@keyframes _si{from{opacity:0}to{opacity:1}}

.legacy-content .lesson-header .kicker {color:var(--ds)}.legacy-content .l-callout b {color:var(--ds)}.legacy-content .btn-ds {background:var(--ds);color:#fff;border:none;padding:10px 26px;border-radius:999px;font-size:14px;font-weight:800;cursor:pointer;font-family:inherit;transition:filter .15s,transform .15s}.legacy-content .btn-ds:hover:not(:disabled) {filter:brightness(1.08);transform:translateY(-1px)}.legacy-content .btn-ds:disabled {background:#c4c8cf;cursor:not-allowed}.legacy-content .hint-line {font-size:12.5px;color:var(--sub);font-weight:600;margin-top:10px}.legacy-content .hint-line b {color:var(--amber)}.legacy-content .hash-lab {position:relative;background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);padding:20px 22px;overflow:hidden}.legacy-content .hl-names {display:flex;flex-wrap:wrap;gap:9px;margin-bottom:16px}.legacy-content .name-chip {border:1.5px solid var(--border);background:var(--card);border-radius:999px;padding:7px 18px;font-size:14px;font-weight:800;color:var(--text);cursor:pointer;font-family:inherit;transition:all .15s}.legacy-content .name-chip:hover:not(:disabled) {border-color:var(--ds-line);transform:translateY(-1px)}.legacy-content .name-chip.active {background:var(--ds);border-color:var(--ds);color:#fff}.legacy-content .name-chip.stored {opacity:.45}.legacy-content .name-chip:disabled {cursor:not-allowed}.legacy-content .hl-machine {background:rgba(0,0,0,.03);border:1.5px dashed var(--border);border-radius:var(--radius-sm);padding:14px 18px;min-height:118px;margin-bottom:18px}.legacy-content .hl-machine-title {font-size:11.5px;font-weight:800;letter-spacing:.6px;color:var(--sub);margin-bottom:8px}.legacy-content .hl-line {font-family:"SF Mono","Fira Code",Menlo,monospace;font-size:15px;font-weight:700;color:var(--text);min-height:26px;line-height:26px;opacity:0;transition:opacity .3s}.legacy-content .hl-line.show {opacity:1}.legacy-content .hl-line .num {color:var(--ds-deep);font-variant-numeric:tabular-nums}.legacy-content .hl-line .op {color:var(--sub);margin:0 4px}.legacy-content .hl-line .bucket-no {color:#fff;background:var(--ds);padding:1px 10px;border-radius:7px}.legacy-content .hl-buckets {display:grid;grid-template-columns:repeat(8,1fr);gap:8px}.legacy-content .bucket {display:flex;flex-direction:column;align-items:center;gap:6px}.legacy-content .bucket-label {font-size:11px;font-weight:800;color:var(--sub);font-variant-numeric:tabular-nums}.legacy-content .bucket-slot {width:100%;min-height:96px;border:1.5px solid var(--border);border-top:none;border-radius:0 0 10px 10px;background:rgba(0,0,0,.02);display:flex;flex-direction:column-reverse;align-items:center;gap:4px;padding:6px 3px;transition:border-color .2s,background .2s,box-shadow .2s;position:relative}.legacy-content .bucket-slot::before {content:'';position:absolute;top:0;left:-1.5px;right:-1.5px;height:3px;background:var(--border);border-radius:3px}.legacy-content .bucket.lit .bucket-slot {border-color:var(--ds);background:var(--ds-soft);box-shadow:0 0 0 2px var(--ds-line)}.legacy-content .bucket.lit .bucket-label {color:var(--ds)}.legacy-content .hl-chip {font-size:12px;font-weight:800;color:#fff;background:var(--ds);border-radius:999px;padding:3px 9px;white-space:nowrap;animation:chipIn .3s ease}.legacy-content .hl-chip.chained {background:var(--amber);position:relative}.legacy-content .hl-chip.chained::after {content:'';position:absolute;left:50%;bottom:-5px;width:2px;height:5px;background:var(--amber)}.legacy-content .hl-chip.hit {box-shadow:0 0 0 2.5px rgba(22,163,74,.6)}.legacy-content .hl-chip.miss {box-shadow:0 0 0 2.5px rgba(220,38,38,.5)}@keyframes chipIn{from{transform:scale(.4);opacity:0}to{transform:scale(1);opacity:1}}.legacy-content .hl-ball {position:absolute;z-index:5;font-size:13px;font-weight:800;color:#fff;background:var(--ds);border-radius:999px;padding:5px 13px;box-shadow:var(--shadow-pop);transform:translate(-50%,-50%);transition:left .65s cubic-bezier(.3,.7,.4,1),top .65s cubic-bezier(.3,.7,.4,1);pointer-events:none;white-space:nowrap}.legacy-content .hl-status {font-size:12.5px;color:var(--sub);font-weight:600;margin-top:12px;min-height:20px}.legacy-content .hl-status b {color:var(--ds-deep)}.legacy-content .crash-box {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);padding:20px 22px;position:relative;overflow:hidden}.legacy-content .crash-steps {display:flex;gap:10px;flex-wrap:wrap;margin-bottom:16px}.legacy-content .crash-formula {font-family:"SF Mono","Fira Code",Menlo,monospace;font-size:14px;font-weight:700;color:var(--text);background:rgba(0,0,0,.03);border-radius:var(--radius-sm);padding:11px 16px;margin-bottom:16px;min-height:44px;opacity:0;transition:opacity .3s}.legacy-content .crash-formula.show {opacity:1}.legacy-content .crash-formula .num {color:var(--ds-deep)}.legacy-content .crash-formula .warn {color:var(--danger);font-weight:800}.legacy-content .crash-count {font-size:13px;font-weight:700;color:var(--sub);margin-top:12px;min-height:20px}.legacy-content .crash-count b {font-size:19px;font-weight:900;color:var(--text);font-variant-numeric:tabular-nums}.legacy-content .crash-count.done b {color:var(--success)}.legacy-content .crash-verdict {margin-top:14px;padding:14px 18px;background:var(--ds-soft);border:1.5px dashed var(--ds-line);border-radius:var(--radius-sm);font-size:13.5px;line-height:1.8;color:var(--sub);opacity:0;transform:translateY(6px);transition:opacity .35s,transform .35s}.legacy-content .crash-verdict.show {opacity:1;transform:translateY(0)}.legacy-content .crash-verdict b {color:var(--ds-deep)}.legacy-content .race-box {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);padding:20px 22px}.legacy-content .race-sizes {display:flex;gap:9px;flex-wrap:wrap;margin-bottom:18px;align-items:center}.legacy-content .race-sizes .lbl {font-size:13px;font-weight:800;color:var(--text);margin-right:2px}.legacy-content .size-chip {border:1.5px solid var(--border);background:var(--card);border-radius:999px;padding:6px 18px;font-size:13.5px;font-weight:800;color:var(--text);cursor:pointer;font-family:inherit;transition:all .15s}.legacy-content .size-chip.active {background:var(--ds);border-color:var(--ds);color:#fff}.legacy-content .race-lane {border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:14px 16px;margin-bottom:10px}.legacy-content .race-lane-head {display:flex;align-items:baseline;justify-content:space-between;gap:10px;margin-bottom:8px;flex-wrap:wrap}.legacy-content .race-lane-head h5 {font-size:14px;font-weight:800;color:var(--text)}.legacy-content .race-cnt {font-size:12.5px;font-weight:700;color:var(--sub)}.legacy-content .race-cnt b {font-size:20px;font-weight:900;font-variant-numeric:tabular-nums}.legacy-content .race-lane.slow .race-cnt b {color:var(--danger)}.legacy-content .race-lane.fast .race-cnt b {color:var(--success)}.legacy-content .race-track {height:12px;border-radius:7px;background:rgba(0,0,0,.05);overflow:hidden}.legacy-content .race-fill {height:100%;border-radius:7px;width:0}.legacy-content .race-lane.slow .race-fill {background:var(--danger)}.legacy-content .race-lane.fast .race-fill {background:var(--success)}.legacy-content .race-done {font-size:12px;font-weight:800;margin-top:6px;min-height:18px}.legacy-content .race-lane.slow .race-done {color:var(--danger)}.legacy-content .race-lane.fast .race-done {color:var(--success)}.legacy-content .race-controls {display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-top:6px}.legacy-content .race-verdict {margin-top:14px;padding:14px 18px;background:var(--ds-soft);border:1.5px dashed var(--ds-line);border-radius:var(--radius-sm);font-size:13.5px;line-height:1.8;color:var(--sub);opacity:0;transform:translateY(6px);transition:opacity .35s,transform .35s}.legacy-content .race-verdict.show {opacity:1;transform:translateY(0)}.legacy-content .race-verdict b {color:var(--ds-deep)}.legacy-content .ai-grid {display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.legacy-content .ai-card {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);padding:16px 16px;box-shadow:var(--shadow-card)}.legacy-content .ai-card .ic {font-size:24px;margin-bottom:7px}.legacy-content .ai-card h4 {font-size:14px;font-weight:800;color:var(--text);margin-bottom:5px}.legacy-content .ai-card p {font-size:12.5px;color:var(--sub);line-height:1.7}.legacy-content .ai-card p b {color:var(--ds-deep)}.legacy-content .takeaway-box {background:linear-gradient(135deg,#f0f9ff,#e0f2fe);border:1.5px solid #bae6fd;border-radius:var(--radius);padding:24px 28px;margin-top:36px}.legacy-content .takeaway-box h3 {font-size:17px;font-weight:800;color:var(--ds-deep);margin-bottom:10px}.legacy-content .takeaway-box ul {list-style:none;padding:0;margin:0}.legacy-content .takeaway-box li {font-size:14.5px;color:#0c4a6e;line-height:1.8;padding:4px 0 4px 22px;position:relative}.legacy-content .takeaway-box li::before {content:'';position:absolute;left:0;top:13px;width:8px;height:8px;border-radius:50%;background:var(--ds)}@media (max-width:768px){.legacy-content .hl-buckets {gap:5px}.legacy-content .bucket-slot {min-height:82px}.legacy-content .hl-chip {font-size:10.5px;padding:2px 6px}.legacy-content .ai-grid {grid-template-columns:1fr 1fr}.legacy-content .hl-line {font-size:12.5px}.legacy-content .crash-formula {font-size:12px}}

.legacy-content .xa-tldr {margin:18px 0 4px;padding:14px 18px;background:rgba(0,102,255,0.04);border:1px solid rgba(0,102,255,0.16);border-radius:10px}.legacy-content .xa-tldr .xa-tldr-tag {display:block;font-size:11px;font-weight:800;letter-spacing:1px;color:var(--accent,#0066ff);margin-bottom:6px}.legacy-content .xa-tldr p {margin:0;font-size:15px;line-height:1.8;color:var(--text,#1f2937)}