:root {
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --text: #0f172a;
  --text-muted: #64748b;
  --accent: #0ea5e9;
  --accent-light: #38bdf8;
  --accent-glow: rgba(14, 165, 233, 0.15);
  --accent-bg: #f0f9ff;
  --card-bg: #ffffff;
  --card-border: #e2e8f0;
  --code-bg: #1e293b;
  --code-text: #e2e8f0;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.08);
  --radius: 12px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --nav-bg: rgba(255,255,255,0.85);
}

[data-theme="dark"] {
  --bg: #0a0a0a;
  --bg-alt: #141414;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --accent: #ef4444;
  --accent-light: #f87171;
  --accent-glow: rgba(239, 68, 68, 0.15);
  --accent-bg: rgba(239, 68, 68, 0.08);
  --card-bg: #141414;
  --card-border: #262626;
  --code-bg: #0a0a0a;
  --shadow: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.4);
  --nav-bg: rgba(10,10,10,0.9);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
}

/* ===== NAV ===== */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--card-border);
  padding: 0 max(24px, 5vw); height: 56px;
  display: flex; align-items: center; justify-content: space-between;
  transition: background var(--transition);
}
nav .logo { font-weight: 700; font-size: 15px; color: var(--text); letter-spacing: -0.3px; }
nav .logo span { color: var(--accent); }
nav .nav-links { display: flex; gap: 20px; align-items: center; }
nav .nav-links a { color: var(--text-muted); text-decoration: none; font-size: 13px; font-weight: 500; transition: color var(--transition); }
nav .nav-links a:hover { color: var(--accent); }
.theme-toggle {
  background: var(--bg-alt); border: 1px solid var(--card-border); border-radius: 8px;
  padding: 5px 10px; cursor: pointer; font-size: 16px; transition: all var(--transition);
}
.theme-toggle:hover { border-color: var(--accent); }
.hamburger { display: none; background: none; border: none; font-size: 22px; cursor: pointer; color: var(--text); }

/* ===== HERO ===== */
.hero {
  min-height: 100vh; display: flex; flex-direction: column; justify-content: center; align-items: center;
  text-align: center; padding: 100px max(24px, 8vw) 80px;
  position: relative; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(ellipse at 30% 20%, var(--accent-glow) 0%, transparent 50%),
    radial-gradient(ellipse at 70% 80%, var(--accent-glow) 0%, transparent 50%);
}
/* Animated grid */
.hero-grid {
  position: absolute; inset: 0; z-index: 0; opacity: 0.04;
  background-image:
    linear-gradient(var(--accent) 1px, transparent 1px),
    linear-gradient(90deg, var(--accent) 1px, transparent 1px);
  background-size: 60px 60px;
  animation: gridMove 20s linear infinite;
}
@keyframes gridMove {
  0% { transform: translate(0, 0); }
  100% { transform: translate(60px, 60px); }
}
.hero > * { position: relative; z-index: 1; }
.hero h1 {
  font-size: clamp(36px, 5.5vw, 60px); font-weight: 800; line-height: 1.1;
  margin-bottom: 16px; letter-spacing: -1.5px;
}
.hero h1 span { color: var(--accent); position: relative; }
.hero h1 span::after {
  content: ''; position: absolute; bottom: 2px; left: 0; right: 0; height: 3px;
  background: var(--accent); border-radius: 2px; opacity: 0.4;
}
.hero .byline { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; font-weight: 500; }
.hero .byline a { color: var(--accent); text-decoration: none; }
.hero p { font-size: clamp(16px, 2vw, 19px); color: var(--text-muted); max-width: 560px; margin-bottom: 36px; }
.cta-btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--accent); color: white; padding: 14px 28px;
  border-radius: 10px; font-weight: 600; font-size: 15px; text-decoration: none;
  transition: all var(--transition); border: none; cursor: pointer;
  box-shadow: 0 4px 20px var(--accent-glow);
}
.cta-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 30px var(--accent-glow); filter: brightness(1.1); }

/* Cursor glow that follows mouse */
.cursor-glow {
  position: fixed; width: 500px; height: 500px; border-radius: 50%;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none; z-index: 0; transform: translate(-50%, -50%);
  transition: opacity 0.3s; opacity: 0;
}
.cursor-glow.visible { opacity: 1; }

/* ===== SECTIONS ===== */
section { padding: 80px max(24px, 8vw); max-width: 1000px; margin: 0 auto; }
section h2 {
  font-size: clamp(26px, 3.5vw, 36px); font-weight: 700; margin-bottom: 8px;
  letter-spacing: -0.5px;
}
section .section-sub { color: var(--text-muted); font-size: 15px; margin-bottom: 40px; max-width: 640px; }

/* ===== CARDS ===== */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 14px; }
.card {
  background: var(--card-bg); border: 1px solid var(--card-border); border-radius: var(--radius);
  padding: 24px; transition: all var(--transition); box-shadow: var(--shadow);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--accent); }
.card .card-icon { font-size: 26px; margin-bottom: 10px; }
.card h3 { font-size: 15px; font-weight: 600; margin-bottom: 4px; }
.card p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ===== WIZARD ===== */
.wizard {
  background: var(--card-bg); border: 1px solid var(--card-border); border-radius: var(--radius);
  padding: 32px; box-shadow: var(--shadow-lg);
}
.wizard-progress { display: flex; gap: 6px; margin-bottom: 24px; }
.wizard-progress .step-dot {
  flex: 1; height: 3px; border-radius: 2px; background: var(--card-border);
  transition: background var(--transition);
}
.wizard-progress .step-dot.active { background: var(--accent); box-shadow: 0 0 8px var(--accent-glow); }
.wizard-step { display: none; animation: fadeIn 0.3s ease; }
.wizard-step.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.wizard-step h3 { font-size: 20px; margin-bottom: 6px; letter-spacing: -0.3px; }
.wizard-step p { color: var(--text-muted); margin-bottom: 20px; font-size: 14px; }
.wizard-options { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 10px; }
.wizard-option {
  background: var(--bg-alt); border: 2px solid var(--card-border); border-radius: 10px;
  padding: 16px 12px; text-align: center; cursor: pointer; transition: all var(--transition);
  font-weight: 500; font-size: 13px;
}
.wizard-option:hover { border-color: var(--accent); background: var(--accent-bg); }
.wizard-option.selected { border-color: var(--accent); background: var(--accent-bg); color: var(--accent); box-shadow: 0 0 12px var(--accent-glow); }
.wizard-option .opt-icon { font-size: 22px; display: block; margin-bottom: 6px; }
.wizard-option.checkbox-opt.selected::after { content: '✓'; position: absolute; top: 6px; right: 8px; color: var(--accent); font-weight: 700; }
.wizard-option.checkbox-opt { position: relative; }
.wizard-nav { display: flex; justify-content: space-between; margin-top: 24px; }
.wizard-nav button {
  padding: 10px 22px; border-radius: 8px; font-weight: 600; cursor: pointer;
  border: none; font-size: 13px; transition: all var(--transition);
}
.wizard-nav .btn-back { background: var(--bg-alt); color: var(--text-muted); border: 1px solid var(--card-border); }
.wizard-nav .btn-next { background: var(--accent); color: white; box-shadow: 0 2px 12px var(--accent-glow); }
.wizard-nav .btn-next:hover { filter: brightness(1.1); transform: translateY(-1px); }

/* Results */
.results-card { background: var(--accent-bg); border: 2px solid var(--accent); border-radius: var(--radius); padding: 32px; animation: fadeIn 0.4s ease; }
.results-card h3 { color: var(--accent); margin-bottom: 16px; font-size: 22px; }
.result-item { margin-bottom: 16px; }
.result-item label { font-weight: 600; font-size: 11px; text-transform: uppercase; letter-spacing: 1px; color: var(--text-muted); display: block; margin-bottom: 4px; }
.result-item .value { font-size: 15px; font-weight: 500; }
.checklist { list-style: none; counter-reset: checklist; }
.checklist li { counter-increment: checklist; padding: 8px 0; border-bottom: 1px solid var(--card-border); font-size: 13px; }
.checklist li::before { content: counter(checklist) "."; font-weight: 700; color: var(--accent); margin-right: 10px; }

/* ===== CODE BLOCKS ===== */
.code-block {
  position: relative; background: var(--code-bg); border-radius: 8px;
  padding: 14px 48px 14px 16px; margin: 10px 0; overflow-x: auto;
  border: 1px solid var(--card-border);
}
.code-block code { color: var(--code-text); font-family: 'SF Mono', 'Fira Code', 'JetBrains Mono', monospace; font-size: 13px; white-space: pre; }
.copy-btn {
  position: absolute; top: 8px; right: 8px; background: #334155; border: none; color: #94a3b8;
  padding: 3px 10px; border-radius: 6px; font-size: 11px; cursor: pointer; transition: all var(--transition);
}
.copy-btn:hover { background: #475569; color: white; }
.copy-btn.copied { color: #4ade80; }

/* ===== ACCORDION ===== */
.accordion-item {
  border: 1px solid var(--card-border); border-radius: var(--radius);
  margin-bottom: 6px; overflow: hidden; transition: all var(--transition);
}
.accordion-header {
  padding: 14px 20px; cursor: pointer; display: flex; justify-content: space-between;
  align-items: center; font-weight: 600; font-size: 14px; background: var(--card-bg);
  transition: all var(--transition);
}
.accordion-header:hover { background: var(--bg-alt); }
.accordion-header .num { color: var(--accent); margin-right: 10px; font-size: 13px; font-weight: 700; }
.accordion-header .arrow { transition: transform var(--transition); color: var(--text-muted); font-size: 12px; }
.accordion-item.open .arrow { transform: rotate(180deg); }
.accordion-body { padding: 0 20px; max-height: 0; overflow: hidden; transition: max-height 0.5s ease, padding 0.3s ease; }
.accordion-item.open .accordion-body { max-height: 1200px; padding: 0 20px 20px; }
.accordion-body p { font-size: 13px; color: var(--text-muted); margin-bottom: 8px; line-height: 1.7; }
.accordion-body strong { color: var(--text); }
.error-note {
  background: #fef2f2; border-left: 3px solid #ef4444; padding: 10px 14px;
  border-radius: 0 8px 8px 0; font-size: 12px; margin-top: 8px; color: #991b1b;
}
[data-theme="dark"] .error-note { background: #450a0a30; color: #fca5a5; border-color: #ef4444; }

/* ===== MODEL CARDS ===== */
.model-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.model-card {
  background: var(--card-bg); border: 1px solid var(--card-border); border-radius: var(--radius);
  padding: 24px; position: relative; transition: all var(--transition);
}
.model-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.model-card.recommended { border-color: var(--accent); box-shadow: 0 0 20px var(--accent-glow); }
.model-card .tag {
  position: absolute; top: 12px; right: 12px; background: var(--accent); color: white;
  font-size: 10px; font-weight: 700; padding: 3px 10px; border-radius: 20px; letter-spacing: 0.3px;
}
.model-card h3 { font-size: 17px; margin-bottom: 2px; }
.model-card .provider { font-size: 12px; color: var(--text-muted); margin-bottom: 10px; }
.model-card .best-for { font-size: 13px; margin-bottom: 10px; line-height: 1.6; }
.model-card .cost { font-weight: 700; color: var(--accent); font-size: 15px; }

/* ===== SECURITY ===== */
.security-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 14px; }
.security-card {
  background: var(--card-bg); border: 1px solid var(--card-border); border-radius: var(--radius);
  padding: 22px; transition: all var(--transition);
}
.security-card:hover { border-color: var(--accent); }
.security-card .icon { font-size: 22px; margin-bottom: 8px; }
.security-card h3 { font-size: 14px; margin-bottom: 4px; }
.security-card p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ===== RESOURCES ===== */
.resource-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; }
.resource-link {
  display: flex; align-items: center; gap: 10px; padding: 14px; background: var(--card-bg);
  border: 1px solid var(--card-border); border-radius: var(--radius); text-decoration: none;
  color: var(--text); transition: all var(--transition);
}
.resource-link:hover { border-color: var(--accent); transform: translateY(-1px); box-shadow: var(--shadow); }
.resource-link .r-icon { font-size: 18px; }
.resource-link span { font-weight: 500; font-size: 13px; }

/* ===== FOOTER ===== */
footer {
  text-align: center; padding: 40px max(24px, 8vw); border-top: 1px solid var(--card-border);
  color: var(--text-muted); font-size: 13px;
}
footer a { color: var(--accent); text-decoration: none; }

/* ===== ANIMATIONS ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* Staggered card animations */
.card-grid .card, .model-grid .model-card, .security-grid .security-card {
  opacity: 0; transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease, border-color var(--transition), box-shadow var(--transition);
}
.reveal.visible .card, .reveal.visible .model-card, .reveal.visible .security-card { opacity: 1; transform: translateY(0); }
.reveal.visible .card:nth-child(1), .reveal.visible .model-card:nth-child(1), .reveal.visible .security-card:nth-child(1) { transition-delay: 0.05s; }
.reveal.visible .card:nth-child(2), .reveal.visible .model-card:nth-child(2), .reveal.visible .security-card:nth-child(2) { transition-delay: 0.1s; }
.reveal.visible .card:nth-child(3), .reveal.visible .model-card:nth-child(3), .reveal.visible .security-card:nth-child(3) { transition-delay: 0.15s; }
.reveal.visible .card:nth-child(4), .reveal.visible .model-card:nth-child(4), .reveal.visible .security-card:nth-child(4) { transition-delay: 0.2s; }
.reveal.visible .card:nth-child(5), .reveal.visible .model-card:nth-child(5), .reveal.visible .security-card:nth-child(5) { transition-delay: 0.25s; }
.reveal.visible .card:nth-child(6), .reveal.visible .security-card:nth-child(6) { transition-delay: 0.3s; }

/* ===== MOBILE ===== */
@media (max-width: 768px) {
  nav .nav-links {
    display: none; position: absolute; top: 56px; left: 0; right: 0;
    background: var(--nav-bg); backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--card-border); flex-direction: column;
    padding: 16px max(24px, 5vw); gap: 12px;
  }
  nav .nav-links.open { display: flex; }
  .hamburger { display: block; }
  section { padding: 60px 20px; }
  .wizard { padding: 20px; }
  .wizard-options { grid-template-columns: 1fr 1fr; }
  .hero { padding: 80px 20px 60px; }
}