:root {
    --gradient-start: #2145b0;
    --gradient-end: #6daded;
    --accent-color: #ff6b6b;
    --text-primary: #2c3e50;
    --text-secondary: #555;
    --background-light: #f8f9fa;
    --card-background: rgba(255, 255, 255, 0.95);
    --timeline-line-color: rgba(255, 255, 255, 0.3);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: 
        linear-gradient(120deg, #2878b950 0%, #d6d1ff50 100%),
        linear-gradient(60deg, #96deda50 0%, #50c9c350 100%);
    background-attachment: fixed;
}

header {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 1.3rem 2.5rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(255,255,255,0.1) 0%, transparent 50%);
}

header h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    position: relative;
}

#ueber-mich p {
    margin-bottom: 0.5rem;
}

.horizontal-timeline {
    margin-top: 3rem;
    padding: 2rem 0;
    width: 100%;
    overflow-x: auto;
}

.timeline-container {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    min-width: 800px;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    padding: 20px 0;
}

.timeline-container::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--timeline-line-color);
    transform: translateY(-50%);
}

.timeline-item-horizontal {
    flex: 1;
    position: relative;
    text-align: center;
    padding: 0 15px;
}

.timeline-dot {
    width: 20px;
    height: 20px;
    background: white;
    border: 4px solid var(--gradient-end);
    border-radius: 50%;
    margin: 0 auto 15px;
    position: relative;
    z-index: 1;
}

.timeline-content {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px;
    border-radius: 8px;
    backdrop-filter: blur(5px);
    transition: transform 0.3s ease;
}

.timeline-content:hover {
    transform: translateY(-5px);
}

.timeline-content h3 {
    margin: 0;
    font-size: 1.1rem;
    color: white;
}

.timeline-content p {
    margin: 5px 0 0;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
}

nav {
    background: rgba(255, 255, 255, 0.95);
    padding: 1rem;
    position: sticky;
    top: 0;
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
    z-index: 1000;
    backdrop-filter: blur(10px);
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

nav a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    transition: all 0.3s ease;
}

nav a:hover {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

section {
    margin: 4rem 0;
    position: relative;
}

.section-title {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -10px;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    border-radius: 2px;
}

.card {
    background: var(--card-background);
    border-radius: 15px;
    padding: 2rem;
    margin: 1rem 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    backdrop-filter: blur(10px);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.timeline {
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(to bottom, var(--gradient-start), var(--gradient-end));
    border-radius: 2px;
}

.timeline-item {
    margin-left: 2rem;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 0.5rem;
    width: 1rem;
    height: 1rem;
    background: white;
    border: 3px solid var(--gradient-end);
    border-radius: 50%;
}

.timeline-item.card > ul {
    margin-left: 1.2rem;
}

.timeline-item.card ul > li > ul {
    margin-left: 1.2rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--card-background);
    border-radius: 15px;
    padding: 2rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.project-card:hover::before {
    transform: scaleX(1);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.skill-tag {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.9rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.contact-item {
    text-align: center;
    padding: 2rem;
    background: var(--card-background);
    border-radius: 15px;
    transition: transform 0.3s ease;
}

.contact-item:hover {
    transform: translateY(-5px);
}

.contact-item a {
    color: var(--text-primary);
    text-decoration: none;
    display: block;
    margin-top: 1rem;
}

.contact-item a:hover {
    color: var(--accent-color);
}

footer {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    nav ul {
        flex-direction: column;
        align-items: center;
    }

    .timeline::before {
        left: 50%;
        transform: translateX(-50%);
    }

    .timeline-item {
        margin-left: 0;
        padding: 0 2rem;
    }

    .timeline-item::before {
        left: 50%;
        transform: translateX(-50%);
    }
}