:root{
  --bg:#0B0F17; --panel:#111725; --panel-2:#0E1420; --ink:#E6ECF5; --ink-2:#B7C2D4; --mute:#7E8BA3; --faint:#586479;
  --blue:#4C8DFF; --blue-deep:#2C6BE0; --cyan:#39D6C6; --amber:#F5B301; --red:#FF5C7A; --green:#37D67A;
  --line:rgba(255,255,255,.08); --line-2:rgba(255,255,255,.15);
  --sans:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:ui-monospace,"SF Mono","JetBrains Mono",Menlo,monospace;
  --r:10px; --r-lg:14px; --ease:cubic-bezier(.16,1,.3,1);
}
*{ box-sizing:border-box; }
[hidden]{ display:none !important; }
html,body{ margin:0; height:100%; }
body{ background:var(--bg); color:var(--ink); font-family:var(--sans); -webkit-font-smoothing:antialiased; line-height:1.5; overflow:hidden; }

/* blueprint grid */
.grid-bg{ position:fixed; inset:0; z-index:0; pointer-events:none; opacity:.5;
  background-image:linear-gradient(rgba(76,141,255,.06) 1px,transparent 1px),linear-gradient(90deg,rgba(76,141,255,.06) 1px,transparent 1px);
  background-size:26px 26px; mask-image:radial-gradient(120% 90% at 50% 0%,#000 40%,transparent 100%); }

/* topbar */
.topbar{ position:relative; z-index:2; display:flex; align-items:center; justify-content:space-between; height:56px; padding:0 clamp(14px,3vw,26px); border-bottom:1px solid var(--line); background:rgba(11,15,23,.7); backdrop-filter:blur(10px); }
.brand{ display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--ink); }
.mark{ width:34px; height:34px; border-radius:9px; display:grid; place-items:center; background:linear-gradient(150deg,#152238,#0d1626); border:1px solid var(--line-2); flex:none; }
.mark svg{ width:20px; height:20px; fill:none; stroke:var(--blue); stroke-width:1.8; }
.wordmark{ font-weight:800; letter-spacing:-.03em; font-size:20px; }
.tag{ font-family:var(--mono); font-size:11px; color:var(--mute); border:1px solid var(--line); padding:3px 8px; border-radius:999px; }
@media(max-width:640px){ .tag{ display:none; } }
.top-actions{ display:flex; align-items:center; gap:10px; }
.badge{ font-family:var(--mono); font-size:11px; color:var(--cyan); border:1px solid rgba(57,214,198,.3); background:rgba(57,214,198,.06); padding:4px 9px; border-radius:999px; }
.badge.gpu{ color:var(--blue); border-color:rgba(76,141,255,.3); background:rgba(76,141,255,.06); }
.badge.warn{ color:var(--amber); border-color:rgba(245,179,1,.3); background:rgba(245,179,1,.06); }

/* buttons */
.btn{ display:inline-flex; align-items:center; gap:7px; border:0; cursor:pointer; font-family:inherit; font-weight:700; font-size:14px;
  background:linear-gradient(150deg,var(--blue),var(--blue-deep)); color:#fff; padding:9px 16px; border-radius:var(--r); transition:.16s var(--ease);
  box-shadow:0 8px 22px -12px rgba(76,141,255,.8); white-space:nowrap; }
.btn:hover{ transform:translateY(-1px); }
.btn:disabled{ opacity:.5; cursor:not-allowed; transform:none; }
.btn.ghost{ background:var(--panel); color:var(--ink-2); border:1px solid var(--line-2); box-shadow:none; }
.btn.ghost:hover{ border-color:var(--blue); color:#fff; }
.btn.sm{ padding:6px 11px; font-size:12.5px; }
.spark{ color:#fff; }

/* studio layout */
.studio{ position:relative; z-index:1; height:calc(100dvh - 56px); display:grid; grid-template-columns:214px minmax(320px,1fr) minmax(360px,1.25fr); }
@media(max-width:900px){ .studio{ grid-template-columns:1fr; grid-auto-rows:min-content; overflow-y:auto; } }

/* rail */
.rail{ border-right:1px solid var(--line); background:var(--panel-2); display:flex; flex-direction:column; min-height:0; }
@media(max-width:900px){ .rail{ display:none; } }
.rail-head{ font-size:11px; text-transform:uppercase; letter-spacing:.1em; color:var(--mute); padding:14px 14px 8px; }
.rail-list{ flex:1; overflow-y:auto; padding:0 8px 12px; display:flex; flex-direction:column; gap:4px; }
.rail-item{ display:flex; align-items:center; gap:8px; padding:8px 10px; border-radius:8px; cursor:pointer; border:1px solid transparent; }
.rail-item:hover{ background:var(--panel); }
.rail-item.active{ background:rgba(76,141,255,.1); border-color:rgba(76,141,255,.25); }
.ri-meta{ min-width:0; flex:1; }
.ri-title{ font-size:13px; font-weight:600; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.ri-sub{ font-family:var(--mono); font-size:10.5px; color:var(--mute); }
.ri-del{ opacity:0; border:0; background:none; color:var(--mute); cursor:pointer; font-size:15px; padding:0 2px; }
.rail-item:hover .ri-del{ opacity:1; } .ri-del:hover{ color:var(--red); }
.rail-empty{ color:var(--faint); font-size:12.5px; padding:8px 10px; }

/* editor */
.editor{ border-right:1px solid var(--line); display:flex; flex-direction:column; min-height:0; padding:14px; gap:10px; }
@media(max-width:900px){ .editor{ border-right:0; border-bottom:1px solid var(--line); height:auto; } }
.prompt-row{ display:flex; gap:8px; }
#prompt{ flex:1; border:1px solid var(--line-2); border-radius:var(--r); padding:10px 12px; font-family:inherit; font-size:14px; background:var(--panel-2); color:var(--ink); }
#prompt::placeholder{ color:var(--faint); } #prompt:focus{ outline:none; border-color:var(--blue); }
.types{ display:flex; flex-wrap:wrap; gap:6px; }
.type{ border:1px solid var(--line); background:var(--panel-2); color:var(--mute); font-family:inherit; font-size:12.5px; font-weight:600; padding:6px 12px; border-radius:999px; cursor:pointer; transition:.15s; }
.type:hover{ color:var(--ink); border-color:var(--line-2); }
.type.is-active{ color:#fff; background:rgba(76,141,255,.14); border-color:var(--blue); }
.code-wrap{ flex:1; min-height:160px; display:flex; }
#code{ flex:1; resize:none; border:1px solid var(--line); border-radius:var(--r); padding:12px; background:var(--panel-2); color:var(--ink-2);
  font-family:var(--mono); font-size:13px; line-height:1.6; tab-size:2; }
#code:focus{ outline:none; border-color:var(--blue); color:var(--ink); }
.ai-status{ font-family:var(--mono); font-size:12px; color:var(--cyan); display:flex; align-items:center; gap:8px; min-height:18px; }
.ai-status.err{ color:var(--amber); }
.ai-bar{ height:4px; flex:1; background:rgba(255,255,255,.08); border-radius:2px; overflow:hidden; }
.ai-bar > i{ display:block; height:100%; width:0; background:linear-gradient(90deg,var(--blue),var(--cyan)); transition:width .3s; }

/* preview */
.preview{ display:flex; flex-direction:column; min-height:0; }
@media(max-width:900px){ .preview{ height:70vh; } }
.preview-bar{ display:flex; align-items:center; gap:10px; padding:12px 14px; border-bottom:1px solid var(--line); }
.title-in{ flex:1; border:0; background:none; color:var(--ink); font-family:inherit; font-size:15px; font-weight:700; padding:4px 2px; }
.title-in:focus{ outline:none; } .title-in::placeholder{ color:var(--faint); }
.pv-actions{ display:flex; gap:6px; }
.canvas{ flex:1; min-height:0; overflow:auto; display:grid; place-items:center; padding:24px;
  background:radial-gradient(60% 60% at 50% 40%, rgba(76,141,255,.05), transparent 70%); }
.diagram{ max-width:100%; }
.diagram svg{ max-width:100%; height:auto; }
.err{ margin:0 14px 12px; padding:10px 12px; border:1px solid rgba(255,92,122,.35); background:rgba(255,92,122,.08); color:#ffb3c1;
  border-radius:var(--r); font-family:var(--mono); font-size:12px; white-space:pre-wrap; }
.foot{ padding:11px 14px; border-top:1px solid var(--line); color:var(--mute); font-size:11.5px; text-align:center; }
.foot a{ color:var(--mute); } .foot a:hover{ color:var(--ink-2); }

@media(prefers-reduced-motion:reduce){ *{ animation:none !important; transition:none !important; } }