-card {
    break-inside: avoid;
    overflow: visible;
    box-shadow: none;
  }

  .lesson-document .lesson-report-media {
    aspect-ratio: auto;
    height: auto;
    overflow: visible;
  }

  .lesson-document .lesson-report-media-track {
    display: block;
    height: auto;
    overflow: visible;
  }

  .lesson-document .lesson-report-media-item {
    display: none;
    height: auto;
  }

  .lesson-document .lesson-report-media-item:first-child {
    display: block;
  }

  .lesson-document .lesson-report-media-item iframe,
  .lesson-document .lesson-report-media-item video {
    display: none;
  }

  .lesson-document .lesson-report-media-item img {
    width: auto;
    max-width: 100%;
    height: auto;
    object-fit: contain;
  }

  .lesson-document .lesson-report-media-dots {
    display: none;
  }

  .lesson-document .page {
    max-width: none;
    padding: 0;
    border-radius: 0;
    box-shadow: none;
  }

  .lesson-document .page-title,
  .lesson-document .page h2,
  .lesson-document .page h3,
  .lesson-document .page h4,
  .lesson-document .page h5,
  .lesson-document .page h6 {
    break-after: avoid;
  }

  .lesson-document .image-figure,
  .lesson-document blockquote,
  .lesson-document .notion-callout,
  .lesson-document pre,
  .lesson-document table {
    break-inside: avoid;
  }

  .lesson-document details {
    overflow: visible;
  }

  .lesson-document details:not([open]) > *:not(summary) {
    display: block !important;
  }
}