/* Interactive lesson activities (loaded only on lessons that have them). Uses the tokens from app.css. */
.acts { margin-top: 56px; }
.acts > h2 { font-size: clamp(24px, 3vw, 32px); font-weight: 720; margin-bottom: 20px; }
.act { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: clamp(18px, 3vw, 30px); margin-bottom: 24px; }
.act-meta { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.act-head h3 { font-size: 21px; font-weight: 700; }
.act-intro { color: var(--ink-2); margin: 8px 0 0; max-width: 70ch; }
.act-body { margin-top: 20px; display: grid; gap: 14px; }
.act-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.act-status { font-size: 14px; color: var(--ink-3); font-weight: 600; }
.act-status.ok { color: var(--good); }
.act-status.no { color: var(--bad); }
.act-note { font-size: 13px; color: var(--ink-3); margin: 0; }
.act-beyond { font-size: 13px; color: var(--ink-2); }
.act-takeaway { margin: 0; padding: 12px 16px; border-radius: var(--radius-sm); background: var(--accent-soft); color: var(--ink); font-weight: 560; }
.btn.small { padding: 8px 14px; font-size: 13px; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

/* classify / match */
.cl-cap { font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 8px; }
[dir="rtl"] .cl-cap { letter-spacing: .02em; }
.cl-pool { display: flex; flex-wrap: wrap; gap: 8px; min-height: 52px; padding: 10px; border: 1px dashed var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2); }
.cl-pool.empty::after { content: '✓'; color: var(--ink-3); align-self: center; margin: 0 auto; }
.cl-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; }
.cl-cols.single { grid-template-columns: 1fr; }
.cl-col { border: 1px solid var(--line-2); border-radius: var(--radius-sm); padding: 12px; background: var(--surface-2); min-height: 120px; transition: border-color .2s, background .2s; cursor: pointer; }
.cl-cols.single .cl-col { display: grid; grid-template-columns: minmax(150px, 220px) 1fr; gap: 12px; align-items: center; min-height: 0; }
.cl-col.over, .cl-col:hover { border-color: var(--accent); background: var(--accent-soft); }
.cl-head { font-weight: 700; font-size: 15px; }
.cl-hint { font-size: 12px; color: var(--ink-3); margin-top: 2px; }
.cl-list { display: flex; flex-direction: column; gap: 8px; margin-top: 10px; min-height: 36px; }
.cl-cols.single .cl-list { margin-top: 0; }
.chip { padding: 9px 13px; border-radius: 12px; background: var(--surface); border: 1px solid var(--line-2); font-size: 14px; line-height: 1.4; cursor: grab; user-select: none; box-shadow: var(--shadow-sm); transition: border-color .15s, transform .15s; }
.chip:hover { border-color: var(--accent); }
.chip.sel { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); transform: translateY(-1px); }
.chip.right { border-color: var(--good); background: var(--good-soft); cursor: default; }
.chip.wrong { border-color: var(--bad); background: var(--bad-soft); cursor: default; }
.chip-why { display: block; margin-top: 6px; font-size: 12.5px; color: var(--ink-2); }
@media (max-width: 640px) { .cl-cols.single .cl-col { grid-template-columns: 1fr; } }

/* flashcards */
.fc-stage { display: grid; }
.fc-card { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; min-height: 190px; padding: 24px; text-align: center; border-radius: var(--radius); border: 1px solid var(--line-2); background: var(--surface-2); transition: background .2s, border-color .2s; }
.fc-card:hover { border-color: var(--accent); }
.fc-card.back { background: var(--accent-soft); }
.fc-side { font-size: 11px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }
.fc-text { font-size: 17px; line-height: 1.55; max-width: 60ch; }
.fc-text.term { font-size: 28px; font-weight: 720; letter-spacing: -.01em; direction: ltr; }
.fc-hint { font-size: 12px; color: var(--ink-3); }
.fc-done { padding: 32px; text-align: center; font-weight: 650; color: var(--good); }

/* tokenizer and context window */
.tok-samples { display: flex; flex-wrap: wrap; gap: 8px; }
.tok-in { width: 100%; padding: 12px 14px; border-radius: var(--radius-sm); border: 1px solid var(--line-2); background: var(--surface-2); resize: vertical; line-height: 1.55; }
.tok-stats { display: flex; flex-wrap: wrap; gap: 10px; }
.tok-stat { flex: 1 1 110px; padding: 10px 14px; border-radius: var(--radius-sm); background: var(--bg-2); }
.tok-stat b { display: block; font-size: 24px; font-weight: 750; letter-spacing: -.02em; }
.tok-stat span { font-size: 12px; color: var(--ink-3); }
.tok-out { display: flex; flex-wrap: wrap; gap: 3px; padding: 12px; min-height: 64px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--surface-2); font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace; font-size: 14px; direction: ltr; align-content: flex-start; }
.tk { padding: 2px 4px; border-radius: 5px; white-space: pre; }
.tk.gone { opacity: .35; text-decoration: line-through; }
.tk-id { font-size: 9px; color: var(--ink-3); margin-inline-start: 3px; }
.tk.c0 { background: rgba(67, 56, 202, .16); }
.tk.c1 { background: rgba(14, 159, 154, .2); }
.tk.c2 { background: rgba(168, 104, 14, .2); }
.tk.c3 { background: rgba(210, 64, 90, .16); }
.tk.c4 { background: rgba(11, 143, 99, .2); }
.tk.c5 { background: rgba(94, 110, 140, .2); }
.tok-ids { font-size: 13px; color: var(--ink-2); }
.ctx-lbl { font-size: 14px; font-weight: 600; }
.act input[type=range] { width: 100%; accent-color: var(--accent); }
.ctx-meter { height: 10px; border-radius: 99px; background: var(--bg-2); overflow: hidden; }
.ctx-meter span { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width .2s; }
.ctx-q { padding: 14px 16px; border-radius: var(--radius-sm); background: var(--bg-2); }
.ctx-qlabel { font-size: 12px; font-weight: 700; color: var(--ink-3); text-transform: uppercase; letter-spacing: .08em; }
.ctx-q blockquote { margin: 6px 0 10px; font-weight: 600; direction: ltr; text-align: start; }
.ctx-verdict { font-weight: 600; }
.ctx-verdict.ok { color: var(--good); }
.ctx-verdict.no { color: var(--bad); }

/* next-token game */
.nt-count { font-size: 12px; font-weight: 700; color: var(--ink-3); }
.nt-stem { font-size: 20px; font-weight: 600; margin: 6px 0; line-height: 1.5; direction: ltr; text-align: start; }
.nt-blank { padding: 0 10px; border-bottom: 2px solid var(--accent); color: var(--accent); }
.nt-ask { color: var(--ink-2); font-size: 14px; margin-bottom: 8px; }
.nt-opts { display: flex; flex-wrap: wrap; gap: 8px; }
.nt-opt { padding: 9px 16px; border-radius: 12px; border: 1px solid var(--line-2); background: var(--surface-2); font-weight: 600; direction: ltr; }
.nt-opt:hover { border-color: var(--accent); }
.nt-opts:has(.nt-row) { flex-direction: column; gap: 2px; }
.nt-row { display: grid; grid-template-columns: 110px 1fr 48px 190px; gap: 10px; align-items: center; width: 100%; padding: 6px 8px; border-radius: 10px; direction: ltr; }
.nt-row.mine { background: var(--accent-soft); }
.nt-track { height: 10px; border-radius: 99px; background: var(--bg-2); overflow: hidden; }
.nt-fill { display: block; height: 100%; background: var(--accent-2); }
.nt-row.top .nt-fill { background: var(--accent); }
.nt-p { font-variant-numeric: tabular-nums; font-size: 13px; text-align: end; }
.nt-tags { display: flex; gap: 4px; min-width: 0; }
.nt-res { display: grid; gap: 12px; margin-top: 12px; justify-items: start; }
.nt-res p { margin: 0; }
@media (max-width: 640px) { .nt-row { grid-template-columns: 80px 1fr 40px; } .nt-tags { grid-column: 1 / -1; } }

/* recorded runs and multimodal */
.rec-prompt { padding: 12px 14px; border-radius: var(--radius-sm); background: var(--bg-2); display: grid; gap: 4px; }
.rec-cap { font-size: 12px; font-weight: 700; color: var(--ink-3); text-transform: uppercase; letter-spacing: .08em; }
.rec-prompt code { font-family: inherit; font-weight: 600; direction: ltr; text-align: start; }
.rec-seg { display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 3px; border-radius: 11px; background: var(--bg-2); width: fit-content; }
.seg-b { border: 0; background: transparent; padding: 7px 14px; border-radius: 8px; font-size: 13px; font-weight: 650; color: var(--ink-3); }
.seg-b.on { background: var(--surface); color: var(--ink); box-shadow: var(--shadow-sm); }
.rec-runs { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; }
.rec-run, .mm-model { padding: 14px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2); }
.rec-head { font-size: 12px; font-weight: 700; color: var(--accent); margin-bottom: 8px; }
.rec-text { font-size: 14px; line-height: 1.6; white-space: pre-wrap; }
.rec-after { display: grid; gap: 10px; }
.mm-grid { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr); gap: 16px; align-items: start; }
.mm-fig { margin: 0; }
.mm-fig img { width: 100%; height: auto; border: 1px solid var(--line-2); border-radius: var(--radius-sm); background: #fff; }
.mm-fig figcaption { font-size: 12px; color: var(--ink-3); margin-top: 6px; }
.mm-report { padding: 16px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2); direction: ltr; text-align: start; }
.mm-rid { font-size: 12px; font-weight: 700; color: var(--bad); }
.mm-report ul { margin: 10px 0 0; padding-inline-start: 20px; font-size: 14px; display: grid; gap: 6px; }
.mm-claims { display: grid; gap: 10px; }
.mm-claim { padding: 12px 14px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); display: grid; gap: 8px; }
.mm-claim.right { border-color: var(--good); background: var(--good-soft); }
.mm-claim.wrong { border-color: var(--bad); background: var(--bad-soft); }
.mm-ct { font-weight: 600; font-size: 14px; direction: ltr; text-align: start; }
.mm-why { font-size: 13px; color: var(--ink-2); }
@media (max-width: 760px) { .mm-grid { grid-template-columns: 1fr; } }

/* choose, order, build, calc (chapter 2) */
.rec-prompt code { white-space: pre-wrap; display: block; }
.ch { display: grid; gap: 12px; }
.ch-stem { margin: 0; font-weight: 600; line-height: 1.5; }
.ch-base { margin: 0; padding: 12px 14px; border-radius: var(--radius-sm); background: var(--bg-2); font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace; font-size: 13px; white-space: pre-wrap; text-align: start; }
.ch-opts { display: grid; gap: 10px; }
.ch-opt { display: grid; grid-template-columns: 28px 1fr; gap: 12px; align-items: start; text-align: start; padding: 12px 14px; border-radius: var(--radius-sm); border: 1px solid var(--line-2); background: var(--surface); line-height: 1.45; transition: border-color .15s; }
.ch-opt:hover { border-color: var(--accent); }
.ch-opt .l { width: 26px; height: 26px; border-radius: 8px; background: var(--bg-2); display: grid; place-items: center; font-size: 12px; font-weight: 700; color: var(--ink-2); }
.ch-opt.sel { border-color: var(--accent); background: var(--accent-soft); }
.ch-opt.right { border-color: var(--good); background: var(--good-soft); }
.ch-opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.ch-opt.dim { opacity: .75; }
.ch-opt .chip-why { grid-column: 2; }
.ch-ot { white-space: pre-wrap; }
.ch-res { display: grid; gap: 10px; justify-items: start; }
.ch-res p { margin: 0; }
.ch-scn { padding: 12px 14px; border-radius: var(--radius-sm); background: var(--bg-2); }
.ch-scn p { margin: 4px 0 0; }
.bd-rows { display: grid; gap: 10px; }
.bd-row { display: grid; gap: 6px; padding: 10px 12px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); }
.bd-row.right { border-color: var(--good); background: var(--good-soft); }
.bd-row.wrong { border-color: var(--bad); background: var(--bad-soft); }
.bd-lab { font-size: 12px; font-weight: 750; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); }
.bd-in { width: 100%; padding: 9px 11px; border-radius: 10px; border: 1px solid var(--line-2); background: var(--surface); font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace; font-size: 13.5px; resize: vertical; text-align: start; }
.bd-fixed { margin: 0; padding: 9px 11px; border-radius: 10px; background: var(--bg-2); font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace; font-size: 13px; white-space: pre-wrap; text-align: start; }
.bd-fb { margin: 0; font-size: 13px; color: var(--ink-2); }
.bd-sol, .bd-live { padding: 14px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2); display: grid; gap: 8px; }
.cal-wrap { overflow-x: auto; }
.cal-tbl { width: 100%; border-collapse: collapse; font-size: 14px; }
.cal-tbl th, .cal-tbl td { padding: 8px 10px; border-bottom: 1px solid var(--line); text-align: start; }
.cal-tbl th { font-size: 12px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
.cal-c { text-align: center !important; white-space: nowrap; }
.cal-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.cal-grid .field { margin: 0; padding: 10px 12px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); }
.cal-grid .field.right { border-color: var(--good); background: var(--good-soft); }
.cal-grid .field.wrong { border-color: var(--bad); background: var(--bad-soft); }
.cal-grid .field input { width: 100%; padding: 8px 10px; border-radius: 8px; border: 1px solid var(--line-2); background: var(--surface); }

/* temperature + energy */
.tp-bar { display: flex; align-items: center; gap: 12px; margin: 8px 0 12px; flex-wrap: wrap; }
.tp-bar input[type=range] { flex: 1 1 200px; max-width: 360px; }
.tp-val { font-variant-numeric: tabular-nums; min-width: 2.5em; direction: ltr; }
.tp-rows { display: grid; gap: 2px; }
.en-res { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 12px 0; }
.en-card { border: 1px solid var(--line-2); border-radius: 12px; padding: 10px 14px; background: var(--surface-2); }
.en-k { font-size: 12px; color: var(--ink-3); font-weight: 700; }
.en-v { font-size: 22px; font-weight: 700; font-variant-numeric: tabular-nums; }
.cal-tbl tr.en-on td { background: var(--accent-soft); }

/* rag + trace */
.rag-q { font-weight: 600; font-size: 17px; margin: 8px 0; padding: 10px 14px; border-radius: 12px; background: var(--accent-soft); }
.rag-ans { display: grid; gap: 10px; margin-top: 12px; }
.rag-prompt summary { cursor: pointer; font-size: 13px; color: var(--ink-3); font-weight: 600; }
.trace { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.trace-step { border: 1px solid var(--line-2); border-radius: 12px; padding: 10px 14px; background: var(--surface-2); }
.trace-step.human { border-color: var(--accent); background: var(--accent-soft); }
.trace-head { display: flex; flex-wrap: wrap; align-items: center; gap: 4px; margin-bottom: 4px; }
.trace-text { margin: 4px 0; white-space: pre-wrap; }

/* costcalc + sanitize (chapter 5) */
.cost-sample textarea { width: 100%; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--line-2); background: var(--surface-2); font: inherit; }
.cost-price { width: 90px; padding: 6px 8px; border-radius: 8px; border: 1px solid var(--line-2); background: var(--surface); }
.sz-box { padding: 14px 16px; border: 1px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2); line-height: 2; white-space: pre-wrap; }
.sz-seg { display: inline; padding: 2px 6px; margin: 0 1px; border-radius: 6px; border: 1px dashed var(--line-2); background: var(--surface); cursor: pointer; }
.sz-seg:hover, .sz-seg:focus-visible { border-color: var(--accent); outline: none; }
.sz-seg.on { background: var(--accent-soft); border-style: solid; border-color: var(--accent); font-weight: 650; }
.sz-seg.right { border-color: var(--good); background: var(--good-soft); }
.sz-seg.wrong { border-color: var(--bad); background: var(--bad-soft); }
.sz-out { white-space: pre-wrap; }