:root {
  --color-bg: #f9fafb;
  --color-text: #1a1a1a;
  --color-primary: #2563eb;
  --color-secondary: #6b7280;
  --color-border: #e5e7eb;
  --font-base: 'Segoe UI', Roboto, sans-serif;
  --font-size-base: 1rem;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --breakpoint-sm: 640px;
  --breakpoint-lg: 1024px;
}

/* === Root & Reset === */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: var(--font-base);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* === App Shell Layout === */
.app-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  flex: 0 0 auto;
  padding: var(--spacing-md);
  background-color: var(--color-primary);
  color: #ffffff;
}

.app-footer {
  flex: 0 0 auto;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-border);
  color: var(--color-secondary);
  text-align: center;
  font-size: 0.875rem;
}

@media (min-width: var(--breakpoint-sm)) {
  .app-header {
    padding: var(--spacing-lg);
  }

  .app-footer {
    font-size: 1rem;
  }
}

@media (min-width: var(--breakpoint-lg)) {
  .app-shell {
    flex-direction: column;
  }
}

/* === Footer Copyright === */
.app-footer::after {
  content: "© 2026 Donau2Space.de";
  display: block;
  margin-top: var(--spacing-xs);
}