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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.15;
  margin: 0 0 var(--space-4);
  color: var(--navy-900);
}

h1 { font-size: clamp(2.25rem, 4vw + 1rem, 3.75rem); }
h2 { font-size: clamp(1.75rem, 2.5vw + 1rem, 2.5rem); }
h3 { font-size: clamp(1.25rem, 1.2vw + 1rem, 1.5rem); }

p {
  margin: 0 0 var(--space-4);
  color: var(--muted);
}

.eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue-600);
  margin-bottom: var(--space-3);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

section {
  padding-block: var(--space-8);
}

@media (max-width: 720px) {
  section { padding-block: var(--space-7); }
  .container { padding-inline: var(--space-4); }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.85em 1.6em;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--brand-gradient);
  color: #fff;
  box-shadow: 0 10px 24px rgba(51, 181, 45, 0.28);
}

.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--navy-900);
}

.btn-glass {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border-color: var(--glass-border);
  color: #fff;
}

/* Glassmorphism panel — the core "Zeta" look */
.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: var(--radius-md);
}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(1, 18, 70, 0.12);
}

.grid {
  display: grid;
  gap: var(--space-5);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* Scroll-reveal (paired with js/animations.js) */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms ease, transform 700ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  html { scroll-behavior: auto; }
}

/* Accordion (native details/summary) */
details.spec-accordion {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-4) var(--space-5);
  margin-bottom: var(--space-3);
  background: var(--surface);
}

details.spec-accordion summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--navy-900);
  list-style: none;
}

details.spec-accordion summary::-webkit-details-marker { display: none; }

details.spec-accordion summary::after {
  content: "+";
  float: right;
  font-size: 1.2rem;
  color: var(--blue-600);
}

details.spec-accordion[open] summary::after {
  content: "\2212";
}

details.spec-accordion p,
details.spec-accordion ul {
  margin-top: var(--space-3);
}