:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --bg-code: #f3f4f6;
  --text: #1f2328;
  --text-soft: #57606a;
  --border: #e5e7eb;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --code-text: #24292f;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 6px 18px rgba(0,0,0,.04);
  --radius: 12px;
  --maxw: 760px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

html[data-theme="dark"] {
  --bg: #0d1117;
  --bg-soft: #161b22;
  --bg-code: #161b22;
  --text: #e6edf3;
  --text-soft: #9aa4b2;
  --border: #30363d;
  --accent: #58a6ff;
  --accent-soft: #16305a;
  --code-text: #e6edf3;
  --shadow: 0 1px 3px rgba(0,0,0,.4), 0 6px 18px rgba(0,0,0,.3);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg-soft);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: saturate(180%) blur(8px);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}
.brand { font-weight: 700; font-size: 18px; color: var(--text); }
.brand:hover { text-decoration: none; }
.nav { display: flex; align-items: center; gap: 16px; }
.nav a { color: var(--text-soft); font-size: 14px; }
.theme-toggle {
  border: 1px solid var(--border); background: var(--bg-soft);
  color: var(--text); border-radius: 8px; cursor: pointer;
  width: 36px; height: 32px; font-size: 16px; line-height: 1;
}
.theme-toggle:hover { border-color: var(--accent); }

/* ---------- Hero ---------- */
.hero { padding: 56px 0 28px; text-align: center; }
.hero h1 { font-size: 34px; margin: 0 0 10px; letter-spacing: .5px; }
.hero p { color: var(--text-soft); margin: 0; font-size: 17px; }
.hero .tag {
  display: inline-block; margin-top: 16px; padding: 4px 14px;
  background: var(--accent-soft); color: var(--accent);
  border-radius: 999px; font-size: 13px;
}

/* ---------- Post list ---------- */
.section-title {
  font-size: 14px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--text-soft); margin: 40px 0 16px; font-weight: 700;
}
.post-card {
  display: block; background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 22px; margin-bottom: 16px;
  box-shadow: var(--shadow); transition: transform .15s ease, border-color .15s ease;
}
.post-card:hover { transform: translateY(-2px); border-color: var(--accent); text-decoration: none; }
.post-card h3 { margin: 0 0 8px; font-size: 19px; color: var(--text); }
.post-card .meta { color: var(--text-soft); font-size: 13px; margin-bottom: 8px; }
.post-card p { margin: 0; color: var(--text-soft); font-size: 15px; }

/* ---------- Projects ---------- */
.project-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
}
.project-card {
  display: flex; align-items: center; gap: 16px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 22px;
  box-shadow: var(--shadow); transition: transform .15s ease, border-color .15s ease;
}
.project-card:hover { transform: translateY(-2px); border-color: var(--accent); text-decoration: none; }
.project-icon {
  flex: 0 0 auto; width: 52px; height: 52px; border-radius: 12px;
  background: var(--accent-soft); color: var(--accent);
  display: flex; align-items: center; justify-content: center; font-size: 26px;
}
.project-body { flex: 1 1 auto; min-width: 0; }
.project-body h3 { margin: 0 0 4px; font-size: 18px; color: var(--text); }
.project-body .meta { color: var(--text-soft); font-size: 12px; margin-bottom: 6px; }
.project-body p { margin: 0; color: var(--text-soft); font-size: 14px; }
.project-go { flex: 0 0 auto; color: var(--accent); font-size: 14px; font-weight: 600; white-space: nowrap; }

/* ---------- Article ---------- */
.article { padding: 40px 0 24px; }
.article h1 { font-size: 30px; margin: 0 0 8px; }
.article .meta { color: var(--text-soft); font-size: 14px; margin-bottom: 28px; }
.article h2 { font-size: 22px; margin: 36px 0 12px; padding-top: 8px; border-top: 1px solid var(--border); }
.article h3 { font-size: 18px; margin: 26px 0 10px; }
.article p { margin: 14px 0; }
.article ul, .article ol { padding-left: 24px; margin: 14px 0; }
.article li { margin: 6px 0; }
.article blockquote {
  margin: 18px 0; padding: 12px 18px; border-left: 4px solid var(--accent);
  background: var(--bg-soft); color: var(--text-soft); border-radius: 0 8px 8px 0;
}
.article img { max-width: 100%; border-radius: var(--radius); display: block; margin: 18px 0; }
.article code {
  font-family: var(--mono); background: var(--bg-code); color: var(--code-text);
  padding: 2px 6px; border-radius: 6px; font-size: 14px;
}
.article pre {
  background: var(--bg-code); color: var(--code-text); padding: 16px 18px;
  border-radius: var(--radius); overflow-x: auto; border: 1px solid var(--border);
  margin: 18px 0;
}
.article pre code { background: none; padding: 0; font-size: 14px; line-height: 1.6; }

.back-link { display: inline-block; margin: 8px 0 0; font-size: 14px; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border); margin-top: 48px;
  padding: 28px 0; color: var(--text-soft); font-size: 13px; text-align: center;
}
.site-footer a { color: var(--text-soft); }
.beian-placeholder {
  display: inline-block; margin-top: 6px; padding: 2px 10px;
  border: 1px dashed var(--border); border-radius: 6px; color: var(--text-soft);
}

@media (max-width: 600px) {
  .hero h1 { font-size: 27px; }
  .article h1 { font-size: 25px; }
  .site-header .wrap { height: 54px; }
  .project-grid { grid-template-columns: 1fr; }
}