/* ==========================================================================
   lesson.css — MakerWorld's project page in GDC's palette.
   Top: media gallery (left) + required files (right).
   Bottom: blog-post style instructions with a sticky table of contents.
   ========================================================================== */

.lesson-page { padding-top: var(--gdc-nav-h); }

.lesson-loading,
.lesson-error {
    padding: 90px 24px;
    text-align: center;
    color: var(--gdc-ink-muted);
    font-family: var(--gdc-font-ui);
}

.lesson-loading i { font-size: 30px; color: var(--gdc-accent); }

.error-card {
    max-width: 620px;
    margin: 0 auto;
    padding: 48px 34px;
}

.error-card i { font-size: 46px; color: var(--gdc-accent-soft); }

.error-card h1 {
    font-size: 32px;
    font-weight: 700;
    color: var(--gdc-navy);
    margin: 16px 0 10px;
}

.error-card p {
    color: var(--gdc-ink-muted);
    line-height: 1.6;
    margin-bottom: 24px;
}

/* ------------------------------------------------------------------ hero  */

.lesson-hero {
    background: var(--gdc-surface);
    border-bottom: 1px solid var(--gdc-border);
    padding: 26px 0 40px;
}

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 9px;
    background: transparent;
    padding: 0;
    margin-bottom: 16px;
    font-family: var(--gdc-font-ui);
    font-size: 13.5px;
    color: var(--gdc-ink-faint);
}

.breadcrumb a { color: var(--gdc-accent); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb i { font-size: 9px; opacity: 0.6; }

.lesson-headline {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 24px;
}

.lesson-title {
    font-size: 46px;
    font-weight: 700;
    color: var(--gdc-navy);
    margin: 0 0 8px;
    line-height: 1.1;
}

.lesson-summary {
    font-family: var(--gdc-font-ui);
    font-size: 18px;
    line-height: 1.55;
    color: var(--gdc-ink-muted);
    margin: 0;
    max-width: 68ch;
}

/* --------------------------------------------------------------- progress */

.lesson-progress {
    flex: 0 0 auto;
    min-width: 210px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
    background: var(--gdc-surface-sunken);
    border: 1px solid var(--gdc-border);
    border-radius: var(--gdc-radius);
    padding: 14px 16px;
}

.progress-track {
    width: 100%;
    height: 8px;
    border-radius: 999px;
    background: var(--gdc-border);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0;
    border-radius: 999px;
    background: var(--gdc-accent);
    transition: width 0.3s ease;
}

.lesson-progress.complete .progress-fill { background: var(--gdc-green); }

.progress-label {
    font-family: var(--gdc-font-ui);
    font-size: 13px;
    font-weight: 600;
    color: var(--gdc-ink-muted);
}

.lesson-progress.complete .progress-label { color: var(--gdc-green-ink); }

/* ------------------------------------------------------------ hero split  */

.lesson-split {
    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: 26px;
    align-items: start;
}

/* -------------------------------------------------------------- gallery   */

.gallery { position: relative; }

.gallery-stage {
    position: relative;
    aspect-ratio: 16 / 9;
    border-radius: var(--gdc-radius);
    overflow: hidden;
    background: var(--gdc-navy-deep);
    box-shadow: var(--gdc-shadow-sm);
}

.gallery-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.gallery-video,
.gallery-video iframe {
    width: 100%;
    height: 100%;
    border: 0;
    display: block;
}

.gallery-nav {
    position: absolute;
    top: calc((100% - 96px) / 2);
    transform: translateY(-50%);
    width: 42px;
    height: 42px;
    border: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    color: var(--gdc-navy);
    cursor: pointer;
    box-shadow: var(--gdc-shadow-sm);
    transition: all 0.2s;
    z-index: 2;
}

.gallery-nav:hover { background: var(--gdc-accent); color: #fff; }
.gallery-nav.prev { left: 12px; }
.gallery-nav.next { right: 12px; }

.gallery-caption {
    font-family: var(--gdc-font-ui);
    font-size: 14px;
    color: var(--gdc-ink-muted);
    margin: 10px 2px 0;
}

.gallery-strip {
    display: flex;
    gap: 10px;
    margin-top: 12px;
    overflow-x: auto;
    padding-bottom: 4px;
}

.gallery-thumb {
    position: relative;
    flex: 0 0 96px;
    height: 58px;
    padding: 0;
    border: 3px solid transparent;
    border-radius: 8px;
    overflow: hidden;
    background: var(--gdc-navy-deep);
    cursor: pointer;
    transition: all 0.2s;
}

.gallery-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.gallery-thumb:hover { border-color: var(--gdc-accent-soft); }
.gallery-thumb.active { border-color: var(--gdc-accent); }

.gallery-thumb-play {
    position: absolute;
    inset: 0;
    display: grid;
    place-items: center;
    background: rgba(0, 0, 0, 0.4);
    color: #fff;
    font-size: 14px;
}

/* ---------------------------------------------------------- files panel   */

.files-panel { padding: 20px; }

.files-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 14px;
}

.files-title {
    font-size: 21px;
    font-weight: 700;
    color: var(--gdc-navy);
    margin: 0;
}

.files-count {
    font-family: var(--gdc-font-ui);
    font-size: 13px;
    color: var(--gdc-ink-faint);
}

.files-empty {
    font-family: var(--gdc-font-ui);
    font-size: 14px;
    color: var(--gdc-ink-muted);
    line-height: 1.55;
    margin: 0 0 8px;
}

.file-list {
    list-style: none;
    margin: 0 0 16px;
    padding: 0;
    /* No cap: the longest lesson has six files, and a mid-row clip reads as a
       rendering bug rather than a scroll affordance. */
}

.file-list.inline { margin-bottom: 0; }

.file-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 11px 10px;
    border-radius: 8px;
    transition: background 0.15s;
}

.file-row + .file-row { border-top: 1px solid var(--gdc-border); }
.file-row:hover { background: var(--gdc-surface-sunken); }

.file-icon {
    flex: 0 0 auto;
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: 8px;
    background: var(--gdc-accent-tint);
    color: var(--gdc-accent);
    font-size: 15px;
}

.file-info {
    flex: 1 1 auto;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.file-name {
    font-family: var(--gdc-font-ui);
    font-size: 14px;
    font-weight: 600;
    color: var(--gdc-ink);
    line-height: 1.35;

    /* A migrated name can still run long; keep every row the same shape. */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.file-meta {
    font-family: var(--gdc-font-ui);
    font-size: 12px;
    color: var(--gdc-ink-faint);
}

.file-action {
    flex: 0 0 auto;
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: 8px;
    background: var(--gdc-surface-sunken);
    color: var(--gdc-accent);
    text-decoration: none;
    transition: all 0.2s;
}

.file-action:hover {
    background: var(--gdc-accent);
    color: #fff;
    text-decoration: none;
}

.files-cta { margin-bottom: 18px; }

.lesson-meta {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    gap: 7px 14px;
    margin: 0;
    padding-top: 16px;
    border-top: 1px solid var(--gdc-border);
    font-family: var(--gdc-font-ui);
    font-size: 13.5px;
}

.lesson-meta dt { color: var(--gdc-ink-faint); font-weight: 500; }
.lesson-meta dd { color: var(--gdc-ink); margin: 0; font-weight: 600; }

/* ------------------------------------------------------------ article     */

.lesson-body { padding: 40px 0 64px; }

.lesson-body-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 244px;
    gap: 40px;
    align-items: start;
    /* Capped so the article fills its column at ~80ch instead of leaving a
       dead gap between the text and the table of contents. */
    max-width: 1120px;
    margin: 0 auto;
}

.lesson-article {
    background: var(--gdc-surface);
    border-radius: var(--gdc-radius);
    box-shadow: var(--gdc-shadow-card);
    padding: 40px 46px;
}

/* Blocks (cards) sit on the same 6-column grid their own figures use — a
   card's `grid-column: span N` (see js/render.js's packRows/renderArticle)
   only goes below 6 when it holds exactly one resizable figure that was
   dragged narrower, which is what lets a different block slide into the
   rest of that row. Row height falls out of normal grid sizing (the
   tallest block in the row). */
.block-row {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 16px;
    align-items: start;
}

.block-row + .block-row { margin-top: 34px; }

.block-row > .block { grid-column: span 6; min-width: 0; }

.block-head {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 14px;
    scroll-margin-top: calc(var(--gdc-nav-h) + 20px);
}

.block-title {
    font-size: 27px;
    font-weight: 700;
    color: var(--gdc-navy);
    margin: 0;
    line-height: 1.25;
}

.block { scroll-margin-top: calc(var(--gdc-nav-h) + 20px); }

.block-check { margin: 5px 0 0; cursor: pointer; }

.block-check input {
    width: 21px;
    height: 21px;
    accent-color: var(--gdc-green);
    cursor: pointer;
}

.block.is-done .block-title {
    color: var(--gdc-ink-faint);
    text-decoration: line-through;
    text-decoration-thickness: 2px;
}

/* Each resizable block type lays its figures out on a 6-column grid. A
   figure's width (in sixths) is set inline as `grid-column: span N`; the
   default here (span 6, i.e. unset) keeps ordinary full-width figures
   stacking exactly as before. Grid's sparse auto-placement wraps a figure
   that doesn't fit the remaining columns onto the next row for free, which
   is what lets narrower figures sit side by side. */
.block-text-row,
.block-images,
.block-code-stack,
.block-video-stack {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 16px 16px;
    align-items: start;
}

.block-text-row > .block-text-item,
.block-images > .block-figure,
.block-code-stack > .code-block,
.block-video-stack > .block-figure {
    grid-column: span 6;
    min-width: 0;
    margin: 0;
}

.block-paragraph {
    font-family: var(--gdc-font-ui);
    font-size: 16.5px;
    line-height: 1.72;
    color: var(--gdc-ink-muted);
    margin: 0;
}

.block-paragraph.muted { color: var(--gdc-ink-faint); font-style: italic; }

.block-list {
    font-family: var(--gdc-font-ui);
    font-size: 16.5px;
    line-height: 1.72;
    color: var(--gdc-ink-muted);
    padding-left: 22px;
    margin: 0;
}

.block-list li { margin-bottom: 7px; }

/* images */

.block-figure img {
    width: 100%;
    border-radius: var(--gdc-radius);
    display: block;
    box-shadow: var(--gdc-shadow-sm);
}

.block-figure figcaption {
    font-family: var(--gdc-font-ui);
    font-size: 13.5px;
    color: var(--gdc-ink-faint);
    margin-top: 9px;
    text-align: center;
}

.video-frame {
    position: relative;
    aspect-ratio: 16 / 9;
    border-radius: var(--gdc-radius);
    overflow: hidden;
    box-shadow: var(--gdc-shadow-sm);
    background: #000;
}

.video-frame iframe { width: 100%; height: 100%; border: 0; display: block; }

/* code */

.code-block {
    border-radius: var(--gdc-radius);
    overflow: hidden;
    box-shadow: var(--gdc-shadow-sm);
    margin-bottom: 16px;
}

.code-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--gdc-navy);
    color: #fff;
    padding: 9px 14px;
    font-family: var(--gdc-font-ui);
    font-size: 13px;
}

.code-filename { font-weight: 700; }

.code-lang {
    background: rgba(255, 255, 255, 0.18);
    border-radius: 4px;
    padding: 2px 8px;
    font-size: 11.5px;
    font-weight: 600;
}

.code-copy {
    margin-left: auto;
    border: 0;
    background: rgba(255, 255, 255, 0.15);
    color: #fff;
    border-radius: 5px;
    padding: 5px 11px;
    font-family: var(--gdc-font-ui);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.code-copy:hover { background: rgba(255, 255, 255, 0.3); }
.code-copy.copied { background: var(--gdc-green); color: #0d3a1d; }

.code-pre {
    margin: 0;
    padding: 18px;
    background: rgb(23, 32, 54);
    color: rgb(220, 228, 240);
    overflow-x: auto;
    font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 13.5px;
    line-height: 1.65;
    tab-size: 4;
}

.code-caption {
    font-family: var(--gdc-font-ui);
    font-size: 13px;
    color: var(--gdc-ink-faint);
    padding: 9px 14px 0;
    margin: 0;
}

/* callouts */

.callout {
    display: flex;
    gap: 13px;
    border-radius: var(--gdc-radius);
    padding: 16px 18px;
    margin-bottom: 15px;
    border-left: 4px solid var(--gdc-accent);
    background: var(--gdc-accent-tint);
}

.callout.tip { border-left-color: var(--gdc-green); background: rgba(127, 209, 134, 0.14); }
.callout.warn { border-left-color: rgb(214, 152, 32); background: var(--gdc-amber-tint); }

.callout-icon { flex: 0 0 auto; color: var(--gdc-accent); font-size: 17px; padding-top: 2px; }
.callout.tip .callout-icon { color: var(--gdc-green-ink); }
.callout.warn .callout-icon { color: rgb(166, 106, 15); }

.callout-body { flex: 1 1 auto; }
.callout-title { display: block; color: var(--gdc-navy); margin-bottom: 5px; }

.callout-body p {
    font-family: var(--gdc-font-ui);
    font-size: 15px;
    line-height: 1.65;
    color: var(--gdc-ink-muted);
    margin: 0;
}

/* link embeds */

.block-links { display: grid; gap: 10px; }

.link-embed {
    display: flex;
    align-items: center;
    gap: 13px;
    border: 2px solid var(--gdc-border);
    border-radius: var(--gdc-radius);
    padding: 14px 16px;
    text-decoration: none;
    color: inherit;
    transition: all 0.2s;
}

.link-embed:hover {
    border-color: var(--gdc-accent);
    background: var(--gdc-accent-tint);
    text-decoration: none;
}

.link-embed-icon {
    flex: 0 0 auto;
    width: 38px; height: 38px;
    display: grid; place-items: center;
    border-radius: 8px;
    background: var(--gdc-accent-tint);
    color: var(--gdc-accent);
}

.link-embed-body { display: flex; flex-direction: column; gap: 2px; min-width: 0; }

.link-embed-label {
    font-family: var(--gdc-font-ui);
    font-size: 15px;
    font-weight: 700;
    color: var(--gdc-navy);
}

.link-embed-site,
.link-embed-desc {
    font-family: var(--gdc-font-ui);
    font-size: 12.5px;
    color: var(--gdc-ink-faint);
}

/* q & a */

.block-qa { display: grid; gap: 9px; }

.qa-item {
    border: 2px solid var(--gdc-border);
    border-radius: var(--gdc-radius);
    padding: 13px 16px;
}

.qa-item[open] { border-color: var(--gdc-accent); }

.qa-question {
    font-family: var(--gdc-font-ui);
    font-size: 15.5px;
    font-weight: 700;
    color: var(--gdc-navy);
    cursor: pointer;
}

.qa-answer {
    font-family: var(--gdc-font-ui);
    font-size: 15px;
    line-height: 1.65;
    color: var(--gdc-ink-muted);
    margin: 10px 0 0;
}

/* ---------------------------------------------------------------- toc     */

.lesson-aside { position: sticky; top: calc(var(--gdc-nav-h) + 20px); }

.lesson-toc {
    background: var(--gdc-surface);
    border-radius: var(--gdc-radius);
    box-shadow: var(--gdc-shadow-sm);
    padding: 20px 18px;
    max-height: calc(100vh - var(--gdc-nav-h) - 50px);
    overflow-y: auto;
}

.toc-title {
    font-family: var(--gdc-font-ui);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 1.2px;
    text-transform: uppercase;
    color: var(--gdc-ink-faint);
    margin: 0 0 12px;
}

.toc-list { list-style: none; margin: 0; padding: 0; counter-reset: toc; }

.toc-link {
    display: block;
    padding: 7px 10px 7px 12px;
    border-left: 3px solid var(--gdc-border);
    font-family: var(--gdc-font-ui);
    font-size: 13.5px;
    line-height: 1.4;
    color: var(--gdc-ink-muted);
    text-decoration: none;
    transition: all 0.15s;
}

.toc-link:hover {
    color: var(--gdc-navy);
    border-left-color: var(--gdc-accent-soft);
    text-decoration: none;
}

.toc-link.active {
    color: var(--gdc-navy);
    font-weight: 700;
    border-left-color: var(--gdc-accent);
    background: var(--gdc-accent-tint);
}

/* --------------------------------------------------------------- pager    */

.lesson-pager {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    margin-top: 34px;
}

.pager-spacer { flex: 1 1 0; }

.pager-link {
    display: flex;
    align-items: center;
    gap: 13px;
    flex: 0 1 auto;
    max-width: 46%;
    background: var(--gdc-surface);
    border: 2px solid transparent;
    border-radius: var(--gdc-radius);
    padding: 15px 19px;
    color: inherit;
    text-decoration: none;
    transition: all 0.2s;
}

.pager-link:hover {
    border-color: var(--gdc-accent);
    text-decoration: none;
    color: inherit;
}

.pager-link i { color: var(--gdc-accent); }
.pager-link.next { margin-left: auto; text-align: right; }
.pager-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }

.pager-label {
    font-family: var(--gdc-font-ui);
    font-size: 11.5px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    color: var(--gdc-ink-faint);
}

.pager-name {
    font-family: var(--gdc-font-body);
    font-size: 16px;
    font-weight: 700;
    color: var(--gdc-navy);
}

/* -------------------------------------------------------------- related   */

.related { margin-top: 48px; }

.related-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--gdc-navy);
    margin: 0 0 18px;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
}

@media screen and (max-width: 560px) {
    .related-grid { grid-template-columns: minmax(0, 1fr); }
}

/* ----------------------------------------------------------- responsive   */

@media screen and (max-width: 1100px) {
    .lesson-body-grid { grid-template-columns: minmax(0, 1fr); }
    .lesson-aside { position: static; }
    .lesson-toc { max-height: none; }
    .toc-list { display: flex; flex-wrap: wrap; gap: 6px; }
    .toc-link { border-left: 0; border-bottom: 3px solid var(--gdc-border); }
}

@media screen and (max-width: 900px) {
    .lesson-split { grid-template-columns: minmax(0, 1fr); }
    .lesson-title { font-size: 34px; }
    .lesson-summary { font-size: 16px; }
    .lesson-article { padding: 28px 22px; }
    .lesson-progress { min-width: 100%; }
}

@media screen and (max-width: 620px) {
    .lesson-pager { flex-direction: column; }
    .pager-link { max-width: 100%; }
    .pager-link.next { margin-left: 0; }
    .block-title { font-size: 22px; }
    .lesson-article { padding: 22px 16px; }

    /* Resized figures/blocks (grid-column: span N) collapse back to full
       width instead of cramming a sixth of a phone-width column. */
    .block-row > .block,
    .block-text-row > .block-text-item,
    .block-images > .block-figure,
    .block-code-stack > .code-block,
    .block-video-stack > .block-figure {
        grid-column: span 6 !important;
    }
}