.lv4{--l-canvas:hsl(var(--background));--l-surface:hsl(var(--card));--l-sunken:hsl(var(--surface-sunken));--l-border:hsl(var(--border));--l-border-strong:hsl(var(--border-strong));--l-text:hsl(var(--foreground));--l-muted:hsl(var(--muted-foreground));--l-subtle:hsl(var(--text-subtle));--l-ink:hsl(var(--primary));--l-on-ink:hsl(var(--primary-foreground));--l-accent:hsl(var(--brand));--l-accent-hover:hsl(var(--brand-hover));--l-on-accent:hsl(var(--brand-foreground));--l-accent-text:hsl(var(--brand-text));--l-accent-soft:hsl(var(--brand-soft));--l-success:hsl(var(--success));--l-success-soft:hsl(var(--success-soft));--l-warning:hsl(var(--warning));--l-warning-soft:hsl(var(--warning-soft));--l-danger:hsl(var(--destructive));--l-danger-soft:hsl(var(--danger-soft));--l-focus:hsl(var(--ring));--l-cursor:hsl(var(--brand-cursor));--l-claude:hsl(var(--provider-claude));--l-openai:hsl(var(--provider-openai));--l-gemini:hsl(var(--provider-gemini));--l-gutter:clamp(16px, 4vw, 40px);background:var(--l-canvas);color:var(--l-text);font:400 16px / 1.55 var(--font-sans);-webkit-font-smoothing:antialiased;overflow-x:clip}.lv4 :focus-visible{outline:2px solid var(--l-focus);outline-offset:2px}@layer base{.lv4 a{color:inherit;text-decoration:none}.lv4 h1,.lv4 h2,.lv4 p,.lv4 ul{margin:0;padding:0}.lv4 ul{list-style:none}}.lv4-btn{height:var(--control-lg);border-radius:var(--radius-md);font:500 15px / 1 var(--font-sans);cursor:pointer;white-space:nowrap;color:inherit;transition:background var(--duration-fast), opacity var(--duration-fast);background:0 0;border:1px solid #0000;align-items:center;gap:8px;padding:0 18px;display:inline-flex}.lv4-btn-sm{height:var(--control-md);padding:0 12px;font-size:14px}.lv4-btn-ink{background:var(--l-ink);color:var(--l-on-ink)}.lv4-btn-ink:hover{opacity:.88}.lv4-btn-accent{background:var(--l-accent);color:var(--l-on-accent)}.lv4-btn-accent:hover{background:var(--l-accent-hover)}.lv4-btn-ghost{border-color:var(--l-border-strong);background:0 0}.lv4-btn-ghost:hover{background:var(--l-sunken)}.lv4-btn:disabled{opacity:.5;cursor:default}.lv4-eyebrow{font:500 12px / 1 var(--font-mono);letter-spacing:.09em;text-transform:uppercase;color:var(--l-accent-text)}.lv4-chip{border-radius:var(--radius-full);height:22px;font:500 12px / 1 var(--font-sans);background:var(--l-sunken);color:var(--l-muted);border:1px solid var(--l-border);align-items:center;gap:6px;padding:0 8px;display:inline-flex}.lv4-chip.ok{background:var(--l-success-soft);color:var(--l-success);border-color:#0000}.lv4-chip.warn{background:var(--l-warning-soft);color:var(--l-warning);border-color:#0000}.lv4-chip.acc{background:var(--l-accent-soft);color:var(--l-accent-text);border-color:#0000}.lv4-logo{color:var(--l-muted);align-items:center;display:inline-flex}.lv4-logo svg{width:16px;height:16px;display:block}@keyframes lv4-blink{50%{opacity:0}}.lv4-note{font:400 12px var(--font-mono);color:var(--l-subtle)}.lv4-hero{min-height:calc(100svh - 64px);padding:48px var(--l-gutter);flex-direction:column;justify-content:center;max-width:1240px;margin:0 auto;display:flex;position:relative}.lv4-hero h1{letter-spacing:-.04em;max-width:14ch;margin:0 0 24px;font-size:clamp(38px,5.2vw,78px);font-weight:600;line-height:1}.lv4-hero p{max-width:56ch;color:var(--l-muted);font-size:19px;line-height:1.5}.lv4-cta{flex-wrap:wrap;align-items:center;gap:12px;margin-top:32px;display:flex}.lv4-bigmark{right:var(--l-gutter);width:clamp(160px,19vw,280px);height:auto;position:absolute;top:50%;overflow:visible;transform:translateY(-50%)}.lv4-bigmark .ink{fill:var(--l-ink)}.lv4-bigmark .chev{stroke:var(--l-on-ink)}.dark .lv4-bigmark .ink{fill:var(--l-surface);stroke:var(--l-border-strong);stroke-width:.6px}.dark .lv4-bigmark .chev{stroke:var(--l-text)}.lv4-bigmark .cur{fill:var(--l-cursor);animation:1.1s step-end infinite lv4-blink}@media (max-width:900px){.lv4-bigmark{display:none}}.lv4-stage{height:720vh;position:relative}.lv4-sticky{height:calc(100svh - 64px);padding:clamp(16px, 3vh, 40px) var(--l-gutter);grid-template-columns:minmax(0,5fr) minmax(0,7fr);align-items:center;gap:clamp(24px,4vw,64px);max-width:1360px;margin:0 auto;display:grid;position:sticky;top:64px}.lv4-story{flex-direction:column;justify-content:center;gap:28px;height:100%;display:flex;position:relative}.lv4-rail{align-items:center;gap:6px;display:flex}.lv4-rail button{cursor:pointer;background:0 0;border:0;flex:1;height:28px;padding:0;position:relative}.lv4-rail button:before{content:"";background:var(--l-border);height:2px;position:absolute;top:13px;left:0;right:0}.lv4-rail button:after{content:attr(data-v);font:500 11px var(--font-mono);color:var(--l-subtle);position:absolute;top:-12px;left:0}.lv4-rail button .fill{background:var(--l-accent-text);width:0;height:2px;position:absolute;top:13px;left:0}.lv4-rail button.on:after{color:var(--l-text)}.lv4-chap{min-height:360px;position:relative}.lv4-bn{font:600 clamp(72px, 9vw, 140px) / .9 var(--font-sans);letter-spacing:-.06em;color:#0000;-webkit-text-stroke:1px var(--l-border-strong);margin-bottom:20px;display:block}.lv4-chap>div{opacity:0;pointer-events:none;transition:opacity .35s,transform .35s;position:absolute;inset:0 0 auto;transform:translateY(14px)}.lv4-chap>div.on{opacity:1;pointer-events:auto;transform:none}.lv4-chap h2{letter-spacing:-.035em;font-size:clamp(30px,3.6vw,52px);font-weight:600;line-height:1.02}.lv4-chap p{color:var(--l-muted);max-width:42ch;margin-top:16px;font-size:18px}.lv4-panel{border:1px solid var(--l-border);background:var(--l-surface);border-radius:var(--radius-lg);min-height:0;max-height:100%;box-shadow:var(--shadow-pop);flex-direction:column;display:flex}.lv4-ph{border-bottom:1px solid var(--l-border);flex-wrap:wrap;align-items:center;gap:10px;padding:12px 16px;display:flex}.lv4-ph .name{font:500 13px var(--font-mono)}.lv4-sp{flex:1}.lv4-pm{border-bottom:1px solid var(--l-border);font:400 12px var(--font-mono);color:var(--l-subtle);background:var(--l-sunken);flex-wrap:wrap;gap:16px;padding:10px 16px;display:flex}.lv4-pb{flex:1;min-height:min(430px,50vh);padding:16px 0;overflow:hidden}.lv4-ln{font:400 15px / 1.7 var(--font-mono);grid-template-columns:44px 20px 1fr;padding:0 20px 0 0;display:grid;overflow:hidden}.lv4-ln .n{text-align:right;color:var(--l-subtle);-webkit-user-select:none;user-select:none;padding-right:12px}.lv4-ln .g{color:var(--l-subtle);-webkit-user-select:none;user-select:none;text-align:center}.lv4-ln.add{background:var(--l-accent-soft)}.lv4-ln.add .g{color:var(--l-accent-text);font-weight:600}.lv4-ln.del{background:var(--l-danger-soft);color:var(--l-danger)}.lv4-ln.del .t{text-decoration:line-through}.lv4-ln.del .g{color:var(--l-danger)}.lv4-pf{border-top:1px solid var(--l-border);font:400 12px var(--font-mono);color:var(--l-subtle);flex-wrap:wrap;align-items:center;gap:12px;padding:10px 16px;display:flex}.lv4-prov{align-items:center;gap:10px;display:flex}.lv4-rb{visibility:hidden}.lv4-rb.show{visibility:visible}.lv4-sec{max-width:1240px;padding:120px var(--l-gutter) 0;margin:0 auto}.lv4-sec h2{letter-spacing:-.04em;max-width:18ch;margin:16px 0 48px;font-size:clamp(32px,4.6vw,64px);font-weight:600;line-height:1}.lv4-feat{border-top:1px solid var(--l-border);grid-template-columns:repeat(3,1fr);display:grid}.lv4-feat>div{border-right:1px solid var(--l-border);padding:28px 28px 40px}.lv4-feat>div:first-child{padding-left:0}.lv4-feat>div:last-child{border-right:0}.lv4-feat b{letter-spacing:-.02em;margin-bottom:8px;font-size:20px;display:block}.lv4-feat p{color:var(--l-muted)}.lv4-feat .tag{color:var(--l-accent-text);font:400 12px var(--font-mono);margin-bottom:28px;display:block}.lv4-band{margin:120px var(--l-gutter) 0;border:1px solid var(--l-border);border-radius:var(--radius-lg);background:var(--l-surface);grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:start;gap:clamp(32px,6vw,80px);padding:clamp(32px,6vw,80px);scroll-margin-top:80px;display:grid}.lv4-band h2{letter-spacing:-.04em;max-width:14ch;margin-bottom:20px;font-size:clamp(30px,4vw,56px);font-weight:600;line-height:1}.lv4-band-head p{max-width:40ch;color:var(--l-muted);font-size:17px;line-height:1.5}@media (max-width:900px){.lv4-band{grid-template-columns:minmax(0,1fr)}.lv4-sticky{grid-template-rows:auto minmax(0,1fr);grid-template-columns:1fr;align-items:start;gap:14px}.lv4-story{gap:12px;height:auto}.lv4-chap{min-height:150px}.lv4-bn{display:none}.lv4-chap p{margin-top:8px;font-size:15px}.lv4-chap h2{font-size:26px}.lv4-ln{font-size:12px}.lv4-feat{grid-template-columns:1fr}.lv4-feat>div{border-right:0;border-bottom:1px solid var(--l-border);padding:24px 0}}@media (prefers-reduced-motion:reduce){.lv4 *,.lv4 :before,.lv4 :after{transition-duration:.001ms!important;animation-duration:.001ms!important;animation-iteration-count:1!important}.lv4-bigmark .cur{animation:none}}