:root {
  --bg: #0b0f14;
  --card: #111827;
  --muted: #9ca3af;
  --text: #e5e7eb;
  --accent: #3b82f6;
  --accent-700: #1d4ed8;
  --success: #10b981;
  --error: #ef4444;
  --border: #1f2937;
  --shadow: 0 10px 30px rgba(0,0,0,0.30);
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0; font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: radial-gradient(1200px 800px at 10% -10%, rgba(59,130,246,0.15), rgba(0,0,0,0)) , var(--bg);
  color: var(--text);
}
.app-header { max-width: 1000px; margin: 24px auto 12px; padding: 0 16px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { display: flex; gap: 12px; align-items: center; }
.brand img { filter: drop-shadow(0 4px 10px rgba(59,130,246,0.4)); }
.titles h1 { font-size: 20px; margin: 0; }
.subtitle { margin: 2px 0 0; color: var(--muted); font-size: 12px; }
.meta { display: flex; gap: 8px; align-items: center; }
.pill { background: #0f172a; border: 1px solid var(--border); padding: 6px 10px; border-radius: 999px; color: var(--muted); font-size: 12px; }
.container { max-width: 1000px; margin: 0 auto 60px; padding: 0 16px; display: grid; gap: 16px; }
.card { background: linear-gradient(180deg, rgba(17,24,39,0.95), rgba(17,24,39,0.98)); border: 1px solid var(--border); border-radius: 14px; padding: 16px; box-shadow: var(--shadow); }
.card h2 { margin: 4px 0 16px; font-size: 18px; }
.field { display: grid; gap: 6px; margin-bottom: 12px; }
.field label { font-weight: 600; }
.field small { color: var(--muted); }
input[type="text"], input[type="file"] { background: #0b1220; color: var(--text); border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; width: 100%; }
input[type="file"] { padding: 8px; }
.actions { display: flex; align-items: center; gap: 10px; margin-top: 8px; flex-wrap: wrap; }
.btn { appearance: none; border: 1px solid var(--accent); background: linear-gradient(180deg, var(--accent), var(--accent-700)); color: white; padding: 10px 14px; border-radius: 10px; cursor: pointer; font-weight: 600; box-shadow: 0 4px 18px rgba(59,130,246,0.35); text-decoration: none; display: inline-flex; align-items: center; gap: 8px; }
.btn:hover { filter: brightness(1.05); }
.btn.ghost { background: transparent; color: var(--text); border: 1px solid var(--border); box-shadow: none; }
.btn.xs { padding: 4px 8px; font-size: 11px; border-radius: 6px; }
.hint { color: var(--muted); font-size: 12px; }
.alert { border-radius: 12px; padding: 10px 12px; border: 1px solid var(--border); }
.alert.success { background: rgba(16,185,129,0.12); border-color: rgba(16,185,129,0.3); }
.alert.error { background: rgba(239,68,68,0.10); border-color: rgba(239,68,68,0.35); }
.empty { color: var(--muted); padding: 6px 2px; }
.grid.two { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.label { color: var(--muted); font-size: 12px; margin-bottom: 4px; }
.value { font-weight: 600; }
.stack { display: grid; gap: 12px; margin-top: 10px; }
.block { background: #0b1220; border: 1px solid var(--border); border-radius: 12px; padding: 12px; }
.block-head { display: flex; justify-content: space-between; align-items: center; gap: 6px; margin-bottom: 6px; }
.mini-block { border-top: 1px dashed var(--border); padding-top: 8px; margin-top: 6px; }
.mini-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 4px; }
ul { margin: 0; padding-left: 18px; }
.mono { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; color: var(--muted); }
.muted { color: var(--muted); }
.history .history-item { margin-bottom: 8px; border: 1px solid var(--border); border-radius: 10px; padding: 8px 10px; background: #0b1220; }
.history summary { cursor: pointer; list-style: none; display: flex; gap: 8px; align-items: center; }
.history summary::-webkit-details-marker { display: none; }
.history .history-body { margin-top: 8px; }
.export-actions { display: flex; gap: 10px; margin-top: 12px; }
.app-footer { max-width: 1000px; margin: 16px auto 24px; padding: 0 16px; color: var(--muted); }

/* Accessibility */
:focus { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn:focus { box-shadow: 0 0 0 3px rgba(59,130,246,0.35); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* Submitting state */
body.submitting { cursor: progress; }
body.submitting .btn.primary { opacity: 0.75; pointer-events: none; }

/* Responsive */
@media (max-width: 700px) {
  .grid.two { grid-template-columns: 1fr; }
  .app-header { flex-direction: column; align-items: flex-start; gap: 8px; }
}