:root {
  --bg: #fafafa;
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #2563eb;
  --card: #ffffff;
  --border: #e5e7eb;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
}

header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
}

nav {
  max-width: 760px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

nav .brand {
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
  color: var(--fg);
}

nav .links {
  display: flex;
  gap: 20px;
}

nav .links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.95rem;
}

nav .links a:hover {
  color: var(--fg);
}

nav .links a.active {
  color: var(--accent);
  font-weight: 600;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 48px 20px 64px;
}

h1 {
  font-size: 1.9rem;
  margin-bottom: 12px;
}

h2 {
  font-size: 1.3rem;
  margin: 32px 0 12px;
}

p {
  margin-bottom: 16px;
  color: #333;
}

.lead {
  color: var(--muted);
  font-size: 1.05rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  text-decoration: none;
  color: var(--fg);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.06);
}

.card h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.card p {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0;
}

.post {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 16px;
}

.post .date {
  color: var(--muted);
  font-size: 0.85rem;
}

.post h3 {
  margin: 6px 0 8px;
}

.post p {
  color: #444;
  font-size: 0.95rem;
  margin: 0;
}

.form-note {
  font-size: 0.85rem;
  color: var(--muted);
}

label {
  display: block;
  font-size: 0.9rem;
  margin-bottom: 4px;
}

input,
textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  margin-bottom: 16px;
}

input:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent);
}

button {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.95rem;
  cursor: pointer;
}

footer {
  border-top: 1px solid var(--border);
  padding: 24px 20px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}