.qa-section{padding:52px 0 76px}.qa-heading{margin-bottom:32px}.qa-heading .back-link{display:inline-block;margin-bottom:30px}.qa-heading h1{font-size:var(--page-title-size);line-height:1.15;letter-spacing:-.035em;max-width:880px;margin:12px 0 20px}.qa-heading .lead{max-width:800px;font-size:18px;line-height:1.65;margin:0}
.qa-strip{overflow-x:auto;scroll-snap-type:x proximity;overscroll-behavior-x:contain;scrollbar-width:thin;padding:4px max(26px,calc((100vw - 1180px)/2)) 20px;scroll-padding-inline:max(26px,calc((100vw - 1180px)/2))}.qa-cards{display:grid;grid-template-columns:repeat(4,minmax(270px,1fr));gap:24px;list-style:none;padding:0;margin:0;min-width:1152px}.qa-card{scroll-snap-align:start;min-width:0}.qa-card h2{font-size:min(var(--page-title-size),19px);line-height:1.3;letter-spacing:-.025em;margin:20px 8px 12px}.qa-card>p{font-size:15px;line-height:1.65;color:var(--muted);margin:0 8px}
.qa-visual{width:100%;height:240px;border:1px solid var(--line);border-radius:21px;color:var(--text);position:relative;overflow:hidden;padding:18px 20px;cursor:pointer;text-align:center;box-shadow:0 10px 24px #183a6106}.qa-visual-0{background:linear-gradient(140deg,var(--blue),var(--surface))}.qa-visual-1{background:linear-gradient(140deg,var(--orange),var(--surface))}.qa-visual-2{background:linear-gradient(140deg,#e8e4f3,var(--surface))}.qa-visual-3{background:linear-gradient(140deg,#e2efe8,var(--surface))}.qa-visual:hover{border-color:var(--muted)}
.qa-visual-content{display:grid;grid-template-rows:164px 30px;gap:8px;width:100%;height:100%;align-content:center;justify-items:center}.qa-stage{width:100%;height:164px;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:12px}.qa-command{height:30px;display:inline-flex;align-items:center;justify-content:center;gap:6px;background:var(--surface);border:1px solid var(--line);border-radius:7px;padding:0 9px;font-size:11px;color:var(--muted);position:relative;white-space:nowrap}.qa-command svg{width:18px;height:18px}.qa-command.is-pressed{animation:qa-command-press .35s ease}
.qa-selection-sheet{width:100%;position:relative}.qa-sheet-top{background:var(--surface);border:1px solid var(--line);border-bottom:0;border-radius:7px 7px 0 0;padding:6px 9px;text-align:left;font-size:10px;color:var(--muted)}.qa-sheet-top span{display:inline-block;width:7px;height:7px;background:#218458;border-radius:2px;margin-right:7px}.qa-selection-grid{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));background:var(--surface);border:1px solid var(--line);overflow:hidden;border-radius:0 0 5px 5px}.qa-selection-grid>span{height:25px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);display:grid;place-items:center;font-size:8px;white-space:nowrap;position:relative;overflow:hidden}.qa-selection-grid>span.qa-hidden-row{height:5px;font-size:0;background:var(--line)}.qa-whole-selection{position:absolute;inset:26px 0 0;border:2px solid #218458;background:#2184580c;pointer-events:none}.qa-whole-selection::after{content:'';position:absolute;right:-4px;bottom:-4px;width:6px;height:6px;background:#218458}.qa-visual-0[data-phase=result] .qa-whole-selection{opacity:0;transition:opacity .2s}.qa-visual-0[data-phase=result] .qa-constant:not(.qa-hidden-row){box-shadow:inset 0 0 0 1.5px #218458;background:#21845812;transition:background .25s,box-shadow .25s}
.qa-sum-sheet{width:100%;display:grid;grid-template-columns:repeat(3,1fr);background:var(--surface);border:1px solid var(--line);border-radius:6px;overflow:hidden}.qa-sum-sheet>span{height:31px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);display:grid;place-items:center;font-size:11px}.qa-sum-selected{box-shadow:inset 0 0 0 1.5px #218458;background:#2184580c}.qa-result{height:36px;display:flex;align-items:center;gap:9px;font-size:20px;color:var(--accent);opacity:0;transform:translateY(4px)}.qa-result strong{font-size:29px;letter-spacing:-.04em}.qa-visual-1[data-phase=result] .qa-result,.qa-visual-1[data-phase=copied] .qa-result{opacity:1;transform:none;transition:opacity .3s,transform .3s}.qa-copied{display:none;align-items:center;gap:6px}.qa-visual-1[data-phase=copied] .qa-copy-label{display:none}.qa-visual-1[data-phase=copied] .qa-copied{display:flex;color:var(--accent)}
.qa-format-cell{height:94px;width:100%;background:var(--surface);border:1px solid var(--line);border-radius:8px;display:grid;place-items:center}.qa-format-cell>span{grid-area:1/1;font-size:42px;font-weight:650;letter-spacing:-.04em;font-variant-numeric:tabular-nums;opacity:0;transition:opacity .15s}.qa-format-cell .qa-format-raw{opacity:1}.qa-visual-2[data-step] .qa-format-raw{opacity:0}.qa-visual-2[data-step="0"] .qa-format-raw,.qa-visual-2[data-step="1"] .qa-format-percent,.qa-visual-2[data-step="2"] .qa-format-rounded,.qa-visual-2[data-step="3"] .qa-format-final{opacity:1}.qa-format-final{color:var(--accent)}
.qa-width-pair{display:grid;grid-template-columns:1fr 1fr;width:100%;gap:10px}.qa-width-sheet{background:var(--surface);border:1px solid var(--line);border-radius:8px;overflow:hidden}.qa-width-sheet>strong{font-size:10px;font-weight:650;display:block;padding:10px 3px;border-bottom:1px solid var(--line)}.qa-columns{display:grid;grid-template-columns:1.6fr 1fr .65fr}.qa-columns span{height:26px;display:grid;place-items:center;font-size:9px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);min-width:0;overflow:hidden}.qa-columns span:nth-child(-n+3){background:var(--blue);color:var(--muted);font-weight:650}.qa-width-target .qa-columns{grid-template-columns:.65fr 1.8fr .8fr}.qa-width-target .qa-columns span:nth-child(-n+3){color:var(--accent);background:var(--orange)}.qa-visual-3[data-phase=result] .qa-width-target .qa-columns{grid-template-columns:1.6fr 1fr .65fr;transition:grid-template-columns .75s ease}
.qa-controls{display:flex;justify-content:flex-end;gap:10px;margin-top:12px}.qa-controls[hidden]{display:none}.qa-controls button{width:39px;height:39px;border:1px solid var(--line);border-radius:50%;color:var(--text);background:var(--surface);font-size:20px;cursor:pointer}.qa-controls button:disabled{opacity:.35;cursor:default}
.qa-stage{position:relative}.qa-visual-1 .qa-sum-sheet{position:absolute;top:50%;transform:translateY(-50%)}.qa-visual-1 .qa-result{position:absolute;top:calc(50% + 51px);height:29px}.qa-visual-1 .qa-result strong{font-size:25px}
@keyframes qa-command-press{0%,100%{transform:none;background:var(--surface);border-color:var(--line)}40%{transform:scale(.96);background:var(--orange);border-color:var(--accent);color:var(--accent)}}
:root[data-theme=dark] .qa-visual-2{background:linear-gradient(140deg,#302b45,var(--surface))}:root[data-theme=dark] .qa-visual-3{background:linear-gradient(140deg,#223c33,var(--surface))}
@media(max-width:760px){.qa-section{padding:32px 0 60px}.qa-heading{margin-bottom:27px}.qa-heading .back-link{margin-bottom:22px}.qa-heading .lead{font-size:16px}.qa-strip{padding-inline:16px;scroll-padding-inline:16px}.qa-cards{grid-template-columns:repeat(4,280px);min-width:1192px;gap:24px}.qa-card h2{font-size:min(var(--page-title-size),19px)}.qa-card>p{font-size:14px}}
.qa-heading{margin-bottom:18px}
.qa-tools{padding-top:70px}.qa-tools .trace-demo{width:100%}
.qa-tools .trace-demos{align-self:start;margin-top:46px}
@media(max-width:760px){.qa-tools{padding-top:50px}.qa-tools .trace-demos{margin-top:0}}
.qa-interaction-hint{display:flex;align-items:center;gap:7px;min-height:23px;margin-bottom:13px;color:var(--accent);font-size:13px;font-weight:700;animation:qa-hint-pulse 3s ease-in-out infinite}
.qa-interaction-hint svg{width:19px;height:19px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.qa-interaction-hint.is-dismissed{color:var(--muted);font-weight:400;animation:none;opacity:1}
@keyframes qa-hint-pulse{0%,75%,100%{opacity:.75}25%,45%{opacity:1}}
.qa-visual{transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}
@media(hover:hover){.qa-visual:hover{transform:translateY(-2px);box-shadow:0 12px 28px #183a6114}}
.qa-helper-section{padding:66px 0 76px;border-top:1px solid var(--line)}
.qa-helper-section .section-heading{margin-bottom:34px}
.qa-helper-strip{overflow-x:auto;scroll-snap-type:x proximity;overscroll-behavior-x:contain;scrollbar-width:thin;padding:4px max(26px,calc((100vw - 1180px)/2)) 20px;scroll-padding-inline:max(26px,calc((100vw - 1180px)/2))}
.qa-helper-cards{--qa-helper-height:190px;display:grid;grid-template-columns:repeat(3,minmax(210px,1fr)) calc(var(--qa-helper-height)*630/278);gap:24px;list-style:none;margin:0;padding:0;min-width:1133px}
.qa-helper-card{min-width:0;scroll-snap-align:start}.qa-helper-card h3{font-size:min(var(--page-title-size),19px);line-height:1.3;letter-spacing:-.025em;margin:20px 8px 12px}.qa-helper-card>p{font-size:14px;line-height:1.65;color:var(--muted);margin:0 8px}
.qa-helper-visual{height:var(--qa-helper-height);border:1px solid var(--line);border-radius:18px;padding:10px;display:flex;align-items:center;justify-content:center;background:var(--surface)}
.qa-helper-visual-0{background:linear-gradient(135deg,var(--blue),var(--surface))}.qa-helper-visual-1{background:linear-gradient(135deg,var(--orange),var(--surface))}.qa-helper-visual-2{background:linear-gradient(135deg,var(--blue),var(--surface))}
.qa-helper-states{display:flex;flex-direction:column;gap:14px;width:100%}.qa-helper-tab-states{gap:24px}.qa-state-label{display:block;margin-bottom:5px;font-size:10px;color:var(--muted);font-weight:600;text-align:left}
.qa-helper-tabs{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:3px;border-top:1px solid var(--line);padding-top:7px}
.qa-helper-tabs>span{font-size:10px;padding:8px 2px;border:1px solid var(--line);border-radius:5px;background:var(--surface);text-align:center;white-space:nowrap}
.qa-helper-tabs .qa-tab-hidden{border-style:dashed;color:var(--muted);background:transparent}.qa-helper-tabs .qa-tab-revealed{color:var(--accent);background:var(--orange);border-color:var(--accent)}
.qa-name-manager{border:1px solid var(--line);border-radius:5px;overflow:hidden;background:var(--surface)}.qa-name-manager>div{display:grid;grid-template-columns:1fr 1.35fr;gap:5px;min-height:16px;padding:2px 5px;font-size:8px;border-bottom:1px solid var(--line)}.qa-name-manager>div:last-child{border-bottom:0}.qa-name-manager span{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.qa-name-header{background:var(--blue);font-weight:650}.qa-name-manager .qa-name-hidden{opacity:.4;border-top:1px dashed var(--muted)}.qa-name-manager .qa-name-revealed{color:var(--accent);background:var(--orange)}
.qa-helper-page-pair{width:100%;display:grid;grid-template-columns:1fr 1fr;gap:10px}.qa-page-sheet{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--line);border-radius:5px;overflow:hidden;position:relative;background:var(--surface)}.qa-page-sheet>span:not(.qa-page-break){height:22px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);font-size:8px;display:grid;place-items:center;color:var(--muted)}.qa-page-sheet>span:nth-child(-n+4){background:var(--blue)}.qa-page-break{position:absolute;pointer-events:none}.qa-page-break-v{height:100%;left:52%;top:0;border-left:1.5px dashed var(--muted)}.qa-page-break-h{width:100%;left:0;top:56%;border-top:1.5px dashed var(--muted)}
.qa-helper-visual-1 .qa-helper-states{gap:8px}.qa-helper-visual-1 .qa-state-label,.qa-name-manager>div{line-height:1.2}
.qa-helper-states{max-width:204px}.qa-helper-page-pair{max-width:204px}.qa-page-sheet{--qa-page-row-height:22px;grid-template-columns:repeat(3,1fr)}.qa-page-sheet>span:nth-child(4){background:var(--surface)}
.qa-page-break-v{left:calc(100% / 3 - 1px)}.qa-page-break-h{top:calc(var(--qa-page-row-height) * 3 - 1px)}
.qa-helper-settings .qa-helper-visual{padding:0;border:0;border-radius:0;overflow:hidden;background:var(--surface)}.qa-helper-settings img{display:block;width:100%;height:auto;max-width:630px;object-fit:contain}
@media(max-width:760px){.qa-helper-section{padding:50px 0 55px}.qa-helper-strip{padding-inline:16px;scroll-padding-inline:16px}.qa-helper-cards{--qa-helper-height:calc(min(430px,100vw - 32px)*278/630);grid-template-columns:repeat(3,260px) min(430px,calc(100vw - 32px));width:max-content;min-width:0}.qa-helper-card>p{font-size:14px}.qa-helper-section .section-heading{margin-bottom:27px}}
@media(prefers-reduced-motion:reduce){.qa-visual,.qa-visual *{animation:none!important;transition:none!important}.qa-interaction-hint{animation:none}}