:root {
    --primary: #2563eb;
    --background: #f9fafb;
    --card-bg: #ffffff;
    --text-dark: #1e293b;
    --text-light: #64748b;
  }
  /* 1. Farbverläufe für Sektionen */
section#ueber {
    background: linear-gradient(135deg, rgba(245,245,255,1) 0%, rgba(235,243,255,1) 100%);
  }
  section#zertifikate {
    background: linear-gradient(135deg, rgba(255,245,245,1) 0%, rgba(255,235,235,1) 100%);
  }
  
  /* 2. Card-Hover & Übergang */
  .card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }
  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 25px rgba(0,0,0,0.1);
  }
  
  /* 3. Akzent-Button für GitHub */
  a.github-btn {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.6rem 1.2rem;
    border-radius: 6px;
    background: var(--primary);
    color: white;
    font-weight: 600;
    text-decoration: none;
    transition: background 0.3s ease;
  }
  a.github-btn:hover {
    background: #1e50c5;
  }
  
  /* 4. Fade-In Animation für Sektionen */
  @keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
  }
  .card {
    opacity: 0;
    animation: fadeInUp 0.6s forwards;
  }
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background);
    color: var(--text-dark);
    line-height: 1.6;
  }
  
  /* Sticky Header & Nav */
  header {
    position: sticky;
    top: 0;
    background: var(--primary);
    color: white;
    z-index: 1000;
  }
  
  .nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1000px;
    margin: 0 auto;
    padding: 1rem;
  }
  
  .hamburger {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    display: none; /* Hidden on desktop */
  }
  
  nav {
    display: flex;
    gap: 1.5rem;
  }
  
  nav a {
    color: #bfdbfe;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s;
  }
  
  nav a:hover {
    color: white;
  }
  
  /* Mobile: Hamburger Menu */
  @media (max-width: 768px) {
    .hamburger {
      display: block;
    }
    nav {
      position: absolute;
      top: 100%;
      left: 0;
      right: 0;
      background: var(--primary);
      flex-direction: column;
      align-items: center;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
    }
    nav.active {
      max-height: 300px;
      padding: 1rem 0;
    }
  }
  
  /* Hero */
  .hero {
    text-align: center;
    padding: 2rem 1rem;
  }
  
  .profile-pic {
    width: 250px;
    height: 270px;
    border-radius: 50%;
    object-fit: cover;
    transform: scale(1.2);
    transition: tranform 0.3s;
    margin: 1rem auto;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    border: 4px solid white;
  }
  
  /* Container & Cards */
  .container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 1rem;
  }
  
  .card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 15px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
  }
  
  h2 {
    margin-bottom: 1rem;
    color: var(--primary);
  }
  
  .card ul {
    padding-left: 1.2rem;
  }
  
  .card ul li {
    list-style: disc;
    margin-bottom: 0.5rem;
  }
  
  .certificate-list {
    list-style: none;
    padding: 0;
  }
  
  .certificate-list li {
    margin-bottom: 1.5rem;
    background: #f1f5f9;
    padding: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  }
  
  .certificate-list a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
  }
  
  .certificate-list a:hover {
    text-decoration: underline;
  }
  
  .contact-list {
    list-style: none;
    padding: 0;
  }
  
  .contact-list li {
    margin-bottom: 0.75rem;
  }
  
  .contact-list li i {
    margin-right: 10px;
    color: var(--primary);
  }
  
  /* Footer */
  footer {
    background: #1e293b;
    color: white;
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
  }
  
  /* Responsive Anpassungen */
  @media (max-width: 600px) {
    .card {
      padding: 1.5rem;
    }
  }