:root {
  --text: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --brand: #06c755; /* LINE green */
  --bg: #f9fafb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 2rem 1.25rem 4rem;
  font-family: system-ui, -apple-system, 'Hiragino Sans', 'Noto Sans JP', sans-serif;
  line-height: 1.8;
  color: var(--text);
  background: var(--bg);
}

main {
  max-width: 34rem;
  margin: 0 auto;
}

.card {
  background: #fff;
  padding: 1.75rem;
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

h1 {
  font-size: 1.4rem;
  margin: 0 0 0.5rem;
}

h2 {
  font-size: 1.05rem;
  margin: 2rem 0 0.5rem;
}

p {
  margin: 0 0 1rem;
}

.lead {
  color: var(--muted);
  margin-bottom: 2rem;
}

ol,
ul {
  padding-left: 1.3rem;
  margin: 0 0 1rem;
}

li {
  margin-bottom: 0.4rem;
}

.step {
  border-top: 1px solid var(--line);
  padding-top: 1.25rem;
  margin-top: 1.25rem;
}

.step:first-of-type {
  border-top: 0;
  padding-top: 0;
  margin-top: 0;
}

.step-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 0.25rem;
}

button,
.button {
  display: inline-block;
  appearance: none;
  border: 0;
  border-radius: 8px;
  background: var(--brand);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  text-decoration: none;
}

button:disabled {
  background: #d1d5db;
  cursor: not-allowed;
}

.secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--line);
}

.note {
  font-size: 0.875rem;
  color: var(--muted);
}

.status {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
  display: none;
}

.status.error {
  display: block;
  background: #fef2f2;
  color: #991b1b;
}

.status.done {
  display: block;
  background: #ecfdf5;
  color: #065f46;
}

footer {
  max-width: 34rem;
  margin: 2rem auto 0;
  font-size: 0.8rem;
  color: var(--muted);
}

footer a {
  color: var(--muted);
}