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

:root {
  --bg: #0f0f1a;
  --surface: #16162a;
  --border: #2a2a4a;
  --text: #e0e0e0;
  --muted: #888;
  --accent: #4f46e5;
  --green: #4ade80;
  --red: #f87171;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.6;
}

.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 60px 24px;
}

/* Hero */

.hero {
  background: linear-gradient(135deg, #1a1a3e 0%, #0f0f1a 100%);
  border-bottom: 1px solid var(--border);
  text-align: center;
  padding: 80px 24px;
}

.hero h1 {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -2px;
  color: #fff;
  font-family: var(--mono);
}

.tagline {
  color: var(--muted);
  font-size: 18px;
  margin-top: 16px;
  line-height: 1.5;
}

.hero-actions {
  margin-top: 32px;
  display: flex;
  gap: 12px;
  justify-content: center;
}

/* Buttons */

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.15s;
}

.btn:hover { opacity: 0.85; }

.btn.primary {
  background: var(--accent);
  color: #fff;
}

.btn.secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

/* Headings */

h2 {
  font-size: 32px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 24px;
}

h3 {
  font-size: 18px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 8px;
  margin-top: 24px;
}

/* Flow steps */

.flow {
  display: grid;
  gap: 20px;
  margin-bottom: 40px;
}

.flow-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
}

.step-body p {
  color: var(--muted);
  margin-top: 4px;
}

/* Diagram */

.diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  overflow-x: auto;
}

.diagram pre {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--green);
  line-height: 1.5;
  white-space: pre;
}

.diagram img {
  width: 100%;
  height: auto;
  display: block;
}

/* Code blocks */

.code-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin: 12px 0;
  overflow-x: auto;
}

.code-label {
  padding: 8px 16px;
  font-size: 12px;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border);
}

.code-block pre {
  padding: 16px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text);
  white-space: pre;
}

code {
  font-family: var(--mono);
  background: var(--surface);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 13px;
  color: var(--green);
}

/* Download cards */

.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.download-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
}

.download-card p {
  color: var(--muted);
  margin-bottom: 12px;
}

/* Table */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
}

th {
  text-align: left;
  padding: 10px 12px;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  border-bottom: 2px solid var(--border);
}

td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}

/* Security grid */

.security-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.sec-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
}

.sec-card p {
  color: var(--muted);
  font-size: 14px;
  margin-top: 4px;
}

/* Lists */

ul {
  padding-left: 20px;
  margin: 12px 0;
}

li {
  margin: 8px 0;
  color: var(--muted);
}

li strong {
  color: var(--text);
}

/* Footer */

footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 32px 24px;
}

footer p {
  color: var(--muted);
  font-size: 13px;
}

/* Responsive */

@media (max-width: 640px) {
  .hero h1 { font-size: 36px; }
  .tagline { font-size: 15px; }
  .download-grid, .security-grid { grid-template-columns: 1fr; }
  .container { padding: 40px 16px; }
}