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.t{min-width:0;padding-top:1px}.qb-ch button[aria-disabled]{cursor:default}.qb-ch button.ok{border-color:#16a34a;background:#f0faf3}.qb-ch button.ok .k{background:#16a34a;border-color:#16a34a;color:#fff}.qb-ch button.no{border-color:#dc2626;background:#fef2f2}.qb-ch button.no .k{background:#dc2626;border-color:#dc2626;color:#fff}.qb-res{min-height:0;margin-top:10px!important;font-size:15px;font-weight:700}.qb-res:empty{display:none}.qb-q[data-done=ok] .qb-res{color:#15803d}.qb-q[data-done=no] .qb-res{color:#b91c1c}.qb-ex{margin-top:14px;border-top:1px solid var(--line)}.qb-ex summary{cursor:pointer;list-style:none;display:flex;justify-content:space-between;padding:12px 0;font-size:15px;font-weight:700;color:var(--blue)}.qb-ex summary::-webkit-details-marker{display:none}.qb-ex summary:after{content:"+";font-weight:400;color:var(--mute)}.qb-ex[open] summary:after{content:"\2212"}.qb-ans,.qb-ex>div{font-size:15.5px;line-height:1.7;color:var(--soft)}.qb-ans{margin-bottom:8px!important}.qb-ans b{color:var(--ink)}.qb-more{display:flex;flex-wrap:wrap;align-items:center;gap:6px 14px;margin-top:16px!important;font-size:14.5px}.qb-more a{font-weight:800;color:var(--blue)!important;text-decoration:underline;text-underline-offset:4px}.qb-more span{color:var(--mute)}.qb .katex{font-size:1.06em}.qb .katex-display{margin:.6em 0}.qb-steps{margin-top:28px!important;border-top:2px solid var(--ink);counter-reset:s}.qb-steps li{counter-increment:s;position:relative;padding:14px 0 14px 40px;border-bottom:1px solid var(--line);font-size:16px;line-height:1.55;color:var(--soft)}.qb-steps li:before{content:counter(s);position:absolute;left:0;top:14px;display:grid;place-items:center;width:26px;height:26px;border-radius:6px;background:var(--blue);color:#fff;font-size:13.5px;font-weight:800}.qb-steps b{color:var(--ink)}.qb-link{font-weight:800;color:var(--blue)!important;text-decoration:underline;text-underline-offset:4px;padding:0 8px}.qb-shot img{display:block;width:100%;height:auto;border-radius:8px;border:1px solid var(--line);box-shadow:0 30px 60px -36px rgba(10,18,64,.45)}.qb-shot figcaption{margin-top:12px;font-size:13.5px;color:var(--mute)}.qb-cmp table{width:100%;border-collapse:collapse;font-size:15.5px;line-height:1.5}.qb-cmp thead th{padding:0 14px 12px;border-bottom:2px solid var(--ink);text-align:left;font-size:15px;font-weight:800;vertical-align:bottom}.qb-cmp thead th:last-child{color:var(--blue)}.qb-cmp tbody th{padding:14px 14px 14px 0;text-align:left;font-weight:700;color:var(--ink);white-space:nowrap;vertical-align:top}.qb-cmp td{padding:14px;color:var(--soft);vertical-align:top}.qb-cmp tbody th,.qb-cmp td{border-bottom:1px solid var(--line)}.qb-cmp td:last-child{color:var(--ink);font-weight:600}.qb-cmp .sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}.qb-note{margin-top:18px!important;font-size:15px;line-height:1.65;color:var(--soft)}.qb-end .xl-h2{max-width:none}@media (max-width:860px){.qb-q.split .qb-q-b{grid-template-columns:minmax(0,1fr);gap:18px}.qb-q.split .qb-pass{padding-right:0;border-right:0}}@media (max-width:640px){.qb-practice{padding-top:72px}.qb-q{padding:26px 0 30px}.qb-q-h h4{font-size:18px}.qb-pass,.qb-stem{font-size:16px}.qb-ch button{font-size:15.5px}.qb-hero .xl-facts{gap:24px}.qb-hero .xl-facts b{font-size:24px}.qb-btn-ghost{min-height:48px}}@media (prefers-reduced-motion:reduce){.qb-ch button{transition:none}}.qb-hero .xl-h1{font-size:clamp(36px,3.6vw,52px)}@media (max-width:640px){.qb-cmp thead{display:none}.qb-cmp table,.qb-cmp tbody,.qb-cmp td,.qb-cmp th,.qb-cmp tr{display:block;width:100%}.qb-cmp tbody{border-top:2px solid var(--ink)}.qb-cmp tr{padding:14px 0;border-bottom:1px solid var(--line)}.qb-cmp tbody th,.qb-cmp td{padding:0;border:0;white-space:normal}.qb-cmp tbody th{margin-bottom:6px}.qb-cmp td{display:grid;grid-template-columns:104px minmax(0,1fr);gap:10px;padding:3px 0}.qb-cmp td:before{content:attr(data-l);font-size:13px;font-weight:700;color:var(--mute)}.qb-cmp td:last-child:before{color:var(--blue)}}