:root {
  --bg-color: #0d1117;
  --text-color: #c9d1d9;
  --accent-color: #58a6ff;
  --accent-hover: #79c0ff;
  --card-bg: rgba(22, 27, 34, 0.6);
  --border-color: #30363d;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow-x: hidden;
  background-image: radial-gradient(circle at top, rgba(88, 166, 255, 0.15), transparent 40%);
}

.container {
  max-width: 900px;
  width: 100%;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.hero-image-container {
  margin-bottom: 3rem;
  width: 100%;
  max-width: 600px;
}

.hero-image-container img {
  width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

h1 {
  font-size: 4rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #c9d1d9, #58a6ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -1px;
}

p.subtitle {
  font-size: 1.25rem;
  color: #8b949e;
  max-width: 600px;
  margin-bottom: 3rem;
}

.download-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background-color: var(--accent-color);
  color: #0d1117;
  padding: 1rem 2rem;
  border-radius: 9999px;
  font-size: 1.125rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 0 20px rgba(88, 166, 255, 0.4);
  position: relative;
  overflow: hidden;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(88, 166, 255, 0.6);
}

.btn-primary::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(rgba(255, 255, 255, 0.2), transparent);
  transform: rotate(45deg);
  transition: all 0.3s ease;
  opacity: 0;
}

.btn-primary:hover::after {
  opacity: 1;
}

.version-info {
  font-size: 0.875rem;
  color: #8b949e;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-top: 5rem;
  width: 100%;
}

.feature-card {
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  text-align: left;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-color);
}

.feature-card h3 {
  font-size: 1.25rem;
  color: #fff;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: #8b949e;
  font-size: 0.95rem;
}

footer {
  margin-top: 5rem;
  padding-bottom: 2rem;
  color: #8b949e;
  font-size: 0.875rem;
  text-align: center;
}

footer a {
  color: var(--accent-color);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Spinner for loading state */
.spinner {
  width: 20px;
  height: 20px;
  border: 3px solid rgba(13, 17, 23, 0.3);
  border-radius: 50%;
  border-top-color: #0d1117;
  animation: spin 1s ease-in-out infinite;
  display: none;
}

.btn-primary.loading .spinner {
  display: block;
}

.btn-primary.loading .btn-text {
  display: none;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}