:root {
  /* Default to Dark Mode variables (will be overridden by media query or class) */
  --background: #0b0c10;
  --card: #141415;
  --primary: #6768a1;
  --primary-hover: #56578a;
  --text: #f8f9fa;
  --muted: #9aa0a6;
  --border: #2a2a2a;
}

[data-theme="light"] {
  --background: #ffffff;
  --card: #f3f4f6;
  /* Isolate card slightly from pure white bg if needed, or use white with shadow */
  --primary: #6768a1;
  --primary-hover: #56578a;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
}

/* System preference detection */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --background: #ffffff;
    --card: #ffffff;
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --text: #111827;
    --muted: #6b7280;
    --border: #e5e7eb;
  }
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: var(--background);
  color: var(--text);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.container {
  width: 100%;
  max-width: 480px;
  padding: 2rem;
  text-align: center;
}

/* Theme Toggle */
.theme-switch {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  background: transparent;
  border: none;
  color: var(--text);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  transition: background-color 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-switch:hover {
  background-color: var(--card);
}

.theme-switch svg {
  width: 24px;
  height: 24px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Logo */
.logo-container {
  margin-bottom: 2rem;
  animation: float 1s ease-in-out infinite;
}

.logo {
  width: 100%;
  height: 100%;
}

@keyframes float {
  0% {
    transform: translateY(0px);
  }

  50% {
    transform: translateY(-10px);
  }

  100% {
    transform: translateY(0px);
  }
}

/* Typography */
h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.025em;
}

.subtitle {
  color: var(--muted);
  font-size: 1.125rem;
  margin-bottom: 2.5rem;
}

.features {
  text-align: left;
  background-color: var(--card);
  padding: 1.5rem;
  border-radius: 1rem;
  border: 1px solid var(--border);
  margin-bottom: 2.5rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.features h3 {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 1rem;
}

.feature-list {
  list-style: none;
}

.feature-list li {
  display: flex;
  align-items: center;
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
}

.feature-list li:last-child {
  margin-bottom: 0;
}

.check-icon {
  color: var(--primary);
  margin-right: 0.75rem;
  width: 18px;
  height: 18px;
}

/* Download Button */
.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary);
  color: white;
  text-decoration: none;
  font-weight: 600;
  padding: 1rem 2rem;
  border-radius: 9999px;
  /* Pill shape */
  width: 100%;
  transition: background-color 0.2s, transform 0.1s;
  box-shadow: 0 4px 14px 0 rgba(0, 0, 0, 0.2);
}

.download-btn:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

.download-btn:active {
  transform: translateY(1px);
}

.download-icon {
  margin-right: 0.75rem;
  width: 24px;
  height: 24px;
}

.version-info {
  margin-top: 1.5rem;
  font-size: 0.875rem;
  color: var(--muted);
}


/* App Preview Section */
.app-preview {
  margin-bottom: 2.5rem;
  width: 100%;
}

.app-preview h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.preview-text {
  color: var(--muted);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.toggle-preview-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background-color: var(--card);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 9999px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  margin-bottom: 2rem;
  width: 100%;
}

.toggle-preview-btn:hover {
  background-color: var(--border);
  transform: translateY(-1px);
}

.toggle-preview-btn.active {
  background-color: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Responsive Iframe */
.iframe-container {
  position: relative;
  width: 100%;
  padding-bottom: 216.79%;
  /* 393x852 Aspect Ratio (852/393 = ~2.1679) */
  height: 0;
  overflow: hidden;
  border-radius: 20px;
  /* More rounded for mobile feel */
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  border: 1px solid var(--border);
  margin-bottom: 2rem;
  background: var(--card);
}

.iframe-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Presentation Link */
.presentation-section {
  background-color: var(--card);
  padding: 1.5rem;
  border-radius: 1rem;
  border: 1px solid var(--border);
  text-align: center;
  margin-top: 2rem;
  /* Added margin for separation */
}

.presentation-section p {
  margin-bottom: 1rem;
  font-size: 0.95rem;
  color: var(--muted);
}

.presentation-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background-color: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
  text-decoration: none;
  border-radius: 9999px;
  font-weight: 600;
  transition: all 0.2s ease;
}

.presentation-link:hover {
  background-color: var(--primary);
  color: white;
  transform: translateY(-1px);
}

.presentation-link .emoji {
  font-size: 1.2rem;
}

/* Responsive */
@media (max-width: 640px) {
  .container {
    padding: 1.5rem;
  }
}