:root {
  /* Premium Dark Palette */
  --bg-color: #0b0f14; /* Deep charcoal */
  --bg-gradient-start: #0b0f14;
  --bg-gradient-end: #111822;
  --surface-color: #1a202c;
  --surface-hover: #2d3748;
  --text-primary: #f7fafc;
  --text-secondary: #a0aec0;
  --accent-color: #38b2ac; /* Teal */
  --accent-glow: rgba(56, 178, 172, 0.4);
  --border-color: #2d3748;
  
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 1200px;
  --nav-height: 70px;
}

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

body {
  background: var(--bg-color);
  background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
  transition: opacity 0.2s ease;
}

ul {
  list-style: none;
}

/* Utilities */
.container {
  width: 90%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--accent-color);
  color: #000;
  box-shadow: 0 0 15px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 25px var(--accent-glow);
}

.btn-secondary {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  color: var(--text-primary);
  border-color: var(--text-primary);
}

/* Header */
header {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,0.05);
  background: rgba(11, 15, 20, 0.8);
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 800;
  font-size: 1.5rem;
  letter-spacing: -0.5px;
  background: linear-gradient(to right, #fff, #a0aec0);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Hero */
.hero {
  padding: 100px 0 60px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero h1 {
  font-size: 3.5rem;
  line-height: 1.1;
  margin-bottom: 20px;
  max-width: 800px;
  background: linear-gradient(to bottom, #fff, #cbd5e0);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p.tagline {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 20px;
  margin-bottom: 80px;
}

/* App Frame (CSS Mockup) */
.app-showcase {
  position: relative;
  width: 100%;
  max-width: 800px;
  aspect-ratio: 16/9;
  background: #1a202c;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  overflow: hidden;
  display: flex;
}

.sidebar-mock {
  width: 25%;
  background: #111822;
  border-right: 1px solid var(--border-color);
  padding: 20px;
}

.content-mock {
  flex: 1;
  padding: 30px;
  background: #171d26;
}

.skeleton-line {
  height: 12px;
  background: #2d3748;
  border-radius: 4px;
  margin-bottom: 10px;
}

.skeleton-rect {
  height: 100px;
  background: #2d3748;
  border-radius: 4px;
  margin-bottom: 20px;
}

/* Features */
.features {
  padding: 80px 0;
  border-top: 1px solid var(--border-color);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 40px;
}

.feature-card {
  padding: 30px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  transition: transform 0.2s ease;
}

.feature-card:hover {
  background: rgba(255,255,255,0.04);
  transform: translateY(-5px);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 20px;
  color: var(--accent-color);
}

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 1.25rem;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* How It Works */
.how-it-works {
  padding: 80px 0;
  text-align: center;
  background: rgba(0,0,0,0.2);
}

.steps {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 30px;
  margin-top: 40px;
  flex-wrap: wrap;
}

.step {
  display: flex;
  flex-direction: column;
  items-align: center;
  gap: 10px;
}

.step span.arrow {
  font-size: 1.5rem;
  color: var(--text-secondary);
  opacity: 0.5;
}

.step-circle {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--surface-color);
  border: 1px solid var(--accent-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: var(--accent-color);
  margin: 0 auto;
}

/* Footer */
footer {
  padding: 60px 0;
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
  color: var(--text-secondary);
}

footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

footer .links {
  display: flex;
  gap: 20px;
}

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

/* Mobile */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }
  .app-showcase {
    display: none; /* Hide mimic on mobile to save space or replace with simpler img */
  }
  footer .container {
    flex-direction: column;
    gap: 20px;
  }
  .steps {
    flex-direction: column;
  }
  .step span.arrow {
    transform: rotate(90deg);
  }
}