/* ── Reset & Base Styles ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --text: #0f172a;
  --text-muted: #475569;
  --text-light: #94a3b8;
  --border: #f1f5f9;
  --border-dark: #e2e8f0;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --bg-card: #f8fafc;
  --bg-code: #0f172a;
  --nav-bg: rgba(255, 255, 255, 0.8);
  --comment: #16a34a;
  --radius: 8px;
  --radius-lg: 12px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

[data-theme="dark"] {
  --bg: #090d16;
  --text: #f8fafc;
  --text-muted: #cbd5e1;
  --text-light: #64748b;
  --border: #1e293b;
  --border-dark: #334155;
  --accent: #818cf8;
  --accent-hover: #a5b4fc;
  --bg-card: #0f172a;
  --nav-bg: rgba(9, 13, 22, 0.8);
  --comment: #4ade80;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.25s, color 0.25s;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s;
}
a:hover { color: var(--accent-hover); }

/* ── Navigation ── */
nav {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--nav-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 100;
  transition: background-color 0.25s, border-color 0.25s;
}
.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}
.nav-logo {
  font-weight: 800;
  font-size: 1.2rem;
  letter-spacing: -0.03em;
  color: var(--text);
  transition: color 0.25s;
}
.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
  align-items: center;
}
.nav-links a {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 500;
  transition: color 0.25s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--text); }
.nav-cta {
  background: var(--text);
  color: var(--bg) !important;
  padding: 6px 14px;
  border-radius: var(--radius);
  font-weight: 600 !important;
  font-size: 0.88rem;
  transition: background-color 0.25s, color 0.25s;
}
.nav-cta:hover {
  background: var(--accent);
  color: var(--bg) !important;
}

/* Theme toggle */
.theme-toggle-btn {
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  outline: none;
}
.theme-toggle-track {
  width: 44px;
  height: 24px;
  border-radius: 99px;
  background: var(--border-dark);
  border: 1px solid var(--border-dark);
  position: relative;
  transition: background-color 0.25s, border-color 0.25s;
  display: block;
}
.theme-toggle-knob {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text);
  position: absolute;
  top: 2px;
  left: 2px;
  transition: transform 0.25s, background-color 0.25s;
  display: block;
}
[data-theme="dark"] .theme-toggle-knob { transform: translateX(20px); }
[data-theme="dark"] .theme-toggle-track {
  background: var(--bg-card);
  border-color: var(--border-dark);
}

/* ── Hero ── */
.hero {
  padding: 96px 0 72px;
  text-align: center;
}
.badge {
  display: inline-block;
  background: var(--bg-card);
  border: 1px solid var(--border-dark);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 4px 14px;
  border-radius: 99px;
  margin-bottom: 28px;
  font-family: var(--font-mono);
  transition: background-color 0.25s, border-color 0.25s, color 0.25s;
}
.hero h1 {
  font-size: clamp(2.2rem, 6vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: 20px;
  color: var(--text);
  transition: color 0.25s;
}
.hero p {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 560px;
  margin: 0 auto 16px;
  transition: color 0.25s;
}
.hero-tagline {
  font-size: 0.88rem !important;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--text-light) !important;
  margin-top: -8px !important;
  margin-bottom: 32px !important;
  font-family: var(--font-mono);
}
.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  padding: 10px 22px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.2s;
  cursor: pointer;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
  border: 1px solid var(--accent);
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3);
}
.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border-dark);
}
.btn-secondary:hover {
  background: var(--bg-card);
  color: var(--text);
  transform: translateY(-1px);
}

/* ── Stats Row ── */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin: 0 0 80px;
}
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 16px;
  text-align: center;
  transition: border-color 0.2s, background-color 0.25s, transform 0.2s;
  opacity: 0;
  transform: translateY(12px);
}
.stat-card.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.4s ease, transform 0.4s ease, border-color 0.2s, background-color 0.25s;
}
.stat-card:hover { border-color: var(--accent); }
.stat-num {
  font-size: 1.4rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent);
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ── Features Section ── */
section {
  padding: 72px 0;
}
.section-title {
  font-size: 1.7rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
  color: var(--text);
}
.section-subtitle {
  color: var(--text-muted);
  margin-bottom: 40px;
  font-size: 1rem;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: border-color 0.2s, background-color 0.25s, transform 0.2s;
  opacity: 0;
  transform: translateY(12px);
}
.feature-card.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.4s ease, transform 0.4s ease, border-color 0.2s, background-color 0.25s;
}
.feature-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.feature-icon {
  font-size: 1.6rem;
  margin-bottom: 12px;
}
.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}
.feature-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
}
.feature-card code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  background: var(--border-dark);
  color: var(--accent);
  padding: 1px 5px;
  border-radius: 4px;
}

/* ── Architecture ── */
#architecture { background: var(--bg); }
.arch-diagram {
  background: var(--bg-code);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-bottom: 28px;
  overflow-x: auto;
  border: 1px solid var(--border);
}
.arch-diagram pre,
.arch-diagram code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: #e2e8f0;
  white-space: pre;
}
.arch-diagram .comment { color: #4ade80; }

.project-structure {
  background: var(--bg-code);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  overflow-x: auto;
  border: 1px solid var(--border);
}
.project-structure h3 {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-light);
  margin-bottom: 16px;
  font-family: var(--font-sans);
}
.project-structure pre,
.project-structure code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.8;
  color: #e2e8f0;
  white-space: pre;
}
.project-structure .dir { color: #818cf8; }
.project-structure .file { color: #cbd5e1; }
.project-structure .comment { color: var(--comment); }

/* ── Steps (Quick Start) ── */
.steps {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.step {
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 24px;
  padding: 32px 0;
  border-bottom: 1px solid var(--border);
  opacity: 0;
  transform: translateY(12px);
}
.step.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.4s ease, transform 0.4s ease;
}
.step:last-child { border-bottom: none; }
.step-num {
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent);
  letter-spacing: 0.06em;
  padding-top: 4px;
}
.step-content h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}
.step-content pre {
  background: var(--bg-code);
  border-radius: var(--radius);
  padding: 18px 20px;
  overflow-x: auto;
  border: 1px solid var(--border);
}
.step-content code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: #e2e8f0;
  white-space: pre;
}
.step-content .comment { color: var(--comment); }

/* ── Commands Table ── */
.cmd-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: 56px;
}
.cmd-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}
.cmd-table thead {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-dark);
}
.cmd-table th {
  text-align: left;
  padding: 12px 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-light);
}
.cmd-table td {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  transition: color 0.25s;
}
.cmd-table tr:last-child td { border-bottom: none; }
.cmd-table tr:hover td { background: var(--bg-card); color: var(--text); }
.cmd-table code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  color: var(--accent);
  white-space: nowrap;
}

/* ── Packets Grid ── */
.packets-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.packet-card {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  opacity: 0;
  transform: translateY(12px);
}
.packet-card.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.4s ease, transform 0.4s ease;
}
.packet-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-light);
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  font-family: var(--font-sans);
}
.packet-card pre {
  padding: 16px;
}
.packet-card code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
  color: #e2e8f0;
  white-space: pre;
}
.packet-card .key { color: #93c5fd; }
.packet-card .str { color: #86efac; }

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  margin-top: 40px;
  transition: border-color 0.25s;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-brand p {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 4px;
}
.footer-links {
  display: flex;
  gap: 20px;
}
.footer-links a {
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: color 0.15s;
}
.footer-links a:hover { color: var(--text); }

/* ── Responsive ── */
@media (max-width: 720px) {
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .features-grid { grid-template-columns: 1fr; }
  .packets-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .hero h1 { font-size: 2.2rem; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

/* ── Terminal Mock UI ── */
.terminal-mock {
  background: #0b0f19;
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: #e2e8f0;
  overflow: hidden;
  margin: 20px 0;
  box-shadow: 0 10px 30px -15px rgba(0, 0, 0, 0.4);
}
[data-theme="dark"] .terminal-mock {
  background: #030712;
  border-color: var(--border);
}
.terminal-header {
  background: #111827;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid #1f2937;
}
[data-theme="dark"] .terminal-header {
  background: #0f172a;
  border-color: #1e293b;
}
.terminal-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}
.terminal-dot.red { background: #ef4444; }
.terminal-dot.yellow { background: #f59e0b; }
.terminal-dot.green { background: #10b981; }
.terminal-title {
  color: #94a3b8;
  font-size: 0.72rem;
  font-family: var(--font-sans);
  font-weight: 600;
  margin-left: 8px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.terminal-body {
  padding: 18px;
  white-space: pre-wrap;
  line-height: 1.6;
}
.terminal-body .green-text { color: #4ade80; }
.terminal-body .cyan-text { color: #22d3ee; }
.terminal-body .yellow-text { color: #facc15; }
.terminal-body .red-text { color: #f87171; }
.terminal-body .magenta-text { color: #f472b6; }
.terminal-body .gray-text { color: #64748b; }
.terminal-body .white-text { color: #f8fafc; }