:root{--pri:#E54D42;--hero-start:#FF9F80;--bg-start:#FFD1C7;--bg-end:#FFC8B5}
*{box-sizing:border-box;margin:0;padding:0}
/* legacy body → scoped */
.app-page{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  background:linear-gradient(180deg,var(--bg-start),var(--bg-end) 50%,#fff5f0);
  height:100vh;display:flex;overflow:hidden;
}

/* ── Sidebar ── */
.sidebar{
  width:200px;background:#fff;border-right:1px solid #f0e0d8;display:flex;flex-direction:column;
  flex-shrink:0;box-shadow:2px 0 8px rgba(0,0,0,0.03);z-index:10;
}
.sidebar .sh{
  padding:16px 14px 10px;font-size:15px;font-weight:600;color:#333;
  border-bottom:1px solid #f5f0eb;
}
.sidebar .slist{flex:1;overflow-y:auto;padding:8px 0}
.sidebar .slist .item{
  padding:10px 14px;cursor:pointer;font-size:13px;color:#555;
  display:flex;align-items:center;justify-content:space-between;
  border-left:3px solid transparent;transition:background 0.1s;
}
.sidebar .slist .item:hover{background:#fdf8f5}
.sidebar .slist .item.active{background:#fff0ed;border-left-color:var(--pri);color:var(--pri);font-weight:600}
.sidebar .slist .item .del{font-size:11px;color:#ccc;visibility:hidden;cursor:pointer}
.sidebar .slist .item:hover .del{visibility:visible}
.sidebar .slist .item .del:hover{color:var(--pri)}
.sidebar .sb{display:flex;gap:6px;padding:10px 12px;border-top:1px solid #f5f0eb}
.sidebar .sb button{
  flex:1;padding:8px 0;border:1px solid #ddd;border-radius:6px;
  background:#fff;font-size:12px;cursor:pointer;color:#555;
}
.sidebar .sb button.primary{background:var(--pri);color:#fff;border-color:var(--pri)}
.sidebar .sb button:active{opacity:0.8}

/* ── Main ── */
.main{flex:1;display:flex;flex-direction:column;overflow:hidden}
.toolbar{
  display:flex;align-items:center;gap:6px;padding:8px 12px;
  background:rgba(255,255,255,0.9);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  border-bottom:1px solid #f0e0d8;flex-shrink:0;flex-wrap:wrap;z-index:10;
}
.toolbar button{
  padding:6px 12px;border:1px solid #ddd;border-radius:6px;
  background:#fff;font-size:13px;cursor:pointer;color:#555;
}
.toolbar button:active{background:#f0ebe5}
.toolbar button.primary{background:var(--pri);color:#fff;border-color:var(--pri)}
.toolbar .sep{width:1px;height:20px;background:#ddd;margin:0 2px}
.toolbar .hint{font-size:11px;color:#aaa;margin-left:auto}
canvas{flex:1;display:block;cursor:grab}
canvas:active{cursor:grabbing}
#editor{position:absolute;display:none;z-index:20}
#editor input{
  padding:4px 8px;border:2px solid var(--pri);border-radius:4px;
  font-size:13px;outline:none;min-width:80px;background:#fff;
}
/* Plus buttons */
#plusChild,#plusSibling{
  position:absolute;display:none;z-index:25;
  width:20px;height:20px;border-radius:50%;
  color:#fff;font-size:14px;font-weight:bold;line-height:20px;
  text-align:center;cursor:pointer;user-select:none;
  pointer-events:auto;
}

/* Mobile */
@media(max-width:600px){
  .sidebar{
    position:fixed;left:0;top:0;bottom:0;width:240px;z-index:30;
    transform:translateX(-100%);transition:transform 0.25s ease;
    box-shadow:4px 0 20px rgba(0,0,0,0.1);
  }
  .sidebar.open{transform:translateX(0)}
  .sidebar .sh{font-size:16px;padding:18px 16px 12px}
  .sidebar .slist .item{font-size:14px;padding:12px 16px}
  .sidebar .sb button{padding:10px 0;font-size:13px}
  /* hamburger */
  .hamburger{
    display:flex!important;position:fixed;top:8px;left:8px;z-index:40;
    width:36px;height:36px;align-items:center;justify-content:center;
    background:rgba(255,255,255,0.9);border-radius:8px;
    border:1px solid #e0d5cf;font-size:18px;cursor:pointer;
    -webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  }
  /* overlay backdrop */
  .overlay{
    display:none;position:fixed;inset:0;z-index:25;
    background:rgba(0,0,0,0.25);
  }
  .overlay.show{display:block}
  /* toolbar compact */
  .toolbar{gap:3px;padding:6px 6px 6px 50px;min-height:42px}
  .toolbar button{padding:6px 10px;font-size:12px;border-radius:8px}
  .toolbar .sep{margin:0 1px}
  .toolbar .hint{font-size:10px;display:none}
  /* canvas */
  canvas{flex:1}
  /* editor bigger for touch */
  #editor input{font-size:16px!important;padding:8px 12px;min-width:100px;border-radius:6px}
  /* node hit area larger on mobile */
  .mobile .toolbar button{min-height:32px}
}
/* Desktop: hide hamburger */
.hamburger{display:none}