:root{
    --bg:#0f1220; --ink:#e9ecf1; --muted:#aeb6c7; --accent:#7aa2ff; --card:#171a2b; --card2:#1d2237; --line:#2a3152;
  }
  *{box-sizing:border-box}
  html,body{height:100%}
  body{
    margin:0; background:linear-gradient(180deg,#0c0f1a 0%, #0f1220 40%, #0a0d18 100%);
    color:var(--ink); font: 15px/1.45 system-ui, -apple-system, Segoe UI, Roboto, Inter, "Helvetica Neue", Arial;
    display:grid; grid-template-columns: 330px 1fr; grid-template-rows:auto 1fr; gap:0; overflow:hidden;
  }
  header{
    grid-column:1 / -1; display:flex; align-items:center; justify-content:space-between;
    padding:12px 16px; border-bottom:1px solid var(--line); background:rgba(9,11,20,.7); backdrop-filter: blur(6px);
  }
  header h1{font-size:16px; margin:0; font-weight:700; letter-spacing:.2px}
  header .hint{color:var(--muted); font-size:13px}
  .sidebar{
    border-right:1px solid var(--line); overflow:auto; padding:12px; background:linear-gradient(180deg, #12162a, #101426);
  }
  .group{border:1px solid var(--line); border-radius:12px; margin-bottom:12px; overflow:hidden; background:var(--card)}
  .group summary{
    cursor:pointer; padding:12px 14px; background:var(--card2); user-select:none; list-style:none; outline:none;
    font-weight:700; letter-spacing:.2px;
  }
  .group summary::-webkit-details-marker{display:none}
  .group .items{padding:10px 8px 12px 8px; display:grid; grid-template-columns:1fr 1fr; gap:8px}
  button.item{
    background:#12162a; color:var(--ink); border:1px solid var(--line); border-radius:10px; padding:10px 8px; cursor:pointer;
    text-align:left; transition:.15s transform, .15s border-color, .15s background;
    min-height:52px;
  }
  button.item:hover{transform:translateY(-1px); border-color:#2f5dff; background:#10152b}
  .main{ position:relative; display:grid; grid-template-rows: 1fr auto; height:100%; min-height:0; }
  #viewport{width:100%; height:100%; display:block; background:radial-gradient(1200px 800px at 70% 20%, #1a2038, #0f1220 60%); min-height:0;}
  .panel{
    border-top:1px solid var(--line); padding:12px 16px; display:flex; align-items:center; gap:16px; background:rgba(16,20,38,.8); flex-wrap:wrap;
  }
  .panel .info{flex:1; min-width:220px}
  .panel .info .title{font-weight:800; margin-bottom:4px}
  .panel .info .desc{color:var(--muted)}
  .controls{display:flex; gap:10px; flex-wrap:wrap; align-items:center}
  .btn{padding:8px 10px; background:#12162a; color:var(--ink); border:1px solid var(--line); border-radius:8px; cursor:pointer}
  .btn:hover{border-color:#2f5dff}
  .kbd{font-family:ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
       font-size:12px; background:#0d1123; border:1px solid var(--line); padding:2px 6px; border-radius:6px; color:#cbd4ff}
  .badge{display:inline-block; padding:2px 8px; border:1px solid var(--line); border-radius:999px; margin-left:6px; font-size:12px; color:#cbd4ff}
  .row{display:flex; align-items:center; gap:6px}
  .col{display:flex; flex-direction:column; gap:6px}
  label{font-size:13px; color:#aeb6c7; min-width:74px}
  input[type="color"]{inline-size:36px; block-size:28px; border:1px solid var(--line); background:#0b0f20; border-radius:6px; padding:0}
  input[type="range"]{width:160px}
  .tiny{font-size:12px; color:#9fb0df}