:root {
  --bg-dark: #09090b;
  --bg-card: #18181b;
  --bg-elevated: #27272a;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent: #06b6d4;
  --accent-gradient: linear-gradient(135deg, #06b6d4 0%, #8b5cf6 100%);
  --border: #3f3f46;
  --radius-lg: 16px;
  --radius-md: 12px;
  --shadow: 0 10px 40px -10px rgba(0,0,0,0.5);
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

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

body {
  background-color: var(--bg-dark);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.presentation-container {
  width: 100vw;
  height: 100vh;
  overflow-y: auto;
  scroll-snap-type: y mandatory;
}

section {
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 40px;
  scroll-snap-align: start;
  position: relative;
  overflow: hidden;
}

/* Typography */
h1 {
  font-size: clamp(2.5rem, 8vw, 5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  margin-bottom: 1.5rem;
  text-align: center;
  line-height: 1.1;
}

h2 {
  font-size: clamp(1.5rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.subtitle {
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  color: var(--text-secondary);
  max-width: 800px;
  text-align: center;
  margin-bottom: 2rem;
}

.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* Layout Elements */
.content-wrapper {
  max-width: 1000px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  width: 100%;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.card:hover {
  transform: translateY(-8px);
  border-color: var(--text-muted);
}

.card h3 {
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.card p {
  color: var(--text-secondary);
}

/* Navigation & Controls */
.nav-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  font-size: 0.875rem;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {transform: translateX(-50%) translateY(0);}
  40% {transform: translateX(-50%) translateY(-10px);}
  60% {transform: translateX(-50%) translateY(-5px);}
}

.brand-badge {
  position: fixed;
  top: 2rem;
  right: 2rem;
  background: rgba(24, 24, 27, 0.8);
  backdrop-filter: blur(8px);
  padding: 0.5rem 1.25rem;
  border-radius: 100px;
  border: 1px solid var(--border);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-size: 0.75rem;
  z-index: 100;
}

/* Specific Component: Timeline */
.timeline {
  position: relative;
  display: flex;
  justify-content: space-between;
  width: 100%;
  margin-top: 4rem;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 15px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--border);
  z-index: 0;
}

.timeline-item {
  position: relative;
  z-index: 1;
  background: var(--bg-dark);
  padding-right: 1rem;
  width: 30%;
}

.timeline-dot {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--accent);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 0.875rem;
}

/* Utility */
.mb-large { margin-bottom: 4rem; }
.mt-large { margin-top: 4rem; }
.text-center { text-align: center; }
.placeholder-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}