*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: #fff;
  color: #000;
  font-family: -apple-system, Helvetica, Arial, sans-serif;
  font-size: 14px;
  line-height: 1.5;
}

a { color: #00f; }
a:visited { color: #551a8b; }

/* ── header ── */
#header {
  background: #000;
  color: #fff;
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
#header a {
  color: #fff;
  text-decoration: none;
  font-size: 13px;
  font-weight: bold;
}
#header nav {
  display: flex;
  gap: 16px;
}
#header nav a {
  font-weight: normal;
  font-size: 12px;
  color: #ccc;
  text-decoration: underline;
}
#header nav a:hover { color: #fff; }
#header nav a.current { color: #fff; font-weight: bold; text-decoration: none; }

/* ── page wrapper ── */
#page {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px;
}

/* ── headings ── */
h1 {
  font-size: 18px;
  font-weight: bold;
  margin-bottom: 4px;
}
h2 {
  font-size: 14px;
  font-weight: bold;
  margin-bottom: 12px;
}
.subtitle {
  font-size: 13px;
  color: #444;
  margin-bottom: 20px;
}

/* ── ad slots ── */
.ad {
  background: #f0f0f0;
  border: 1px solid #ccc;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: #999;
}
.ad-top { margin-bottom: 16px; }
.ad-bottom { margin-top: 24px; }

/* ── horizontal rule ── */
hr {
  border: none;
  border-top: 1px solid #ccc;
  margin: 20px 0;
}

/* ── FAQ ── */
#faq details {
  border-top: 1px solid #ccc;
  padding: 8px 0;
}
#faq details:last-child { border-bottom: 1px solid #ccc; }
#faq summary {
  font-size: 13px;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
#faq summary::-webkit-details-marker { display: none; }
#faq summary::after { content: '+'; color: #00f; font-size: 16px; }
#faq details[open] summary::after { content: '−'; }
#faq details p {
  font-size: 13px;
  color: #333;
  margin-top: 6px;
  line-height: 1.6;
  max-width: 520px;
}

/* ── footer ── */
#footer {
  border-top: 1px solid #ccc;
  padding: 10px 16px;
  font-size: 11px;
  color: #666;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 6px;
  max-width: 640px;
  margin: 24px auto 0;
}
#footer a { color: #00f; font-size: 11px; }

@media (max-width: 480px) {
  #header nav { display: none; }
}