/**
 * layout.css — Structural Layout Styles
 * =======================================
 * Header, footer, container, and grid utilities.
 */

/* ── Container ───────────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

/* ── Section Spacing ─────────────────────────────────────────────────────── */
.section {
  padding-block: clamp(var(--space-16), 10vw, var(--space-32));
}

.section--sm {
  padding-block: clamp(var(--space-10), 6vw, var(--space-20));
}

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

/* ── Section Header (centered intro block) ───────────────────────────────── */
.section-header {
  text-align: center;
  max-width: 680px;
  margin-inline: auto;
  margin-bottom: clamp(var(--space-10), 6vw, var(--space-16));
}

.section-header p {
  margin-inline: auto;
  font-size: var(--text-lg);
  color: var(--color-text-muted);
}

/* ── Grids ───────────────────────────────────────────────────────────────── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-5);
}

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

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

/* ── Flex Utilities ──────────────────────────────────────────────────────── */
.flex       { display: flex; }
.flex-col   { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-4      { gap: var(--space-4); }
.gap-6      { gap: var(--space-6); }
.gap-8      { gap: var(--space-8); }

/* ── Site Header ─────────────────────────────────────────────────────────── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--header-border);
  transition:
    background var(--transition-slow),
    border-color var(--transition-slow),
    box-shadow var(--transition-base);
}

/* Scrolled state — slightly stronger shadow */
.site-header.scrolled {
  box-shadow: 0 2px 24px rgba(0,0,0,0.18);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: var(--space-6);
}

.logo-link { text-decoration: none; }

/* ── Desktop Navigation ──────────────────────────────────────────────────── */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  transition:
    color var(--transition-fast),
    background var(--transition-fast);
  text-decoration: none;
}

.nav-link:hover {
  color: var(--color-text);
  background: var(--color-bg-raised);
}

.nav-link.active {
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  font-weight: 600;
}

/* ── Header Actions (right side) ─────────────────────────────────────────── */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* ── Theme Toggle Button ─────────────────────────────────────────────────── */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--color-bg-raised);
  border: 1px solid var(--color-border);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    transform var(--transition-spring);
}

.theme-toggle:hover {
  background: var(--color-bg-overlay);
  border-color: var(--color-accent);
  transform: scale(1.08);
}

/* Show the right icon depending on current theme */
[data-theme="dark"]  .theme-icon--light { display: none; }
[data-theme="light"] .theme-icon--dark  { display: none; }

/* ── Hamburger (mobile) ───────────────────────────────────────────────────── */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text-muted);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base), background var(--transition-fast);
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Mobile Navigation Drawer ────────────────────────────────────────────── */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-4) var(--container-pad) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  transform: translateY(-110%);
  opacity: 0;
  transition:
    transform var(--transition-base),
    opacity var(--transition-base);
  z-index: 99;
  pointer-events: none;
}

.mobile-nav.open {
  transform: translateY(0);
  opacity: 1;
  pointer-events: all;
}

.mobile-nav-link {
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  color: var(--color-accent);
  background: var(--color-accent-subtle);
}

.mobile-nav-cta {
  margin-top: var(--space-2);
  text-align: center;
  width: 100%;
  justify-content: center;
}

/* ── Footer ──────────────────────────────────────────────────────────────── */
.site-footer {
  background: var(--color-bg-elevated);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-24);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: var(--space-16);
  padding-block: var(--space-16);
}

.footer-tagline {
  font-size: var(--text-sm);
  color: var(--color-text-subtle);
  margin-top: var(--space-3);
  max-width: 28ch;
}

.footer-meta {
  font-size: var(--text-sm);
  color: var(--color-text-subtle);
  margin-top: var(--space-4);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-col h4 {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-1);
}

.footer-col a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-5);
}

.footer-bottom .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
  color: var(--color-text-subtle);
  flex-wrap: wrap;
  gap: var(--space-3);
}

.footer-bottom a {
  color: var(--color-text-subtle);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.footer-bottom a:hover { color: var(--color-accent); }

/* ── 404 Page ────────────────────────────────────────────────────────────── */
.page-404 {
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: var(--space-6);
}

.page-404 .error-code {
  font-family: var(--font-display);
  font-size: clamp(6rem, 20vw, 14rem);
  font-weight: 800;
  line-height: 1;
  color: var(--color-accent);
  opacity: 0.15;
}

/* ── Responsive Mobile Breakpoints ───────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }
  /* Hide text CTA on very small screens */
  .header-actions .btn { display: none; }
  .header-actions .btn + .hamburger { display: flex; } /* keep hamburger */

  .footer-inner { grid-template-columns: 1fr; gap: var(--space-10); }
  .footer-links { grid-template-columns: repeat(2, 1fr); gap: var(--space-6); }
}

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