:root {
  --bg: #fafaf9;
  --surface: #ffffff;
  --text: #1c1917;
  --muted: #6b6560;
  --border: #e7e5e4;
  --accent: #111111;
  --accent-text: #ffffff;
  --selected: #111111;
  --error: #b42318;
  --radius: 14px;
  font-family: -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', Meiryo,
    sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0c0c;
    --surface: #171717;
    --text: #f5f5f4;
    --muted: #a8a29e;
    --border: #2e2e2e;
    --accent: #f5f5f4;
    --accent-text: #0c0c0c;
    --selected: #f5f5f4;
    --error: #f97066;
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); }
main { max-width: 720px; margin: 0 auto; padding: 0 16px 64px; }
[hidden] { display: none !important; }

.mock-banner { background: #fef3c7; color: #78350f; text-align: center; font-size: 13px; padding: 6px 16px; }
.site-header { max-width: 720px; margin: 0 auto; padding: 20px 16px; }
.logo { font-weight: 700; font-size: 22px; letter-spacing: -0.02em; color: var(--text); text-decoration: none; }
.site-footer { text-align: center; color: var(--muted); font-size: 12px; padding: 32px 16px; }

.hero h1 { font-size: clamp(26px, 6vw, 38px); line-height: 1.35; margin: 24px 0 12px; letter-spacing: -0.01em; }
.hero p { color: var(--muted); margin: 0 0 28px; }

.steps { list-style: none; padding: 0; margin: 0 0 32px; display: grid; gap: 8px; }
.steps li { display: flex; align-items: center; gap: 12px; font-size: 15px; }
.steps span {
  flex: none; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center;
  border: 1px solid var(--border); font-size: 13px; font-weight: 600;
}

.interval-toggle { display: inline-flex; padding: 4px; border: 1px solid var(--border); border-radius: 999px; margin-bottom: 16px; }
.interval-toggle button {
  border: 0; background: transparent; color: var(--muted); font: inherit; font-size: 14px;
  padding: 6px 18px; border-radius: 999px; cursor: pointer;
}
.interval-toggle button[aria-pressed='true'] { background: var(--accent); color: var(--accent-text); }

.plan-list { display: grid; gap: 12px; }
.plan {
  display: flex; gap: 14px; align-items: flex-start; padding: 18px; background: var(--surface);
  border: 1.5px solid var(--border); border-radius: var(--radius); cursor: pointer;
}
.plan:has(input:checked) { border-color: var(--selected); }
.plan input { margin-top: 6px; accent-color: var(--selected); }
.plan-body { display: grid; gap: 4px; flex: 1; }
.plan-name { font-weight: 700; font-size: 17px; }
.plan-desc { color: var(--muted); font-size: 14px; }
.plan-price { font-size: 22px; font-weight: 700; margin-top: 4px; }
.plan-price small { font-size: 14px; font-weight: 400; color: var(--muted); }
.note { color: var(--muted); font-size: 13px; margin: 12px 0 0; }

.account { margin-top: 32px; padding: 20px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.account-lead { margin: 0 0 16px; font-size: 15px; overflow-wrap: anywhere; }
.signin-buttons { display: grid; gap: 10px; }

.btn {
  display: inline-flex; justify-content: center; align-items: center; min-height: 48px; padding: 0 20px;
  border-radius: 12px; border: 1px solid var(--border); background: var(--surface); color: var(--text);
  font: inherit; font-weight: 600; font-size: 16px; text-decoration: none; cursor: pointer; width: 100%;
}
.btn:disabled { opacity: 0.5; cursor: default; }
.btn-primary, .btn-apple { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.btn-link { background: none; border: 0; color: var(--muted); font: inherit; font-size: 14px; margin-top: 12px; cursor: pointer; text-decoration: underline; }
.error { color: var(--error); font-size: 14px; margin: 14px 0 0; }

.result { text-align: center; padding-top: 40px; }
.result h1 { font-size: 26px; margin: 12px 0; }
.result p { color: var(--muted); }
.result-icon {
  width: 56px; height: 56px; margin: 0 auto; border-radius: 50%; display: grid; place-items: center;
  background: var(--accent); color: var(--accent-text); font-size: 28px;
}
.store-links { display: grid; gap: 10px; max-width: 360px; margin: 28px auto 0; }

.mock-params { display: grid; grid-template-columns: auto 1fr; gap: 6px 16px; text-align: left; max-width: 420px; margin: 20px auto; font-size: 14px; }
.mock-params dt { color: var(--muted); }
.mock-params dd { margin: 0; overflow-wrap: anywhere; }