:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --text: #1d2633;
  --muted: #5f6b7a;
  --primary: #0057d9;
  --border: #dbe2ee;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "SF Pro Text", "PingFang TC", "Noto Sans TC", sans-serif;
  background: linear-gradient(180deg, #f6f8ff 0%, #f8fafc 45%, #f6f7fb 100%);
  color: var(--text);
  line-height: 1.65;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 24px 18px 64px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  margin-top: 14px;
}

h1, h2, h3 {
  line-height: 1.25;
  margin: 0 0 12px;
}

h1 {
  font-size: 30px;
}

h2 {
  font-size: 22px;
  margin-top: 18px;
}

p, li {
  color: var(--text);
  margin: 0 0 10px;
}

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

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 8px;
}

nav a {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  padding: 7px 12px;
  font-size: 14px;
}

ul {
  padding-left: 20px;
}

footer {
  margin-top: 28px;
  font-size: 13px;
  color: var(--muted);
}