:root {
  --bg: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #2563eb;
  --border: #e5e7eb;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}
.container { max-width: 820px; margin: 0 auto; padding: 0 20px; }
.site-header { border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 20px; }
.logo { font-size: 1.15rem; font-weight: 700; color: var(--text); text-decoration: none; }
.main-nav a { margin-left: 18px; color: var(--text); text-decoration: none; font-size: 0.95rem; }
.main-nav a:hover { color: var(--accent); }
main { padding: 40px 20px 60px; }
h1 { font-size: 2rem; margin: 0 0 16px; }
h2 { font-size: 1.35rem; margin: 32px 0 12px; }
p { color: var(--muted); }
ul { padding-left: 20px; }
li { margin-bottom: 6px; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 22px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
}
.btn:hover { opacity: 0.9; }
.card-list { list-style: none; padding: 0; }
.card-list li {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 14px;
}
.card-list h3 { margin: 0 0 6px; font-size: 1.1rem; }
.card-list h3 a { color: var(--text); text-decoration: none; }
.card-list h3 a:hover { color: var(--accent); }
.card-list p { margin: 0; font-size: 0.95rem; }
.price { font-size: 2rem; font-weight: 700; margin: 24px 0 8px; color: var(--text); }
.price span { font-size: 0.95rem; color: var(--muted); font-weight: 400; }
.preview {
  display: block;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin: 8px 0 20px;
}
.card-list img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 10px;
  border: 1px solid var(--border);
}
code {
  background: #f3f4f6;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}
h3 { margin-top: 24px; }
.site-footer { border-top: 1px solid var(--border); padding: 20px 0 30px; }
.site-footer p { margin: 0; font-size: 0.85rem; color: var(--muted); }
@media (max-width: 640px) {
  .header-inner { flex-direction: column; align-items: flex-start; gap: 10px; }
  .main-nav a { margin-left: 0; margin-right: 16px; }
}