:root {
  color-scheme: light dark;
  --bg: #f1f5f9;
  --surface: #ffffff;
  --text: #172033;
  --muted: #5b667a;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --border: #dbe2ec;
  --notice: #eff6ff;
  --notice-border: #bfdbfe;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.7;
}

.page-shell {
  width: min(100% - 32px, 720px);
  margin: 0 auto;
  padding: 32px 0 24px;
}

.hero {
  padding: 32px 8px 28px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .14em;
}

h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 12px; font-size: clamp(2rem, 8vw, 3.2rem); line-height: 1.15; }
h2 { margin-bottom: 12px; font-size: 1.25rem; line-height: 1.3; }
.lead { margin: 0 auto 24px; max-width: 560px; color: var(--muted); font-size: 1.05rem; }

.download-button {
  display: inline-flex;
  min-height: 64px;
  width: min(100%, 420px);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: var(--accent);
  color: #fff;
  font-size: 1.2rem;
  font-weight: 800;
  text-decoration: none;
  box-shadow: 0 10px 24px rgb(37 99 235 / 25%);
  transition: background .15s ease, transform .15s ease;
}

.download-button:hover, .download-button:focus-visible { background: var(--accent-dark); }
.download-button:active { transform: translateY(1px); }
.download-meta { font-size: .78rem; font-weight: 500; opacity: .9; }
.size-note { margin: 10px 0 0; color: var(--muted); font-size: .88rem; }

.card {
  margin: 16px 0;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: 0 6px 20px rgb(15 23 42 / 5%);
}

.card p:last-child, .card ul:last-child, .card ol:last-child { margin-bottom: 0; }
li + li { margin-top: 6px; }
.notice { margin-top: 18px; padding: 14px; border: 1px solid var(--notice-border); border-radius: 12px; background: var(--notice); }
.checksum code { display: block; overflow-wrap: anywhere; padding: 12px; border-radius: 10px; background: #0f172a; color: #dbeafe; font-size: .78rem; line-height: 1.55; }
footer { padding: 12px 0; color: var(--muted); font-size: .85rem; text-align: center; }

@media (prefers-color-scheme: dark) {
  :root { --bg: #0b1220; --surface: #111b2e; --text: #e5edf9; --muted: #aab7ca; --border: #26344d; --notice: #102442; --notice-border: #1e4d83; }
  .download-button { box-shadow: 0 10px 24px rgb(0 0 0 / 30%); }
}