@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=Google+Sans+Code:wght@400;500&display=swap');

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

:root {
  --font: 'Inter', system-ui, sans-serif;
  --font-mono: 'Google Sans Code', 'Courier New', monospace;
  --bg: #f5f5f5;
  --glass-bg: #ffffff;
  --glass-border: #e5e7eb;
  --glass-shadow: 0 1px 4px rgba(0,0,0,0.06);
  --glass-blur: none;
  --text: #111827;
  --muted: #6b7280;
  --accent-blue: #378ADD;
  --accent-green: #1D9E75;
  --accent-purple: #6450C8;
  --code-bg: #1a1f2e;
  --code-text: #e2e8f0;
}

/* ---- DARK MODE ---- */
[data-theme="dark"] {
  --bg: #0f1117;
  --glass-bg: #1a1d27;
  --glass-border: #2a2d3a;
  --glass-shadow: 0 1px 4px rgba(0,0,0,0.3);
  --text: #e8eaf2;
  --muted: #8892a4;
  --code-bg: #0d1117;
}

[data-theme="dark"] body { color: var(--text); }

[data-theme="dark"] nav {
  background: var(--glass-bg);
  border-bottom-color: var(--glass-border);
}

[data-theme="dark"] .nav-btn:hover,
[data-theme="dark"] .nav-btn.active {
  background: rgba(255,255,255,0.07);
  color: var(--text);
}

[data-theme="dark"] .theme-btn {
  background: transparent;
  border-color: var(--glass-border);
  color: var(--muted);
}

[data-theme="dark"] .tab-btn {
  background: transparent;
  border-color: var(--glass-border);
  color: var(--muted);
}
[data-theme="dark"] .tab-btn:hover { background: rgba(255,255,255,0.06); color: var(--text); }
[data-theme="dark"] .tab-btn.active { background: rgba(255,255,255,0.1); color: var(--text); }

[data-theme="dark"] .key {
  background: rgba(255,255,255,0.08);
  border-color: var(--glass-border);
  color: var(--text);
  box-shadow: 0 1px 0 rgba(0,0,0,0.4);
}

[data-theme="dark"] .symbol-table td { border-top-color: var(--glass-border); }
[data-theme="dark"] code { background: rgba(55,138,221,0.15); color: #60a5fa; }
[data-theme="dark"] pre code { background: transparent; color: inherit; }

[data-theme="dark"] .article-body p,
[data-theme="dark"] .article-body li { color: #b0bec8; }

[data-theme="dark"] .intro-note { background: rgba(255,255,255,0.04); }

html, body {
  min-height: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  min-height: 100vh;
  color: var(--text);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

/* ---- NAV ---- */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.75rem 2.5rem;
  background: var(--glass-bg);
  border-bottom: 1px solid var(--glass-border);
}

.logo {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.4px;
  margin-right: 1.25rem;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 0.15rem;
  flex: 1;
}

.nav-btn {
  font-family: var(--font);
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
  background: transparent;
  border: none;
  padding: 0.35rem 0.9rem;
  border-radius: 100px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: color 0.15s, background 0.15s;
}

.nav-btn:hover,
.nav-btn.active {
  color: var(--text);
  background: var(--bg);
}

.theme-btn {
  margin-left: auto;
  font-family: var(--font);
  font-size: 12.5px;
  font-weight: 500;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--glass-border);
  padding: 0.3rem 1rem;
  border-radius: 100px;
  cursor: pointer;
  transition: color 0.15s;
}
.theme-btn:hover { color: var(--text); }

/* ---- GLASS CARD ---- */
.glass {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: 16px;
}

/* ---- CODE BLOCK ---- */
pre {
  background: var(--code-bg);
  color: var(--code-text);
  border-radius: 14px;
  padding: 1.2rem 1.5rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.75;
  margin: 1rem 0;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
}

code {
  font-family: var(--font-mono);
  font-size: 13px;
  background: rgba(55,138,221,0.1);
  color: #2563eb;
  padding: 0.15em 0.45em;
  border-radius: 5px;
}

pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

/* ---- LAYOUT ---- */
.page-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 2.5rem 5rem;
}

.page-title {
  font-size: 30px;
  font-weight: 600;
  letter-spacing: -0.8px;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.page-desc {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 2.5rem;
  line-height: 1.7;
}

hr.divider {
  border: none;
  border-top: 1px solid rgba(255,255,255,0.6);
  margin: 2rem 0;
}

/* ---- TAG ---- */
.tag {
  display: inline-block;
  font-size: 11px;
  padding: 0.2em 0.65em;
  border-radius: 100px;
  background: rgba(55,138,221,0.12);
  color: var(--accent-blue);
  margin-right: 0.3rem;
}

.tag.green { background: rgba(29,158,117,0.11); color: var(--accent-green); }
.tag.purple { background: rgba(100,80,200,0.1); color: var(--accent-purple); }