/* ===== Pi — Design System ===== */
:root {
  --pi-purple: #7c3aed;
  --pi-purple-light: #a78bfa;
  --pi-purple-dark: #5b21b6;
  --pi-indigo: #4f46e5;
  --pi-pink: #ec4899;
  --pi-teal: #14b8a6;
  --pi-orange: #f59e0b;
  --pi-slate-50: #f8fafc;
  --pi-slate-100: #f1f5f9;
  --pi-slate-200: #e2e8f0;
  --pi-slate-600: #475569;
  --pi-slate-700: #334155;
  --pi-slate-800: #1e293b;
  --pi-slate-900: #0f172a;
  --pi-white: #ffffff;
  --gradient-hero: linear-gradient(135deg, #7c3aed 0%, #4f46e5 50%, #0ea5e9 100%);
  --gradient-card: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  --gradient-cta: linear-gradient(135deg, #7c3aed 0%, #ec4899 100%);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --radius: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--pi-slate-800);
  background: var(--pi-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== Typography ===== */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.2; }
h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.015em; }
h3 { font-size: 1.5rem; }
p { color: var(--pi-slate-600); }

a { color: inherit; text-decoration: none; }

/* ===== Layout ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== Navigation ===== */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--pi-slate-200);
  transition: all 0.3s ease;
}
nav .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 72px;
}
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.5rem; font-weight: 800; color: var(--pi-purple);
}
.nav-logo .logo-icon {
  width: 40px; height: 40px; border-radius: 12px;
  background: var(--gradient-hero); display: flex;
  align-items: center; justify-content: center;
  color: white; font-size: 1.2rem; font-weight: 800;
}
.nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
.nav-links a {
  font-size: 0.95rem; font-weight: 500; color: var(--pi-slate-600);
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--pi-purple); }
.nav-cta {
  padding: 10px 24px; border-radius: var(--radius-full);
  background: var(--pi-purple); color: white !important;
  font-weight: 600; font-size: 0.9rem;
  transition: all 0.3s ease;
}
.nav-cta:hover { background: var(--pi-purple-dark); transform: translateY(-1px); box-shadow: var(--shadow-md); }

/* Mobile nav */
.nav-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--pi-slate-700); }

/* ===== Hero ===== */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(180deg, #f5f3ff 0%, #ffffff 100%);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(124,58,237,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.hero::after {
  content: ''; position: absolute; bottom: -30%; left: -10%; width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(79,70,229,0.06) 0%, transparent 70%);
  border-radius: 50%;
}
.hero .container { position: relative; z-index: 1; text-align: center; max-width: 860px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 20px; border-radius: var(--radius-full);
  background: rgba(124,58,237,0.08); color: var(--pi-purple);
  font-size: 0.85rem; font-weight: 600; margin-bottom: 24px;
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--pi-teal); animation: pulse 2s infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.4; } }
.hero h1 { margin-bottom: 24px; }
.hero h1 .gradient-text {
  background: var(--gradient-hero);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p.hero-sub { font-size: 1.25rem; color: var(--pi-slate-600); max-width: 640px; margin: 0 auto 40px; line-height: 1.7; }
.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 16px 32px; border-radius: var(--radius-full);
  font-size: 1rem; font-weight: 600; cursor: pointer;
  transition: all 0.3s ease; border: none;
}
.btn-primary {
  background: var(--gradient-cta); color: white;
  box-shadow: 0 4px 15px rgba(124,58,237,0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(124,58,237,0.4); }
.btn-secondary {
  background: white; color: var(--pi-slate-700);
  border: 2px solid var(--pi-slate-200);
}
.btn-secondary:hover { border-color: var(--pi-purple-light); color: var(--pi-purple); }

/* Hero visual */
.hero-visual {
  margin-top: 64px;
  background: white; border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl), 0 0 0 1px rgba(0,0,0,0.03);
  overflow: hidden; max-width: 800px; margin-left: auto; margin-right: auto;
}
.hero-visual-header {
  display: flex; align-items: center; gap: 8px;
  padding: 16px 20px; background: var(--pi-slate-50); border-bottom: 1px solid var(--pi-slate-200);
}
.hero-visual-header .dot-row { display: flex; gap: 6px; }
.hero-visual-header .dot-row span { width: 12px; height: 12px; border-radius: 50%; }
.hero-visual-header .dot-row span:nth-child(1) { background: #ef4444; }
.hero-visual-header .dot-row span:nth-child(2) { background: #f59e0b; }
.hero-visual-header .dot-row span:nth-child(3) { background: #22c55e; }
.hero-visual-body { padding: 32px; display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.mock-card {
  padding: 20px; border-radius: var(--radius);
  border: 1px solid var(--pi-slate-200); background: var(--pi-slate-50);
}
.mock-card h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--pi-slate-600); margin-bottom: 12px; }
.mock-tag {
  display: inline-block; padding: 4px 12px; border-radius: var(--radius-full);
  font-size: 0.8rem; font-weight: 500; margin: 3px;
}
.mock-tag.travel { background: #dbeafe; color: #1d4ed8; }
.mock-tag.food { background: #fef3c7; color: #b45309; }
.mock-tag.music { background: #fce7f3; color: #be185d; }
.mock-tag.active { background: #d1fae5; color: #065f46; }
.mock-tag.email { background: #ede9fe; color: #5b21b6; }
.mock-bar { height: 8px; border-radius: 4px; background: var(--pi-slate-200); margin: 8px 0; }
.mock-bar .fill { height: 100%; border-radius: 4px; }
.mock-bar .fill.purple { background: var(--pi-purple); }
.mock-bar .fill.teal { background: var(--pi-teal); }
.mock-bar .fill.pink { background: var(--pi-pink); }

/* ===== Social Proof ===== */
.social-proof {
  padding: 60px 0; border-bottom: 1px solid var(--pi-slate-200);
}
.social-proof .container { text-align: center; }
.social-proof p { font-size: 0.9rem; color: var(--pi-slate-600); margin-bottom: 24px; font-weight: 500; }
.proof-logos { display: flex; justify-content: center; align-items: center; gap: 48px; flex-wrap: wrap; opacity: 0.5; }
.proof-stat {
  text-align: center; padding: 0 24px;
}
.proof-stat .number { font-size: 2rem; font-weight: 800; color: var(--pi-purple); }
.proof-stat .label { font-size: 0.85rem; color: var(--pi-slate-600); }

/* ===== Features ===== */
.features { padding: 120px 0; }
.section-header { text-align: center; margin-bottom: 64px; }
.section-badge {
  display: inline-block; padding: 6px 16px; border-radius: var(--radius-full);
  background: rgba(124,58,237,0.08); color: var(--pi-purple);
  font-size: 0.8rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.08em; margin-bottom: 16px;
}
.section-header h2 { margin-bottom: 16px; }
.section-header p { max-width: 600px; margin: 0 auto; font-size: 1.1rem; }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.feature-card {
  padding: 36px; border-radius: var(--radius-lg);
  background: white; border: 1px solid var(--pi-slate-200);
  transition: all 0.3s ease; position: relative; overflow: hidden;
}
.feature-card:hover {
  border-color: var(--pi-purple-light); transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.feature-card::after {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--gradient-hero); opacity: 0; transition: opacity 0.3s;
}
.feature-card:hover::after { opacity: 1; }
.feature-icon {
  width: 56px; height: 56px; border-radius: 14px; display: flex;
  align-items: center; justify-content: center; font-size: 1.5rem;
  margin-bottom: 20px;
}
.feature-icon.purple { background: #ede9fe; }
.feature-icon.teal { background: #ccfbf1; }
.feature-icon.pink { background: #fce7f3; }
.feature-icon.orange { background: #fef3c7; }
.feature-icon.indigo { background: #e0e7ff; }
.feature-icon.green { background: #d1fae5; }
.feature-card h3 { margin-bottom: 12px; font-size: 1.25rem; }
.feature-card p { font-size: 0.95rem; line-height: 1.7; }

/* ===== How It Works ===== */
.how-it-works {
  padding: 120px 0;
  background: linear-gradient(180deg, var(--pi-slate-50) 0%, white 100%);
}
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; margin-top: 64px; }
.step { text-align: center; position: relative; }
.step-number {
  width: 64px; height: 64px; border-radius: 50%; display: flex;
  align-items: center; justify-content: center; margin: 0 auto 20px;
  background: var(--gradient-hero); color: white;
  font-size: 1.5rem; font-weight: 800;
  box-shadow: 0 4px 15px rgba(124,58,237,0.25);
}
.step h3 { margin-bottom: 8px; font-size: 1.15rem; }
.step p { font-size: 0.9rem; }
.step-connector {
  position: absolute; top: 32px; left: 60%; width: 80%;
  height: 2px; background: var(--pi-slate-200);
}
.step:last-child .step-connector { display: none; }

/* ===== Testimonials ===== */
.testimonials { padding: 120px 0; }
.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.testimonial-card {
  padding: 32px; border-radius: var(--radius-lg);
  background: white; border: 1px solid var(--pi-slate-200);
  transition: box-shadow 0.3s;
}
.testimonial-card:hover { box-shadow: var(--shadow-lg); }
.testimonial-stars { color: #f59e0b; font-size: 1.1rem; margin-bottom: 16px; }
.testimonial-card blockquote { font-size: 1rem; line-height: 1.7; color: var(--pi-slate-700); margin-bottom: 20px; font-style: italic; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1rem; color: white;
}
.testimonial-author .info .name { font-weight: 600; font-size: 0.95rem; color: var(--pi-slate-800); }
.testimonial-author .info .role { font-size: 0.8rem; color: var(--pi-slate-600); }

/* ===== CTA ===== */
.cta-section {
  padding: 120px 0; text-align: center;
  background: var(--gradient-hero); color: white;
  position: relative; overflow: hidden;
}
.cta-section::before {
  content: ''; position: absolute; top: -100px; right: -100px;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  border-radius: 50%;
}
.cta-section h2 { color: white; margin-bottom: 16px; }
.cta-section p { color: rgba(255,255,255,0.85); max-width: 560px; margin: 0 auto 40px; font-size: 1.15rem; }
.btn-white {
  background: white; color: var(--pi-purple); font-weight: 700;
  box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,0,0,0.2); }

/* ===== Footer ===== */
footer {
  padding: 80px 0 40px;
  background: var(--pi-slate-900); color: rgba(255,255,255,0.7);
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 48px; }
.footer-brand .logo { font-size: 1.5rem; font-weight: 800; color: white; margin-bottom: 12px; }
.footer-brand p { font-size: 0.9rem; line-height: 1.7; }
.footer-col h4 { color: white; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { font-size: 0.9rem; transition: color 0.2s; }
.footer-col a:hover { color: white; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 32px; display: flex; justify-content: space-between;
  align-items: center; font-size: 0.85rem; flex-wrap: wrap; gap: 16px;
}
.footer-bottom a:hover { color: white; }

/* ===== Pricing Page ===== */
.pricing-hero {
  padding: 160px 0 80px;
  background: linear-gradient(180deg, #f5f3ff 0%, #ffffff 100%);
  text-align: center;
}
.pricing-hero p { max-width: 600px; margin: 16px auto 0; font-size: 1.15rem; }
.pricing-toggle {
  display: flex; justify-content: center; align-items: center;
  gap: 16px; margin-top: 40px;
}
.pricing-toggle span { font-size: 0.95rem; font-weight: 500; color: var(--pi-slate-600); }
.pricing-toggle span.active { color: var(--pi-purple); font-weight: 700; }
.toggle-switch {
  width: 56px; height: 28px; border-radius: 14px;
  background: var(--pi-purple); position: relative; cursor: pointer;
  border: none;
}
.toggle-switch::after {
  content: ''; position: absolute; top: 3px; left: 3px;
  width: 22px; height: 22px; border-radius: 50%;
  background: white; transition: transform 0.3s ease;
}
.toggle-switch.annual::after { transform: translateX(28px); }
.save-badge {
  padding: 4px 12px; border-radius: var(--radius-full);
  background: #d1fae5; color: #065f46; font-size: 0.75rem; font-weight: 600;
}

.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; padding: 64px 0 120px; }
.pricing-card {
  padding: 40px; border-radius: var(--radius-lg);
  background: white; border: 2px solid var(--pi-slate-200);
  position: relative; transition: all 0.3s ease;
}
.pricing-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-xl); }
.pricing-card.featured {
  border-color: var(--pi-purple);
  box-shadow: 0 0 0 1px var(--pi-purple), var(--shadow-xl);
}
.pricing-card.featured .popular-badge {
  position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
  padding: 6px 20px; border-radius: var(--radius-full);
  background: var(--gradient-cta); color: white;
  font-size: 0.8rem; font-weight: 600;
}
.pricing-card .plan-name { font-size: 1.1rem; font-weight: 700; color: var(--pi-slate-700); margin-bottom: 8px; }
.pricing-card .plan-price { font-size: 3rem; font-weight: 800; color: var(--pi-slate-900); margin-bottom: 4px; }
.pricing-card .plan-price span { font-size: 1rem; font-weight: 500; color: var(--pi-slate-600); }
.pricing-card .plan-desc { font-size: 0.9rem; color: var(--pi-slate-600); margin-bottom: 28px; padding-bottom: 28px; border-bottom: 1px solid var(--pi-slate-200); }
.pricing-card .features-list { list-style: none; margin-bottom: 32px; }
.pricing-card .features-list li {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 8px 0; font-size: 0.95rem; color: var(--pi-slate-700);
}
.pricing-card .features-list li .check { color: var(--pi-teal); font-weight: 700; flex-shrink: 0; }
.pricing-card .btn { width: 100%; justify-content: center; }
.pricing-card.featured .btn { background: var(--gradient-cta); color: white; box-shadow: 0 4px 15px rgba(124,58,237,0.3); }

/* FAQ */
.faq { padding: 80px 0 120px; }
.faq-grid { max-width: 800px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--pi-slate-200); padding: 24px 0;
}
.faq-item summary {
  font-size: 1.1rem; font-weight: 600; color: var(--pi-slate-800);
  cursor: pointer; list-style: none; display: flex;
  justify-content: space-between; align-items: center;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; font-size: 1.5rem; color: var(--pi-purple); transition: transform 0.3s; }
.faq-item[open] summary::after { content: '−'; }
.faq-item p { margin-top: 12px; font-size: 0.95rem; line-height: 1.7; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .step-connector { display: none; }
  .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-card:last-child { grid-column: span 2; max-width: 480px; margin: 0 auto; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .hero { padding: 120px 0 80px; }
  .hero-visual-body { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; gap: 40px; }
  .testimonials-grid { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
  .pricing-card:last-child { grid-column: span 1; max-width: 100%; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-actions { flex-direction: column; align-items: center; }
}