:root {
  --bg-primary: #0b0f19;
  --bg-secondary: #111827;
  --bg-card: #1f2937;
  --bg-card-hover: #283548;
  --border-color: #374151;
  --border-subtle: #2d3748;
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent-primary: #38bdf8;
  --accent-hover: #0ea5e9;
  --accent-subtle: rgba(56, 189, 248, 0.1);
  --success: #10b981;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --max-width: 1040px;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Header & Nav */
header.site-header {
  background-color: rgba(17, 24, 39, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  letter-spacing: -0.025em;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-badge {
  background: linear-gradient(135deg, #0284c7, #38bdf8);
  color: #fff;
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  font-weight: 600;
}

nav.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background-color: var(--bg-card);
  text-decoration: none;
}

/* Main Layout */
main.main-content {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 3rem 1rem 4rem;
  max-width: 780px;
  margin: 0 auto;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--accent-subtle);
  color: var(--accent-primary);
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(56, 189, 248, 0.2);
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 1.25rem;
}

.hero h1 span.gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  color: var(--text-secondary);
  font-size: 1.15rem;
  line-height: 1.7;
}

/* Grid Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
  margin: 2.5rem 0;
}

.feature-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #38bdf8, #818cf8);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.feature-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
  background-color: var(--bg-card);
}

.feature-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background-color: var(--accent-subtle);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.feature-card h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.card-action {
  font-weight: 600;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

/* Document Layout (Terms & Privacy) */
.doc-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 2rem;
  margin-bottom: 2.5rem;
}

.doc-header h1 {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
}

.doc-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.doc-meta span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.doc-container {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 3rem;
  position: relative;
}

@media (max-width: 860px) {
  .doc-container {
    grid-template-columns: 1fr;
  }
  .doc-sidebar {
    display: none;
  }
}

.doc-sidebar {
  position: sticky;
  top: 5.5rem;
  height: fit-content;
}

.toc-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 1rem;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.9rem;
  border-left: 2px solid var(--border-color);
  padding-left: 0.75rem;
}

.toc-list a {
  color: var(--text-secondary);
  display: block;
  padding: 0.2rem 0;
}

.toc-list a:hover {
  color: var(--accent-primary);
  text-decoration: none;
}

.doc-body {
  max-width: 720px;
}

.doc-section {
  margin-bottom: 3rem;
  scroll-margin-top: 6rem;
}

.doc-section h2 {
  font-size: 1.45rem;
  font-weight: 700;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-primary);
}

.doc-section h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 1.25rem 0 0.5rem;
  color: #e2e8f0;
}

.doc-section p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-size: 1rem;
  line-height: 1.7;
}

.doc-section ul, .doc-section ol {
  color: var(--text-secondary);
  margin: 0.75rem 0 1.25rem 1.5rem;
  line-height: 1.7;
}

.doc-section li {
  margin-bottom: 0.5rem;
}

.highlight-box {
  background-color: var(--bg-secondary);
  border-left: 4px solid var(--accent-primary);
  padding: 1.25rem 1.5rem;
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
}

.highlight-box p {
  margin: 0;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.contact-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.5rem;
  margin-top: 1rem;
}

.contact-card p {
  margin-bottom: 0.5rem;
}

/* Footer */
footer.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 2.5rem 1.5rem;
  margin-top: auto;
}

.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--text-primary);
}