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

:root {
    /* Dark Theme Colors (Standard) */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-primary: #e9ecef;
    --text-secondary: #adb5bd;
    --accent-color: #4dabf7;
    --accent-hover: #339af0;
    --border-color: #495057;
    --card-bg: #2d2d2d;
    --shadow: rgba(0, 0, 0, 0.3);
    --nav-bg: rgba(26, 26, 26, 0.95);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ============================================
   Navigation
   ============================================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--nav-bg);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px var(--shadow);
    z-index: 1000;
    transition: background-color 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-logo a:hover {
    color: var(--accent-color);
}

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

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--accent-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    transition: all 0.3s ease;
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-container {
    max-width: 800px;
    text-align: center;
}

.hero-avatar-wrapper {
    width: 180px;
    height: 180px;
    margin: 0 auto 2rem;
    border-radius: 50%;
    border: 4px solid var(--accent-color);
    padding: 10px;
    box-sizing: border-box;
    box-shadow: 0 4px 20px var(--shadow);
    transition: transform 0.3s ease;
}

.hero-avatar-wrapper:hover {
    transform: scale(1.05);
}

.hero-avatar {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    display: block;
}

.hero-avatar:hover {
    transform: scale(1.05);
}

.hero-name {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.hero-title {
    font-size: 2rem;
    font-weight: 400;
    color: var(--accent-color);
    margin-bottom: 2rem;
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-description p {
    padding: 0.5rem 0;
}

.hero-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 2rem;
    font-size: 1rem;
    color: var(--text-secondary);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent-color);
    border: 2px solid var(--accent-color);
}

.btn-secondary:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-2px);
}

/* ============================================
   Sections
   ============================================ */

.section {
    padding: 5rem 2rem;
}

.section-alt {
    background-color: var(--bg-secondary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--text-primary);
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

.projects-note {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-style: italic;
    margin: -2rem auto 3rem;
    max-width: 700px;
}

.content-box {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.content-box p {
    margin-bottom: 1.5rem;
}

/* ============================================
   Lebenslauf / CV
   ============================================ */

.cv-section {
    margin-bottom: 3rem;
}

.cv-section-title {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.cv-personal {
    display: grid;
    gap: 0.75rem;
}

.cv-personal p {
    color: var(--text-secondary);
}

.cv-personal a {
    color: var(--accent-color);
    text-decoration: none;
}

.cv-personal a:hover {
    text-decoration: underline;
}

.cv-item {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cv-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.cv-item-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.cv-item-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

.cv-item-date {
    color: var(--accent-color);
    font-weight: 500;
    white-space: nowrap;
}

.cv-item-list {
    list-style: none;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

.cv-item-list li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    position: relative;
}

.cv-item-list li::before {
    content: '▸';
    position: absolute;
    left: -1.5rem;
    color: var(--accent-color);
}

.cv-item-tech {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

/* ============================================
   Skills
   ============================================ */

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

.skill-category {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
}

.skill-category-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.skill-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.skill-name {
    font-weight: 500;
    color: var(--text-primary);
}

.skill-percentage {
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.9rem;
}

.skill-progress-bar {
    width: 100%;
    height: 10px;
    background-color: var(--bg-secondary);
    border-radius: 5px;
    overflow: hidden;
    position: relative;
}

.skill-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-hover));
    border-radius: 5px;
    transition: width 0.6s ease;
    box-shadow: 0 0 10px rgba(77, 171, 247, 0.3);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.skill-tag:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-2px);
}

/* ============================================
   Projekte
   ============================================ */

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.project-card {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:first-child {
    grid-column: 1 / -1;
    border: 2px solid var(--accent-color);
    padding: 2.5rem;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 16px var(--shadow);
}

.project-card:first-child:hover {
    box-shadow: 0 6px 24px rgba(77, 171, 247, 0.5);
}

.project-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-details {
    list-style: none;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.project-details li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    position: relative;
}

.project-details li::before {
    content: '▸';
    position: absolute;
    left: -1.5rem;
    color: var(--accent-color);
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--nav-bg);
        width: 100%;
        text-align: center;
        transition: left 0.3s ease;
        box-shadow: 0 10px 27px var(--shadow);
        padding: 2rem 0;
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        width: 100%;
        padding: 1rem 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-avatar-wrapper {
        width: 140px;
        height: 140px;
        margin-bottom: 1.5rem;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-description {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

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

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

    .cv-item-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 1rem;
    }

    .hero {
        padding: 6rem 1rem 3rem;
    }

    .section {
        padding: 3rem 1rem;
    }

    .btn {
        width: 100%;
        text-align: center;
    }
}