/* ============================================
   Stefan Thormann — Premium Onepager
   ============================================ */

:root {
  --color-navy: #1a2332;
  --color-navy-light: #2a3a4e;
  --color-navy-dark: #0f1620;
  --color-navy-deepest: #0a1422;
  --color-white: #ffffff;
  --color-off-white: #f8f9fa;
  --color-gray-100: #f1f3f5;
  --color-gray-200: #e9ecef;
  --color-gray-300: #dee2e6;
  --color-gray-400: #ced4da;
  --color-gray-500: #adb5bd;
  --color-gray-600: #6c757d;
  --color-gray-700: #495057;
  --color-gray-800: #343a40;
  --color-accent: #4a90a4;
  --color-accent-light: #5ba3b7;
  --color-muted-silver: #a0aab4;

  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Georgia', 'Times New Roman', serif;

  --max-width: 960px;
  --section-padding: 6rem 2rem;
  --section-padding-mobile: 3.5rem 1.25rem;

  --transition: 0.3s ease;
  --transition-slow: 0.7s ease;
}

/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  color: var(--color-gray-800);
  background: var(--color-white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Language switching */
[data-lang-en] { display: none; }
[data-lang-de] { display: block; }
span[data-lang-de] { display: inline; }
span[data-lang-en] { display: none; }

body.lang-en [data-lang-de] { display: none; }
body.lang-en [data-lang-en] { display: block; }
body.lang-en span[data-lang-en] { display: inline; }
body.lang-en span[data-lang-de] { display: none; }
body.lang-en li[data-lang-en] { display: list-item; }
body.lang-en li[data-lang-de] { display: none; }
li[data-lang-en] { display: none; }
li[data-lang-de] { display: list-item; }

/* Typography */
h1, h2, h3, h4 {
  color: var(--color-navy);
  font-weight: 600;
  line-height: 1.25;
}

h1 { font-size: 2.5rem; margin-bottom: 1rem; }
h2 { font-size: 1.75rem; margin-bottom: 1.5rem; }
h3 { font-size: 1.25rem; margin-bottom: 0.75rem; }

p {
  margin-bottom: 1.25rem;
  color: var(--color-gray-700);
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-light);
}

/* ============================================
   Header / Navigation
   ============================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 20, 34, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding: 1rem 2rem;
  transition: box-shadow var(--transition), background var(--transition);
}

.site-header.scrolled {
  background: rgba(10, 20, 34, 0.92);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  color: var(--color-white);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}

.logo:hover {
  color: var(--color-white);
}

.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 4px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--color-gray-400);
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 4px;
  padding: 0.3rem 0.6rem;
  cursor: pointer;
  transition: background var(--transition);
}

.lang-toggle:hover {
  background: rgba(255, 255, 255, 0.18);
}

.lang-toggle button {
  background: none;
  border: none;
  color: var(--color-gray-500);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  padding: 0.1rem 0.25rem;
  transition: color var(--transition);
}

.lang-toggle button.active {
  color: var(--color-white);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-white);
  margin: 5px 0;
  transition: var(--transition);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  background: var(--color-navy-deepest);
  color: var(--color-white);
  padding: 0 2rem;
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

/* Atmospheric background elements */
.hero::before {
  content: '';
  position: absolute;
  top: -10%;
  right: -5%;
  width: 500px;
  height: 500px;
  background: rgba(74, 144, 164, 0.05);
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -10%;
  left: -5%;
  width: 400px;
  height: 400px;
  background: rgba(26, 35, 50, 0.4);
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 1;
  padding: 8rem 0 4rem;
}

.hero-content h1 {
  color: var(--color-white);
  font-size: 4rem;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 0;
}

.hero-subtitle {
  color: var(--color-gray-300);
  font-size: 1.35rem;
  font-weight: 500;
  line-height: 1.4;
  margin-top: 1rem;
  margin-bottom: 0;
  letter-spacing: -0.01em;
}

.hero-tagline {
  color: var(--color-accent);
  font-size: 1.05rem;
  font-style: italic;
  line-height: 1.6;
  margin-top: 0.75rem;
  margin-bottom: 0;
}

.hero-content .intro {
  color: var(--color-muted-silver);
  font-size: 1rem;
  line-height: 1.8;
  max-width: 520px;
  margin-top: 1.5rem;
}

.hero-accent-line {
  width: 4rem;
  height: 2px;
  background: linear-gradient(to right, var(--color-accent), transparent);
  opacity: 0.4;
  margin-top: 2.5rem;
}

.hero-image {
  display: flex;
  justify-content: center;
}

.hero-image-wrapper {
  position: relative;
  width: 100%;
  max-width: 340px;
}

/* Geometric offset accent frame */
.hero-image-wrapper::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 2px solid rgba(74, 144, 164, 0.2);
  border-radius: 12px;
  transform: translate(-8px, -8px);
  transition: transform var(--transition-slow);
  pointer-events: none;
}

.hero-image-wrapper:hover::before {
  transform: translate(-4px, -4px);
}

.hero-image img {
  width: 100%;
  max-width: 340px;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 12px;
  position: relative;
  z-index: 1;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

/* ============================================
   Content Sections
   ============================================ */
.section {
  padding: var(--section-padding);
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-alt {
  background: var(--color-off-white);
}

.section-dark {
  background: var(--color-navy);
  color: var(--color-white);
}

.section-dark h2,
.section-dark h3 {
  color: var(--color-white);
}

.section-dark p {
  color: var(--color-gray-300);
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.section-dark .section-label {
  color: var(--color-accent-light);
}

/* ============================================
   Focus Areas (Cards)
   ============================================ */
.focus-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2.5rem;
}

.focus-card {
  padding: 2.5rem;
  background: var(--color-white);
  border: none;
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.03);
  transition: box-shadow var(--transition), transform var(--transition);
}

.focus-card:hover {
  box-shadow: 0 12px 32px rgba(25, 28, 29, 0.06);
  transform: translateY(-3px);
}

.focus-card h3 {
  color: var(--color-navy);
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

.focus-card p {
  font-size: 0.92rem;
  color: var(--color-gray-600);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ============================================
   Methodology
   ============================================ */
.methodology-text {
  max-width: 720px;
  font-size: 1.05rem;
  line-height: 1.85;
}

/* ============================================
   About / Timeline
   ============================================ */
.about-intro {
  max-width: 720px;
  font-size: 1.05rem;
  line-height: 1.85;
  margin-bottom: 2.5rem;
}

.timeline {
  list-style: none;
  border-left: 2px solid rgba(74, 144, 164, 0.2);
  padding-left: 2rem;
  margin-top: 2rem;
}

.section-dark .timeline {
  border-left-color: rgba(74, 144, 164, 0.15);
}

.timeline li {
  position: relative;
  padding-bottom: 1.5rem;
  font-size: 1rem;
  color: var(--color-gray-300);
}

.timeline li::before {
  content: '';
  position: absolute;
  left: -2.35rem;
  top: 0.5rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
}

/* ============================================
   Blog Section
   ============================================ */
.blog-articles {
  margin-top: 2rem;
}

.blog-article {
  border: 1px solid var(--color-gray-200);
  border-radius: 6px;
  margin-bottom: 1rem;
  overflow: hidden;
  transition: box-shadow var(--transition);
}

.blog-article:hover {
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.04);
}

.blog-article-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 2rem;
  cursor: pointer;
  background: var(--color-white);
  border: none;
  width: 100%;
  text-align: left;
  transition: background var(--transition);
}

.blog-article-header:hover {
  background: var(--color-off-white);
}

.blog-article-header h3 {
  margin-bottom: 0;
  font-size: 1.05rem;
  color: var(--color-navy);
  flex: 1;
  padding-right: 1rem;
}

.blog-article-toggle {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  position: relative;
  transition: transform var(--transition);
}

.blog-article-toggle::before,
.blog-article-toggle::after {
  content: '';
  position: absolute;
  background: var(--color-gray-500);
  transition: transform var(--transition);
}

.blog-article-toggle::before {
  width: 14px;
  height: 2px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.blog-article-toggle::after {
  width: 2px;
  height: 14px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.blog-article.open .blog-article-toggle::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.blog-article-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.5s ease;
}

.blog-article.open .blog-article-body {
  max-height: 5000px;
}

.blog-article-content {
  padding: 0 2rem 2rem;
  font-size: 0.95rem;
  line-height: 1.8;
}

.blog-article-content h4 {
  font-size: 1.05rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  color: var(--color-navy);
}

.blog-article-content ul,
.blog-article-content ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--color-gray-700);
}

.blog-article-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.blog-article-content strong {
  color: var(--color-navy);
  font-weight: 600;
}

.blog-article-content .highlight-box {
  background: var(--color-off-white);
  border-left: 3px solid var(--color-accent);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  border-radius: 0 4px 4px 0;
}

/* ============================================
   FAQ Section
   ============================================ */
.faq-list {
  margin-top: 2rem;
}

.faq-item {
  border-bottom: 1px solid var(--color-gray-200);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 1.5rem 0;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-navy);
  font-family: var(--font-primary);
}

.faq-question::after {
  content: '+';
  font-size: 1.25rem;
  color: var(--color-gray-500);
  flex-shrink: 0;
  margin-left: 1rem;
  transition: transform var(--transition);
}

.faq-item.open .faq-question::after {
  content: '\2212';
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}

.faq-item.open .faq-answer {
  max-height: 500px;
}

.faq-answer p {
  padding-bottom: 1.5rem;
  font-size: 0.95rem;
  color: var(--color-gray-600);
}

/* ============================================
   Contact
   ============================================ */
.contact-section {
  text-align: center;
  padding: 5rem 2rem;
}

.contact-email {
  font-size: 1.15rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-top: 1rem;
}

.contact-email a {
  color: var(--color-white);
  border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  padding-bottom: 2px;
  transition: border-color var(--transition);
}

.contact-email a:hover {
  border-color: var(--color-white);
}

/* ============================================
   Footer / Legal
   ============================================ */
.site-footer {
  background: var(--color-navy-dark);
  color: var(--color-gray-500);
  padding: 3rem 2rem;
  font-size: 0.85rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 2rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links button {
  background: none;
  border: none;
  color: var(--color-gray-500);
  font-size: 0.85rem;
  cursor: pointer;
  font-family: var(--font-primary);
  transition: color var(--transition);
}

.footer-links button:hover {
  color: var(--color-white);
}

.footer-copy {
  color: var(--color-gray-600);
}

/* Legal Modals */
.legal-modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.legal-modal.open {
  display: flex;
}

.legal-modal-content {
  background: var(--color-white);
  border-radius: 8px;
  max-width: 700px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 3rem;
}

.legal-modal-content h2 {
  margin-bottom: 2rem;
}

.legal-modal-content h3 {
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.legal-modal-content p {
  font-size: 0.92rem;
  line-height: 1.7;
}

.legal-close {
  float: right;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-gray-600);
  line-height: 1;
  padding: 0.25rem;
}

.legal-close:hover {
  color: var(--color-navy);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    text-align: center;
  }

  .hero-content h1 {
    font-size: 3rem;
  }

  .hero-content .intro {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-accent-line {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-image {
    order: -1;
  }

  .hero-image img,
  .hero-image-wrapper {
    max-width: 280px;
  }
}

@media (max-width: 768px) {
  h1 { font-size: 1.85rem; }
  h2 { font-size: 1.4rem; }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-navy);
    flex-direction: column;
    padding: 1.5rem 2rem;
    gap: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .hero {
    padding: 0 1.25rem;
    min-height: auto;
  }

  .hero-inner {
    padding: 6rem 0 3rem;
  }

  .hero-content h1 {
    font-size: 2.25rem;
  }

  .hero-subtitle {
    font-size: 1.1rem;
  }

  .hero-image img,
  .hero-image-wrapper {
    max-width: 240px;
  }

  .section {
    padding: var(--section-padding-mobile);
  }

  .focus-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .blog-article-header {
    padding: 1.25rem 1.25rem;
  }

  .blog-article-content {
    padding: 0 1.25rem 1.5rem;
  }

  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

@media (max-width: 480px) {
  html { font-size: 15px; }

  .hero-content h1 { font-size: 1.85rem; }

  .site-header { padding: 0.85rem 1.25rem; }
}

/* ============================================
   Animations
   ============================================ */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}