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

:root {
  --transition-speed: 0.3s;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;
}

/* Dark theme (default) */
[data-theme="dark"] {
  --bg: #05080E;
  --bg-elevated: #0F1629;
  --text: #E8EDF6;
  --text-muted: #5A6B8A;
  --text-dim: #3B4A6B;
  --accent: #34D399;
  --accent-base: #10B981;
  --accent-glow: rgba(16, 185, 129, 0.15);
  --divider: #1C2742;
  --toggle-bg: #131B2E;
  --toggle-border: #1C2742;
  --toggle-hover: #182240;
}

/* Light theme */
[data-theme="light"] {
  --bg: #F8FAFF;
  --bg-elevated: #ECFDF5;
  --text: #1a1a2e;
  --text-muted: #5A6B8A;
  --text-dim: #8B9DC3;
  --accent: #059669;
  --accent-base: #10B981;
  --accent-glow: rgba(16, 185, 129, 0.1);
  --divider: rgba(200, 210, 230, 0.4);
  --toggle-bg: #e8edf6;
  --toggle-border: rgba(200, 210, 230, 0.4);
  --toggle-hover: #dce3f0;
}

html {
  height: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  min-height: 100%;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-speed), color var(--transition-speed);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Starfield */
.starfield {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

.starfield canvas {
  width: 100%;
  height: 100%;
}

.page-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header */
header {
  display: flex;
  justify-content: flex-end;
  padding: 1.5rem 2rem;
}

.theme-toggle {
  background: var(--toggle-bg);
  border: 1px solid var(--toggle-border);
  border-radius: 50%;
  width: 44px;
  height: 44px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--text);
  transition: background-color var(--transition-speed), color var(--transition-speed), border-color var(--transition-speed);
}

.theme-toggle:hover {
  background: var(--toggle-hover);
}

[data-theme="dark"] .icon-sun {
  display: none;
}

[data-theme="dark"] .icon-moon {
  display: inline;
}

[data-theme="light"] .icon-sun {
  display: inline;
}

[data-theme="light"] .icon-moon {
  display: none;
}

/* Main content */
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.container {
  text-align: center;
  max-width: 540px;
}

/* Astronaut */
.astronaut {
  width: 180px;
  height: auto;
  margin-bottom: 2rem;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }
  25% {
    transform: translateY(-14px) rotate(1.5deg);
  }
  50% {
    transform: translateY(-6px) rotate(-1deg);
  }
  75% {
    transform: translateY(-18px) rotate(0.5deg);
  }
}

.brand {
  font-family: var(--font-sans);
  font-size: 48px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--accent);
  transition: color var(--transition-speed);
}

[data-theme="dark"] .brand {
  text-shadow: 0 0 40px var(--accent-glow);
}

.tagline {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-base);
  margin-top: 16px;
  background: var(--accent-glow);
  display: inline-block;
  padding: 6px 14px;
  border-radius: 6px;
  border: 1px solid rgba(16, 185, 129, 0.2);
  transition: background-color var(--transition-speed), border-color var(--transition-speed);
}

.divider {
  width: 40px;
  height: 1px;
  background: var(--divider);
  margin: 2rem auto;
  transition: background-color var(--transition-speed);
}

.description {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-muted);
  transition: color var(--transition-speed);
}

/* Footer */
footer {
  padding: 1.5rem 2rem;
  text-align: center;
}

footer p {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-dim);
  transition: color var(--transition-speed);
}

/* Light mode: invert astronaut lines to dark */
[data-theme="light"] .astronaut {
  filter: invert(1) brightness(0.25);
}

/* Responsive */
@media (max-width: 480px) {
  .astronaut {
    width: 140px;
  }

  .brand {
    font-size: 36px;
  }

  .description {
    font-size: 15px;
  }

  header {
    padding: 1rem 1.25rem;
  }
}