* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, 'Apple Color Emoji', 'Segoe UI Emoji';
  color: #0f172a;
  background: #f8fafc;
}

.container {
  width: min(1100px, 92vw);
  margin: 0 auto;
}

.app-header {
  background: linear-gradient(135deg, #0ea5e9, #6366f1);
  color: white;
  padding: 40px 0 28px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.25);
}
.app-header h1 { margin: 0 0 8px; font-weight: 700; letter-spacing: -0.02em; }
.app-header .subtitle { margin: 0; opacity: 0.95; }

.app-footer {
  padding: 24px 0 48px;
  color: #475569;
  text-align: center;
}

.card {
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 14px;
  padding: 20px;
  margin: 22px 0;
  box-shadow: 0 2px 6px rgba(15, 23, 42, 0.04);
}
.card h2 {
  margin: 0 0 14px;
  font-size: 20px;
}

.label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
}

.import-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
@media (max-width: 860px) {
  .import-grid { grid-template-columns: 1fr; }
}

#fileInput {
  display: block;
  width: 100%;
}

.drop-zone {
  margin-top: 10px;
  border: 2px dashed #94a3b8;
  border-radius: 10px;
  padding: 16px;
  text-align: center;
  color: #64748b;
  background: #f8fafc;
}
.drop-zone.dragover {
  border-color: #3b82f6;
  background: #eff6ff;
  color: #1d4ed8;
}

#textInput {
  width: 100%;
  min-height: 170px;
  resize: vertical;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  padding: 12px 14px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
  line-height: 1.45;
}

.actions { margin-top: 12px; display: flex; gap: 10px; flex-wrap: wrap; }

.btn {
  appearance: none;
  border: 1px solid #cbd5e1;
  background: white;
  color: #0f172a;
  border-radius: 10px;
  padding: 10px 14px;
  font-weight: 600;
  cursor: pointer;
}
.btn:hover { border-color: #94a3b8; background: #f8fafc; }
.btn:disabled { opacity: 0.6; cursor: not-allowed; }

.btn-primary {
  background: #2563eb;
  border-color: #1d4ed8;
  color: white;
}
.btn-primary:hover { background: #1d4ed8; }

.btn-secondary {
  background: #f1f5f9;
}

.stats { margin-top: 10px; color: #475569; display: flex; gap: 8px; align-items: center; }
.hint { color: #64748b; margin-top: 6px; }
.feedback { margin-top: 10px; min-height: 22px; }
.feedback.error { color: #b91c1c; }
.feedback.success { color: #065f46; }

.preview {
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  background: #0b1020;
  color: #d1e7ff;
  padding: 0;
  overflow: auto;
  max-height: 420px;
}

.line { display: grid; grid-template-columns: 64px 1fr; gap: 0; border-bottom: 1px solid rgba(255, 255, 255, 0.06); }
.line:last-child { border-bottom: none; }

.lineno {
  background: #0a0f1d;
  color: #64748b;
  padding: 6px 10px;
  text-align: right;
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  user-select: none;
  font-variant-numeric: tabular-nums;
}
.content {
  padding: 6px 10px;
  white-space: pre-wrap;
  word-break: break-word;
}

.removed .content { color: #fca5a5; text-decoration: line-through; }

.ranges-row { display: flex; gap: 10px; }
.ranges-input {
  flex: 1;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  padding: 10px 12px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
}

#resultStats { color: #334155; }