/* === Reset === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }

/* === Theme === */
:root {
  --bg-deep: #08090d;
  --bg-surface: #0d0f14;
  --bg-elevated: #131620;
  --emerald-500: #10b981;
  --emerald-400: #34d399;
  --emerald-300: #6ee7b7;
  --emerald-200: #a7f3d0;
  --emerald-glow: rgba(16, 185, 129, 0.15);
  --emerald-glow-strong: rgba(16, 185, 129, 0.3);
  --emerald-border: rgba(16, 185, 129, 0.25);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-dim: #334155;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', system-ui, sans-serif;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-deep);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}

/* === Slide System === */
.deck {
  width: 100vw;
  height: 100vh;
  position: relative;
}

.slide {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 48px 64px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.6s ease, visibility 0.6s ease;
  z-index: 0;
}

.slide.active {
  opacity: 1;
  visibility: visible;
  z-index: 1;
}

/* === Typography === */
.slide h1 {
  font-size: 64px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--text-primary);
}

.slide h2 {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text-primary);
  text-align: center;
}

.slide h3 {
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.slide p {
  font-size: 20px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.slide .tagline {
  font-size: 26px;
  color: var(--emerald-400);
  font-weight: 500;
  letter-spacing: -0.01em;
}

.slide .callout {
  font-size: 18px;
  color: var(--emerald-300);
  font-style: italic;
  margin-top: 32px;
  text-align: center;
  max-width: 800px;
}

/* === Particle Background === */
.particle-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

.slide > *:not(.particle-bg) {
  position: relative;
  z-index: 1;
}

/* === Progress Bar === */
.progress {
  position: fixed;
  bottom: 0;
  left: 0;
  height: 3px;
  background: var(--emerald-500);
  transition: width 0.4s ease;
  z-index: 100;
}

/* === Slide Number === */
.slide-number {
  position: fixed;
  bottom: 16px;
  right: 24px;
  font-size: 13px;
  color: var(--text-dim);
  z-index: 100;
  font-variant-numeric: tabular-nums;
}

/* === Password Gate === */
#password-gate {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: var(--bg-deep);
  display: flex;
  align-items: center;
  justify-content: center;
}

.gate-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.gate-logo { margin-bottom: 8px; }

.gate-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.03em;
}

.gate-sub {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

#gate-form {
  display: flex;
  gap: 8px;
}

#gate-input {
  background: var(--bg-elevated);
  border: 1px solid var(--text-dim);
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 15px;
  color: var(--text-primary);
  font-family: var(--font-sans);
  width: 240px;
  outline: none;
  transition: border-color 0.2s ease;
}

#gate-input:focus {
  border-color: var(--emerald-500);
}

#gate-input::placeholder {
  color: var(--text-dim);
}

#gate-form button {
  background: var(--emerald-500);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: background 0.2s ease;
}

#gate-form button:hover {
  background: var(--emerald-400);
}

.gate-error {
  font-size: 13px;
  color: #f87171;
  min-height: 20px;
}

/* === Responsive === */
@media (max-width: 1200px) {
  .slide { padding: 40px 48px; }
  .slide h1 { font-size: 48px; }
  .slide h2 { font-size: 36px; }
  .slide h3 { font-size: 22px; }
}