:root{
  --bg:#f5f6fa;
  --panel:#ffffff;
  --line:#e6e8ef;
  --text:#1b1f2a;
  --muted:#7a8296;
  --brand:#4f46e5;
  --brand-soft:#eef0fe;
  --radius:10px;
  --side-w:250px;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font:14px/1.5 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  -webkit-font-smoothing:antialiased;
  display:flex;
  overflow:hidden;
}

/* ---------- sidebar ---------- */
.sidebar{
  width:var(--side-w);
  flex:0 0 var(--side-w);
  height:100%;
  background:var(--panel);
  border-right:1px solid var(--line);
  display:flex;
  flex-direction:column;
  transition:margin-left .22s ease;
  z-index:30;
}
body.collapsed .sidebar{margin-left:calc(-1 * var(--side-w))}

.brand{
  display:flex;flex-direction:column;align-items:center;
  padding:18px 14px 14px;
  border-bottom:1px solid #f0f1f6;
}
.brand-logo{
  display:flex;flex:0 0 auto;
  transition:transform .2s ease;
}
.brand-logo:hover{transform:scale(1.04) rotate(-2deg)}
.brand-logo img{
  width:88px;height:88px;display:block;
  border-radius:22px;
  box-shadow:0 4px 16px rgba(65,143,244,.30), 0 0 0 1.5px rgba(65,143,244,.16);
}
.brand-text{
  display:flex;flex-direction:column;align-items:center;
  line-height:1.3;min-width:0;margin-top:10px;
}
.brand-text strong{
  font-size:15px;font-weight:600;letter-spacing:.1px;
  white-space:nowrap;
}
.brand-text span{font-size:12px;color:var(--muted);margin-top:1px}

.nav{flex:1;overflow:auto;padding:6px 12px 12px}
.nav-label{
  font-size:11px;color:var(--muted);letter-spacing:.6px;
  padding:10px 8px 6px;text-transform:uppercase;
}
.nav-item{
  display:flex;align-items:center;gap:11px;
  padding:9px 10px;margin-bottom:3px;
  border-radius:var(--radius);
  color:#3a4152;text-decoration:none;
  cursor:pointer;user-select:none;
  border:1px solid transparent;
  transition:background .15s,color .15s;
}
.nav-item:hover{background:#f3f4f8}
.nav-item.active{background:var(--brand-soft);color:var(--brand);border-color:#e0e3fd;font-weight:600}
.nav-item .ico{
  width:30px;height:30px;flex:0 0 30px;
  display:flex;align-items:center;justify-content:center;
  border-radius:8px;background:#f1f2f7;color:#5b6478;
}
.nav-item.active .ico{background:var(--brand);color:#fff}
.nav-item .txt{display:flex;flex-direction:column;min-width:0}
.nav-item .t1{font-size:13.5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.nav-item .t2{font-size:11.5px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.nav-item.active .t2{color:#7b7fe0}

.side-foot{padding:10px 14px 14px;border-top:1px solid var(--line)}
.side-brand{
  display:flex;align-items:center;gap:9px;
  padding:2px 8px 10px;font-size:12.5px;color:#8b93a7;
}
.side-brand img{border-radius:8px;display:block}
.mini{
  display:flex;align-items:center;gap:6px;width:100%;
  background:none;border:0;color:var(--muted);
  font-size:12.5px;padding:8px 8px;border-radius:8px;cursor:pointer;
}
.mini:hover{background:#f3f4f8;color:var(--text)}

/* ---------- main ---------- */
.main{flex:1;min-width:0;height:100%;display:flex;flex-direction:column}
.topbar{
  height:64px;flex:0 0 64px;
  background:var(--panel);border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:12px;padding:0 16px;
}
.topbar-logo{
  display:flex;flex:0 0 auto;text-decoration:none;
  border-radius:11px;
  transition:transform .2s ease;
}
.topbar-logo:hover{transform:scale(1.05) rotate(-3deg)}
.topbar-logo img{
  width:40px;height:40px;display:block;border-radius:11px;
  box-shadow:0 2px 9px rgba(65,143,244,.26), 0 0 0 1px rgba(65,143,244,.14);
}
.icon-btn{
  display:none;background:none;border:0;color:var(--text);
  padding:6px;border-radius:8px;cursor:pointer;
}
.icon-btn:hover{background:#f3f4f8}
.topbar-title{min-width:0;flex:1}
.topbar-title h1{margin:0;font-size:15.5px;font-weight:600}
.topbar-title p{margin:1px 0 0;font-size:12px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-actions{display:flex;gap:8px}
.ghost-btn{
  display:inline-flex;align-items:center;gap:6px;
  border:1px solid var(--line);background:#fff;color:#495060;
  padding:7px 11px;border-radius:9px;font-size:12.5px;text-decoration:none;cursor:pointer;
}
.ghost-btn:hover{border-color:#c9cddb;color:var(--brand)}

.stage{position:relative;flex:1;min-height:0;background:var(--bg)}
.stage iframe{width:100%;height:100%;border:0;display:block;background:#fff}
.loading{
  position:absolute;inset:0;display:none;
  align-items:center;justify-content:center;gap:9px;
  background:var(--bg);color:var(--muted);font-size:13px;z-index:5;
}
body.is-loading .loading{display:flex}
.loading .spinner{
  width:16px;height:16px;border:2px solid #d6d9e3;border-top-color:var(--brand);
  border-radius:50%;animation:spin .7s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}

.mask{
  position:fixed;inset:0;background:rgba(17,20,30,.42);
  opacity:0;pointer-events:none;transition:opacity .2s;z-index:25;
}

/* ---------- responsive ---------- */
/* 收起后 / 窄屏时，汉堡按钮始终可见 —— 保证永远有入口把侧边栏拉回来 */
.icon-btn{display:none}
body.collapsed .icon-btn{display:block}

@media (max-width:900px){
  .sidebar{position:fixed;inset:0 auto 0 0;margin-left:calc(-1 * var(--side-w))}
  body.mobile-open .sidebar{margin-left:0}
  body.mobile-open .mask{opacity:1;pointer-events:auto}
  .icon-btn{display:block}
  body.collapsed .sidebar{margin-left:calc(-1 * var(--side-w))}
  .side-foot{display:none}
  .topbar-title p{display:none}
  .ghost-btn span{display:none}
  .ghost-btn{padding:7px 9px}
}