/* Eigendeck website — minimal, dark */

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

:root {
  --bg: #0a0a0a;
  --bg-card: #141414;
  --border: #222;
  --text: #e8e8e8;
  --text-muted: #888;
  --accent: #7b61ff;
  --accent-hover: #9580ff;
  --font: 'PT Sans', sans-serif;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

code {
  font-size: 0.85em;
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--text-muted);
}

/* Nav */

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  gap: 28px;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.15s;
}

.nav-links a:hover {
  color: var(--text);
}

/* Hero */

.hero {
  max-width: 720px;
  margin: 0 auto;
  padding: 160px 24px 60px;
  text-align: center;
}

.eyebrow {
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2.4rem, 6vw, 3.6rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
}

.hero-cta {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */

.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 8px;
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 700;
  transition: background 0.15s, border-color 0.15s;
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.btn-secondary:hover {
  border-color: #444;
  color: var(--text);
}

/* Preview window */

.preview {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.preview-window {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--bg-card);
  animation: fadeUp 0.8s ease both;
  animation-delay: 0.2s;
}

.window-bar {
  padding: 12px 16px;
  display: flex;
  gap: 7px;
  border-bottom: 1px solid var(--border);
}

.dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #333;
}

.window-body {
  padding: 32px;
}

.mock-slide {
  background: #fff;
  border-radius: 6px;
  padding: 28px 32px;
  color: #111;
  aspect-ratio: 16 / 9;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
}

.mock-title {
  font-size: clamp(1rem, 2.5vw, 1.6rem);
  font-weight: 700;
}

.mock-math {
  font-size: clamp(0.85rem, 2vw, 1.2rem);
  font-style: italic;
  color: #333;
}

.math-accent {
  color: var(--accent);
  font-weight: 700;
}

.mock-demo {
  flex: 1;
  min-height: 0;
  border: 2px dashed #ccc;
  border-radius: 6px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.mock-demo-label {
  position: absolute;
  top: 6px;
  right: 8px;
  font-size: 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #aaa;
}

.mock-graph svg {
  width: 100%;
  max-width: 220px;
  height: auto;
}

.mock-graph circle {
  animation: pulse 3s ease-in-out infinite alternate;
}

.mock-graph circle:nth-child(7) { animation-delay: 0.3s; }
.mock-graph circle:nth-child(8) { animation-delay: 0.6s; }
.mock-graph circle:nth-child(9) { animation-delay: 0.9s; }
.mock-graph circle:nth-child(10) { animation-delay: 1.2s; }

/* Features */

.features {
  max-width: 960px;
  margin: 0 auto;
  padding: 80px 24px;
}

.features h2 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  margin-bottom: 48px;
  text-align: center;
  letter-spacing: -0.01em;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.feature {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 24px;
  transition: border-color 0.2s;
}

.feature:hover {
  border-color: #333;
}

.feature-icon {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: var(--accent);
}

.feature h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Download */

.download {
  max-width: 600px;
  margin: 0 auto;
  padding: 80px 24px;
  text-align: center;
}

.download h2 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  margin-bottom: 12px;
}

.download-note {
  color: var(--text-muted);
  margin-bottom: 28px;
}

.download-buttons {
  margin-bottom: 24px;
}

.download-alt {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Footer */

footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

footer a {
  color: var(--text-muted);
  text-decoration: underline;
  text-underline-offset: 2px;
}

footer a:hover {
  color: var(--text);
}

/* Animations */

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  from { opacity: 0.7; }
  to { opacity: 1; }
}

/* Responsive */

@media (max-width: 600px) {
  .hero {
    padding-top: 120px;
  }

  .nav-links {
    gap: 16px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .mock-slide {
    padding: 16px 20px;
  }
}