:root {
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #121826;
  --muted: #5b6475;
  --line: #dbe1ea;
  --brand: #0b6bcb;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Arial, sans-serif; background: var(--bg); color: var(--text); }
.topbar { padding: 16px 20px; border-bottom: 1px solid var(--line); background: var(--card); }
.topbar h1 { margin: 0; font-size: 22px; }
.topbar p { margin: 4px 0 0; color: var(--muted); }
.layout { display: grid; grid-template-columns: 280px 1fr; gap: 16px; padding: 16px; min-height: calc(100vh - 150px); }
.sidebar, .panel { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px; }
#search { width: 100%; padding: 10px; border: 1px solid var(--line); border-radius: 8px; }
.tool-btn { width: 100%; text-align: left; border: 1px solid var(--line); background: #fff; padding: 9px; margin-top: 8px; border-radius: 8px; cursor: pointer; }
.tool-btn:hover, .tool-btn.active { border-color: var(--brand); background: #eef6ff; }
.panel h2 { margin: 0 0 6px; }
.panel p { margin: 0 0 14px; color: var(--muted); }
.block { border: 1px solid var(--line); border-radius: 8px; padding: 10px; margin-bottom: 10px; }
input, textarea, select, button { font: inherit; }
textarea, input[type="text"], input[type="number"], input[type="password"], input[type="file"] { width: 100%; padding: 8px; border: 1px solid var(--line); border-radius: 8px; margin: 6px 0; }
button { padding: 8px 12px; border: none; background: var(--brand); color: #fff; border-radius: 8px; cursor: pointer; }
button.secondary { background: #3d495d; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.footer { border-top: 1px solid var(--line); background: var(--card); padding: 12px 16px; }
canvas.preview, img.preview { max-width: 100%; border: 1px solid var(--line); border-radius: 8px; margin-top: 8px; }
pre { background: #0f172a; color: #dbeafe; padding: 10px; border-radius: 8px; overflow: auto; }
@media (max-width: 900px) { .layout { grid-template-columns: 1fr; } }