:root {
  --bg: #f5f5f7;
  --card: #ffffff;
  --card-alt: #ffffff;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --primary: #0071e3; /* Apple link blue */
  --primary-ink: #ffffff;
  --border: #e5e5ea;
  --shadow: 0 1px 2px rgba(0,0,0,0.04), 0 6px 16px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", Inter, system-ui, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.6;
}

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 24px;
}

header h1 { margin: 0 0 6px; font-size: 34px; font-weight: 700; letter-spacing: -0.02em; }
.subtitle { color: var(--muted); margin: 0; font-size: 17px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.card.alt { background: var(--card-alt); }

.muted { color: var(--muted); }

.actions { display: flex; gap: 10px; flex-wrap: wrap; }
.btn {
  appearance: none;
  border: 1px solid var(--border);
  background: #ffffff;
  color: var(--text);
  padding: 10px 16px;
  border-radius: 12px;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 1px 0 rgba(0,0,0,0.02), inset 0 -1px 0 rgba(0,0,0,0.03);
  transition: transform .06s ease, box-shadow .2s ease, background-color .2s ease, border-color .2s ease;
}
.btn.primary {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--primary-ink);
  box-shadow: 0 1px 0 rgba(0,0,0,0.04), 0 6px 14px rgba(0,113,227,0.25);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:focus { outline: none; box-shadow: 0 0 0 3px rgba(0,113,227,0.2); }

ol { padding-left: 20px; }
code { background: #f2f2f7; color: #1d1d1f; padding: 2px 6px; border-radius: 6px; border: 1px solid var(--border); }

.footer { color: var(--muted); font-size: 14px; }

@media (max-width: 560px) {
  header h1 { font-size: 28px; }
}