:root {
  --bg: #f8f9fb;
  --panel: #ffffff;
  --border: #d7d9e0;
  --accent: #6e2ca8;
  --accent-hover: #5a2289;
  --muted: #6a7280;
  --text: #1f2230;
  --radius: 8px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  max-width: 640px;
  width: 100%;
  margin: 3rem auto 0;
  padding: 0 1.5rem 2rem;
  flex: 1;
}

header h1 {
  margin: 0 0 0.25rem;
  font-size: 2rem;
  color: var(--accent);
}

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

h2 {
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  margin: 1.5rem 0 0.75rem;
}

#drop-zone {
  display: block;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  padding: 2.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

#drop-zone:hover,
#drop-zone.dragover {
  border-color: var(--accent);
  background: #f3ebfa;
}

#drop-zone-text,
#file-name {
  color: var(--muted);
  font-size: 0.95rem;
}

#file-name { color: var(--text); font-weight: 600; }

.checkbox-list {
  list-style: none;
  padding: 0;
  margin: 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.checkbox-list li + li { border-top: 1px solid var(--border); }

.checkbox-list label {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.7rem 1rem;
  cursor: pointer;
  font-size: 0.95rem;
}

.actions {
  margin-top: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

button {
  background: var(--accent);
  color: white;
  border: 0;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius);
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.15s;
}
button:hover:not([disabled]) { background: var(--accent-hover); }
button[disabled] { background: #aaa; cursor: not-allowed; }

#status {
  color: var(--muted);
  font-size: 0.9rem;
}
#status.error { color: #c03030; }
#status.ok { color: #2e8031; }

footer {
  border-top: 1px solid var(--border);
  padding: 0.75rem 1.5rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  background: var(--panel);
}