:root {
  --bg: #0f1419;
  --card: #1a222c;
  --text: #e6edf3;
  --muted: #8b9caa;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --err: #f87171;
  --ok: #4ade80;
  --border: #2d3a47;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(1200px 600px at 20% -10%, #1e3a5f 0%, transparent 50%),
    var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.wrap {
  max-width: 32rem;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 3rem;
}

h1 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
}

.intro {
  color: var(--muted);
  font-size: 0.85rem;
  margin: 0 0 2rem;
  line-height: 1.45;
}

h2 {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
}

.section {
  margin-bottom: 2.75rem;
}

.section:last-of-type {
  margin-bottom: 0;
}

.optional-hint {
  color: var(--muted);
  font-size: 0.82rem;
  margin: -0.25rem 0 0;
  line-height: 1.45;
}

.optional-hint code {
  font-size: 0.8em;
  color: var(--text);
}

.file-label--muted {
  padding: 1rem;
  opacity: 0.95;
}

.lede {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 1.5rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.file-label {
  display: block;
  border: 2px dashed var(--border);
  border-radius: 8px;
  padding: 2rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.file-label:hover,
.file-label:focus-within {
  border-color: var(--accent);
  background: rgba(59, 130, 246, 0.06);
}

.file-label input {
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
  pointer-events: none;
}

.file-prompt {
  color: var(--muted);
  font-size: 0.9rem;
}

.btn {
  appearance: none;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  transition: background 0.15s, opacity 0.15s;
}

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

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

.status {
  margin: 1rem 0 0;
  min-height: 1.5rem;
  font-size: 0.9rem;
  color: var(--ok);
}

.err {
  margin: 0.5rem 0 0;
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--err);
}

.file-label.drag {
  border-color: var(--accent);
  background: rgba(59, 130, 246, 0.1);
}