/* =========================
   Zentrale Variablen
   ========================= */
:root {
  --site-width: 1440px;

  /* Akzentfarben (Logo & Buttons) */
  --primary-blue: #1f4e79;
  --primary-blue-dark: #163a59;
  --primary-blue-light: #2f6fa3;

  /* Flächenfarben */
  --header-bg: #3a5a6b;          /* neutrales Blau, KEIN Aquamarin */
  --page-bg: #1f2f38;            /* dunkles Blau-Grau */
  --frame-aqua: #2f6f78;         /* Aquamarin-Blau für Umgebung */
  --content-bg: #ffffff;
  --aside-bg: #223845;
  --footer-bg: #18232b;

  /* Text */
  --text-dark: #1e1e1e;
  --text-light: #e6eef4;
}

/* =========================
   Basis
   ========================= */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  background: var(--page-bg);
  color: var(--text-dark);
}

/* =========================
   Links
   ========================= */
a {
  color: var(--primary-blue);
  text-decoration: none;
}

/* Unterstreichung NUR im Inhalt */
main a:hover,
aside a:hover,
footer a:hover {
  text-decoration: underline;
}

/* Navigation: NIE unterstreichen */
nav a,
nav a:hover,
nav a.active {
  text-decoration: none !important;
}

/* =========================
   Skip-Link
   ========================= */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--primary-blue);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 2000;
}

.skip-link:focus {
  left: 0;
}

/* =========================
   Header
   ========================= */
header {
  background: var(--header-bg);
}

/* gleicher Rahmen wie Content */
.header-inner {
  max-width: var(--site-width);
  margin: 0 auto;
  padding: 1.6rem 2rem 1.3rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Logo */
.site-branding {
  display: flex;
  align-items: center;
}

.site-logo {
  height: 88px;
  width: auto;
  filter: drop-shadow(0 2px 3px rgba(0,0,0,0.35));
}

/* =========================
   Navigation
   ========================= */
nav {
  padding-top: 0.75rem;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 0.75rem;
  padding: 0;
  margin: 0;
  flex-wrap: wrap;
}

nav a {
  padding: 0.55rem 1.2rem;
  border-radius: 6px;
  background: #f4f8fb;           /* hell, neutral */
  color: var(--primary-blue);
  font-weight: 700;
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
  transition: background 0.2s ease, color 0.2s ease;
}

nav a:hover {
  background: var(--primary-blue-light);
  color: #ffffff;
}

nav a.active {
  background: var(--primary-blue);
  color: #ffffff;
}

/* =========================
   Seitenrahmen (Aquamarin)
   ========================= */
.page-frame {
  background: var(--frame-aqua);
  padding: 3rem 0;
}

/* =========================
   Hauptlayout
   ========================= */
.container {
  max-width: var(--site-width);
  margin: 0 auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 6fr 1fr;
  gap: 3rem;
}

/* Hauptinhalt */
main {
  background: var(--content-bg);
  padding: 3rem;
  border-radius: 8px;
  box-shadow: 0 1rem 2rem rgba(0,0,0,0.25);
}

/* Sidebar */
aside {
  background: var(--aside-bg);
  padding: 1.75rem;
  border-radius: 8px;
  color: var(--text-light);
  font-size: 0.95rem;
}

/* =========================
   Überschriften
   ========================= */
h1, h2, h3, h4 {
  margin-top: 0;
  color: var(--primary-blue);
}

/* =========================
   Footer
   ========================= */
footer {
  background: var(--footer-bg);
}

footer > p {
  max-width: var(--site-width);
  margin: 0 auto;
  padding: 1.4rem 2rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-light);
}

/* =========================
   Mobile
   ========================= */
@media (max-width: 900px) {
  .container {
    grid-template-columns: 1fr;
  }

  aside {
    margin-top: 2rem;
  }

  .header-inner {
    padding: 1.3rem 1.5rem;
  }
}