/* -------------------------------------------------- */
/* Layout: header, nav, footer, grids                  */
/* -------------------------------------------------- */

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 20, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: background var(--transition), border-color var(--transition), padding var(--transition);
}

:root[data-theme="light"] .site-header {
  background: rgba(247, 249, 251, 0.7);
}

.site-header.is-scrolled {
  background: rgba(10, 14, 20, 0.92);
  border-bottom-color: var(--border);
}

:root[data-theme="light"] .site-header.is-scrolled {
  background: rgba(247, 249, 251, 0.92);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding-block: 1.1rem;
  transition: padding var(--transition);
}

.site-header.is-scrolled .header-inner {
  padding-block: 0.75rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  color: var(--text);
  flex-shrink: 0;
}

.logo svg {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.logo-word span {
  color: var(--accent);
}

/* Primary nav */
.main-nav {
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, 2.5vw, 2.25rem);
}

.main-nav a:not(.btn) {
  position: relative;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  padding-block: 0.4rem;
}

.main-nav a:not(.btn)::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

.main-nav a:not(.btn):hover,
.main-nav a:not(.btn):focus-visible {
  color: var(--text);
}

.main-nav a:not(.btn):hover::after,
.main-nav a:not(.btn):focus-visible::after {
  width: 100%;
}

.main-nav a.is-active {
  color: var(--text);
}

.main-nav a.is-active::after {
  width: 100%;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, 2.5vw, 2.25rem);
}

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  z-index: 200;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin-inline: auto;
  transition: transform var(--transition), opacity var(--transition);
}

.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);
}

@media (max-width: 860px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    inset: 0;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    background: var(--bg);
    background-image: radial-gradient(circle at 50% 30%, var(--bg-elevated), var(--bg) 70%);
    transform: translateX(100%);
    transition: transform 320ms cubic-bezier(.4,0,.2,1);
    z-index: 150;
  }

  .nav-links.is-open {
    transform: translateX(0);
  }

  .nav-links a:not(.btn) {
    font-size: 1.4rem;
  }
}

/* Footer */
.site-footer {
  background: var(--bg-subtle);
  border-top: 1px solid var(--border);
  padding-top: var(--space-section);
}

.footer-grid {
  display: grid;
  gap: 2.5rem;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  padding-bottom: 3rem;
}

@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 560px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-col h4 {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 1.1rem;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.footer-col a:hover {
  color: var(--accent);
}

.footer-brand .logo {
  margin-bottom: 1rem;
}

.footer-brand p {
  max-width: 32ch;
  margin-bottom: 1rem;
}

.footer-newsletter {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
}

.footer-newsletter input {
  flex: 1;
  min-width: 0;
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-block: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-faint);
}

.footer-bottom-links {
  display: flex;
  gap: 1.5rem;
}

.footer-bottom-links a {
  color: var(--text-faint);
}

.footer-bottom-links a:hover {
  color: var(--accent);
}

/* Grids */
.grid {
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
}

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

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

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

@media (max-width: 960px) {
  .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* Two-column layouts (contact page etc.) */
.split {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}

@media (max-width: 860px) {
  .split {
    grid-template-columns: 1fr;
  }
}