* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Segoe UI', Tahoma, Geneva, sans-serif;
  font-size: 12px;
  background: #fff;
  color: #000;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.titlebar {
  background: linear-gradient(to bottom, #dce9f8 0%, #b8d4f0 40%, #9bbde8 60%, #b2cfe8 100%);
  border-bottom: 1px solid #6a9fd4;
  display: flex;
  align-items: center;
  padding: 4px 6px;
  gap: 6px;
  user-select: none;
}
.titlebar-icon {
  width: 16px; height: 16px;
  background: radial-gradient(circle at 40% 35%, #ffe066, #e08000);
  border-radius: 2px;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 10px;
}
.titlebar-text {
  font-size: 12px;
  color: #1a1a1a;
  font-weight: normal;
  flex: 1;
}
.titlebar-btns {
  display: flex; gap: 2px;
}
.tbtn {
  width: 21px; height: 17px;
  border: 1px solid #7badd4;
  border-radius: 3px;
  font-size: 11px;
  cursor: default;
  display: flex; align-items: center; justify-content: center;
  color: #333;
}
.tbtn.min { background: linear-gradient(to bottom, #e8f0fa, #c8d8ee); }
.tbtn.max { background: linear-gradient(to bottom, #e8f0fa, #c8d8ee); }
.tbtn.cls { background: linear-gradient(to bottom, #f4a0a0, #d84040); color: #fff; border-color: #b03030; }

.addressbar {
  background: linear-gradient(to bottom, #f0f4fc, #dce8f8);
  border-bottom: 1px solid #b0c8e0;
  padding: 4px 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-btn {
  width: 26px; height: 22px;
  background: linear-gradient(to bottom, #e0ecf8, #c0d8f0);
  border: 1px solid #90b8d8;
  border-radius: 3px;
  font-size: 13px;
  color: #2060a0;
  cursor: default;
  display: flex; align-items: center; justify-content: center;
}
.nav-btn.fwd { color: #aaa; }
.address-box {
  flex: 1;
  background: #fff;
  border: 1px solid #90b8d8;
  border-radius: 2px;
  padding: 2px 6px;
  font-size: 12px;
  color: #333;
  display: flex; align-items: center; gap: 4px;
}
.address-crumb { color: #0066cc; cursor: default; }
.address-crumb:hover { text-decoration: underline; }
.address-sep { color: #888; }
.search-box {
  width: 160px;
  background: #fff;
  border: 1px solid #90b8d8;
  border-radius: 10px;
  padding: 2px 8px;
  font-size: 11px;
  color: #aaa;
  display: flex; align-items: center; gap: 4px;
}

.toolbar {
  background: linear-gradient(to bottom, #f8faff, #e8f0fc);
  border-bottom: 1px solid #c8d8ee;
  padding: 3px 10px;
  display: flex;
  align-items: center;
  gap: 2px;
  font-size: 12px;
}
.tool-btn {
  padding: 3px 8px;
  border: 1px solid transparent;
  border-radius: 3px;
  cursor: default;
  color: #333;
  display: flex; align-items: center; gap: 4px;
  font-size: 12px;
}
.tool-btn:hover {
  background: linear-gradient(to bottom, #e8f4ff, #c8e0f8);
  border-color: #90b8d8;
}
.tool-sep { width: 1px; height: 18px; background: #c0d0e0; margin: 0 4px; }
.view-by {
  margin-left: auto;
  display: flex; align-items: center; gap: 6px;
  color: #555;
}
.view-select {
  border: 1px solid #90b8d8;
  border-radius: 2px;
  padding: 1px 4px;
  background: #fff;
  font-size: 11px;
  color: #333;
}

.shell {
  display: flex;
  flex: 1;
}

.nav-pane {
  width: 180px;
  background: linear-gradient(to bottom, #dce8f8 0%, #c8dcf4 100%);
  border-right: 1px solid #a8c4e0;
  padding: 8px 0;
  flex-shrink: 0;
}
.nav-section-title {
  font-size: 11px;
  font-weight: bold;
  color: #1a4880;
  padding: 6px 10px 3px;
  margin-top: 4px;
}
.nav-link {
  display: block;
  padding: 3px 10px 3px 16px;
  color: #0033aa;
  text-decoration: none;
  font-size: 11px;
  line-height: 1.5;
}
.nav-link:hover {
  background: rgba(255,255,255,0.5);
  text-decoration: underline;
}
.nav-divider {
  height: 1px;
  background: #a8c4e0;
  margin: 6px 8px;
}

.content {
  flex: 1;
  padding: 16px 20px;
  background: #fff;
  overflow-y: auto;
}
.content-title {
  font-size: 13px;
  color: #1a4880;
  font-weight: normal;
  margin-bottom: 16px;
  padding-bottom: 6px;
  border-bottom: 1px solid #dde8f4;
}

.category-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}
.category-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 2px;
  cursor: default;
}
.category-item:hover {
  background: #e8f0fc;
}
.cat-icon {
  width: 40px; height: 40px;
  flex-shrink: 0;
  border-radius: 2px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
}
.cat-text { flex: 1; }
.cat-title {
  display: block;
  color: #0033cc;
  font-size: 12.5px;
  font-weight: normal;
  text-decoration: none;
  line-height: 1.4;
}
.cat-title:hover { text-decoration: underline; }
.cat-sub {
  display: block;
  margin-top: 2px;
}
.cat-sub a {
  display: block;
  color: #0033cc;
  font-size: 11px;
  text-decoration: none;
  line-height: 1.6;
}
.cat-sub a:hover { text-decoration: underline; }

.statusbar {
  background: linear-gradient(to bottom, #dce8f8, #c8dcf4);
  border-top: 1px solid #a8c4e0;
  padding: 3px 10px;
  font-size: 11px;
  color: #444;
}

footer {
  background: #f0f4fc;
  border-top: 1px solid #c8d8ee;
  padding: 8px 16px;
  font-size: 10px;
  color: #666;
  text-align: center;
  line-height: 1.7;
}
footer a { color: #0044aa; text-decoration: none; }
footer a:hover { text-decoration: underline; }