:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --line: #dbe3ef;
  --text: #1f2d3d;
  --muted: #5a6b7f;
  --brand: #1565c0;
  --brand-soft: #e8f1fb;
  --accent: #0d9488;
  --shadow: 0 12px 30px rgba(18, 40, 72, 0.08);
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font: 16px/1.7 "PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
.site-shell { max-width: 1080px; margin: 0 auto; padding: 0 24px 64px; }
.site-header { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 28px 0; border-bottom: 1px solid var(--line); }
.brand { font-size: 24px; font-weight: 700; color: var(--text); }
.nav { display: flex; gap: 18px; flex-wrap: wrap; }
.nav a { color: var(--muted); font-weight: 600; }
.hero { padding: 56px 0 28px; }
.hero h1 { margin: 0 0 12px; font-size: 40px; line-height: 1.2; }
.hero p { margin: 0; color: var(--muted); max-width: 760px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 20px; padding: 24px; box-shadow: var(--shadow); }
.card h2, .card h3 { margin-top: 0; }
.badge { display: inline-flex; align-items: center; padding: 6px 12px; border-radius: 999px; background: var(--brand-soft); color: var(--brand); font-size: 13px; font-weight: 700; }
.section-title { margin: 40px 0 18px; font-size: 24px; }
.post-list { display: grid; gap: 16px; }
.post-item { background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 22px; box-shadow: var(--shadow); }
.post-item h3 { margin: 0 0 8px; font-size: 22px; }
.post-item p { margin: 0; color: var(--muted); }
.meta { color: var(--muted); font-size: 14px; margin-bottom: 10px; }
.article { background: var(--surface); border: 1px solid var(--line); border-radius: 22px; padding: 28px; box-shadow: var(--shadow); }
.article h1 { margin-top: 0; font-size: 34px; }
.article p, .article li { color: var(--text); }
.article ul, .article ol { padding-left: 22px; }
.tools { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }
.tool-card textarea, .tool-card input { width: 100%; border: 1px solid var(--line); border-radius: 14px; padding: 12px 14px; font: inherit; background: #fff; color: var(--text); }
.tool-card button { border: 0; background: var(--brand); color: #fff; border-radius: 12px; padding: 10px 16px; cursor: pointer; font-weight: 700; }
.tool-card pre { white-space: pre-wrap; word-break: break-word; background: #0f172a; color: #dbeafe; padding: 16px; border-radius: 14px; overflow: auto; }
.tool-actions { display: flex; gap: 10px; margin: 12px 0 0; flex-wrap: wrap; }
.site-footer { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.note { color: var(--muted); font-size: 14px; }
@media (max-width: 720px) {
  .site-shell { padding: 0 18px 52px; }
  .hero h1 { font-size: 30px; }
  .site-header { padding: 20px 0; align-items: flex-start; flex-direction: column; }
}