:root {
    --bg-color: #0D1117;
    --primary-text: #E6EDF3;
    --secondary-text: #8B949E;
    --accent-color: #58A6FF;
    --card-bg: rgba(22, 27, 34, 0.75);
    --border-color: rgba(255, 255, 255, 0.1);
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

body {
    font-family: var(--font-family);
    margin: 0;
    background-color: var(--bg-color);
    color: var(--primary-text);
    line-height: 1.6;
}

.page-wrapper {
    position: relative;
    z-index: 1;
    overflow: hidden;
}

.background-aurora {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-image: radial-gradient(circle at 10% 20%, rgba(88, 166, 255, 0.2) 0%, rgba(88, 166, 255, 0) 25%),
                      radial-gradient(circle at 90% 80%, rgba(46, 216, 182, 0.2) 0%, rgba(46, 216, 182, 0) 25%);
    animation: aurora-flow 20s infinite linear;
    z-index: -1;
}

@keyframes aurora-flow {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.main-header {
    position: sticky;
    top: 0;
    padding: 20px 0;
    z-index: 100;
    background: rgba(13, 17, 23, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}
.nav-container { display: flex; justify-content: space-between; align-items: center; }
.logo { font-weight: 700; font-size: 1.5rem; }
.main-nav { display: flex; align-items: center; gap: 25px; }
.main-nav a, .lang-btn {
    text-decoration: none;
    color: var(--secondary-text);
    font-weight: 500;
    transition: color 0.3s ease;
}
.main-nav a:hover { color: var(--primary-text); }
.lang-switcher { display: flex; gap: 5px; margin-left: 15px; }
.lang-btn { background: none; border: none; cursor: pointer; font-size: 1rem; }
.lang-btn.active { color: var(--accent-color); font-weight: 700; }

/* General Card Style */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

/* Hero */
.hero-section {
    padding: 80px 0;
    text-align: center;
}
.hero-image {
    width: 225px;
    height: 225px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--accent-color);
    margin-bottom: 25px;
    box-shadow: 0 0 40px rgba(88, 166, 255, 0.5);
}
.hero-title { font-size: clamp(2rem, 5vw, 3rem); margin: 0 0 15px 0; line-height: 1.2; }
.hero-subtitle { font-size: 1.125rem; color: var(--secondary-text); max-width: 600px; margin: 0 auto 30px auto; }
.hero-cta-group { display: flex; justify-content: center; gap: 15px; flex-wrap: wrap; }
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}
.btn-primary { background-color: var(--accent-color); color: var(--bg-color); font-weight: 700; }
.btn-primary:hover { background-color: #79b8ff; transform: translateY(-2px); }
.btn-secondary { background: none; color: var(--primary-text); border-color: var(--border-color); }
.btn-secondary:hover { background-color: var(--border-color); transform: translateY(-2px); }

/* Content Sections */
.content-section { margin-bottom: 60px; }
h2 { font-size: clamp(1.8rem, 4vw, 2.25rem); text-align: center; margin: 0 0 40px 0; }
#summary p { font-size: 1.1rem; color: var(--secondary-text); text-align: center; }

/* Experience Timeline */
.timeline { position: relative; }
.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 10px;
    bottom: 10px;
    width: 2px;
    background: linear-gradient(to bottom, var(--accent-color), transparent);
}
.timeline-item { position: relative; margin-left: 50px; margin-bottom: 30px; }
.timeline-item::before {
    content: '';
    position: absolute;
    left: -38px;
    top: 5px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 3px solid var(--bg-color);
    box-shadow: 0 0 10px var(--accent-color);
}
.timeline-date { color: var(--secondary-text); font-size: 0.9rem; margin-bottom: 5px; }
.timeline-content h3 { margin: 0; font-size: 1.25rem; }
.company { color: var(--accent-color); font-weight: 500; margin-bottom: 15px; }
.timeline-content ul { padding-left: 20px; margin: 0; }
.timeline-content ul li { margin-bottom: 10px; color: var(--secondary-text); }
.timeline-content ul li::marker { color: var(--accent-color); }

/* Education Section */
.education-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.education-item {
    padding: 30px;
}

.education-item h3 {
    margin: 0 0 5px 0;
    font-size: 1.25rem;
    color: var(--primary-text);
}

.education-item p {
    margin: 0 0 10px 0;
    color: var(--accent-color);
    font-weight: 500;
}

.education-item .education-date {
    color: var(--secondary-text);
    font-size: 0.9rem;
}

/* Responsive Anpassung für den Education-Abschnitt */
@media (max-width: 768px) {
    .education-grid {
        grid-template-columns: 1fr;
    }
}

/* Skills Section */
.skills-container { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.skills-chart-wrapper, .skills-tech-wrapper { padding: 30px; }
.skills-tech-wrapper h3 { margin-top: 0; text-align: center; }
.tech-tags { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.tag {
    background-color: rgba(88, 166, 255, 0.1);
    color: var(--accent-color);
    padding: 5px 12px;
    border-radius: 15px;
    font-weight: 500;
    font-size: 0.9rem;
}

/* Footer */
.footer-section { text-align: center; padding: 60px 20px; }
.contact-links { display: flex; justify-content: center; gap: 30px; margin: 30px 0; flex-wrap: wrap; }
.contact-links a { color: var(--secondary-text); text-decoration: none; font-weight: 500; transition: color 0.3s ease; }
.contact-links a:hover { color: var(--accent-color); }
.footer-note { font-size: 0.9rem; color: var(--secondary-text); margin-top: 40px; }

/* Animations */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.animate-on-scroll.is-visible { opacity: 1; transform: translateY(0); }

/* Responsive Design */
@media (max-width: 768px) {
    .main-nav a { display: none; }
    .skills-container { grid-template-columns: 1fr; }
    .timeline::before { left: 10px; }
    .timeline-item { margin-left: 30px; }
    .timeline-item::before { left: -28px; }
    .skills-chart-wrapper {
        max-width: 400px;
        max-height: 400px;
        margin: 0 auto;
    }
}