:root {
  --yl-navy: #0f172a;
  --yl-navy-soft: #1e293b;
  --yl-accent: #6366f1;
  --yl-accent-hover: #4f46e5;
  --yl-surface: #f8fafc;
  --yl-radius: 1rem;
  --yl-font-sans: "DM Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --yl-font-display: "Outfit", var(--yl-font-sans);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--yl-font-sans);
  color: var(--yl-navy);
  background: #fff;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1020;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(15, 23, 42, 0.06);
}

.navbar-brand {
  font-family: var(--yl-font-display);
  font-weight: 600;
  color: var(--yl-navy) !important;
}

.brand-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 0.5rem;
  background: linear-gradient(135deg, var(--yl-accent), #22d3ee);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.brand-mark--sm {
  width: 1.5rem;
  height: 1.5rem;
}

.navbar .nav-link {
  color: var(--yl-navy-soft);
  font-weight: 500;
}

.navbar .nav-link:hover,
.navbar .nav-link:focus {
  color: var(--yl-accent);
}

.btn-primary {
  --bs-btn-bg: var(--yl-accent);
  --bs-btn-border-color: var(--yl-accent);
  --bs-btn-hover-bg: var(--yl-accent-hover);
  --bs-btn-hover-border-color: var(--yl-accent-hover);
  --bs-btn-active-bg: var(--yl-accent-hover);
  --bs-btn-active-border-color: var(--yl-accent-hover);
}

.btn-outline-primary {
  --bs-btn-color: var(--yl-accent);
  --bs-btn-border-color: var(--yl-accent);
  --bs-btn-hover-bg: var(--yl-accent);
  --bs-btn-hover-border-color: var(--yl-accent);
}

.liang {
  background: var(--yl-navy);
  min-height: 28rem;
}

.liang-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% -20%, rgba(99, 102, 241, 0.45), transparent),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(34, 211, 238, 0.25), transparent);
  pointer-events: none;
}

.py-lg-6 {
  padding-top: 4.5rem !important;
  padding-bottom: 4.5rem !important;
}

.liang-mini-card {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
}

.section-surface {
  background: var(--yl-surface);
}

.section-title {
  font-family: var(--yl-font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.feature-tile .icon-wrap {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 0.75rem;
  background: rgba(99, 102, 241, 0.12);
  color: var(--yl-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.app-card {
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.app-card-link:hover .app-card,
.app-card-link:focus-visible .app-card {
  transform: translateY(-4px);
  box-shadow: 0 1rem 2.5rem rgba(15, 23, 42, 0.12) !important;
}

.app-card-link:focus-visible {
  outline: 3px solid rgba(99, 102, 241, 0.45);
  outline-offset: 4px;
  border-radius: var(--yl-radius);
}

.app-card-media {
  min-height: 12rem;
  background: #e2e8f0;
}

.section-cta {
  background: linear-gradient(120deg, #312e81, var(--yl-navy));
}

.cta-prose {
  max-width: 32rem;
}

.site-footer {
  background: #fff;
}

.skip-link:focus {
  z-index: 2000;
}

.navbar-toggler {
  padding: 0.35rem 0.55rem;
}

@media (max-width: 575.98px) {
  .app-card-media {
    min-height: 10rem;
  }
}