/* === Layout === */

/* --- Page Shell --- */
.page-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.page-shell main {
  flex: 1;
}

/* --- Header --- */
#site-header {
  min-height: var(--header-height);
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.logo {
  display: flex;
  align-items: center;
}

.logo-image {
  display: block;
  height: 40px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-links a {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-gray-300);
  transition: color var(--transition-fast);
  position: relative;
}

.nav-links a.btn-primary,
.nav-links a.btn-primary:hover,
.nav-links a.btn-primary.active {
  color: var(--color-primary-dark) !important;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-white);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
}

.nav-cta {
  margin-left: var(--space-4);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-2);
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-gray-200);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

/* --- Mobile Nav --- */
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--header-height);
    right: -100%;
    width: 280px;
    height: calc(100vh - var(--header-height));
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: var(--space-6);
    background: var(--color-primary-dark);
    box-shadow: var(--shadow-xl);
    transition: right var(--transition-base);
    z-index: 999;
  }

  .nav-links a {
    display: block;
    width: 100%;
    padding: var(--space-3) 0;
    font-size: var(--text-base);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .nav-links a.active::after {
    display: none;
  }

  .nav-cta {
    margin-left: 0;
    margin-top: var(--space-4);
    width: 100%;
  }

  .nav-cta .btn {
    width: 100%;
    text-align: center;
  }

  body.nav-open .nav-links {
    right: 0;
  }

  body.nav-open .hamburger span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  body.nav-open .hamburger span:nth-child(2) {
    opacity: 0;
  }

  body.nav-open .hamburger span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
}

/* --- Mobile Nav Overlay --- */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  top: var(--header-height);
  background: rgba(0, 0, 0, 0.3);
  z-index: 998;
}

body.nav-open .nav-overlay {
  display: block;
}

/* --- Footer --- */
#site-footer {
  min-height: 300px;
}

.site-footer {
  background: var(--color-primary-dark);
  color: var(--color-gray-300);
  padding: var(--space-16) 0 var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-brand p {
  color: var(--color-gray-300);
  font-size: var(--text-sm);
  margin-top: var(--space-4);
  line-height: 1.6;
}

.footer-col h4 {
  color: var(--color-white);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
}

.footer-col a {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-gray-300);
  padding: var(--space-1) 0;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-8);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
}

.footer-bottom a {
  color: var(--color-gray-300);
  transition: color var(--transition-fast);
}

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

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-4);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

/* --- Sections --- */
.section {
  padding: var(--space-20) 0;
}

.section-sm {
  padding: var(--space-12) 0;
}

.section-lg {
  padding: var(--space-24) 0;
}

.section-dark {
  background: var(--color-primary-dark);
  color: var(--color-white);
}

.section-dark p {
  color: var(--color-gray-300);
}

.section-gray {
  background: var(--color-gray-50);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-12);
}

.section-header p {
  margin-top: var(--space-4);
  font-size: var(--text-lg);
}

/* --- Grid System --- */
.grid {
  display: grid;
  gap: var(--space-8);
}

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

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

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

.grid-auto {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .section {
    padding: var(--space-12) 0;
  }

  .section-lg {
    padding: var(--space-16) 0;
  }
}

@media (max-width: 480px) {
  .grid-4 {
    grid-template-columns: 1fr;
  }
}