/* interactive demos (js/widgets) */
.widget { border-radius: var(--radius-card); background: var(--ground); padding: 16px; display: flex; flex-direction: column; gap: 14px; }
.w-head h5 { margin: 0; font: 500 14px var(--font); }
.w-head p { font-size: 13px; color: var(--muted); margin-top: 2px; }
.w-note { font-size: 13px; color: var(--text); }
.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 8px; }
fieldset { margin: 0; padding: 10px 12px 12px; border: 1px solid var(--border); border-radius: var(--radius-control); background: var(--surface); display: grid; grid-template-columns: minmax(0, 1fr) 84px; gap: 6px 8px; align-items: center; min-width: 0; }
legend { font: 500 13px var(--font); padding: 0 4px; }
label { font-size: var(--fs-small); color: var(--muted); }
.field { display: flex; align-items: center; gap: 4px; font-size: 13px; color: var(--muted); }
.field input { width: 100%; min-width: 0; height: 30px; font: 400 13px var(--font); font-variant-numeric: tabular-nums; text-align: right; padding: 0 6px; border-radius: var(--radius-control); border: 1px solid var(--control); background: var(--surface); color: var(--text); }
input[type="range"] { width: 100%; accent-color: var(--text); }
.slider-row { display: grid; grid-template-columns: 110px minmax(0, 1fr) 64px; gap: 12px; align-items: center; }
.slider-row .num { text-align: right; }
@media (max-width: 520px) { .slider-row { grid-template-columns: minmax(0, 1fr) 64px; } .slider-row input { grid-column: 1 / -1; grid-row: 2; } }

.rank { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; }
.rank li { display: grid; grid-template-columns: 22px 96px minmax(0, 1fr) 70px; gap: 10px; align-items: center; min-height: 40px; border-top: 1px solid var(--rule); font-size: 13px; }
.rank li:first-child { border-top: 0; }
.rank .pos { color: var(--muted); font-variant-numeric: tabular-nums; }
.rank .nm { white-space: nowrap; }
.rank .bar { height: 8px; border-radius: 4px; background: var(--edge); }
.rank li.win .bar { background: var(--hue); }
.rank .val { text-align: right; font-variant-numeric: tabular-nums; }
.rank .calc { grid-column: 3 / -1; font-size: var(--fs-small); color: var(--muted); margin-top: -8px; padding-bottom: 6px; }
.win-tag { font-size: 11px; font-weight: 500; color: var(--pill-positive-ink); background: var(--pill-positive-bg); border-radius: 4px; padding: 1px 6px; margin-left: 4px; white-space: nowrap; }
@media (max-width: 760px) { .rank li { grid-template-columns: 18px 76px minmax(0, 1fr) 62px; } }

.outcomes { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 8px; }
.outcome { background: var(--surface); border-radius: var(--radius-control); border: 1px solid var(--border); padding: 12px 14px; display: flex; flex-direction: column; gap: 2px; font-size: 13px; }
.outcome .label { font-size: var(--fs-small); color: var(--muted); }
.outcome .big { font-size: 22px; font-variant-numeric: tabular-nums; }
.pos-v { color: var(--positive); } .neg-v { color: var(--negative); } .zero-v { color: var(--muted); }

.chart { width: 100%; height: auto; display: block; }
.chart .grid-l { stroke: var(--border); }
.chart .base { stroke: var(--control); }
.chart .lbl { fill: var(--muted); font: 400 11px var(--font); }
.chart .curve { stroke: var(--hue); fill: none; stroke-width: 2; }
.chart .marker { fill: var(--text); }
.chart .guide { stroke: var(--text); stroke-dasharray: 3 3; opacity: .5; }

/* quiz */
.quiz { display: flex; flex-direction: column; gap: 18px; }
.q { display: flex; flex-direction: column; gap: 8px; }
.q-text { font-size: 14px; font-weight: 500; }
.opts { display: flex; flex-wrap: wrap; gap: 6px; }
.opt { font: 400 13px var(--font); min-height: 32px; padding: 6px 12px; border-radius: var(--radius-control); border: 1px solid var(--control); background: var(--surface); color: var(--text); cursor: pointer; text-align: left; }
.opt:hover:not(:disabled) { background: var(--raised); }
.opt.right { background: var(--pill-positive-bg); color: var(--pill-positive-ink); border-color: transparent; }
.opt.wrong { color: var(--negative); border-color: var(--negative); }
.opt:disabled { cursor: default; }
.expl { font-size: 13px; color: var(--muted); }

/* relevance + quality score demos */
.rel-table td { vertical-align: middle; }
.rel-table tr.pick td { background: var(--hue-soft); }
.cellbar { white-space: nowrap; text-align: right; }
.rel-table th:nth-child(n+3) { text-align: right; }
.mini { display: inline-block; width: 64px; height: 6px; border-radius: 3px; background: var(--border); overflow: hidden; vertical-align: middle; margin-right: 8px; }
.mini span { display: block; height: 100%; background: var(--muted); }
.cellbar.m .mini span { background: var(--hue); }
.qs-bar { display: flex; height: 14px; border-radius: 4px; overflow: hidden; background: var(--border); }
.qs-bar span { height: 100%; transition: width .2s; }
.qs-bar .b0, .qs-legend .b0 { background: var(--muted); }
.qs-bar .b1, .qs-legend .b1 { background: var(--hue); }
.qs-bar .b2, .qs-legend .b2 { background: var(--text); }
.qs-bar .b3, .qs-legend .b3 { background: var(--edge); }
.qs-legend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: var(--fs-small); color: var(--muted); }
.qs-legend span { display: inline-flex; align-items: center; gap: 6px; }
.qs-legend i { width: 10px; height: 10px; border-radius: 2px; display: inline-block; }

/* CPC demos */
.pricebar { position: relative; height: 12px; border-radius: 6px; background: var(--border); }
.pb-paid { position: absolute; left: 0; top: 0; bottom: 0; border-radius: 6px; background: var(--hue); transition: width .2s; }
.pb-mark { position: absolute; top: -4px; width: 2px; height: 20px; background: var(--text); transform: translateX(-1px); transition: left .2s; }
.pb-labels { display: flex; justify-content: space-between; font-size: var(--fs-small); color: var(--muted); margin-top: -8px; }
.prose .funnel, .funnel { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 22px; }
.funnel li { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-control); padding: 12px 14px; display: flex; flex-direction: column; gap: 2px; font-size: 12px; color: var(--muted); min-width: 0; }
.funnel .label { font-size: var(--fs-small); }
.funnel .big { font-size: 22px; color: var(--text); font-variant-numeric: tabular-nums; }
.funnel li:not(:last-child)::after { content: "→"; position: absolute; right: -16px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: 14px; }
@media (max-width: 640px) { .prose .funnel { grid-template-columns: repeat(2, minmax(0, 1fr)); } .funnel li::after { display: none; } }

/* pCTR demo */
.ctl-list { display: flex; flex-direction: column; gap: 8px; }
.sel { height: 30px; border-radius: var(--radius-control); border: 1px solid var(--control); background: var(--surface); color: var(--text); font: 400 13px var(--font); padding: 0 8px; width: 100%; min-width: 0; }
.chk input { width: 18px; height: 18px; accent-color: var(--text); }
.contrib { display: flex; flex-direction: column; gap: 6px; padding: 12px 14px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-control); }
.crow { display: grid; grid-template-columns: minmax(0, 200px) minmax(0, 1fr) 44px; gap: 10px; align-items: center; font-size: 13px; }
.cl { color: var(--muted); }
.ctrack { position: relative; height: 10px; }
.ctrack::before { content: ""; position: absolute; left: 50%; top: -3px; bottom: -3px; width: 1px; background: var(--control); }
.cbar { position: absolute; top: 0; height: 100%; border-radius: 2px; transition: width .2s, left .2s; }
.cbar.up { background: var(--hue); }
.cbar.down { background: var(--edge); }
.cv { text-align: right; }
.pctr-out { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
@media (max-width: 520px) { .crow { grid-template-columns: minmax(0, 1fr) 44px; } .ctrack { grid-column: 1 / -1; grid-row: 2; } }

/* AdX simulator */
.flow { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)) minmax(0, 1.3fr); gap: 26px; align-items: center; }
.fnode { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-control); padding: 9px 11px; display: flex; flex-direction: column; gap: 1px; font-size: 13px; line-height: 1.35; min-width: 0; transition: border-color .25s, background .25s, opacity .25s; }
.fnode b { font-weight: 500; }
.fnode span { font-size: var(--fs-small); color: var(--muted); }
.fnode:not(.buyer)::after { content: "→"; position: absolute; right: -19px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: 13px; }
.fnode.on { border-color: var(--hue); background: var(--hue-soft); }
.fbuyers { display: flex; flex-direction: column; gap: 8px; min-width: 0; }
.buyer .bid { font-variant-numeric: tabular-nums; }
.buyer.out { opacity: .5; }
.buyer.out .bid { text-decoration: line-through; }
.buyer.win { border-color: var(--hue); }
.buyer.win .bid { color: var(--hue); font-weight: 500; }
.tl { display: flex; flex-direction: column; gap: 4px; }
.tl-bar { height: 6px; border-radius: 3px; background: var(--border); overflow: hidden; }
.tl-fill { display: block; height: 100%; width: 0; background: var(--hue); transition: width .5s; }
.tl-labels { display: flex; justify-content: space-between; font-size: var(--fs-small); color: var(--muted); }
.prose .fsteps, .fsteps { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; }
.fsteps li { display: grid; grid-template-columns: 56px minmax(0, 1fr); gap: 10px; padding: 6px 8px; border-radius: var(--radius-control); font-size: 13px; line-height: 1.5; color: var(--muted); transition: background .2s, color .2s; }
.fsteps li.done { color: var(--text); }
.fsteps li.cur { color: var(--text); background: var(--surface); }
.fsteps li.cur .ms { color: var(--hue); font-weight: 500; }
.ctrls { display: flex; gap: 8px; flex-wrap: wrap; }
.btn-sm { height: 32px; font-size: 13px; padding: 0 12px; }
@media (max-width: 760px) {
  .flow { grid-template-columns: minmax(0, 1fr); gap: 22px; }
  .fnode:not(.buyer)::after { content: "↓"; right: auto; left: 50%; top: auto; bottom: -19px; transform: translateX(-50%); }
  .fsteps li { grid-template-columns: 48px minmax(0, 1fr); }
}

/* truthful bidding strip (Vickrey page) */
.tstrip { position: relative; height: 28px; border-radius: var(--radius-control); background: var(--border); overflow: hidden; }
.tstrip span { position: absolute; top: 0; bottom: 0; transition: left .2s, width .2s; }
.tstrip .same, .tlegend .same { background: var(--edge); }
.tstrip .loss, .tlegend .loss { background: var(--negative); }
.tstrip .miss, .tlegend .miss { background: var(--pill-warning-ink); }
.tstrip .tmark { width: 2px; margin-left: -1px; background: var(--text); }
.tstrip-axis { position: relative; height: 16px; margin-top: -8px; font-size: var(--fs-small); color: var(--muted); }
.tstrip-axis span { position: absolute; transform: translateX(-50%); }
.tstrip-axis span:first-child { transform: none; }
.tstrip-axis span:last-child { transform: translateX(-100%); }
.tlegend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: var(--fs-small); color: var(--muted); }
.tlegend span { display: inline-flex; align-items: center; gap: 6px; }
.tlegend i { width: 10px; height: 10px; border-radius: 2px; display: inline-block; }

/* logistic regression trainer */
.lr-weights { display: flex; flex-direction: column; gap: 6px; padding: 12px 14px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-control); }
.lw-row { display: grid; grid-template-columns: minmax(0, 190px) minmax(0, 1fr) 96px; gap: 10px; align-items: center; font-size: 13px; }
.tmarker { position: absolute; top: -4px; bottom: -4px; width: 2px; margin-left: -1px; background: var(--text); transition: left .2s; }
.tlegend .lw { background: var(--hue); }
.tlegend .tw { background: var(--text); width: 3px; }
@media (max-width: 520px) { .lw-row { grid-template-columns: minmax(0, 1fr) 96px; } .lw-row .ctrack { grid-column: 1 / -1; grid-row: 2; } }