/* Basic Reset & Typography */
:root {
  --hue: 205;
  --brand-sat: 85%;
  --brand-light: 45%;
  --brand-primary: hsl(var(--hue), var(--brand-sat), var(--brand-light));
  --brand-primary-light: hsl(var(--hue), var(--brand-sat), 96%);
  --brand-primary-dark: hsl(var(--hue), var(--brand-sat), 25%);
  --text-primary: hsl(var(--hue), 20%, 20%);
  --text-secondary: hsl(var(--hue), 15%, 45%);
  --surface: hsl(var(--hue), 20%, 99%);
  --border-color: hsl(var(--hue), 20%, 90%);
  --card-bg: #fff;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
}
*, *::before, *::after { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", "Liberation Sans", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--surface);
  color: var(--text-primary);
  line-height: 1.6;
}
h1, h2, h3 {
  line-height: 1.2;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--brand-primary-dark);
}
h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); }
h2 { font-size: clamp(2rem, 4vw, 2.75rem); text-align: center; }
h3 { font-size: 1.25rem; }
p { max-width: 65ch; }
a { color: var(--brand-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
ul { list-style: none; padding: 0; }
img { max-width: 100%; height: auto; display: block; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Layout */
.container {
  width: 100%;
  max-width: 1140px;
  margin-inline: auto;
  padding-inline: 1.5rem;
}
.section {
  padding-block: 4rem;
  border-bottom: 1px solid var(--border-color);
}
.section:last-of-type {
  border-bottom: none;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background-color: color-mix(in srgb, var(--surface) 90%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-color);
  z-index: 10;
  padding-block: 1rem;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.brand img {
  height: 36px;
  display: block;
}
.nav {
  display: flex;
  gap: 1.5rem;
}
.nav a {
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}
.nav a:hover {
  color: var(--brand-primary);
  text-decoration: none;
}
#lang-select {
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  padding: 0.25rem 0.5rem;
  font-size: 0.875rem;
  background-color: var(--card-bg);
}

/* Hero Section */
.hero {
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
  gap: 3rem;
  min-height: calc(80vh - 5rem);
  padding-block: 4rem;
}
@media (min-width: 768px) {
  .hero {
    grid-template-columns: 1fr 1fr;
    text-align: left;
  }
}
.hero-content p {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

/* Modules Section */
.cards {
  display: grid;
  gap: 1.5rem;
  margin-top: 3rem;
}
@media (min-width: 768px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
  .cards { grid-template-columns: repeat(4, 1fr); }
}
.card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.card-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background-color: var(--brand-primary-light);
  margin-bottom: 1rem;
}
.card ul {
  padding-left: 1rem;
  list-style: disc;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.card ul li + li {
  margin-top: 0.5rem;
}

/* Tech & Differentials Section */
.grid {
  display: grid;
  gap: 1rem;
  margin-top: 3rem;
  list-style-position: inside;
  font-size: 1.1rem;
}
@media (min-width: 768px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
}
.grid li {
  background-color: var(--brand-primary-light);
  padding: 1rem 1.5rem;
  border-radius: var(--radius);
}

/* Footer */
.site-footer {
  background-color: var(--brand-primary-dark);
  color: hsl(var(--hue), 10%, 90%);
  padding-block: 2rem;
  margin-top: 4rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.copyright {
  font-size: 0.9rem;
  color: hsl(var(--hue), 10%, 70%);
}
.footer-inner .brand img {
  opacity: 0.8;
}