:root {
    --card-bg: white;
    --text-gray: rgb(79, 77, 77);
    --background: rgb(235, 228, 228);
    --card-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
    --primary-color: #4a90e2;
    --border-radius: 15px;
    --spacing-sm: 10px;
    --spacing-md: 20px;
    --spacing-lg: 30px;
    --text-primary: #2d3748;
    --border-color: #e2e8f0;
    --hover-bg: #f8fafc;
}

/* Base Styles */
body {
    background-color: var(--background);
    font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Helvetica Neue, Arial, sans-serif;
    margin: 0;
    padding: var(--spacing-md);
    line-height: 1.6;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-md);
}

/* Card Base */
.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    box-shadow: var(--card-shadow);
    margin-bottom: var(--spacing-md);
}

/* Tab Navigation */
.tab-navigation {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    position: relative;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 2px;
}

.tab-btn {
    padding: 8px 16px;
    border: none;
    background: none;
    color: var(--text-gray);
    font-size: 1rem;
    cursor: pointer;
    position: relative;
    transition: all 0.3s ease;
}

.tab-btn::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.tab-btn.active {
    color: var(--primary-color);
}

.tab-btn.active::after {
    transform: scaleX(1);
}

/* Content Sections */
.content-section {
    display: none;
    animation: fadeIn 0.5s ease;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Profile Section */
.profile-header {
    position: relative;
    margin: calc(-1 * var(--spacing-md)) calc(-1 * var(--spacing-md)) 0;
}

.background-image {
    height: 120px;
    background: linear-gradient(45deg, var(--primary-color), #63b3ed);
    border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    border: 4px solid white;
    position: absolute;
    bottom: -50px;
    left: var(--spacing-md);
    object-fit: cover;
}

.profile-info {
    margin-top: 60px;
    padding: var(--spacing-sm);
}

.profile-info h2 {
    margin: 0;
    color: var(--text-primary);
}

.profile-info p {
    color: var(--text-gray);
    margin: 5px 0;
}

/* Social Links */
.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
    justify-content: center;
}

.social-links a {
    color: var(--text-gray);
    text-decoration: none;
    font-size: 1.2em;
    transition: all 0.3s ease;
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Information Grid */
.info-grid {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-sm);
    color: var(--text-gray);
    padding: var(--spacing-sm);
}

/* Skills Section */
.skills-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.skills-category h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1em;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 5px;
}

.skills-grid {
    display: grid;
    gap: var(--spacing-sm);
}

.skill-item {
    background: var(--hover-bg);
    padding: var(--spacing-sm);
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.skill-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.skill-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.skill-header i {
    color: var(--primary-color);
    font-size: 1.2em;
}

.skill-level {
    font-size: 0.9em;
    padding: 4px 8px;
    border-radius: 4px;
    font-weight: 500;
}

.skill-level.expert {
    background-color: #c6f6d5;
    color: #2f855a;
}

.skill-level.advanced {
    background-color: #e9d8fd;
    color: #6b46c1;
}

.skill-level.intermediate {
    background-color: #feebc8;
    color: #c05621;
}

.skill-level.beginner {
    background-color: #fed7d7;
    color: #c53030;
}

/* Timeline */
.timeline-item {
    display: flex;
    margin-bottom: var(--spacing-md);
    position: relative;
    padding-left: 60px;
}

.timeline-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    position: absolute;
    left: 0;
}

.timeline-content {
    margin-left: 20px;
}

.timeline-content h4 {
    margin: 0;
    color: var(--text-primary);
}

.timeline-content p {
    margin: 2px 0;
    color: var(--text-gray);
}

.timeline-content p:first-of-type {
    margin-top: 2px;
    font-weight: 500;
}

.timeline-content p:not(:first-of-type) {
    margin-top: 8px;
}

.timeline-date {
    color: var(--text-gray);
    font-size: 0.9em;
    margin-top: 4px;
    display: block;
}

/* Projects Section */
.project-item {
    padding: var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: var(--spacing-md);
    transition: all 0.3s ease;
}

.project-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
}

.project-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.project-title h4 {
    margin: 0;
    color: var(--text-primary);
}

.project-links {
    display: flex;
    gap: 10px;
}

.project-link {
    color: var(--text-gray);
    text-decoration: none;
    font-size: 1.2em;
    transition: color 0.3s ease;
}

.project-link:hover {
    color: var(--primary-color);
}

.project-date {
    color: var(--text-gray);
    font-size: 0.9em;
    margin: 0;
}

.project-description {
    color: var(--text-gray);
    margin-bottom: var(--spacing-md);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tech-tag {
    background: var(--hover-bg);
    color: var(--primary-color);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.85em;
    border: 1px solid var(--border-color);
}

/* Volunteer Section */
.volunteer-item {
    display: flex;
    margin-bottom: var(--spacing-md);
    position: relative;
    padding-left: 60px;
}

.volunteer-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    position: absolute;
    left: 0;
    flex-shrink: 0;
}

.volunteer-icon i {
    font-size: 1.2em;
    color: white;
}

.volunteer-info {
    margin-left: 20px;
}

.volunteer-info h4 {
    margin: 0;
    color: var(--text-primary);
}

.volunteer-info p {
    margin: 2px 0;
    color: var(--text-gray);
}

.volunteer-date {
    color: var(--text-gray);
    font-size: 0.9em;
    margin-top: 4px;
}

/* Certificate Styles */
.certificate-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.certificate-item:last-child {
    margin-bottom: 0;
}

.certificate-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--hover-bg);
    border-radius: 8px;
    margin-right: var(--spacing-sm);
    color: var(--primary-color);
}

.certificate-info {
    flex: 1;
}

.certificate-info h4 {
    margin: 0;
    color: var(--text-primary);
}

.certificate-info p {
    margin: 2px 0;
    color: var(--text-gray);
}

.certificate-date {
    color: var(--text-gray);
    font-size: 0.9em;
    white-space: nowrap;
    margin-left: var(--spacing-md);
}

.certificate-id {
    font-family: monospace;
    font-size: 0.85em;
    color: var(--text-gray);
    background: var(--hover-bg);
    padding: 4px 8px;
    border-radius: 4px;
    display: inline-block;
    margin: 8px 0;
}

.verify-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    margin-top: 8px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: transparent;
    color: var(--primary-color);
    font-size: 0.9em;
    cursor: pointer;
    transition: all 0.2s ease;
}

.verify-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.certificate-link {
    text-decoration: none;
}

/* Dark Theme */
.dark-theme {
    --card-bg: #1a1c23;
    --text-gray: #a0aec0;
    --background: #111827;
    --card-shadow: 0 2px 15px rgba(0, 0, 0, 0.2);
    --text-primary: #e2e8f0;
    --border-color: #2d3748;
    --hover-bg: #252836;
}

.dark-theme .skill-level.expert {
    background-color: #234e52;
    color: #e6fffa;
}

.dark-theme .skill-level.advanced {
    background-color: #44337a;
    color: #e9d8fd;
}

.dark-theme .skill-level.intermediate {
    background-color: #7b341e;
    color: #fffaf0;
}

.dark-theme .skill-level.beginner {
    background-color: #742a2a;
    color: #fff5f5;
}

.dark-theme .certificate-id {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}

.dark-theme .verify-btn {
    color: var(--primary-color);
    border-color: var(--border-color);
}

.dark-theme .verify-btn:hover {
    background: var(--primary-color);
    color: var(--card-bg);
}

/* Share Button & Dark Mode Toggle */
.share-button,
.dark-mode-toggle {
    position: fixed;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    box-shadow: var(--card-shadow);
    cursor: pointer;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

/* Fortsetzung von wo es aufhörte */
.dark-mode-toggle {
    bottom: 20px;
    right: 20px;
    background: var(--card-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.share-button {
    bottom: 80px;
    right: 20px;
    background: var(--primary-color);
    color: white;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 400px;
    position: relative;
    border: 1px solid var(--border-color);
}

.close-modal {
    position: absolute;
    right: 20px;
    top: 10px;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-gray);
}

.share-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-top: 20px;
}

.share-option {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 10px;
    border: none;
    border-radius: 8px;
    background: var(--hover-bg);
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-primary);
}

.share-option:hover {
    background: var(--primary-color);
    color: white;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--hover-bg);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: 8px;
    box-shadow: var(--card-shadow);
    z-index: 1002;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.toast.show {
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        order: 1;
    }
    
    .main-content {
        order: 2;
    }

    .project-title {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    
    .project-header {
        flex-direction: column;
        gap: 5px;
    }

    .timeline-item,
    .volunteer-item {
        padding-left: 50px;
    }
}

@media (max-width: 480px) {
    body {
        padding: var(--spacing-sm);
    }
    
    .card {
        padding: var(--spacing-sm);
    }
    
    .volunteer-item {
        flex-direction: row;
        text-align: left;
    }

    .tab-navigation {
        gap: 10px;
    }

    .tab-btn {
        padding: 8px 12px;
        font-size: 0.9rem;
    }

    .share-options {
        grid-template-columns: 1fr;
    }
}

.footer {
    padding: 20px;
    text-align: center;
    font-family: Arial, sans-serif; 
    color: #555;
}

.footer-content span {
    display: block;
    font-size: 14px;
    margin: 5px 0; 
}

.footer-content a {
    text-decoration: none;
    color: #0073e6;
    font-weight: bold; 
}

.footer-content a:hover {
    text-decoration: underline;
    color: #005bb5; 
}