@import url("https://fonts.googleapis.com/css2?family=DM+Serif+Display&family=Space+Mono:wght@400;700&family=Inter:wght@300;400;500;600;700&display=swap");:root{--bg:#0f172a;--bg-mid:#162032;--surface:#1e293b;--surface-hi:#293548;--surface-2:#334155;--border:rgba(148,163,184,.12);--border-hi:rgba(59,130,246,.45);--text:#f1f5f9;--muted:#94a3b8;--dim:#64748b;--dimmer:#475569;--accent:#3b82f6;--accent-hi:#2563eb;--accent-lo:#1d4ed8;--blue:#60a5fa;--blue-dim:rgba(59,130,246,.15);--blue-border:rgba(59,130,246,.25);--green:#34d399;--red:#f87171;--yellow:#fbbf24;--font-sans:"Inter",system-ui,sans-serif;--font-serif:"DM Serif Display",Georgia,serif;--font-mono:"Space Mono","Courier New",monospace;--radius-sm:5px;--radius:8px;--radius-lg:12px;--radius-pill:999px;--transition:0.15s ease}*,:after,:before{box-sizing:border-box;margin:0;padding:0}body,html{height:100%;background:var(--bg);color:var(--text);font-family:var(--font-sans);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{color:inherit}::-webkit-scrollbar{width:4px;height:4px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--surface-2);border-radius:2px}::-webkit-scrollbar-thumb:hover{background:var(--dim)}.btn-primary{display:inline-flex;align-items:center;gap:6px;background:var(--accent);color:#fff;border:none;border-radius:var(--radius-pill);padding:11px 28px;font-family:var(--font-sans);font-size:14px;font-weight:600;letter-spacing:.02em;cursor:pointer;text-decoration:none;transition:background var(--transition),transform var(--transition),box-shadow var(--transition);box-shadow:0 0 0 0 rgba(59,130,246,0)}.btn-primary:hover{background:var(--accent-hi);box-shadow:0 4px 20px rgba(59,130,246,.35);transform:translateY(-1px)}.btn-primary:active{transform:translateY(0)}.btn-secondary{display:inline-flex;align-items:center;gap:6px;background:transparent;color:var(--text);border:1px solid var(--border);border-radius:var(--radius-pill);padding:10px 26px;font-family:var(--font-sans);font-size:14px;font-weight:500;cursor:pointer;text-decoration:none;transition:border-color var(--transition),background var(--transition)}.btn-secondary:hover{border-color:var(--blue);background:rgba(96,165,250,.06)}input[type=email],input[type=number],input[type=text],select{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-family:var(--font-sans);outline:none;transition:border-color var(--transition)}input:focus,select:focus{border-color:var(--border-hi)}input::-webkit-inner-spin-button,input::-webkit-outer-spin-button{-webkit-appearance:none}input[type=number]{-moz-appearance:textfield}@media print{#engcentral-sidebar,#engcentral-topbar{display:none!important}body{background:#fff!important}body,h1,h2,h3{color:#111!important}li,p,span{color:#333!important}.btn-primary,.btn-secondary{display:none!important}}.ec-tr-content .katex-display{margin:4px 0!important;display:inline-block!important;text-align:left!important;margin:2px 0!important}