/* CSS Variables for Light / Dark Mode */
:root {
  --bg-color: #fcfcfc;
  --card-bg: #ffffff;
  --text-color: #1a1a1a;
  --muted-color: #666666;
  --border-color: #e5e5e5;
  --badge-bg: #1a1a1a;
  --badge-text: #ffffff;
  --hover-bg: #f0f0f0;
  --font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
}

[data-theme="dark"] {
  --bg-color: #0f1115;
  --card-bg: #161920;
  --text-color: #eceff4;
  --muted-color: #9aa2b1;
  --border-color: #272c36;
  --badge-bg: #eceff4;
  --badge-text: #0f1115;
  --hover-bg: #222733;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-family);
  line-height: 1.6;
  padding: 2rem 1rem;
  transition:
    background-color 0.25s ease,
    color 0.25s ease;
}

.container {
  max-width: 800px;
  margin: 0 auto;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 3.5rem;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.lang-switch {
  display: flex;
  gap: 0.35rem;
}

.control-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  padding: 0.3rem 0.65rem;
  font-size: 0.85rem;
  cursor: pointer;
  border-radius: 4px;
  color: var(--muted-color);
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.control-btn.active,
.control-btn:hover {
  color: var(--text-color);
  border-color: var(--text-color);
  background-color: var(--hover-bg);
}

.theme-toggle {
  padding: 0.3rem 0.5rem;
  font-size: 0.9rem;
}

.hero {
  margin-bottom: 3.5rem;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.hero p.lead {
  font-size: 1.15rem;
  color: var(--muted-color);
  max-width: 680px;
}

.section {
  margin-bottom: 3.5rem;
}

.section h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted-color);
}

/* Fix for smooth layout height during language toggle */
.concept-text {
  line-height: 1.65;
  margin-bottom: 0.5rem;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1.25rem;
}

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

.card {
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: 6px;
  background-color: var(--card-bg);
  transition:
    background-color 0.25s ease,
    border-color 0.25s ease;
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.card p {
  font-size: 0.925rem;
  color: var(--muted-color);
}

.notice-box {
  border: 1px solid var(--border-color);
  background-color: var(--card-bg);
  padding: 1.75rem;
  border-radius: 6px;
  transition:
    background-color 0.25s ease,
    border-color 0.25s ease;
}

.badge {
  display: inline-block;
  background-color: var(--badge-bg);
  color: var(--badge-text);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  margin-bottom: 1rem;
}

.notice-box p {
  font-size: 1rem;
  color: var(--text-color);
  margin-bottom: 1rem;
}

.contact-info {
  font-size: 0.925rem !important;
  color: var(--muted-color) !important;
  margin-bottom: 0 !important;
}

a {
  color: var(--text-color);
  text-decoration: underline;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--muted-color);
}

footer {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--muted-color);
  display: flex;
  justify-content: space-between;
}

/* Language switching utilities */
[lang="en"] {
  display: none;
}
.show-en [lang="en"] {
  display: block;
}
.show-en [lang="de"] {
  display: none;
}

span[lang="en"],
a[lang="en"] {
  display: none;
}
.show-en span[lang="en"],
.show-en a[lang="en"] {
  display: inline;
}
.show-en span[lang="de"],
.show-en a[lang="de"] {
  display: none;
}