/* T^AI NEXT — M5 foundation — additive /tai/ surface */
:root{color-scheme:light dark;--bg:#f7f7f5;--fg:#0a0a0a;--muted:#636363;--soft:#ecece8;--line:#cfcfc8;--panel:rgba(255,255,255,.72);--glass:rgba(247,247,245,.82);--shadow:0 14px 50px rgba(0,0,0,.08);--ok:#286b45;--warn:#8a6500;--err:#9c3030;--radius:22px;--max:1240px}
html[data-theme="dark"]{color-scheme:dark;--bg:#080909;--fg:#f2f2ef;--muted:#a3a39d;--soft:#161716;--line:#30312e;--panel:rgba(19,20,19,.78);--glass:rgba(8,9,9,.86);--shadow:0 18px 60px rgba(0,0,0,.36);--ok:#78c498;--warn:#d7b760;--err:#e28b8b}
html[data-theme="light"]{color-scheme:light;--bg:#f7f7f5;--fg:#0a0a0a;--muted:#636363;--soft:#ecece8;--line:#cfcfc8;--panel:rgba(255,255,255,.72);--glass:rgba(247,247,245,.82);--shadow:0 14px 50px rgba(0,0,0,.08);--ok:#286b45;--warn:#8a6500;--err:#9c3030}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]){color-scheme:dark;--bg:#080909;--fg:#f2f2ef;--muted:#a3a39d;--soft:#161716;--line:#30312e;--panel:rgba(19,20,19,.78);--glass:rgba(8,9,9,.86);--shadow:0 18px 60px rgba(0,0,0,.36);--ok:#78c498;--warn:#d7b760;--err:#e28b8b}}
*{box-sizing:border-box}html{scroll-behavior:smooth;background:var(--bg)}body{margin:0;background:radial-gradient(circle at 72% -10%,color-mix(in srgb,var(--fg) 4%,transparent),transparent 28rem),var(--bg);color:var(--fg);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.55;min-height:100vh}a{color:inherit;text-decoration:none}button,input,textarea,select{font:inherit}.shell{max-width:var(--max);margin:auto;padding:0 26px 80px}.top{position:sticky;top:0;z-index:30;background:var(--glass);backdrop-filter:blur(18px);border-bottom:1px solid color-mix(in srgb,var(--line) 75%,transparent)}.top-in{max-width:var(--max);margin:auto;padding:13px 26px;display:flex;align-items:center;gap:20px}.brand{font-weight:760;letter-spacing:-.035em;white-space:nowrap}.brand sup{font-size:.6em}.nav{display:flex;gap:4px;align-items:center;overflow-x:auto;scrollbar-width:none;margin-left:auto}.nav::-webkit-scrollbar{display:none}.nav a{font-size:13px;color:var(--muted);padding:8px 10px;border-radius:999px;white-space:nowrap}.nav a[aria-current="page"],.nav a:hover{background:var(--soft);color:var(--fg)}.theme{width:28px;height:28px;flex:0 0 28px;border:1px solid var(--line);border-radius:50%;background:linear-gradient(90deg,#090909 0 50%,#f6f6f2 50% 100%);cursor:pointer;box-shadow:inset 0 0 0 2px rgba(127,127,127,.12)}.hero{padding:84px 0 46px;border-bottom:1px solid var(--line)}.eyebrow{font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);font-weight:700}.hero h1{font-size:clamp(44px,8vw,104px);letter-spacing:-.065em;line-height:.9;margin:18px 0 22px;max-width:1000px;font-weight:760}.hero p{font-size:clamp(18px,2.2vw,25px);color:var(--muted);max-width:820px;margin:0}.statusline{display:flex;flex-wrap:wrap;gap:9px;margin-top:28px}.pill{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);border-radius:999px;padding:7px 11px;font-size:12px;color:var(--muted);background:var(--panel)}.dot{width:7px;height:7px;border-radius:50%;background:currentColor}.grid{display:grid;grid-template-columns:repeat(12,1fr);gap:14px;padding:42px 0}.card{grid-column:span 4;border:1px solid var(--line);border-radius:var(--radius);background:var(--panel);box-shadow:var(--shadow);padding:24px;min-height:190px;display:flex;flex-direction:column}.card.wide{grid-column:span 8}.card.full{grid-column:1/-1}.card h2,.card h3{letter-spacing:-.025em;margin:0 0 10px}.card p{color:var(--muted);margin:0 0 14px}.kicker{font-size:11px;text-transform:uppercase;letter-spacing:.11em;color:var(--muted);margin-bottom:14px}.arrow{margin-top:auto;color:var(--muted);font-size:20px}.section{padding:44px 0;border-bottom:1px solid var(--line)}.section h2{font-size:clamp(30px,5vw,58px);letter-spacing:-.045em;line-height:1;margin:0 0 18px}.lede{max-width:850px;font-size:18px;color:var(--muted)}.matrix{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:26px}.cell{border:1px solid var(--line);border-radius:16px;padding:16px;background:var(--panel)}.cell b{display:block;font-size:13px}.cell small{color:var(--muted)}.mono,code,pre{font-family:"SFMono-Regular",Consolas,"Liberation Mono",monospace}.code{border:1px solid var(--line);background:var(--soft);border-radius:16px;padding:16px;overflow:auto;font-size:12px;color:var(--muted)}.form{display:grid;gap:12px}.form textarea,.form input,.form select{width:100%;border:1px solid var(--line);border-radius:14px;background:var(--bg);color:var(--fg);padding:12px 14px;outline:none}.form textarea{min-height:150px;resize:vertical}.form textarea:focus,.form input:focus,.form select:focus{border-color:var(--fg)}.row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.btn{border:1px solid var(--fg);background:var(--fg);color:var(--bg);border-radius:999px;padding:10px 16px;cursor:pointer;font-weight:700}.btn.secondary{background:transparent;color:var(--fg);border-color:var(--line)}.result{white-space:pre-wrap;min-height:90px}.state{font-size:11px;text-transform:uppercase;letter-spacing:.08em;font-weight:800}.state.ok{color:var(--ok)}.state.warn{color:var(--warn)}.state.err{color:var(--err)}table{width:100%;border-collapse:collapse;font-size:13px}th,td{text-align:left;border-bottom:1px solid var(--line);padding:12px 8px;vertical-align:top}th{color:var(--muted);font-size:11px;text-transform:uppercase;letter-spacing:.08em}.flow{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:24px}.flow span{border:1px solid var(--line);background:var(--panel);border-radius:999px;padding:8px 12px;font-size:12px}.flow i{color:var(--muted);font-style:normal}.footer{padding:40px 0;color:var(--muted);font-size:12px;display:flex;justify-content:space-between;gap:20px}.small{font-size:12px;color:var(--muted)}.list{display:grid;gap:8px;margin:14px 0 0;padding:0;list-style:none}.list li{padding:10px 0;border-top:1px solid var(--line)}.split{display:grid;grid-template-columns:1.15fr .85fr;gap:22px}.tracebar{height:1px;background:var(--line);position:relative;margin:32px 0}.tracebar:after{content:"χ_min";position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);background:var(--bg);padding:5px 10px;color:var(--muted);font:11px ui-monospace,monospace}.notice{border-left:2px solid var(--fg);padding:4px 0 4px 16px;color:var(--muted)}
@media(max-width:900px){.card,.card.wide{grid-column:span 6}.matrix{grid-template-columns:repeat(2,1fr)}.split{grid-template-columns:1fr}.top-in{gap:10px}.nav{margin-left:0}.brand{margin-right:auto}}
@media(max-width:620px){.shell{padding-left:17px;padding-right:17px}.top-in{padding-left:17px;padding-right:17px}.nav a{padding:7px 8px}.hero{padding-top:58px}.card,.card.wide{grid-column:1/-1}.matrix{grid-template-columns:1fr}.row{grid-template-columns:1fr}.footer{flex-direction:column}.hero h1{font-size:52px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}