:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

.container {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.site-brand {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.site-tagline {
  color: var(--muted);
  font-size: 14px;
}

.hero {
  padding: 48px 0 24px;
}

.hero h1 {
  margin: 0 0 12px;
  font-size: 34px;
}

.hero p {
  margin: 0;
  color: var(--muted);
  max-width: 720px;
}

.category-nav {
  position: sticky;
  top: 64px;
  z-index: 9;
  display: flex;
  gap: 8px;
  padding: 12px 0;
  background: var(--bg);
}

.category-nav a {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
}

.category-section {
  --accent: #2563eb;
  padding: 32px 0;
  scroll-margin-top: 120px;
}

.category-chatgpt {
  --accent: #2563eb;
}

.category-writing {
  --accent: #db2777;
}

.category-aipainting {
  --accent: #7c3aed;
}

.category-programming {
  --accent: #059669;
}

.category-head h2 {
  margin: 0 0 8px;
  font-size: 24px;
}

.category-head p {
  margin: 0 0 20px;
  color: var(--muted);
}

.prompt-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.prompt-card {
  display: flex;
  flex-direction: column;
  min-height: 220px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.prompt-card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.prompt-card h3 {
  margin: 0;
  font-size: 17px;
}

.copy-btn {
  flex: 0 0 auto;
  min-width: 56px;
  padding: 7px 12px;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  font-size: 14px;
}

.copy-btn.copied {
  background: #047857;
}

.prompt-desc {
  margin: 8px 0 12px;
  color: var(--muted);
  font-size: 14px;
}

.prompt-card pre {
  flex: 1;
  margin: 0;
  padding: 12px;
  overflow: auto;
  border-radius: 6px;
  background: #f1f5f9;
  color: #0f172a;
  white-space: pre-wrap;
  word-break: break-word;
}

.prompt-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding-top: 12px;
}

.prompt-tags span {
  padding: 3px 8px;
  border-radius: 6px;
  background: #eef2ff;
  color: #3730a3;
  font-size: 12px;
}

.site-footer {
  margin-top: 48px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 720px) {
  .prompt-grid {
    grid-template-columns: 1fr;
  }

  .site-tagline {
    display: none;
  }

  .hero h1 {
    font-size: 28px;
  }
}