:root {
  --bg: #0c111d;
  --panel: #151d2e;
  --text: #e8edf5;
  --muted: #8b96ad;
  --accent: #38bdf8;
  --danger: #f87171;
  --success: #4ade80;
  --border: #253047;
  font-family: "DM Sans", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at 20% 0%, #1e3a5f 0%, transparent 45%), var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.wrap {
  max-width: 900px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

h1 {
  font-weight: 600;
  font-size: 1.75rem;
  letter-spacing: -0.03em;
  margin: 0 0 0.5rem;
}

.sub {
  color: var(--muted);
  margin: 0 0 2rem;
  font-size: 0.95rem;
}

.zone {
  border: 2px dashed var(--border);
  border-radius: 14px;
  padding: 2.5rem 1.25rem;
  text-align: center;
  background: rgba(21, 29, 46, 0.65);
  transition: border-color 0.18s ease, background 0.18s ease;
}

.zone.dragover {
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.08);
}

.zone p {
  margin: 0.35rem 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.btn {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.65rem 1.4rem;
  border-radius: 10px;
  border: none;
  background: linear-gradient(140deg, #0ea5e9, #2563eb);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.9rem;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn.secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--accent);
}

.row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.25rem;
  justify-content: center;
}

.progress {
  height: 4px;
  border-radius: 4px;
  background: var(--border);
  margin-top: 1rem;
  overflow: hidden;
  display: none;
}

.progress.on {
  display: block;
}

.progress > span {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.1s linear;
}

.out {
  margin-top: 2rem;
  padding: 1rem 1rem 1rem;
  background: var(--panel);
  border-radius: 12px;
  border: 1px solid var(--border);
  display: none;
}

.out.visible {
  display: block;
}

.out h2 {
  font-size: 1rem;
  margin: 0 0 0.75rem;
  font-weight: 600;
}

pre {
  margin: 0;
  padding: 0.85rem 1rem;
  background: rgba(0, 0, 0, 0.25);
  border-radius: 8px;
  font-size: 0.74rem;
  overflow: auto;
  max-height: 420px;
  white-space: pre-wrap;
  word-break: break-word;
}

.err {
  color: var(--danger);
  font-size: 0.89rem;
  margin-top: 1rem;
  display: none;
}

.err.visible {
  display: block;
}

.meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.65rem;
}

kbd {
  background: rgba(255, 255, 255, 0.06);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.78rem;
}

@media (max-width: 520px) {
  .wrap {
    padding-top: 1.5rem;
  }
}