:root{
  --bg:#0f1115; --panel:#141821; --panel2:#10131a;
  --line:#242a36; --text:#e8ecf2; --muted:#9aa6b2;
  --accent:#3aa0ff; --select:rgba(58,160,255,.18);
  --selectBorder:rgba(58,160,255,.45);
  --shadow:0 10px 30px rgba(0,0,0,.45);
  --radius:12px;
  --mono:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;
  --ui:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
}

*{ box-sizing:border-box; }
body{
  margin:0;
  background: radial-gradient(1200px 800px at 20% 10%, #192033 0%, var(--bg) 60%);
  color:var(--text);
  font-family:var(--ui);
}

.window{
  width:min(1400px, 96vw);
  height:min(820px, 92vh);
  margin:4vh auto;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  overflow:hidden;
  display:flex;
  flex-direction:column;
}

.topbar{
  display:grid;
  grid-template-columns: auto 1fr 320px;
  gap:12px;
  align-items:center;
  padding:10px 12px;
  border-bottom:1px solid var(--line);
  background:linear-gradient(180deg, rgba(255,255,255,.03), rgba(255,255,255,0));
}

.navbtns{ display:flex; gap:6px; }
.iconbtn{
  width:34px; height:30px;
  border:1px solid var(--line);
  border-radius:8px;
  background:var(--panel2);
  color:var(--text);
  cursor:pointer;
}
.iconbtn:disabled{ opacity:.4; cursor:not-allowed; }

.crumbs{
  border:1px solid var(--line);
  background:var(--panel2);
  border-radius:10px;
  padding:6px 10px;
  overflow:hidden;
  white-space:nowrap;
  text-overflow:ellipsis;
}
.crumbs a{ color:var(--text); text-decoration:none; }
.crumbs .sep{ color:var(--muted); padding:0 6px; }
.crumbs .current{ color:var(--muted); }

.search input{
  width:100%;
  border:1px solid var(--line);
  background:var(--panel2);
  border-radius:10px;
  padding:8px 10px;
  color:var(--text);
  outline:none;
}
.search input:focus{
  border-color:var(--accent);
  box-shadow:0 0 0 3px rgba(58,160,255,.15);
}

.main{
  flex:1;
  display:grid;
  grid-template-columns: 280px 1fr 360px;
  min-height:0;
}

.sidebar, .content, .preview{
  min-height:0;
  display:flex;
  flex-direction:column;
}

.sidebar{
  border-right:1px solid var(--line);
  background:rgba(0,0,0,.12);
}
.preview{
  border-left:1px solid var(--line);
  background:rgba(0,0,0,.10);
}

.paneTitle{
  padding:10px 12px;
  border-bottom:1px solid var(--line);
  color:var(--muted);
  font-size:12px;
  letter-spacing:.08em;
  text-transform:uppercase;
}

.tree{
  padding:8px;
  overflow:auto;
}
.tree .node{
  display:flex;
  align-items:center;
  gap:8px;
  padding:6px 8px;
  border-radius:8px;
  cursor:pointer;
  user-select:none;
}
.tree .node:hover{ background:rgba(255,255,255,.04); }
.tree .node.active{
  background:var(--select);
  outline:1px solid var(--selectBorder);
}
.tree .twisty{ width:14px; color:var(--muted); text-align:center; }
.tree .icon{ width:16px; opacity:.9; }
.tree .label{ flex:1; }
.tree .children{ margin-left:18px; border-left:1px dashed rgba(255,255,255,.08); padding-left:10px; }

.content{ background:rgba(0,0,0,.06); }

/* 3 columns only: Name | Type | Size */
.listHeader{
  display:grid;
  grid-template-columns: 1fr 140px 90px;
  gap:12px;
  padding:8px 12px;
  border-bottom:1px solid var(--line);
  font-size:12px;
  color:var(--muted);
}

.list{
  overflow:auto;
}

.row{
  display:grid;
  grid-template-columns: 1fr 140px 90px;
  gap:12px;
  padding:8px 12px;
  border-bottom:1px solid rgba(255,255,255,.06);
  cursor:pointer;
}
.row:hover{ background:rgba(255,255,255,.03); }
.row.selected{
  background:var(--select);
  outline:1px solid var(--selectBorder);
}

.nameCell{
  display:flex;
  align-items:center;
  gap:10px;
  min-width:0;
}
.nameCell .fileIcon{ width:18px; opacity:.95; }
.nameCell .text{
  overflow:hidden;
  white-space:nowrap;
  text-overflow:ellipsis;
}

.previewInner{
  padding:12px;
  overflow:auto;
}
.preview img{
  width:100%;
  height:auto;
  border-radius:12px;
  border:1px solid var(--line);
  background:#0b0d12;
}
.preview .meta{
  margin-top:10px;
  font-family:var(--mono);
  font-size:12px;
  color:var(--muted);
  line-height:1.5;
}
.muted{ color:var(--muted); }

.statusbar{
  display:flex;
  justify-content:space-between;
  gap:12px;
  padding:8px 12px;
  border-top:1px solid var(--line);
  background:rgba(0,0,0,.12);
  color:var(--muted);
  font-size:12px;
}