:root{
  --zygo:#2b3f9e; --ink:#1c2230; --muted:#6b7280; --line:#e3e6ee;
  --bg:#f4f6fb; --panel:#ffffff; --ok:#1f9d55; --accent:#2b3f9e;
  --shadow:0 6px 24px rgba(30,40,80,.08);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);}
header{padding:18px 28px;background:var(--panel);border-bottom:1px solid var(--line);
  display:flex;align-items:baseline;gap:14px;position:sticky;top:0;z-index:20;}
.brand{font-size:30px;font-weight:800;letter-spacing:2px;color:var(--zygo);}
.subtitle{color:var(--muted);font-size:14px;}

main{max-width:1180px;margin:22px auto;padding:0 20px;display:grid;
  grid-template-columns:390px 1fr;gap:20px;align-items:start;}
@media(max-width:900px){main{grid-template-columns:1fr}}

.panel{background:var(--panel);border:1px solid var(--line);border-radius:16px;
  padding:20px;box-shadow:var(--shadow);}
.panel h2{margin:0 0 16px;font-size:16px;color:var(--zygo);}

.field{display:block;margin-bottom:16px;}
.field>span{display:block;font-size:13px;color:var(--muted);margin-bottom:6px;font-weight:600;}
input[type=text],input[type=number],select{
  width:100%;padding:11px 12px;border:1.5px solid var(--line);border-radius:10px;
  font-size:15px;background:#fff;color:var(--ink);transition:border .15s;}
input:focus,select:focus{outline:none;border-color:var(--zygo);}
.row{display:flex;gap:8px;align-items:stretch;}
.row select{flex:1;}
.mini{width:44px;border:1.5px solid var(--line);background:#fff;border-radius:10px;
  font-size:20px;cursor:pointer;color:var(--zygo);}
.mini:hover{background:#f0f2fb;}
.check{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin:-8px 0 16px;cursor:pointer;}
.check.inline{margin:0;}
.check input{width:16px;height:16px;accent-color:var(--zygo);}

.dims{display:flex;align-items:center;gap:8px;flex-wrap:wrap;direction:ltr;justify-content:flex-start;}
.dims input{width:84px;text-align:center;}
.dims .x{color:var(--muted);font-weight:700;}
.unit-toggle{display:inline-flex;border:1.5px solid var(--line);border-radius:9px;overflow:hidden;}
.unit-toggle button{border:0;background:#fff;padding:8px 12px;cursor:pointer;font-size:13px;color:var(--muted);}
.unit-toggle button.active{background:var(--zygo);color:#fff;font-weight:700;}
.unit-label{color:var(--muted);font-weight:700;font-size:14px;}
.dims-extra{margin-top:8px;display:flex;flex-direction:column;gap:6px;}
.convert{font-size:13px;color:var(--zygo);font-weight:600;min-height:16px;}

/* image panel */
.dropzone{border:2.5px dashed var(--line);border-radius:14px;padding:38px 20px;text-align:center;
  background:#fafbff;transition:.15s;cursor:pointer;}
.dropzone.drag{border-color:var(--zygo);background:#eef1fc;}
.dz-icon{font-size:34px;color:var(--zygo);}
.dz-inner small{display:block;color:var(--muted);margin-top:8px;font-size:12px;}
.link{border:0;background:none;color:var(--zygo);font-weight:700;cursor:pointer;font-size:15px;text-decoration:underline;padding:0;}

.editor.hidden,.hidden{display:none!important;}
.stage-wrap{background:
   linear-gradient(45deg,#e9edf5 25%,transparent 25%,transparent 75%,#e9edf5 75%),
   linear-gradient(45deg,#e9edf5 25%,#fff 25%,#fff 75%,#e9edf5 75%);
  background-size:22px 22px;background-position:0 0,11px 11px;
  border-radius:12px;padding:10px;display:flex;justify-content:center;}
.stage{position:relative;max-width:100%;line-height:0;}
#canvas{max-width:100%;max-height:60vh;border-radius:6px;touch-action:none;}
.handles{position:absolute;inset:0;}
.handle{position:absolute;width:22px;height:22px;margin:-11px;border-radius:50%;
  background:rgba(43,63,158,.9);border:2px solid #fff;cursor:grab;box-shadow:0 2px 6px rgba(0,0,0,.3);}
.handle:active{cursor:grabbing;}
.quad-line{position:absolute;inset:0;pointer-events:none;}

.brush-cursor{position:absolute;border:1.5px solid #2b3f9e;border-radius:50%;
  box-shadow:0 0 0 1.5px rgba(255,255,255,.85);pointer-events:none;transform:translate(-50%,-50%);
  z-index:5;background:rgba(43,63,158,.06);}
.brush-cursor.hidden{display:none;}
.brush-cursor.restore{border-color:#1f9d55;background:rgba(31,157,85,.08);}

.busy{position:absolute;inset:0;background:rgba(255,255,255,.72);display:flex;
  flex-direction:column;align-items:center;justify-content:center;gap:12px;border-radius:6px;}
.spinner{width:38px;height:38px;border:4px solid #cfd6ee;border-top-color:var(--zygo);
  border-radius:50%;animation:spin 1s linear infinite;}
.busy span{color:var(--zygo);font-weight:700;font-size:14px;}
@keyframes spin{to{transform:rotate(360deg)}}

.tools{margin-top:14px;display:flex;flex-direction:column;gap:12px;}
.tool-group{display:flex;gap:8px;align-items:center;flex-wrap:wrap;}
.tool{border:1.5px solid var(--line);background:#fff;padding:9px 14px;border-radius:10px;
  cursor:pointer;font-size:14px;color:var(--ink);font-weight:600;transition:.12s;}
.tool:hover:not(:disabled){background:#f0f2fb;border-color:#c9cfe6;}
.tool:disabled{opacity:.45;cursor:not-allowed;}
.tool.primary{background:var(--zygo);color:#fff;border-color:var(--zygo);}
.tool.primary:hover{background:#233488;}
.tool.ghost{background:none;border-color:transparent;color:var(--muted);}
.tool.small{padding:6px 10px;font-size:13px;}
.tool.toggle.on{background:var(--zygo);color:#fff;border-color:var(--zygo);}
.tool.danger{border-color:#e0b4b4;color:#c0392b;background:#fdf3f3;font-weight:700;}
.tool.danger:hover:not(:disabled){background:#f9e6e6;border-color:#d99;}
.badge{background:#eef1fc;color:var(--zygo);padding:4px 9px;border-radius:20px;font-size:12px;font-weight:700;}

.brush-group .slider-mini,.sliders label{font-size:12px;color:var(--muted);display:flex;
  flex-direction:column;gap:2px;font-weight:600;}
.sliders{background:#fafbff;border:1px solid var(--line);border-radius:10px;padding:10px 12px;}
.sliders label{flex:1;min-width:90px;}
input[type=range]{accent-color:var(--zygo);cursor:pointer;}

.actions{max-width:1180px;margin:8px auto 60px;padding:0 20px;display:flex;align-items:center;gap:18px;}
.generate{background:var(--ok);color:#fff;border:0;padding:15px 40px;border-radius:12px;
  font-size:17px;font-weight:800;cursor:pointer;box-shadow:0 6px 18px rgba(31,157,85,.3);}
.generate:hover{background:#188047;}
.generate:disabled{opacity:.5;cursor:not-allowed;}
.result{display:flex;align-items:center;gap:14px;}
.dl{background:var(--zygo);color:#fff;padding:12px 22px;border-radius:10px;text-decoration:none;font-weight:700;}
.result-name{color:var(--muted);font-size:13px;}

.modal{position:fixed;inset:0;z-index:50;display:flex;align-items:center;justify-content:center;}
.modal-bg{position:absolute;inset:0;background:rgba(15,20,40,.6);}
.modal-body{position:relative;background:#fff;padding:16px;border-radius:14px;max-height:92vh;
  display:flex;flex-direction:column;gap:10px;align-items:center;box-shadow:var(--shadow);}
#preview-img{max-height:78vh;max-width:80vw;border:1px solid var(--line);border-radius:6px;}
.modal-actions{display:flex;gap:12px;align-items:center;}

.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:#1c2230;color:#fff;
  padding:12px 22px;border-radius:10px;font-size:14px;z-index:80;box-shadow:var(--shadow);
  opacity:0;transition:opacity .2s;}
.toast.show{opacity:1;}

/* login gate */
.login{position:fixed;inset:0;z-index:100;background:linear-gradient(160deg,#eef1fb,#f7f8fc);
  display:flex;align-items:center;justify-content:center;}
.login.hidden{display:none;}
.login-box{background:#fff;border:1px solid var(--line);border-radius:18px;padding:38px 40px;
  box-shadow:var(--shadow);display:flex;flex-direction:column;gap:14px;align-items:center;width:330px;}
.brand.big{font-size:44px;}
.login-sub{color:var(--muted);font-size:14px;margin-bottom:6px;}
.login-box input{width:100%;padding:13px 14px;border:1.5px solid var(--line);border-radius:10px;
  font-size:16px;text-align:center;letter-spacing:2px;}
.login-box input:focus{outline:none;border-color:var(--zygo);}
.generate.full{width:100%;padding:13px;font-size:16px;}
.login-err{color:#d33;font-size:13px;min-height:16px;}
.logout{margin-inline-start:auto;}
.sval{color:var(--zygo);font-weight:700;}