@import "https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;600;700&family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@500;700&display=swap";:root{--bg:#f4f6f8;--surface:#fff;--surface-sunken:#eef1f5;--ink:#1b232e;--ink-soft:#5b6472;--rule:#dde2e9;--data:#0e7c86;--data-soft:#e3f2f1;--parity:#e8a33d;--parity-soft:#fbf0dd;--ok:#2f9e58;--ok-soft:#e6f5ec;--fault:#d1453b;--fault-soft:#fbe9e7;--font-display:"Space Grotesk", "Trebuchet MS", sans-serif;--font-body:"Inter", "Trebuchet MS", sans-serif;--font-mono:"JetBrains Mono", "Courier New", monospace;--radius-sm:6px;--radius-md:10px;--radius-lg:16px;--shadow-card:0 1px 2px #1b232e0f, 0 8px 24px #1b232e0d;--max-width:1180px}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--ink);font-family:var(--font-body);-webkit-font-smoothing:antialiased;font-size:16px;line-height:1.55}#root{min-height:100vh}h1,h2,h3{font-family:var(--font-display);letter-spacing:-.01em;color:var(--ink);margin:0 0 .5em;font-weight:600}p{color:var(--ink-soft);margin:0 0 1em}code,.mono{font-family:var(--font-mono)}button{font-family:var(--font-body);cursor:pointer}button:focus-visible,input:focus-visible,a:focus-visible{outline:3px solid var(--data);outline-offset:2px}@media (prefers-reduced-motion:reduce){*,:before,:after{transition-duration:.001ms!important;animation-duration:.001ms!important}}.app{max-width:var(--max-width);margin:0 auto;padding:32px 24px 80px}.app-header{grid-template-columns:1fr auto;align-items:center;gap:4px 16px;margin-bottom:28px;display:grid}.eyebrow{font-family:var(--font-mono);letter-spacing:.12em;text-transform:uppercase;color:var(--data);grid-area:1/1;font-size:13px;font-weight:700}.app-header h1{grid-area:2/1;font-size:clamp(28px,4vw,38px)}.logo{grid-area:1/2/3;align-self:center;width:auto;height:128px}.app-header .subtitle{grid-area:3/1/auto/-1;max-width:60ch;margin:0;font-size:17px}.stage-nav{border-bottom:1px solid var(--rule);flex-wrap:wrap;gap:8px;margin-bottom:28px;padding-bottom:16px;display:flex}.stage-nav button{background:var(--surface);border:1px solid var(--rule);color:var(--ink-soft);border-radius:999px;align-items:center;gap:8px;padding:8px 16px 8px 10px;font-size:14px;font-weight:500;transition:border-color .15s,color .15s,background .15s;display:flex}.stage-nav button .stage-num{background:var(--surface-sunken);width:22px;height:22px;font-family:var(--font-mono);color:var(--ink-soft);border-radius:50%;justify-content:center;align-items:center;font-size:12px;font-weight:700;display:inline-flex}.stage-nav button.active{border-color:var(--data);color:var(--ink);background:var(--data-soft)}.stage-nav button.active .stage-num{background:var(--data);color:#fff}.stage-nav button.complete .stage-num{background:var(--ok);color:#fff}.stage-nav button:disabled{opacity:.45;cursor:not-allowed}.workspace{grid-template-columns:280px 1fr;align-items:start;gap:28px;display:grid}@media (width<=860px){.workspace{grid-template-columns:1fr}}.drive-rack{background:var(--surface);border:1px solid var(--rule);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);padding:20px;position:sticky;top:24px}.drive-rack h2{font-size:14px;font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.08em;color:var(--ink-soft);margin-bottom:14px}.drive-bay{background:var(--surface-sunken);border-radius:var(--radius-md);border:1px solid #0000;align-items:center;gap:10px;margin-bottom:8px;padding:10px 12px;transition:border-color .2s,background .2s;display:flex}.drive-bay:last-child{margin-bottom:0}.drive-bay .bay-label{font-family:var(--font-mono);width:30px;color:var(--ink-soft);flex-shrink:0;font-size:12px;font-weight:700}.drive-bay.role-parity .bay-label{color:var(--parity)}.drive-bay .bay-bits{flex-wrap:wrap;flex:1;gap:2px;display:flex}.bit-chip{border:1px solid var(--rule);width:16px;height:16px;font-family:var(--font-mono);color:var(--ink-soft);background:#fff;border-radius:3px;justify-content:center;align-items:center;font-size:9px;display:flex}.bit-chip.set{background:var(--data);border-color:var(--data);color:#fff}.drive-bay.role-parity .bit-chip.set{background:var(--parity);border-color:var(--parity)}.drive-bay .activity-led{background:var(--rule);border-radius:50%;flex-shrink:0;width:9px;height:9px}.drive-bay.active .activity-led{background:var(--parity);box-shadow:0 0 0 4px var(--parity-soft)}.drive-bay.failed{border-color:var(--fault);background:var(--fault-soft)}.drive-bay.failed .activity-led{background:var(--fault);box-shadow:0 0 0 4px var(--fault-soft)}.drive-bay.failed .bay-bits{visibility:hidden}.drive-bay.failed .bay-label:after{content:" ✕"}.drive-bay.verified .activity-led{background:var(--ok);box-shadow:0 0 0 4px var(--ok-soft)}.stage-card{background:var(--surface);border:1px solid var(--rule);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);padding:28px 32px}.stage-card h2{font-size:22px}.stage-card .lede{font-size:16px}.truth-table{border-collapse:collapse;font-family:var(--font-mono);margin:16px 0 20px;font-size:14px}.truth-table th,.truth-table td{border:1px solid var(--rule);text-align:center;padding:8px 16px}.truth-table th{background:var(--surface-sunken);color:var(--ink-soft);font-weight:700}.truth-table td.result-1{background:var(--data-soft);color:var(--data);font-weight:700}.truth-table td.result-0{color:var(--ink-soft)}.column-drill{margin:20px 0}.bit-columns{gap:6px;margin-bottom:18px;padding-bottom:8px;display:flex;overflow-x:auto}.bit-column{border-radius:var(--radius-sm);border:1px solid var(--rule);background:var(--surface-sunken);flex-direction:column;align-items:center;gap:6px;min-width:44px;padding:8px 4px;display:flex}.bit-column.current{border-color:var(--parity);background:var(--parity-soft)}.bit-column.done{border-color:var(--ok)}.bit-column .col-bit{font-family:var(--font-mono);border:1px solid var(--rule);background:#fff;border-radius:4px;justify-content:center;align-items:center;width:26px;height:26px;font-size:14px;display:flex}.bit-column .col-parity{font-family:var(--font-mono);border-radius:4px;justify-content:center;align-items:center;width:26px;height:26px;font-size:14px;font-weight:700;display:flex}.bit-column .col-parity.unknown{border:1px dashed var(--rule);color:var(--ink-soft);background:#fff}.bit-column .col-parity.correct{background:var(--ok-soft);border:1px solid var(--ok);color:var(--ok)}.bit-column .col-divider{background:var(--rule);width:100%;height:1px}.entry-row{flex-wrap:wrap;align-items:center;gap:16px;margin:18px 0;display:flex}.bit-toggle-group{border:1px solid var(--rule);border-radius:var(--radius-sm);display:inline-flex;overflow:hidden}.bit-toggle-group button{background:var(--surface);width:52px;height:44px;font-family:var(--font-mono);color:var(--ink-soft);border:none;font-size:18px;font-weight:700}.bit-toggle-group button+button{border-left:1px solid var(--rule)}.bit-toggle-group button.selected{background:var(--data);color:#fff}.feedback-banner{border-radius:var(--radius-sm);align-items:center;gap:8px;padding:8px 14px;font-size:14px;font-weight:600;display:inline-flex}.feedback-banner.correct{background:var(--ok-soft);color:var(--ok)}.feedback-banner.incorrect{background:var(--fault-soft);color:var(--fault)}.btn{border-radius:var(--radius-sm);border:1px solid var(--rule);background:var(--surface);color:var(--ink);align-items:center;gap:6px;padding:10px 18px;font-size:14px;font-weight:600;transition:border-color .15s,background .15s,transform 50ms;display:inline-flex}.btn:active{transform:translateY(1px)}.btn-primary{background:var(--ink);border-color:var(--ink);color:#fff}.btn-primary:hover{background:#0d141c}.btn:disabled{opacity:.4;cursor:not-allowed}.btn-ghost{color:var(--ink-soft);background:0 0;border-color:#0000}.result-panel{border-radius:var(--radius-md);background:var(--surface-sunken);border:1px solid var(--rule);margin-top:18px;padding:18px 20px}.result-row{font-family:var(--font-mono);justify-content:space-between;padding:4px 0;font-size:14px;display:flex}.result-row .value{font-weight:700}.progress-bar{background:var(--surface);border:1px solid var(--rule);border-radius:var(--radius-md);color:var(--ink-soft);justify-content:space-between;align-items:center;gap:16px;margin-top:28px;padding:14px 20px;font-size:14px;display:flex}.progress-bar .streak{font-family:var(--font-mono);color:var(--parity);font-weight:700}.callout{border-left:3px solid var(--data);background:var(--data-soft);border-radius:0 var(--radius-sm) var(--radius-sm) 0;margin:16px 0;padding:12px 16px;font-size:14px}.callout p:last-child{margin-bottom:0}.callout strong{color:var(--ink)}ul.plain-list{color:var(--ink-soft);margin:0 0 1em;padding-left:20px}ul.plain-list li{margin-bottom:6px}.xor-drawer-trigger{z-index:40;border:1px solid var(--ink);background:var(--ink);color:#fff;box-shadow:var(--shadow-card);border-radius:999px;align-items:center;gap:8px;padding:12px 20px;font-size:14px;font-weight:600;display:inline-flex;position:fixed;bottom:75px;right:24px}.xor-drawer-trigger:hover{background:#0d141c}.xor-drawer-trigger:before{content:"⊕";font-family:var(--font-mono);color:var(--parity);font-size:16px}.xor-drawer-backdrop{z-index:50;cursor:pointer;background:#1b232e59;border:none;padding:0;position:fixed;inset:0}.xor-drawer{z-index:51;background:var(--surface);border-left:1px solid var(--rule);width:min(380px,100vw);padding:24px;transition:transform .25s;position:fixed;top:0;bottom:0;right:0;overflow-y:auto;transform:translate(100%);box-shadow:-8px 0 24px #1b232e1f}.xor-drawer.open{transform:translate(0)}.xor-drawer-header{justify-content:space-between;align-items:center;margin-bottom:12px;display:flex}.xor-drawer-header h2{margin:0;font-size:18px}.xor-drawer-close{background:var(--surface-sunken);width:32px;height:32px;color:var(--ink-soft);border:none;border-radius:50%;font-size:20px;line-height:1}.xor-drawer-close:hover{background:var(--rule);color:var(--ink)}@media (prefers-reduced-motion:reduce){.xor-drawer{transition:none}}