:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --border: #2d3a4d;
  --text: #e8edf4;
  --muted: #8b9cb3;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --error: #f87171;
  --warning: #fbbf24;
  --success: #34d399;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

header h1 {
  font-size: 1.75rem;
  margin: 0 0 0.25rem;
}

.subtitle {
  color: var(--muted);
  margin: 0;
}

.upload-section {
  margin-top: 2rem;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 2.5rem 1.5rem;
  text-align: center;
  background: var(--surface);
  transition: border-color 0.2s, background 0.2s;
}

.drop-zone.drag-over {
  border-color: var(--primary);
  background: #1e2d42;
}

.drop-zone .hint {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

.link-btn {
  background: none;
  border: none;
  color: var(--primary);
  cursor: pointer;
  text-decoration: underline;
  font-size: inherit;
}

.file-name {
  margin: 1rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  cursor: pointer;
  font-weight: 500;
}

.btn.primary {
  background: var(--primary);
  color: white;
}

.btn.primary:hover:not(:disabled) {
  background: var(--primary-hover);
}

.btn.primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn.secondary:hover {
  background: #243044;
}

.hidden {
  display: none !important;
}

.error-section {
  margin-top: 1.5rem;
  padding: 1rem;
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid var(--error);
  border-radius: 8px;
}

.error-msg {
  color: var(--error);
  margin: 0;
}

.preview-section {
  margin-top: 2rem;
}

.preview-section h2 {
  font-size: 1.25rem;
  margin: 0 0 0.5rem;
}

.meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.warnings {
  margin-bottom: 1rem;
  padding: 0.75rem 1rem;
  background: rgba(251, 191, 36, 0.1);
  border: 1px solid var(--warning);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--warning);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

th, td {
  padding: 0.6rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  background: var(--surface);
  color: var(--muted);
  font-weight: 600;
}

tbody tr:hover {
  background: rgba(255, 255, 255, 0.03);
}

.actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn-icon {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--primary);
  cursor: pointer;
  font-size: 0.8rem;
  padding: 0.25rem 0.5rem;
}

.btn-icon:hover {
  background: var(--surface);
  border-color: var(--primary);
}