/* =============================================================================
   SectraTEK Lab: datasets.css
   Datasets, Open Source and Challenges pages, and the in-browser image browser (prefix ib-).
   Loaded after lab.css. Reads tokens only. Motion sits behind the reduced-motion guard.
   ============================================================================= */

/* ---------------------------------------------------------------- catalogue and detail */
.ds-grid { display: grid; gap: var(--space-5); grid-template-columns: repeat(auto-fill, minmax(min(100%, 24rem), 1fr)); margin: 0; padding: 0; list-style: none; }
.ds-grid > li { display: flex; }
.ds-grid > li[hidden] { display: none; }
.ds-card { width: 100%; }
.ds-card .lab-card__title { font-size: 1.375rem; }
.ds-card__truth { margin: 0; padding: var(--space-3) var(--space-4); border-radius: var(--radius-card); background: var(--surface-2); border: 1px solid var(--line); font-size: var(--text-small); color: var(--ink-2); }
.ds-card__truth strong { display: block; margin-bottom: 2px; color: var(--ink); font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; font-weight: var(--weight-semibold); }
.ds-card__hash { display: flex; align-items: center; gap: var(--space-2); margin: 0; font-family: var(--font-mono); font-size: var(--text-micro); color: var(--muted); }
.ds-card__hash span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ds-chipline { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-block-start: var(--space-5); }
.ds-jump { display: flex; flex-wrap: wrap; gap: var(--space-2); margin: var(--space-6) 0 0; padding: 0; list-style: none; }
.ds-jump a { display: inline-flex; align-items: center; min-height: 36px; padding: 0 var(--space-4); border: 1px solid var(--line-strong); border-radius: var(--radius-pill); color: var(--ink); font-size: var(--text-ui); text-decoration: none; background: var(--surface); }
.ds-jump a:hover { border-color: var(--accent); color: var(--link); }
.ds-head { padding-block: var(--space-8) var(--space-6); }
.ds-head h1 { max-width: 22ch; }
.ds-head .lab-lead, .ds-lead { max-width: 44rem; color: var(--ink-2); font-size: 1.25rem; line-height: 1.5; margin-block: var(--space-4) 0; }
.ds-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-block-start: var(--space-6); }
.ds-sec { padding-block: var(--space-8); border-block-start: 1px solid var(--line); }
.ds-sec > .container > h2, .ds-sec > .container--wide > h2 { margin-block: 0 var(--space-2); }
.ds-sec__lead { max-width: 44rem; color: var(--ink-2); margin: 0 0 var(--space-6); }
.ds-two { display: grid; gap: var(--space-8); }
@media (min-width: 60em) { .ds-two { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); } .ds-two--even { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.ds-table td, .ds-table th { vertical-align: top; }
.ds-table .cell-mono { white-space: nowrap; }
.ds-t0 { font-family: var(--font-mono); font-size: var(--text-caption); white-space: nowrap; color: var(--ink-2); }
.ds-manifest .hash { margin: 0; }
.ds-tl { margin-block-start: var(--space-6); }
.ds-note { font-size: var(--text-small); color: var(--muted); margin: var(--space-3) 0 0; }

/* licence box and the acceptance step */
.dl { display: grid; gap: var(--space-5); max-width: 56rem; }
.dl__step { display: grid; grid-template-columns: 2.25rem 1fr; gap: var(--space-4); }
.dl__n { display: grid; place-items: center; width: 2.25rem; height: 2.25rem; border-radius: 50%; border: 1px solid var(--line-strong); font-weight: var(--weight-semibold); font-size: var(--text-ui); color: var(--ink-2); background: var(--surface); }
.dl__step h3 { margin: 0.3rem 0 var(--space-3); font-size: var(--text-h4); letter-spacing: -0.012em; }
.dl__licence { padding: var(--space-5); border: 1px solid var(--line); border-radius: var(--radius-card); background: var(--surface-2); max-height: 25rem; overflow: auto; }
.dl__licence h4 { margin: 0 0 var(--space-2); font-size: var(--text-ui); letter-spacing: 0; }
.dl__licence h4:not(:first-child) { margin-block-start: var(--space-4); }
.dl__licence ul { margin: 0 0 var(--space-4); padding-inline-start: 1.25rem; color: var(--ink-2); }
.dl__licence li { margin-block: 4px; }
.dl__licence .chip { margin-inline-start: var(--space-2); vertical-align: middle; }
.dl__out { padding: var(--space-5); border: 1px dashed var(--line-strong); border-radius: var(--radius-card); min-height: 5rem; }
.dl__idle { display: flex; align-items: center; gap: var(--space-3); margin: 0; color: var(--muted); }
.dl__ready, .dl__expired { display: grid; gap: var(--space-4); }
.dl__expired p { margin: 0; color: var(--ink-2); }
.dl__row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--space-3); }
.dl__row > .btn:only-child { margin-inline-end: auto; }
.dl__time { color: var(--ink-2); font-size: var(--text-small); font-variant-numeric: tabular-nums; }
.dl__url .hash__value { font-size: var(--text-caption); word-break: break-all; }
.dl__ready .code-block { margin: 0; }
.dl__ready .code-block__pre { max-height: 14rem; }
.ib-spinner { display: inline-block; width: 14px; height: 14px; margin-inline-end: 10px; border: 2px solid var(--line-strong); border-top-color: var(--accent); border-radius: 50%; vertical-align: -2px; flex: none; }
@media (prefers-reduced-motion: no-preference) { html:not([data-motion="reduce"]) .ib-spinner { animation: ib-spin 0.8s linear infinite; } }
@keyframes ib-spin { to { transform: rotate(360deg); } }
@media (max-width: 39.99em) { .dl__step { grid-template-columns: 1fr; } .dl__n { width: 2rem; height: 2rem; } }

/* ---------------------------------------------------------------- image browser */
.ib { --ib-line: var(--navy-line); --ib-hover: rgba(255, 255, 255, 0.06); --ib-pane: rgba(255, 255, 255, 0.035); --ib-code: #05101b; padding: 0; overflow: hidden; border-radius: var(--radius-xl); color: var(--on-navy); font-size: var(--text-small); }
:where(.ib) h3, :where(.ib) h4, :where(.ib) p { margin: 0; }
.ib .icon { width: 16px; height: 16px; flex: none; }
.ib button { font: inherit; }
.ib-boot, .ib-fail { display: flex; align-items: center; gap: var(--space-3); padding: var(--space-8); min-height: 18rem; justify-content: center; color: var(--on-navy-2); text-align: left; }
.ib-fail { gap: var(--space-5); align-items: flex-start; max-width: 40rem; margin-inline: auto; }
.ib-fail h3 { color: var(--on-navy); font-size: var(--text-h4); margin-bottom: var(--space-2); }
.ib-fail p + p { margin-top: var(--space-3); }
.ib-fail__icon { color: var(--navy-accent); }
.ib-fail__icon .icon { width: 28px; height: 28px; }

.ib__top { display: grid; gap: var(--space-3) var(--space-5); grid-template-columns: 1fr; align-items: center; padding: var(--space-4) var(--space-5); border-block-end: 1px solid var(--ib-line); }
@media (min-width: 64em) { .ib__top { grid-template-columns: auto 1fr minmax(18rem, 24rem); } }
.ib__id { display: flex; align-items: center; gap: var(--space-3); min-width: 0; }
.ib__id-icon { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 9px; background: var(--accent-soft); color: var(--navy-accent); flex: none; }
.ib__id-t { font-weight: var(--weight-semibold); color: var(--on-navy); letter-spacing: -0.01em; }
.ib__id-s { font-size: var(--text-caption); color: var(--on-navy-2); font-family: var(--font-mono); overflow-wrap: anywhere; }
.ib__chips { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.ib__search { position: relative; display: flex; align-items: center; }
.ib__search-i { position: absolute; inset-inline-start: 12px; display: inline-flex; color: var(--on-navy-2); pointer-events: none; }
.ib__search-in { width: 100%; min-height: 40px; padding: 0 40px 0 38px; border: 1px solid var(--ib-line); border-radius: var(--radius-pill); background: var(--ib-pane); color: var(--on-navy); font: inherit; font-size: var(--text-ui); }
.ib__search-in::placeholder { color: var(--on-navy-2); opacity: 0.85; }
.ib__search-in:focus-visible { outline: var(--focus-width) solid var(--navy-accent); outline-offset: 1px; border-color: transparent; }
.ib__search-in::-webkit-search-cancel-button { display: none; }
.ib__iconbtn { display: inline-grid; place-items: center; width: 32px; height: 32px; border: 0; border-radius: 8px; background: transparent; color: var(--on-navy-2); cursor: pointer; }
.ib__iconbtn:hover { background: var(--ib-hover); color: var(--on-navy); }
.ib__iconbtn:focus-visible, .ib button:focus-visible, .ib a:focus-visible { outline: var(--focus-width) solid var(--navy-accent); outline-offset: 1px; }
.ib__search .ib__iconbtn { position: absolute; inset-inline-end: 4px; }
.ib__iconbtn[hidden] { display: none; }

.ib__pathbar { display: flex; align-items: center; gap: var(--space-3); padding: var(--space-2) var(--space-5); border-block-end: 1px solid var(--ib-line); background: var(--ib-pane); min-width: 0; }
.ib__crumbs { min-width: 0; flex: 1; overflow-x: auto; scrollbar-width: thin; }
.ib__crumbs ol { display: flex; align-items: center; gap: 0; margin: 0; padding: 0; list-style: none; font-family: var(--font-mono); font-size: var(--text-caption); white-space: nowrap; }
.ib__crumbs li + li::before { content: "/"; margin-inline: 6px; color: var(--on-navy-2); opacity: 0.6; }
.ib__crumb-root { color: var(--on-navy-2); margin-inline-end: 4px; }
.ib__crumbs li:nth-child(2)::before { content: none; }
.ib__crumbs li:nth-child(2) { margin-inline-start: 0; }
.ib__crumbs button { padding: 4px 6px; margin-inline: -6px; border: 0; border-radius: 6px; background: transparent; color: var(--link); cursor: pointer; font: inherit; }
.ib__crumbs button:hover { background: var(--ib-hover); text-decoration: underline; }
.ib__crumbs [aria-current] { color: var(--on-navy); font-weight: var(--weight-medium); }
.ib__copy { display: inline-flex; align-items: center; gap: 6px; flex: none; min-height: 30px; padding: 0 var(--space-3); border: 1px solid var(--ib-line); border-radius: var(--radius-pill); background: transparent; color: var(--on-navy); cursor: pointer; font-size: var(--text-caption); }
.ib__copy:hover { background: var(--ib-hover); }
@media (max-width: 39.99em) { .ib__copy span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); } .ib__copy { padding: 0 8px; } }

/* body grid: side | (list over view) */
.ib__body { display: grid; grid-template-columns: minmax(0, 1fr); }
.ib__side { padding: var(--space-4); border-block-end: 1px solid var(--ib-line); min-width: 0; }
.ib__h { font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--navy-accent); font-weight: var(--weight-semibold); }
.ib__side .ib__h { margin: 0 0 var(--space-2) var(--space-2); }
.ib__side .ib__h + ul + .ib__h { margin-top: var(--space-5); }
.ib__vols, .ib__tree, .ib__tree ul, .ib__files, .ib__results { list-style: none; margin: 0; padding: 0; }
.ib__vols { display: flex; gap: var(--space-2); overflow-x: auto; padding-block-end: 2px; }
.ib__vol { display: flex; align-items: center; gap: var(--space-3); width: 100%; min-height: 48px; padding: var(--space-2) var(--space-3); border: 1px solid transparent; border-radius: 10px; background: transparent; color: var(--on-navy-2); cursor: pointer; text-align: left; }
.ib__vols > li { flex: 0 0 auto; }
.ib__vol:hover { background: var(--ib-hover); color: var(--on-navy); }
.ib__vol[aria-pressed="true"] { background: var(--accent-soft); border-color: rgba(74, 155, 245, 0.35); color: var(--on-navy); }
.ib__vol-i { display: inline-grid; place-items: center; color: var(--navy-accent); }
.ib__vol-t { display: grid; min-width: 0; flex: 1; line-height: 1.25; }
.ib__vol-t strong { font-weight: var(--weight-semibold); color: var(--on-navy); }
.ib__vol-t small { font-size: var(--text-micro); color: var(--on-navy-2); font-family: var(--font-mono); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ib__vol-n { margin-inline-start: auto; flex: none; font-size: var(--text-micro); font-family: var(--font-mono); color: var(--on-navy-2); }
.ib__tree { max-height: 14rem; overflow: auto; }
.ib__tree ul { padding-inline-start: 16px; margin-inline-start: 11px; border-inline-start: 1px solid var(--ib-line); }
.ib__row { display: flex; align-items: center; gap: 6px; width: 100%; min-height: 32px; padding: 3px 8px; border: 0; border-radius: 8px; background: transparent; color: var(--on-navy-2); text-align: left; cursor: pointer; }
.ib__row:hover { background: var(--ib-hover); color: var(--on-navy); }
.ib__row[aria-selected="true"] { background: var(--accent-soft); color: #9ccdff; font-weight: var(--weight-medium); }
.ib__row .icon { color: var(--on-navy-2); }
.ib__row[aria-selected="true"] .icon { color: var(--navy-accent); }
.ib__chev { transition: transform var(--dur-fast) var(--ease-out); }
.ib__row[aria-expanded="true"] > .ib__chev { transform: rotate(90deg); }
.ib__sp { width: 16px; flex: none; }
.ib__name { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.ib__list { border-block-end: 1px solid var(--ib-line); min-width: 0; display: flex; flex-direction: column; }
.ib__listhead { display: flex; align-items: baseline; justify-content: space-between; gap: var(--space-3); padding: var(--space-3) var(--space-4) var(--space-2); }
.ib__listhead .ib__h { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; text-transform: none; letter-spacing: 0; font-family: var(--font-mono); font-size: var(--text-caption); }
.ib__count { font-size: var(--text-caption); color: var(--on-navy-2); white-space: nowrap; }
.ib__listbody { padding: 0 var(--space-2) var(--space-3); min-height: 9rem; max-height: 12.5rem; overflow: auto; }
.ib__cols, .ib__file { display: grid; grid-template-columns: minmax(0, 1fr) 4.75rem 4.25rem 6.75rem; gap: var(--space-3); align-items: center; }
.ib__cols { padding: 4px var(--space-3); font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--on-navy-2); position: sticky; top: 0; background: var(--navy-2); z-index: 1; }
.ib__file { width: 100%; min-height: 34px; padding: 4px var(--space-3); border: 0; border-radius: 8px; background: transparent; color: var(--on-navy); text-align: left; cursor: pointer; }
.ib__file:hover { background: var(--ib-hover); }
.ib__file[aria-selected="true"] { background: var(--accent-soft); box-shadow: inset 2px 0 0 var(--navy-accent); }
.ib__f-name { display: flex; align-items: center; gap: 8px; min-width: 0; }
.ib__f-name .icon { color: var(--navy-accent); }
.ib__f-type, .ib__f-size, .ib__f-mod { color: var(--on-navy-2); font-size: var(--text-caption); white-space: nowrap; }
.ib__f-size, .ib__f-mod { font-family: var(--font-mono); }
.ib__badge { display: inline-flex; align-items: center; gap: 3px; padding: 1px 7px; border-radius: var(--radius-pill); border: 1px solid var(--ib-line); font-size: var(--text-micro); color: var(--on-navy-2); white-space: nowrap; }
.ib__badge .icon { width: 12px; height: 12px; }
@media (max-width: 39.99em) { .ib__cols, .ib__file { grid-template-columns: minmax(0, 1fr) 3.75rem 5.5rem; } .ib__cols span:nth-child(2), .ib__f-type { display: none; } }

.ib__results { display: grid; gap: 2px; }
.ib__res { display: grid; gap: 2px; width: 100%; padding: var(--space-2) var(--space-3); border: 0; border-radius: 8px; background: transparent; color: var(--on-navy); text-align: left; cursor: pointer; }
.ib__res:hover { background: var(--ib-hover); }
.ib__res-t { display: flex; align-items: center; gap: 8px; }
.ib__res-t .icon { color: var(--navy-accent); }
.ib__res-n { margin-inline-start: auto; font-size: var(--text-micro); color: var(--on-navy-2); font-family: var(--font-mono); }
.ib__res-p { font-family: var(--font-mono); font-size: var(--text-micro); color: var(--on-navy-2); overflow-wrap: anywhere; }
.ib__res-s { font-family: var(--font-mono); font-size: var(--text-caption); color: var(--on-navy-2); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ib mark { background: rgba(74, 155, 245, 0.35); color: #fff; border-radius: 3px; padding: 0 1px; }

.ib__view { display: grid; grid-template-columns: minmax(0, 1fr); min-width: 0; }
.ib__viewmain { min-width: 0; display: flex; flex-direction: column; border-block-end: 1px solid var(--ib-line); }
.ib__viewmain > .ib__code { flex: 1 1 auto; min-height: 15rem; }
.ib__ann { padding: var(--space-4) var(--space-5); display: grid; gap: var(--space-4); align-content: start; min-width: 0; }
.ib__ann section { display: grid; gap: 4px; }
.ib__ann h4 { font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--navy-accent); font-weight: var(--weight-semibold); }
.ib__ann p { color: var(--on-navy); line-height: 1.5; }
.ib__ann-limit { padding: var(--space-3) var(--space-4); border-radius: 10px; border: 1px solid var(--ib-line); background: var(--ib-pane); }
.ib__ann-limit h4 { color: var(--on-navy-2); }
.ib__ann-foot { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.ib__ann-empty { color: var(--on-navy-2); display: grid; gap: var(--space-2); }
.ib__ann-empty h4 { color: var(--on-navy); font-size: var(--text-ui); text-transform: none; letter-spacing: 0; }
.ib__parsers { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.ib__parsers li { display: grid; gap: 1px; }
.ib__parsers a { color: var(--link); font-weight: var(--weight-medium); }
.ib__parsers a .icon { width: 12px; height: 12px; margin-inline-start: 4px; vertical-align: -1px; }
.ib__parsers span { color: var(--on-navy-2); font-size: var(--text-caption); }

.ib__vbar { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--space-3); padding: var(--space-3) var(--space-4); }
.ib__vtitle h3 { font-size: 1rem; font-weight: var(--weight-semibold); letter-spacing: -0.01em; font-family: var(--font-mono); overflow-wrap: anywhere; }
.ib__vtitle p { color: var(--on-navy-2); font-size: var(--text-caption); margin-top: 2px; }
.ib__tabs { display: inline-flex; padding: 3px; border-radius: var(--radius-pill); background: var(--ib-pane); border: 1px solid var(--ib-line); }
.ib__tab { min-height: 28px; padding: 0 var(--space-4); border: 0; border-radius: var(--radius-pill); background: transparent; color: var(--on-navy-2); cursor: pointer; font-size: var(--text-caption); font-weight: var(--weight-medium); }
.ib__tab[aria-selected="true"] { background: var(--accent-fill); color: var(--on-accent); }
.ib__hash { display: flex; align-items: center; gap: var(--space-2); padding: 0 var(--space-4) var(--space-3); min-width: 0; }
.ib__hash-l { font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--on-navy-2); flex: none; }
.ib__hash-v { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-family: var(--font-mono); font-size: var(--text-micro); color: var(--on-navy-2); background: none; padding: 0; }
.ib__code { margin: 0 var(--space-4); padding: var(--space-3) 0; max-height: 20rem; overflow: auto; background: var(--ib-code); border: 1px solid var(--ib-line); border-radius: 10px; font-family: var(--font-mono); font-size: 0.8125rem; line-height: 1.6; }
.ib__code:focus-visible { outline: var(--focus-width) solid var(--navy-accent); outline-offset: 1px; }
.ib__line { display: grid; grid-template-columns: 3.25rem minmax(max-content, 1fr) auto; align-items: baseline; padding-inline-end: var(--space-3); white-space: pre; }
.ib__line.is-mark { background: rgba(74, 155, 245, 0.14); box-shadow: inset 3px 0 0 var(--navy-accent); }
.ib__ln { padding-inline-end: var(--space-3); text-align: right; color: var(--on-navy-2); opacity: 0.55; user-select: none; font-variant-numeric: tabular-nums; }
.ib__tx { color: var(--on-navy); }
.ib__tag { margin-inline-start: var(--space-4); padding: 0 8px; border-radius: var(--radius-pill); background: var(--accent-soft); color: #9ccdff; font-size: var(--text-micro); letter-spacing: 0.02em; align-self: center; line-height: 1.7; position: sticky; inset-inline-end: 10px; white-space: nowrap; }
.ib-t-c { color: var(--on-navy-2); font-style: italic; }
.ib-t-k, .ib-t-a { color: #9ccdff; }
.ib-t-t { color: #6fb6ff; }
.ib-t-p { color: var(--on-navy-2); }
.ib-t-v { color: #e8eef6; }
.ib__code--hex { padding: var(--space-3) var(--space-4); }
.ib__code--hex pre { margin: 0; font: inherit; white-space: pre; color: var(--on-navy); }
.ib-hx-o { color: var(--on-navy-2); opacity: 0.7; }
.ib-hx-a { color: #9ccdff; }
.ib__code--tbl { padding: 0; }
.ib__table { width: 100%; border-collapse: collapse; font-size: var(--text-caption); }
.ib__table th { position: sticky; top: 0; padding: 7px 12px; text-align: left; background: #0d2034; color: var(--on-navy-2); font-weight: var(--weight-semibold); white-space: nowrap; border-block-end: 1px solid var(--ib-line); z-index: 1; }
.ib__table td { padding: 6px 12px; border-block-end: 1px solid var(--ib-line); color: var(--on-navy); vertical-align: top; white-space: nowrap; }
.ib__table td:last-child { white-space: normal; min-width: 12rem; }
.ib__table .ib__num { color: var(--on-navy-2); width: 2rem; text-align: right; }
.ib__table .ib__n { font-variant-numeric: tabular-nums; }
.ib__when { display: block; color: var(--navy-accent); font-size: var(--text-micro); }
.ib__schema { margin: 0 var(--space-4) var(--space-2); }
.ib__schema code { display: block; padding: 0; background: none; color: var(--on-navy-2); font-size: var(--text-micro); line-height: 1.5; overflow-wrap: anywhere; }
.ib__tblsw { display: flex; gap: var(--space-2); margin: 0 var(--space-4) var(--space-2); }
.ib__tblbtn { min-height: 28px; padding: 0 var(--space-3); border: 1px solid var(--ib-line); border-radius: var(--radius-pill); background: transparent; color: var(--on-navy-2); cursor: pointer; font-family: var(--font-mono); font-size: var(--text-caption); }
.ib__tblbtn small { opacity: 0.7; margin-inline-start: 4px; }
.ib__tblbtn[aria-pressed="true"] { background: var(--accent-soft); color: #9ccdff; border-color: rgba(74, 155, 245, 0.4); }
.ib__note { margin: var(--space-2) var(--space-4) var(--space-3); color: var(--on-navy-2); font-size: var(--text-caption); display: flex; align-items: center; gap: 8px; }
.ib__legend { width: 10px; height: 10px; border-radius: 2px; background: rgba(74, 155, 245, 0.5); flex: none; }

.ib__empty, .ib__state, .ib__intro { display: grid; gap: var(--space-2); justify-items: start; padding: var(--space-6) var(--space-5); color: var(--on-navy-2); }
.ib__empty { justify-items: center; text-align: center; margin: var(--space-3); border: 1px dashed var(--ib-line); border-radius: 12px; }
.ib__empty h4, .ib__state h3, .ib__intro h3 { color: var(--on-navy); font-size: var(--text-h4); letter-spacing: -0.012em; }
.ib__empty p, .ib__state p, .ib__intro p { max-width: 34rem; }
.ib__state { min-height: 12rem; align-content: center; }
.ib__state-i, .ib__intro-i { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; background: var(--accent-soft); color: var(--navy-accent); }
.ib__state--err .ib__state-i { background: var(--warning-soft); color: var(--warning); }
.ib__state .icon, .ib__intro-i .icon { width: 20px; height: 20px; }
.ib__intro-l { margin-top: var(--space-3); font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--navy-accent); }
.ib__guide { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.ib__skel { display: grid; gap: 10px; width: min(100%, 28rem); margin-top: var(--space-3); }
.ib__skel i { display: block; height: 10px; border-radius: 5px; background: var(--ib-hover); }
.ib__skel i:nth-child(2n) { width: 82%; }
.ib__skel i:nth-child(3n) { width: 58%; }
@media (prefers-reduced-motion: no-preference) { html:not([data-motion="reduce"]) .ib__skel i { animation: ib-pulse 1.4s ease-in-out infinite; } }
@keyframes ib-pulse { 50% { opacity: 0.45; } }
.ib__status { padding: var(--space-2) var(--space-5); border-block-start: 1px solid var(--ib-line); color: var(--on-navy-2); font-size: var(--text-caption); min-height: 2rem; font-family: var(--font-mono); }

@media (min-width: 64em) {
  .ib__body { grid-template-columns: 15.5rem minmax(0, 1fr); grid-template-rows: auto; }
  .ib__side { border-inline-end: 1px solid var(--ib-line); border-block-end: 0; }
  .ib__vols { flex-direction: column; overflow: visible; }
  .ib__vols > li { flex: initial; }
  .ib__tree { max-height: 16rem; }
  .ib__main { min-width: 0; }
  .ib__list, .ib__view { grid-column: 2; }
  .ib__side { grid-row: 1 / span 2; }
  .ib__view { grid-template-columns: minmax(0, 1fr) 19.5rem; }
  .ib__viewmain { border-block-end: 0; border-inline-end: 1px solid var(--ib-line); padding-block-end: var(--space-3); }
  .ib__code { max-height: 32rem; }
  .ib__body { min-height: 43rem; }
}
@media (max-width: 63.99em) { .ib__code { max-height: 18rem; } .ib__ann { border-block-start: 1px solid var(--ib-line); } .ib__vols { padding-block-end: var(--space-2); } }
@media (max-width: 39.99em) { .ib__top, .ib__pathbar, .ib__ann { padding-inline: var(--space-4); } .ib__vol { min-width: 11rem; } .ib__code { margin-inline: var(--space-3); } }
@media (forced-colors: active) { .ib__row[aria-selected="true"], .ib__file[aria-selected="true"], .ib__vol[aria-pressed="true"] { outline: 2px solid Highlight; } .ib__line.is-mark { border-inline-start: 3px solid Highlight; } }

/* ---------------------------------------------------------------- open source */
.os-tools { display: grid; gap: var(--space-5); grid-template-columns: repeat(auto-fill, minmax(min(100%, 19rem), 1fr)); margin: 0; padding: 0; list-style: none; }
.os-tool { display: flex; flex-direction: column; gap: var(--space-3); padding: var(--space-6); border: 1px solid var(--card-line); border-radius: var(--radius-xl); background: var(--card); height: 100%; }
.lab-band .os-tool { background: var(--surface); border-color: var(--line); }
.os-tool h3 { margin: 0; font-size: 1.375rem; letter-spacing: -0.02em; }
.os-tool p { margin: 0; color: var(--ink-2); }
.os-tool__by { font-size: var(--text-small); color: var(--muted); }
.os-tool__foot { margin-block-start: auto; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--space-2); padding-block-start: var(--space-3); }
.os-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr)); gap: var(--space-5); margin: 0; padding: var(--space-5) var(--space-6); list-style: none; border: 1px solid var(--line); border-radius: var(--radius-xl); background: var(--surface); }
.os-stats li { display: grid; gap: 2px; }
.os-stats strong { font-size: 1.75rem; line-height: 1.1; letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.os-stats span { color: var(--ink-2); font-size: var(--text-small); }
.os-spark { display: block; width: 100%; max-width: 15rem; height: 28px; margin-top: 4px; }
.os-spark path { fill: none; stroke: var(--accent); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.os-principle { max-width: 44rem; margin: 0; padding-inline-start: var(--space-6); border-inline-start: 3px solid var(--accent); font-size: clamp(1.375rem, 1.1rem + 1vw, 1.875rem); line-height: 1.3; letter-spacing: -0.02em; font-weight: var(--weight-semibold); text-wrap: balance; }
.os-steps { display: grid; gap: var(--space-5); counter-reset: s; margin: 0; padding: 0; list-style: none; grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr)); }
.os-steps li { counter-increment: s; display: grid; gap: var(--space-2); padding-block-start: var(--space-4); border-block-start: 1px solid var(--line-strong); }
.os-steps li::before { content: counter(s); font-family: var(--font-mono); font-size: var(--text-caption); color: var(--accent); }
.os-steps h3 { margin: 0; font-size: var(--text-h4); letter-spacing: -0.012em; }
.os-steps p { margin: 0; color: var(--ink-2); }

/* ---------------------------------------------------------------- challenges */
.ch-grid { display: grid; gap: var(--space-5); grid-template-columns: repeat(auto-fill, minmax(min(100%, 22rem), 1fr)); margin: 0; padding: 0; list-style: none; }
.ch-state { display: inline-flex; align-items: center; gap: 6px; }
.ch-layout { display: grid; gap: var(--space-8); }
@media (min-width: 64em) { .ch-layout { grid-template-columns: minmax(0, 1fr) 20rem; align-items: start; } .ch-side { position: sticky; top: calc(var(--header-h) + var(--space-5)); } }
.ch-side { display: grid; gap: var(--space-5); }
.ch-panel { padding: var(--space-5); border: 1px solid var(--line); border-radius: var(--radius-card); background: var(--surface); display: grid; gap: var(--space-3); }
.ch-panel h2, .ch-panel h3 { margin: 0; font-size: var(--text-h4); letter-spacing: -0.012em; }
.ch-score { display: flex; align-items: baseline; gap: var(--space-2); }
.ch-score strong { font-size: 2.5rem; line-height: 1; letter-spacing: -0.035em; font-variant-numeric: tabular-nums; }
.ch-score span { color: var(--muted); }
.ch-q { display: grid; gap: var(--space-3); padding: var(--space-5); border: 1px solid var(--line); border-radius: var(--radius-card); background: var(--surface); }
.ch-q.is-solved { border-color: var(--success); }
.ch-q.is-wrong { border-color: var(--line-strong); }
.ch-q__head { display: flex; align-items: baseline; justify-content: space-between; gap: var(--space-3); }
.ch-q__n { font-family: var(--font-mono); font-size: var(--text-caption); color: var(--ink-2); }
.ch-q h3 { margin: 0; font-size: 1.125rem; letter-spacing: -0.012em; line-height: 1.35; }
.ch-q form { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: flex-start; }
.ch-q form .control { flex: 1 1 12rem; max-width: 20rem; }
.ch-q__meta { display: flex; flex-wrap: wrap; gap: var(--space-3) var(--space-5); align-items: center; font-size: var(--text-small); color: var(--muted); }
.ch__err, .ch__ok { display: flex; align-items: center; gap: 6px; margin: 0; font-size: var(--text-small); }
.ch__err { color: var(--danger); }
.ch__ok { color: var(--success); }
.ch-q [data-msg]:empty { display: none; }
.ch-hints { display: grid; gap: var(--space-2); justify-items: start; }
.ch-hints [data-hint] { margin: 0; padding: var(--space-3) var(--space-4); border-radius: var(--radius-card); background: var(--accent-soft); color: var(--ink-2); font-size: var(--text-small); }
.ch-hints [hidden] { display: none; }
.ch-bar { width: 100%; height: 8px; border-radius: 4px; overflow: hidden; border: 0; background: var(--surface-3); accent-color: var(--accent); appearance: none; }
.ch-bar::-webkit-progress-bar { background: var(--surface-3); }
.ch-bar::-webkit-progress-value { background: var(--accent-fill); }
.ch-bar::-moz-progress-bar { background: var(--accent-fill); }
.ch-board td, .ch-board th { white-space: nowrap; }
.ch-board tr[data-board-me] { background: var(--accent-soft); font-weight: var(--weight-medium); }
.ch-board tr[hidden] { display: none; }
.ch-lock { display: grid; gap: var(--space-3); justify-items: start; padding: var(--space-6); border: 1px dashed var(--line-strong); border-radius: var(--radius-xl); }
.ch-lock h3 { margin: 0; font-size: var(--text-h4); }
.ch-lock p { margin: 0; max-width: 40rem; color: var(--ink-2); }
.ch-rules { margin: 0; padding-inline-start: 1.25rem; display: grid; gap: var(--space-2); color: var(--ink-2); }
.ch-timeline { display: grid; gap: 0; margin: 0; padding: 0; list-style: none; }
.ch-timeline li { display: grid; grid-template-columns: 8.5rem 1fr; gap: var(--space-4); padding-block: var(--space-3); border-block-end: 1px solid var(--hair); }
.ch-timeline li span:first-child { font-family: var(--font-mono); font-size: var(--text-caption); color: var(--ink-2); }
.ch-story { max-width: 40rem; font-size: 1.1875rem; line-height: 1.6; }
.ch-story p { margin: 0 0 1em; }
@media (max-width: 39.99em) { .ch-timeline li { grid-template-columns: 1fr; gap: 2px; } }

/* refinements */
.os-stats li .chip { justify-self: start; }
@media (min-width: 64em) { .os-steps { grid-template-columns: repeat(5, minmax(0, 1fr)); } }
.ch-layout .lab-stack > div + div { margin-block-start: var(--space-8); }
.ch-layout h2 { margin: 0 0 var(--space-3); }
.ch-layout .lab-h2-sm { margin-block: var(--space-8) var(--space-3); }
.ch-qs { margin: var(--space-5) 0 0; padding: 0; list-style: none; }
.ch-bar { margin-block-start: var(--space-4); }

/* tables become stacked cards on phones */
@media (max-width: 39.99em) {
  .ds-stack, .ds-stack tbody, .ds-stack tr, .ds-stack th, .ds-stack td { display: block; width: auto; }
  .ds-stack thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .ds-stack tr { padding: var(--space-4); border-block-end: 1px solid var(--line); }
  .ds-stack th[scope="row"] { padding: 0; border: 0; display: inline-block; margin-inline-end: var(--space-3); font-weight: var(--weight-semibold); }
  .ds-stack th, .ds-stack td { height: auto; line-height: 1.45; white-space: normal; }
  .ds-stack td { padding: 2px 0; border: 0; text-align: left; }
  .ds-stack td.ds-t0 { display: inline-block; padding: 0; }
  .ds-stack td.ds-what { padding-block: var(--space-2) var(--space-1); color: var(--ink); }
  .ds-stack td[data-label]::before { content: attr(data-label); display: block; font-size: var(--text-micro); letter-spacing: var(--track-eyebrow); text-transform: uppercase; color: var(--muted); margin-block-start: var(--space-2); }
  .ds-stack td.num { text-align: left; }
}