@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;800&display=swap');

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f3f4f6;
  color: #111827;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header & Navigation */

.site-header {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  z-index: 40;
}

.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 0;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
}

.brand-badge {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: #6b7280;
}

.brand-title {
  font-size: 1.9rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brand-title span {
  color: #0ea5e9; /* Akzent */
}

.brand-subtitle {
  font-size: 0.9rem;
  color: #6b7280;
}

.main-nav {
  border-top: 1px solid #e5e7eb;
}

.main-nav nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0.45rem 0;
  display: flex;
  gap: 1.4rem;
}

.main-nav a {
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: #374151;
  position: relative;
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.28rem;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #0ea5e9, #f97316);
  transition: width 0.16s ease-out;
}

.main-nav a:hover::after {
  width: 100%;
}

/* Hauptbereich */

.main-content {
  padding: 1.8rem 0 2.6rem;
}

/* Hero-Bereich Startseite */

.hero {
  background: #ffffff;
  border-radius: 18px;
  padding: 1.8rem 1.9rem;
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.07);
  border: 1px solid #e5e7eb;
  margin-bottom: 2rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(0, 1.4fr);
  gap: 1.6rem;
}

.hero-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.7rem;
}

.hero-chip {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  padding: 0.22rem 0.7rem;
  border-radius: 999px;
  border: 1px solid #0ea5e9;
  background: #e0f2fe;
  color: #0f172a;
}

.hero-update {
  font-size: 0.8rem;
  color: #6b7280;
}

.hero-title {
  font-size: 2.1rem;
  margin: 0.25rem 0 0.4rem;
}

.hero-meta {
  font-size: 0.86rem;
  color: #6b7280;
  margin-bottom: 0.9rem;
}

.hero-excerpt {
  font-size: 0.98rem;
  margin-bottom: 1.2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-bottom: 0.8rem;
}

.btn-solid {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.48rem 1.2rem;
  border-radius: 999px;
  border: none;
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  cursor: pointer;
  background: linear-gradient(135deg, #0ea5e9, #22c55e);
  color: #ffffff;
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.46rem 1.1rem;
  border-radius: 999px;
  border: 1px solid #cbd5f5;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  cursor: pointer;
  background: #ffffff;
  color: #111827;
}

.hero-tagline {
  font-size: 0.86rem;
  color: #6b7280;
}

.hero-visual {
  border-radius: 14px;
  overflow: hidden;
  position: relative;
  min-height: 230px;
  background: #e5e7eb;
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-visual-badge {
  position: absolute;
  left: 0.8rem;
  bottom: 0.8rem;
  background: rgba(15, 23, 42, 0.92);
  color: #f9fafb;
  padding: 0.5rem 0.8rem;
  border-radius: 9px;
  font-size: 0.8rem;
}

/* Sektionstitel */

.section-title-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin: 1.7rem 0 0.8rem;
}

.section-title {
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: #111827;
}

.section-subtitle {
  font-size: 0.85rem;
  color: #6b7280;
}

/* Artikel-Grid (Startseite) */

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.1rem;
}

.article-card {
  background: #ffffff;
  border-radius: 14px;
  border: 1px solid #e5e7eb;
  box-shadow: 0 14px 28px rgba(15, 23, 42, 0.06);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-height: 100%;
}

.article-thumb {
  height: 140px;
  overflow: hidden;
}

.article-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.article-body {
  padding: 0.9rem 0.95rem 0.95rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.article-tag-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.article-tag {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
}

.article-level {
  font-size: 0.78rem;
  color: #6b7280;
}

.article-title {
  font-size: 1.04rem;
  font-weight: 700;
}

.article-meta {
  font-size: 0.8rem;
  color: #6b7280;
}

.article-excerpt {
  font-size: 0.9rem;
  color: #4b5563;
}

.article-meta-tags {
  font-size: 0.78rem;
  color: #6b7280;
}

.tag-pill {
  display: inline-flex;
  align-items: center;
  padding: 0.14rem 0.5rem;
  border-radius: 999px;
  font-size: 0.75rem;
  margin-right: 0.25rem;
  border: 1px solid #e5e7eb;
  background: #f9fafb;
}

.tag-pill strong {
  margin-right: 0.22rem;
}

.article-card-footer {
  margin-top: 0.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: #0f766e;
}
/* Themen-Übersicht */

.topics-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.1rem;
  margin-top: 1.1rem;
}

.topic-card {
  background: #ffffff;
  border-radius: 14px;
  border: 1px solid #e5e7eb;
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.05);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.topic-thumb {
  height: 120px;
  background: repeating-linear-gradient(
    45deg,
    #e5e7eb,
    #e5e7eb 10px,
    #f3f4f6 10px,
    #f3f4f6 20px
  );
  display: flex;
  align-items: center;
  justify-content: center;
  color: #6b7280;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
}

.topic-body {
  padding: 0.9rem 0.95rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.topic-title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
}

.topic-text {
  font-size: 0.9rem;
  color: #4b5563;
}

.topic-links {
  margin-top: 0.4rem;
  font-size: 0.85rem;
}

.topic-links a {
  color: #0f766e;
}

/* Thema-Farben (optional) */

.tag-physik .article-tag { color: #1d4ed8; }
.tag-biologie .article-tag { color: #15803d; }
.tag-chemie .article-tag { color: #a21caf; }
.tag-technik .article-tag { color: #0ea5e9; }

/* Seitenlayout (Unterseiten) */

.page-header {
  padding-top: 1.4rem;
  padding-bottom: 0.5rem;
}

.page-title {
  font-size: 1.8rem;
  margin: 0 0 0.25rem;
}

.page-subtitle {
  font-size: 0.95rem;
  color: #4b5563;
  max-width: 640px;
}

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 2.2fr) minmax(0, 1fr);
  gap: 1.5rem;
  margin-top: 1.15rem;
}

.page-main-box {
  background: #ffffff;
  border-radius: 12px;
  border: 1px solid #e5e7eb;
  padding: 1.2rem 1.3rem 1.3rem;
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.06);
}

.page-sidebar {
  background: #f1f5f9;
  border-radius: 12px;
  border: 1px solid #e5e7eb;
  padding: 1rem 1rem 1.1rem;
  font-size: 0.9rem;
}

.page-sidebar h3 {
  margin-top: 0;
  font-size: 1rem;
}

.page-sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0.4rem 0 0;
}

.page-sidebar li + li {
  margin-top: 0.35rem;
}

/* Breadcrumb & Artikel-Detail */

.breadcrumb {
  font-size: 0.82rem;
  color: #6b7280;
  margin-bottom: 0.4rem;
}

.breadcrumb a {
  color: #0f766e;
}

.article-detail-meta {
  font-size: 0.84rem;
  color: #6b7280;
  margin-bottom: 0.9rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid #e5e7eb;
}

.article-detail-tags {
  font-size: 0.83rem;
  color: #4b5563;
  margin-bottom: 0.8rem;
}

.article-detail h2 {
  margin-top: 1.1rem;
  font-size: 1.25rem;
}

.article-detail p {
  margin-bottom: 0.9rem;
  font-size: 0.96rem;
  color: #111827;
}

/* Formular */

.form-group {
  margin-bottom: 0.9rem;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  margin-bottom: 0.2rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.55rem 0.6rem;
  border-radius: 8px;
  border: 1px solid #d1d5db;
  font: inherit;
  color: #111827;
  background: #ffffff;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: 2px solid #0ea5e9;
  outline-offset: 1px;
}

.form-group textarea {
  min-height: 130px;
}

button.btn-primary {
  padding: 0.5rem 1.3rem;
  border-radius: 999px;
  border: none;
  background: linear-gradient(135deg, #0ea5e9, #f97316);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  color: #ffffff;
}

/* Footer */

.site-footer {
  background: #ffffff;
  border-top: 1px solid #e5e7eb;
  padding: 1.6rem 0 1.9rem;
  font-size: 0.86rem;
  color: #4b5563;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.2rem;
}

.site-footer h4 {
  margin-top: 0;
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.site-footer a {
  color: #0f766e;
}

/* Responsiv */

@media (max-width: 980px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .topics-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .articles-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-layout {
    grid-template-columns: 1fr;
  }

  .page-sidebar {
    order: -1;
  }

  .footer-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }
}

@media (max-width: 640px) {
  .top-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.2rem;
  }
  .topics-grid {
    grid-template-columns: 1fr;
  }
  .brand-title {
    font-size: 1.6rem;
  }

  .main-nav nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .main-nav ul {
    flex-wrap: wrap;
    gap: 1rem;
  }

  .articles-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }
}