/* === Base === */

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #111827;
  background-color: #f9fafb;
  line-height: 1.6;
}

img,
video {
  max-width: 100%;
  display: block;
}

/* === Layout helpers === */

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.section {
  padding: 3.5rem 0;
}

.section-alt {
  background: #ffffff;
}

/* === Header & Nav === */

.site-header {
  background: linear-gradient(135deg, #0f172a, #1f2937);
  color: #f9fafb;
  padding-bottom: 2.5rem;
}

.nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.nav-title {
  font-weight: 700;
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.9rem;
}

.nav-links a {
  color: #e5e7eb;
  text-decoration: none;
  padding: 0.25rem 0.5rem;
  border-radius: 999px;
  transition: background 0.15s ease, color 0.15s ease;
}

.nav-links a:hover {
  background: rgba(249, 250, 251, 0.1);
  color: #ffffff;
}

/* === Hero === */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: center;
  padding: 1.5rem 0 0;
}

.hero-text h1 {
  font-size: 2.6rem;
  margin: 0 0 0.3rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  margin: 0 0 0.5rem;
  color: #d1d5db;
}

.hero-tagline {
  margin: 0 0 0.25rem;
  color: #e5e7eb;
}

.hero-tagline-small {
  margin: 0 0 1rem;
  color: #9ca3af;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.stat-pill {
  font-size: 0.8rem;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.5);
  color: #e5e7eb;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.6rem 1.1rem;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.16s ease, color 0.16s ease, border-color 0.16s ease,
    transform 0.08s ease;
}

.btn.primary {
  background: #3b82f6;
  color: #f9fafb;
}

.btn.primary:hover {
  background: #2563eb;
  transform: translateY(-1px);
}

.btn.secondary {
  background: transparent;
  color: #e5e7eb;
  border-color: #6b7280;
}

.btn.secondary:hover {
  background: rgba(31, 41, 55, 0.8);
  color: #f9fafb;
  transform: translateY(-1px);
}

.hero-image img {
  border-radius: 1rem;
  border: 1px solid rgba(148, 163, 184, 0.45);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.45);
}

/* === Sections === */

.section h2 {
  font-size: 1.8rem;
  margin: 0 0 1.25rem;
}

.section p {
  margin: 0 0 1rem;
  color: #374151;
}

.section a {
  color: #2563eb;
}

/* Two-column layout */

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: flex-start;
  margin-top: 1.5rem;
}

/* Feature list */

.feature-list {
  padding-left: 1.1rem;
  margin: 0;
}

.feature-list li {
  margin-bottom: 0.4rem;
}

/* Figures */

.figure,
.figure-large {
  margin-top: 1rem;
}

.figure img,
.figure-large img {
  border-radius: 0.75rem;
  border: 1px solid #e5e7eb;
  background: #ffffff;
}

.figure-caption {
  font-size: 0.85rem;
  color: #6b7280;
  margin-top: 0.4rem;
}

.figure-group {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.75rem;
  margin-top: 1.5rem;
}

/* === Comparisons === */

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.75rem;
  margin-top: 1.75rem;
}

.comparison-card {
  background: #ffffff;
  border-radius: 1rem;
  border: 1px solid #e5e7eb;
  padding: 1rem;
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.06);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.comparison-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.1rem;
}

.video-wrapper {
  border-radius: 0.75rem;
  overflow: hidden;
  border: 1px solid #e5e7eb;
  background: #000000;
}

.comparison-points {
  padding-left: 1.1rem;
  margin: 0.4rem 0 0;
  font-size: 0.9rem;
  color: #4b5563;
}

/* === Demo gallery === */

.demo-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.demo-card {
  background: #ffffff;
  border-radius: 1rem;
  border: 1px solid #e5e7eb;
  padding: 1rem;
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.05);
}

.demo-card img {
  border-radius: 0.75rem;
  border: 1px solid #e5e7eb;
  margin-bottom: 0.75rem;
}

.demo-card h3 {
  margin: 0 0 0.3rem;
  font-size: 1.05rem;
}

.demo-card p {
  font-size: 0.92rem;
  color: #4b5563;
}

.demo-card-wide {
  grid-column: span 3;
}

/* === Steps / Usage === */

.steps-list {
  padding-left: 1.1rem;
  margin-top: 1rem;
}

.steps-list li {
  margin-bottom: 0.75rem;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.85rem;
  padding: 0.15rem 0.3rem;
  border-radius: 0.3rem;
  background: #e5e7eb;
}

/* === BibTeX === */

.bibtex {
  background: #111827;
  color: #e5e7eb;
  border-radius: 0.75rem;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
}

/* === Footer === */

.site-footer {
  background: #0f172a;
  color: #9ca3af;
  padding: 1.5rem 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.footer-text p {
  margin: 0.1rem 0;
  font-size: 0.85rem;
}

.footer-logo img {
  max-width: 140px;
  opacity: 0.9;
}

#responsive-video-container{
  display: flex;
  justify-content: center;
}

#responsive-video-container video{
  width: min(100%, 900px);   /* pick your max display width */
  aspect-ratio: 640 / 368;   /* your video ratio */
  height: auto;
  display: block;
}
/* === Responsive === */

@media (max-width: 900px) {
  .hero {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-image {
    order: -1;
    margin-bottom: 1.5rem;
  }

  .two-column {
    grid-template-columns: minmax(0, 1fr);
  }

  .figure-group {
    grid-template-columns: minmax(0, 1fr);
  }

  .comparison-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .demo-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .demo-card-wide {
    grid-column: span 1;
  }

  .nav-links {
    display: none; /* keep it simple; could add mobile nav later */
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

}