/* =============================================================================
   layout.css — Mobile-first structural layout.
   Uses Grid/Flexbox and rem/%/fr only (no fixed-px layout widths).
   ============================================================================= */

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image:
    radial-gradient(circle at 15% 0%, rgba(34, 211, 238, 0.08), transparent 40%),
    radial-gradient(circle at 85% 10%, rgba(52, 211, 153, 0.06), transparent 35%);
  background-attachment: fixed;
  display: flex;
  flex-direction: column;
}

/* Skip link for keyboard users */
.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -3rem;
  z-index: var(--z-modal);
  padding: var(--space-2) var(--space-4);
  background: var(--color-accent);
  color: var(--color-bg);
  font-weight: var(--fw-semibold);
  border-radius: var(--radius-sm);
  transition: top var(--transition-base);
}

.skip-link:focus {
  top: var(--space-3);
}

/* Centered content container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.container--narrow {
  max-width: var(--container-narrow);
}

/* Vertical section rhythm */
.section {
  padding-block: var(--space-8);
}

.section__header {
  margin-bottom: var(--space-6);
  text-align: center;
}

.section__eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}

.section__title {
  font-size: var(--fs-xl);
}

.section__lead {
  margin-top: var(--space-3);
  color: var(--color-text-muted);
  max-width: var(--container-narrow);
  margin-inline: auto;
}

/* Header / nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: var(--header-height);
  display: flex;
  align-items: center;
  background: rgba(10, 14, 22, 0.72);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

.nav__list {
  display: none;
  gap: var(--space-5);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav__toggle {
  display: inline-flex;
}

@media (min-width: 48rem) {
  .nav__list {
    display: flex;
  }
  /* Scoped to .nav so it outranks the .btn display rule from components.css
     (the toggle also carries .btn, which sets display: inline-flex). */
  .nav .nav__toggle {
    display: none;
  }
}

/* Mobile nav panel (toggled open) */
.nav__list.is-open {
  display: flex;
  position: absolute;
  top: var(--header-height);
  right: var(--space-4);
  left: var(--space-4);
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

/* Hero */
.hero {
  padding-block: var(--space-9) var(--space-8);
  text-align: center;
}

.hero__title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
}

.hero__subtitle {
  margin-top: var(--space-4);
  font-size: var(--fs-md);
  color: var(--color-text-muted);
  max-width: 42rem;
  margin-inline: auto;
}

.hero__actions {
  margin-top: var(--space-6);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
}

/* Responsive tools grid: 1 -> 2 -> 3 columns */
.tools-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
}

@media (min-width: 36rem) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 60rem) {
  .tools-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* About layout */
.about {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 52rem) {
  .about {
    grid-template-columns: 1.4fr 1fr;
    align-items: start;
  }
}

/* Two-column content for detail pages */
.detail-grid {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 52rem) {
  .detail-grid {
    grid-template-columns: 2fr 1fr;
    align-items: start;
  }
}

/* Contact layout */
.contact {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 52rem) {
  .contact {
    grid-template-columns: 1fr 1fr;
  }
}

/* Footer */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  padding-block: var(--space-6);
}

.site-footer .container {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  align-items: center;
  text-align: center;
}

.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-4);
  justify-content: center;
  list-style: none;
  padding: 0;
  margin: 0;
}

@media (min-width: 48rem) {
  .site-footer .container {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

/* Legal/document pages: readable single column */
.doc {
  padding-block: var(--space-7) var(--space-8);
}

.doc h2 {
  margin-top: var(--space-6);
  margin-bottom: var(--space-3);
  font-size: var(--fs-lg);
}

.doc h3 {
  margin-top: var(--space-5);
  margin-bottom: var(--space-2);
  font-size: var(--fs-md);
}

.doc p,
.doc ul,
.doc ol {
  margin-bottom: var(--space-4);
  color: var(--color-text-muted);
}

.doc ul,
.doc ol {
  padding-left: var(--space-5);
}

.doc li {
  margin-bottom: var(--space-2);
}