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

:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --surface-alt: #243044;
  --text: #e8edf4;
  --text-muted: #8b9cb3;
  --accent: #22c55e;
  --accent-dim: #16a34a;
  --warning: #f59e0b;
  --border: #2d3a4f;
  --radius: 12px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
}

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

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 20, 25, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 960px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--accent);
}

.header nav {
  display: flex;
  gap: 24px;
}

.header nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

.header nav a:hover {
  color: var(--accent);
}

/* Hero */
.hero {
  padding: 72px 0 56px;
  background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  color: var(--text-muted);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto 40px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}

.stat {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 28px;
  min-width: 160px;
}

.stat strong {
  display: block;
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: 4px;
}

.stat span {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Content */
.content {
  padding: 48px 24px 64px;
}

.content section {
  margin-bottom: 48px;
}

.content h2 {
  font-size: 1.5rem;
  margin-bottom: 16px;
  color: var(--text);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--accent-dim);
}

.content h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  color: var(--accent);
}

.content p {
  margin-bottom: 16px;
  color: var(--text-muted);
}

.content ul, .content ol {
  margin: 12px 0 16px 24px;
  color: var(--text-muted);
}

.content li {
  margin-bottom: 8px;
}

.content strong {
  color: var(--text);
}

.tip-box, .warning-box {
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 20px 0;
}

.tip-box {
  background: rgba(34, 197, 94, 0.08);
  border: 1px solid rgba(34, 197, 94, 0.25);
}

.warning-box {
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.warning-box h3 {
  color: var(--warning);
}

.checklist {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.checklist label {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--text-muted);
  transition: border-color 0.2s;
}

.checklist label:hover {
  border-color: var(--accent-dim);
}

.checklist input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
}

.footer p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-note {
  margin-top: 8px;
  color: var(--accent-dim);
}

@media (max-width: 640px) {
  .header nav {
    display: none;
  }

  .hero-stats {
    flex-direction: column;
    align-items: center;
  }

  .stat {
    width: 100%;
    max-width: 280px;
  }
}