/* ========================================
   BASE
   ======================================== */
html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   SKIP LINK (ACCESSIBILITY)
   ======================================== */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  background: var(--color-accent);
  color: #fff;
  padding: var(--space-sm) var(--space-md);
  z-index: 1000;
  font-size: 14px;
  font-weight: 500;
}

.skip-link:focus { top: var(--space-sm); }

/* ========================================
   TYPOGRAPHY
   ======================================== */
h1, h2, h3, h4 { line-height: 1.25; font-weight: 600; }
h1 { font-size: clamp(32px, 5vw, 48px); letter-spacing: -0.02em; }
h2 { font-size: clamp(24px, 3.5vw, 36px); letter-spacing: -0.015em; }
h3 { font-size: clamp(18px, 2.5vw, 22px); }
h4 { font-size: 16px; font-weight: 500; }
p + p { margin-top: var(--space-md); }

/* ========================================
   LAYOUT
   ======================================== */
.container {
  width: 100%;
  max-width: var(--width-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

.section + .section {
  border-top: 1px solid var(--color-border);
}

.section--surface {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

/* ========================================
   NAVIGATION
   ======================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav__brand {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav__link {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color 0.15s ease;
}

.nav__link:hover,
.nav__link:focus-visible { color: var(--color-text); }

.nav__link--active { color: var(--color-accent); }

.nav__cta {
  font-size: 14px;
  padding: 10px 20px;
}

.nav__cta--disabled {
  background: var(--color-border);
  color: var(--color-text-secondary);
  pointer-events: none;
  cursor: default;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ========================================
   PAGE HEADER
   ======================================== */
.page-header {
  padding: var(--space-3xl) 0 var(--space-2xl);
}

.page-header h1 { margin-bottom: var(--space-md); }

.page-header__intro {
  font-size: 18px;
  color: var(--color-text-secondary);
  max-width: 580px;
  line-height: 1.6;
}

/* ========================================
   SECTION HEADER
   ======================================== */
.section-header { margin-bottom: var(--space-xl); }

.section-header p {
  color: var(--color-text-secondary);
  font-size: 15px;
  margin-top: var(--space-xs);
}

/* ========================================
   PAGE CTA (bottom band on every page)
   ======================================== */
.page-cta {
  padding: var(--space-3xl) 0;
  text-align: center;
  background: var(--color-dark);
  color: var(--color-dark-text);
}

.page-cta h2 { margin-bottom: var(--space-sm); }

.page-cta p {
  color: var(--color-dark-muted);
  margin-bottom: var(--space-xl);
  font-size: 17px;
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
  background: var(--color-dark);
  color: var(--color-dark-muted);
  padding: var(--space-3xl) 0 var(--space-xl);
  border-top: 1px solid #333;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-2xl);
}

.footer__brand-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-dark-text);
  margin-bottom: var(--space-sm);
}

.footer__tagline { font-size: 14px; line-height: 1.5; max-width: 300px; }

.footer__heading {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-dark-text);
  margin-bottom: var(--space-md);
}

.footer__links { display: flex; flex-direction: column; gap: var(--space-sm); }

.footer__link {
  font-size: 14px;
  color: var(--color-dark-muted);
  transition: color 0.15s ease;
}

.footer__link:hover,
.footer__link:focus-visible { color: var(--color-dark-text); }

.footer__bottom {
  border-top: 1px solid #333;
  padding-top: var(--space-lg);
  font-size: 13px;
}

/* ========================================
   RESPONSIVE: TABLET
   ======================================== */
@media (max-width: 1023px) {
  .footer__grid { grid-template-columns: 1fr 1fr; }
}

/* ========================================
   RESPONSIVE: MOBILE
   ======================================== */
@media (max-width: 767px) {
  .section { padding: var(--space-2xl) 0; }

  .nav__links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-md);
    align-items: stretch;
  }

  .nav__links.is-open { display: flex; }
  .nav__link { font-size: 16px; padding: var(--space-sm) 0; }
  .nav__cta { text-align: center; margin-top: var(--space-sm); }
  .nav__toggle { display: flex; }

  .btn-row { flex-direction: column; align-items: center; }
  .btn { width: 100%; text-align: center; }

  .footer__grid { grid-template-columns: 1fr; gap: var(--space-xl); }
}

/* ========================================
   REDUCED MOTION
   ======================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
  html { scroll-behavior: auto; }
}