/* ==========================================================================
   MELLINOR Lernplattform – Layout
   Container, Header, Navigation (inkl. mobilem Drawer), Sections, Grids, Footer.
   ========================================================================== */

/* Container --------------------------------------------------------------- */

.container {
  width: 100%;
  max-width: calc(var(--content-width) + 2 * var(--content-gutter));
  margin-inline: auto;
  padding-inline: var(--content-gutter);
}

/* Header ------------------------------------------------------------------ */

.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: var(--header-height);
  border-bottom: 1px solid var(--color-line);
}

/* Unschärfe liegt auf einem Pseudo-Element: ein backdrop-filter direkt am
   Header würde den fest positionierten mobilen Drawer an den Header binden. */
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--color-header-bg);
  backdrop-filter: blur(12px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  height: 100%;
}

/* Marke: Logo-Platz + Wortmarke */
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex: none;
}

.brand__logo {
  height: 40px;
  width: auto;
}

.brand__text {
  display: grid;
  line-height: 1;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: 0.16em;
}

.brand__sub {
  margin-top: 5px;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.3em;
  color: var(--color-sakura);
}

/* Navigation -------------------------------------------------------------- */

.site-nav {
  display: flex;
  align-items: center;
  flex: 1;
  gap: var(--space-5);
}

.site-nav__list {
  display: flex;
  gap: var(--space-1);
}

.site-nav__link {
  position: relative;
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.site-nav__link:hover {
  color: var(--color-text);
  background: var(--color-hover);
}

.site-nav__link[aria-current] {
  color: var(--color-text);
}

.site-nav__link[aria-current]::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: 0;
  height: 2px;
  background: var(--color-sakura);
  border-radius: 2px;
}

.site-nav__aside {
  margin-left: auto;
}

.nav-toggle,
.nav-backdrop {
  display: none;
}

/* Sections ---------------------------------------------------------------- */

.section {
  padding-block: var(--space-section);
  border-top: 1px solid var(--color-line);
}

.section--panel {
  background: linear-gradient(180deg, var(--color-bg-secondary), transparent);
}

.section__head {
  display: grid;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  max-width: 42rem;
}

.section__title {
  font-size: var(--text-2xl);
}

/* Grids ------------------------------------------------------------------- */

.grid {
  display: grid;
  gap: var(--space-4);
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr);
  gap: var(--space-7);
  align-items: start;
}

.split__aside {
  position: sticky;
  top: calc(var(--header-height) + var(--space-6));
}

.split__aside .section__head {
  margin-bottom: 0;
}

/* Footer ------------------------------------------------------------------ */

.site-footer {
  border-top: 1px solid var(--color-line);
  padding-block: var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-faint);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3) var(--space-5);
}

.site-footer__brand {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 1024px) {
  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid--3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .split {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .split__aside {
    position: static;
  }
}

/* Mobile Navigation als Drawer */
@media (max-width: 860px) {
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    margin-left: auto;
    background: none;
    border: 1px solid var(--color-line-strong);
    border-radius: var(--radius-md);
    cursor: pointer;
  }

  .nav-toggle .icon {
    width: 22px;
    height: 22px;
  }

  .nav-toggle__close,
  .nav-open .nav-toggle__open {
    display: none;
  }

  .nav-open .nav-toggle__close {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    right: 0;
    bottom: 0;
    z-index: var(--z-drawer);
    flex-direction: column;
    align-items: stretch;
    width: min(20rem, 86vw);
    padding: var(--space-5);
    background: var(--color-panel);
    border-left: 1px solid var(--color-line);
    transform: translateX(100%);
    visibility: hidden;
    transition: transform var(--transition-base), visibility var(--transition-base);
  }

  .nav-open .site-nav {
    transform: none;
    visibility: visible;
  }

  .site-nav__list {
    flex-direction: column;
  }

  .site-nav__link {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
  }

  .site-nav__link[aria-current]::after {
    left: 0;
    right: auto;
    top: var(--space-3);
    bottom: var(--space-3);
    width: 2px;
    height: auto;
  }

  .site-nav__aside {
    margin: auto 0 0;
    padding-top: var(--space-4);
    border-top: 1px solid var(--color-line);
  }

  /* Im Drawer klappt das Menü "Darstellung" über dem Benutzerbereich auf */
  .site-nav__aside .user-menu {
    display: flex;
    flex-direction: column-reverse;
    gap: var(--space-3);
    align-items: flex-start;
  }

  .site-nav__aside .user-menu__panel {
    position: static;
    width: 100%;
    box-shadow: none;
  }

  .nav-backdrop {
    display: block;
    position: fixed;
    inset: var(--header-height) 0 0 0;
    z-index: calc(var(--z-header) - 1);
    background: var(--color-overlay);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
  }

  .nav-open .nav-backdrop {
    opacity: 1;
    visibility: visible;
  }

  .nav-open body {
    overflow: hidden;
  }
}

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