:root {
  --violet: #7c3aed;
  --violet-dark: #5b21b6;
  --ink: #1f2937;
  --ink-light: #374151;
  --muted: #6b7280;
  --line: #e5e7eb;
  --bg: #f3f4f6;
  --card-bg: #ffffff;
}

* { box-sizing: border-box; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
  margin: 0;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
}

.wrap { 
  width: 100%;
  max-width: 800px; 
}

/* Card Styling (Premium Feel) */
.card {
  background: var(--card-bg);
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08), 0 1px 3px rgba(0,0,0,0.05);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.card-header {
  padding: 30px 40px;
  border-bottom: 1px solid var(--line);
  background: #fdfdfd;
}

.card-header .brand {
  font-weight: 700;
  font-size: 20px;
  color: var(--ink);
  background: linear-gradient(135deg, #6366f1, #d946ef);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.card-body {
  padding: 40px;
}

.card-body h1 {
  font-size: 32px;
  margin: 0 0 8px;
  color: var(--ink);
  letter-spacing: -0.5px;
}

.card-body .date {
  color: var(--muted);
  font-size: 14px;
  margin: 0 0 30px;
  font-weight: 500;
}

.card-body h2 {
  font-size: 20px;
  margin-top: 36px;
  margin-bottom: 16px;
  color: var(--ink-light);
  letter-spacing: -0.3px;
}

.card-body h3 {
  font-size: 16px;
  margin-top: 28px;
  margin-bottom: 10px;
  color: var(--ink-light);
}

.card-body p {
  margin-top: 0;
  margin-bottom: 16px;
}

.card-body ul {
  padding-left: 20px;
  margin-bottom: 24px;
}

.card-body li {
  margin-bottom: 10px;
}

.card-body code {
  background: #f3f4f6;
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 13px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  color: #db2777;
}

.card-body a {
  color: var(--violet);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

.card-body a:hover {
  color: var(--violet-dark);
  text-decoration: underline;
}

.section-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 32px;
}

.section-nav a {
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink-light);
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  padding: 10px 14px;
  text-decoration: none;
}

.section-nav a:hover {
  border-color: var(--violet);
  color: var(--violet-dark);
  text-decoration: none;
}

.card-body section {
  border-top: 1px solid var(--line);
  margin-top: 36px;
  padding-top: 2px;
  scroll-margin-top: 24px;
}

.card-body section:first-of-type {
  border-top: 0;
  margin-top: 0;
}

.card-footer {
  padding: 24px 40px;
  background: #f9fafb;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

@media (max-width: 600px) {
  body { padding: 20px 10px; }
  .card-header, .card-body, .card-footer { padding: 24px 20px; }
  .card-body h1 { font-size: 26px; }
}