/* SuperPosition – brand: navy ground, one cyan→violet→magenta line (frontend/brand/, scripts/make_brand_assets.py).
   The brand colours dress the chrome only; A red / B blue / the orange region frame are data colours and stay. */
:root{
  --bg:#f5f6f9;--panel:#fff;--line:#e3e6ec;--ink:#1b2130;--muted:#6b7385;
  --navy:#0f172a;--navy-2:#18233b;--navy-line:#2a3650;
  --cyan:#3eebff;--sky:#7db6ff;--violet:#ac98ff;--magenta:#f55af6; /* sampled from the wordmark, left to right */
  --grad:linear-gradient(90deg,var(--cyan),var(--sky) 45%,var(--violet) 70%,var(--magenta));
  --grad-deep:linear-gradient(90deg,#0b86a3,#5a55d6 55%,#a83cbd);
  --acc:#5a55d6;--red:#d32f2f;--blue:#1e5ce6;--bad:#991b1b;--warn:#b45309;
}
*{box-sizing:border-box}
[hidden]{display:none!important}
html,body{height:100%;margin:0;font-family:"Segoe UI",Arial,sans-serif;color:var(--ink);background:var(--bg);font-size:14px;-webkit-font-smoothing:antialiased}
button{font:inherit;padding:6px 12px;border-radius:8px;border:1px solid var(--line);background:#fff;cursor:pointer;color:var(--ink);transition:background .15s,border-color .15s,box-shadow .15s,filter .15s}
button:hover{background:#f3f4f8}
button:disabled{opacity:.45;cursor:default}
:focus-visible{outline:2px solid var(--cyan);outline-offset:2px}
button.primary{background:var(--grad-deep);color:#fff;border-color:transparent;font-weight:700;box-shadow:0 8px 20px -10px rgba(90,85,214,.75)}
button.primary:hover{background:var(--grad-deep);filter:brightness(1.1)}
button.primary:disabled{box-shadow:none;filter:grayscale(.7)}
button.ghost{background:transparent;color:#e2e8f0;border-color:var(--navy-line)}
button.ghost:hover{background:var(--navy-2);border-color:#3b4a68}
select{font:inherit;padding:5px 6px;border-radius:8px;border:1px solid var(--line);background:#fff}
input[type=range]{accent-color:var(--acc)}
.hint{color:var(--muted);font-size:12.5px}
.error{color:var(--bad);margin-top:12px}
.spinner{display:inline-block;width:14px;height:14px;border:2px solid rgba(139,128,245,.22);border-top-color:var(--cyan);border-right-color:var(--magenta);border-radius:50%;animation:sp .9s linear infinite;vertical-align:middle}
@keyframes sp{to{transform:rotate(360deg)}}
.tag{display:inline-flex;align-items:center;justify-content:center;min-width:20px;height:20px;padding:0 5px;border-radius:5px;color:#fff;font-weight:800;font-size:12px}
.tag.a{background:var(--red)}.tag.b{background:var(--blue)}
.tag.big{min-width:34px;height:34px;font-size:18px;border-radius:8px}

/* header */
header{position:relative;height:52px;display:flex;align-items:center;gap:14px;padding:0 18px;background:var(--navy);color:#e2e8f0}
header::after{content:"";position:absolute;inset:auto 0 0;height:1px;background:var(--grad);opacity:.5}
.brand{display:flex;align-items:center;gap:9px;direction:ltr;text-decoration:none;flex-shrink:0}
.brand img{display:block}
.wordmark{font-weight:600;font-size:14.5px;letter-spacing:.17em;text-transform:uppercase;white-space:nowrap;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.tagline{font-size:12.5px;color:#8a96ad;padding-inline-start:14px;border-inline-start:1px solid var(--navy-line);white-space:nowrap}
header .pair{display:flex;align-items:center;gap:6px;min-width:0;font-size:13px}
header .pair b{font-weight:600;color:#f1f5f9;max-width:320px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
header .pair .vs{opacity:.55;margin:0 6px}
header #btnNew{margin-inline-start:auto}
main{height:calc(100% - 52px)}
@media (max-width:760px){.tagline{display:none}header .pair b{max-width:110px}}

/* step 1 */
#uploadView{height:100%;display:flex;align-items:center;justify-content:center;padding:24px;overflow:auto}
.upload-card{background:var(--panel);border:1px solid var(--line);border-radius:16px;width:min(760px,100%);box-shadow:0 18px 50px -24px rgba(15,23,42,.35);text-align:center;overflow:hidden}
.card-hero{position:relative;padding:26px 32px 22px;color:#fff;background:radial-gradient(90% 130% at 50% 0%,#1c2846 0%,var(--navy) 62%)}
.card-hero::after{content:"";position:absolute;inset:auto 0 0;height:1px;background:var(--grad);opacity:.6}
.hero-mark{display:block;margin:0 auto 8px}
.card-hero h1{margin:0 0 6px;font-size:22px;font-weight:700;color:#fff}
.card-hero p{margin:0;color:#9aa6bd;font-size:13px}
.card-body{padding:24px 32px 28px}
.slots{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:0 0 22px}
.slot{display:flex;flex-direction:column;align-items:center;gap:6px;padding:22px 14px;border:1.5px dashed #cfd5e0;border-radius:12px;cursor:pointer;background:#fafbfd;transition:background .15s,border-color .15s}
.slot:hover,.slot.drag{background:#f6f5ff;border-color:var(--violet)}
.slot small{color:var(--muted)}
.slot .file{margin-top:6px;font-size:12.5px;color:var(--muted);max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.slot.has{border-style:solid;border-color:#c9c6f7;background:#fff}
.slot.has .file{color:var(--ink);font-weight:600}
.sheet-pick{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin:-6px 0 16px}
.sheet-pick label{display:flex;gap:6px;align-items:center;font-size:13px}
#btnStart{font-size:15.5px;padding:10px 46px;border-radius:10px}
#progress{margin-top:18px}
.progress-text{font-size:14px}
.bar{height:6px;background:#e7e9f0;border-radius:3px;margin-top:10px;overflow:hidden}
.bar div{height:100%;background:var(--grad);width:2%;transition:width .5s}
@media (max-width:640px){.slots{grid-template-columns:1fr}.card-body{padding:20px}.card-hero{padding:22px 20px 18px}}

/* step 2 */
#resultView{height:100%;display:grid;grid-template-columns:1fr 380px}
#viewerArea{display:flex;flex-direction:column;min-width:0;background:#fff}
.viewctl{display:flex;gap:12px;align-items:center;flex-wrap:wrap;padding:8px 12px;border-bottom:1px solid var(--line);background:#fafbfc;font-size:13px}
.presets{display:inline-flex;gap:4px}
.preset{padding:4px 10px;font-size:13px}
.preset.active{background:var(--navy);border-color:var(--navy);color:#fff}
.layer{display:inline-flex;align-items:center;gap:6px;padding:3px 8px;border:1px solid var(--line);border-radius:8px;background:#fff;cursor:pointer;font-weight:600}
.layer input{width:90px;margin:0}
.layer.off{opacity:.5;border-style:dashed}
.layer.disabled{opacity:.4;pointer-events:none}
.sw{display:inline-block;width:14px;height:14px;border-radius:3px}
.sw.a{background:var(--red)}.sw.b{background:var(--blue)}.sw.c{background:#282830}
.sw.t{background:#f3f4f6;color:#374151;font-size:9px;font-style:normal;font-weight:700;display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line)}
.viewer{flex:1;position:relative;min-height:0;background:#fff}
aside#regionsPane{background:var(--panel);border-right:1px solid var(--line);overflow:auto;padding:12px;scrollbar-width:thin}
aside h3{margin:2px 0 10px;font-size:15px;display:flex;gap:8px;align-items:baseline}
aside h3 span{font-weight:400;color:var(--muted);font-size:12.5px}
.note{background:#fffbeb;border:1px solid #fde68a;color:#7c2d12;border-radius:8px;padding:8px 10px;font-size:12.5px;margin-bottom:10px}
.region{border:1px solid var(--line);border-radius:10px;padding:10px;margin-bottom:8px;cursor:pointer;background:#fff;transition:background .15s,border-color .15s}
.region:hover{background:#fafbfd;border-color:#d5d9e2}
.region.active{border-color:#ff9800;box-shadow:0 0 0 2px #ffe0b2}
.region .top{display:flex;gap:8px;align-items:center}
.region .idx{font-weight:800;color:#374151;min-width:20px}
.region .kind{font-size:11.5px;padding:1px 8px;border-radius:10px;color:#fff;font-weight:600;white-space:nowrap}
.kind.only_a{background:var(--red)}.kind.only_b{background:var(--blue)}.kind.changed{background:#6a1b9a}
.region .size{color:var(--muted);font-size:12px}
.region .ask{margin-inline-start:auto;padding:3px 10px;font-size:12.5px}
.region .ai{margin-top:8px;font-size:13px;line-height:1.5}
.region .ai .t{font-weight:700}
.region .ai .meta{display:flex;gap:6px;margin-top:4px;flex-wrap:wrap}
.region .ai .chip{font-size:11px;padding:1px 7px;border-radius:9px;background:#f1f2f6;color:#374151}
.chip.high{background:#fee2e2;color:#b00020}.chip.medium{background:#fef9c3;color:#a16207}.chip.low{background:#dcfce7;color:#166534}
.region .ai.muted{color:var(--muted)}
.region .ai.err{color:var(--bad);display:flex;align-items:flex-start;gap:8px}
.region .ai.err span{flex:1 1 auto;min-width:0;overflow-wrap:anywhere}
.region .ai .retry{flex:0 0 auto;padding:2px 9px;font-size:11.5px;border-color:var(--bad);color:var(--bad)}
.region .ai .retry:hover{background:#fee2e2}
.more{width:100%;margin-top:4px}
#toast{position:fixed;bottom:16px;left:50%;transform:translateX(-50%);background:var(--navy);color:#fff;padding:10px 16px;border-radius:10px;z-index:100;max-width:70%;font-size:13px;box-shadow:0 12px 30px -12px rgba(15,23,42,.6)}

/* vector viewer (frontend/viewer.js) */
.vv{overflow:hidden;touch-action:none;user-select:none}
.vv-canvas{position:absolute;inset:0;width:100%;height:100%;display:block;cursor:grab}
.vv-canvas:active{cursor:grabbing}
.vv-ui{position:absolute;top:8px;left:8px;z-index:6;display:flex;flex-direction:column;gap:4px}
.vv-ui button{width:30px;height:30px;padding:0;font-size:17px;line-height:1;background:rgba(255,255,255,.94);box-shadow:0 1px 3px rgba(15,23,42,.2)}
.vv-nav{position:absolute;bottom:8px;left:8px;z-index:6;border:1px solid #9ca3af;background:#fff;box-shadow:0 1px 4px rgba(0,0,0,.2);cursor:pointer;line-height:0}
.vv-nav img{display:block;object-fit:fill;opacity:.85}
.vv-navrect{position:absolute;border:2px solid var(--red);background:rgba(211,47,47,.08);pointer-events:none}
.vv-loading{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);z-index:7;background:rgba(15,23,42,.88);color:#fff;padding:10px 16px;border-radius:10px;font-size:13px;pointer-events:none}
.vv-error{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:var(--bad);font-weight:600}
.vv-ov{position:absolute;z-index:5;pointer-events:none;box-sizing:border-box}
.region-box{border:3px dashed #ff9800;background:rgba(255,152,0,.08)}
.region-box .cap{position:absolute;bottom:100%;right:-3px;margin-bottom:6px;background:#ff9800;color:#111827;font-weight:700;font-size:13px;padding:3px 10px;border-radius:6px;white-space:nowrap;max-width:460px;overflow:hidden;text-overflow:ellipsis;box-shadow:0 2px 6px rgba(0,0,0,.2)}
.region-box .cap.muted{background:#e5e7eb;color:#374151}