/* ==========================================================================
   AvoOnce GitHub Pages - Design System & Modern Aesthetics
   ========================================================================== */

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;

  /* Color Palette */
  --bg-dark: #0b0f19;
  --bg-card: #131b2e;
  --bg-card-hover: #1c2742;
  --bg-code: #0d121f;

  --accent-primary: #10b981; /* Emerald Green */
  --accent-secondary: #6366f1; /* Indigo */
  --accent-cyan: #06b6d4;
  --accent-warning: #f59e0b;
  --accent-danger: #ef4444;

  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-dim: #6b7280;

  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(16, 185, 129, 0.4);

  --shadow-glow: 0 0 30px rgba(16, 185, 129, 0.15);
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.4);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a:hover {
  color: #34d399;
}

/* Header & Nav */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background-color: rgba(11, 15, 25, 0.85);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-main);
}

.nav-brand img {
  height: 36px;
  width: auto;
  border-radius: var(--radius-sm);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text-main);
}

.btn-github {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
}

.btn-github:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
  transform: translateY(-1px);
}

/* Hero Section */
.hero {
  padding: 5rem 2rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-badge-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

.badge-green { background: rgba(16, 185, 129, 0.1); color: var(--accent-primary); border-color: rgba(16, 185, 129, 0.3); }
.badge-blue { background: rgba(99, 102, 241, 0.1); color: var(--accent-secondary); border-color: rgba(99, 102, 241, 0.3); }
.badge-cyan { background: rgba(6, 182, 212, 0.1); color: var(--accent-cyan); border-color: rgba(6, 182, 212, 0.3); }

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, #ffffff 30%, #9ca3af 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-title span {
  background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 760px;
  margin-bottom: 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--accent-primary), #059669);
  color: #042f2e;
  font-weight: 700;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.3);
  transition: all var(--transition-fast);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.45);
  color: #042f2e;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  font-weight: 600;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
  transform: translateY(-2px);
}

.hero-graphic {
  width: 100%;
  max-width: 900px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-glow), var(--shadow-card);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
}

.hero-graphic img {
  width: 100%;
  height: auto;
  display: block;
}

/* Container & Sections */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-tag {
  color: var(--accent-primary);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 680px;
  margin: 0 auto;
}

/* Feature Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(16, 185, 129, 0.3);
  box-shadow: var(--shadow-card);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.feature-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Comparison Table */
.table-container {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.compare-table th, .compare-table td {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.compare-table th {
  background: rgba(255, 255, 255, 0.03);
  font-weight: 700;
  color: var(--text-main);
}

.compare-table tr:last-child td {
  border-bottom: none;
}

.compare-table td:nth-child(2) {
  color: var(--accent-danger);
  background: rgba(239, 68, 68, 0.03);
}

.compare-table td:nth-child(3) {
  color: var(--accent-primary);
  background: rgba(16, 185, 129, 0.03);
  font-weight: 600;
}

/* Code Quickstart Tabs */
.quickstart-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.tabs-header {
  display: flex;
  background: rgba(0, 0, 0, 0.2);
  border-bottom: 1px solid var(--border-color);
  overflow-x: auto;
}

.tab-btn {
  padding: 1rem 1.5rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.tab-btn:hover {
  color: var(--text-main);
}

.tab-btn.active {
  color: var(--accent-primary);
  border-bottom-color: var(--accent-primary);
  background: rgba(16, 185, 129, 0.05);
}

.tab-content {
  display: none;
  padding: 1.5rem;
}

.tab-content.active {
  display: block;
}

.code-wrapper {
  position: relative;
  margin-bottom: 1.5rem;
}

.code-wrapper:last-child {
  margin-bottom: 0;
}

.code-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

pre {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: #e5e7eb;
}

.copy-btn {
  position: absolute;
  top: 2rem;
  right: 0.75rem;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--text-main);
}

/* State Machine Visualizer */
.state-flow {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

.state-step {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.state-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-secondary);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.state-title {
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

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

/* Footer */
.footer {
  background: #070a12;
  border-top: 1px solid var(--border-color);
  padding: 3rem 2rem;
  margin-top: auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 2rem;
  align-items: center;
}

.footer-brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.footer-links a {
  color: var(--text-dim);
  font-size: 0.9rem;
}

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

.copyright {
  color: var(--text-dim);
  font-size: 0.85rem;
  width: 100%;
  text-align: center;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .hero-title { font-size: 2.5rem; }
  .navbar { padding: 1rem; }
  .nav-links { display: none; }
  .hero-actions { flex-direction: column; width: 100%; }
  .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
}