/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--background-light);
}

/* CSS Variables for Theming - Bitcoin Orange Color Scheme */
:root {
    --primary-color: #000000;
    --secondary-color: #F7931A;
    --accent-color: #F7931A;
    --bitcoin-orange: #F7931A;
    --text-dark: #000000;
    --text-light: #666666;
    --background-light: #ffffff;
    --background-dark: #f5f5f5;
    --border-color: #e0e0e0;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.15);
    --gradient-primary: linear-gradient(135deg, #000000 0%, #333333 100%);
    --gradient-secondary: linear-gradient(135deg, #F7931A 0%, #FF8C00 100%);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 16px;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.btn-secondary {
    background: transparent;
    color: var(--bitcoin-orange);
    border-color: var(--bitcoin-orange);
}

.btn-secondary:hover {
    background: var(--bitcoin-orange);
    color: white;
}

/* Section Styles */
.section {
    padding: 80px 0;
}

.section:nth-child(even) {
    background-color: var(--background-dark);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 50px;
    color: var(--text-dark);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 20px auto;
    border-radius: 2px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: var(--transition);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo {
    width: 40px;
    height: 40px;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--bitcoin-orange);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    margin: 3px 0;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--gradient-primary);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="0.5" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content {
    max-width: 500px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.highlight {
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.hero-visual {
    position: relative;
    height: 400px;
}

.floating-elements {
    position: relative;
    width: 100%;
    height: 100%;
}

.floating-item {
    position: absolute;
    font-size: 2rem;
    color: rgba(255, 255, 255, 0.3);
    animation: float 6s ease-in-out infinite;
}

.floating-item:nth-child(1) {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-item:nth-child(2) {
    top: 60%;
    left: 70%;
    animation-delay: 2s;
}

.floating-item:nth-child(3) {
    top: 80%;
    left: 20%;
    animation-delay: 4s;
}

.floating-item:nth-child(4) {
    top: 30%;
    left: 80%;
    animation-delay: 1s;
}

.floating-item:nth-child(5) {
    top: 50%;
    left: 50%;
    animation-delay: 3s;
}

.bitcoin-float {
    font-size: 3rem !important;
    color: #F7931A !important;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 50px;
    align-items: start;
}

.about-text {
    font-size: 1.1rem;
    line-height: 1.8;
}

.about-photo {
    float: right;
    margin: 0 0 30px 30px;
    width: 200px;
}

.profile-photo {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    border: 3px solid var(--bitcoin-orange);
    transition: var(--transition);
}

.profile-photo:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.about-intro {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 20px;
    color: var(--bitcoin-orange);
}

.about-text p {
    margin-bottom: 20px;
}

.about-skills h3 {
    margin-bottom: 25px;
    color: var(--text-dark);
    font-size: 1.3rem;
}

.skills-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.skill-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px;
    background: var(--background-light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
}

.skill-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.skill-item i {
    color: var(--bitcoin-orange);
    font-size: 1.2rem;
}

/* Professional Section */
.professional-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.timeline {
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gradient-primary);
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
    padding-left: 80px;
}

.timeline-marker {
    position: absolute;
    left: 22px;
    top: 0;
    width: 16px;
    height: 16px;
    background: var(--background-light);
    border: 3px solid var(--bitcoin-orange);
    border-radius: 50%;
}

.timeline-content h3 {
    color: var(--text-dark);
    margin-bottom: 5px;
    font-size: 1.2rem;
}

.timeline-period {
    color: var(--bitcoin-orange);
    font-weight: 500;
    margin-bottom: 10px;
}

.tech-stack h3 {
    margin-bottom: 30px;
    color: var(--text-dark);
    font-size: 1.3rem;
}

.tech-grid {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.tech-category h4 {
    margin-bottom: 15px;
    color: var(--bitcoin-orange);
}

.tech-items {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tech-item {
    background: var(--gradient-primary);
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Hobbies Section */
.hobbies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.hobby-card {
    background: var(--background-light);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.hobby-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.hobby-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.hobby-icon i {
    font-size: 1.5rem;
    color: white;
}

.hobby-card h3 {
    margin-bottom: 15px;
    color: var(--text-dark);
    font-size: 1.2rem;
}

.hobby-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 50px;
    align-items: start;
}

.contact-info h3 {
    margin-bottom: 20px;
    color: var(--text-dark);
    font-size: 1.5rem;
}

.contact-info p {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-light);
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 20px;
    background: var(--background-light);
    border-radius: var(--border-radius);
    text-decoration: none;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.contact-link:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.contact-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
}

.contact-link.email .contact-icon {
    background: var(--gradient-primary);
}

.contact-link.github .contact-icon {
    background: linear-gradient(135deg, #24292e 0%, #586069 100%);
}

.contact-link.xing .contact-icon {
    background: linear-gradient(135deg, #026466 0%, #064e56 100%);
}

.contact-details h4 {
    margin-bottom: 5px;
    color: var(--text-dark);
}

.contact-details p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 30px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--bitcoin-orange);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-medium);
        padding: 20px 0;
    }

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

    .nav-item {
        margin: 10px 0;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

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

    .about-content,
    .professional-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

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

    .hero-buttons {
        justify-content: center;
    }

    .footer-content {
        justify-content: center;
        text-align: center;
    }

    .timeline {
        padding-left: 20px;
    }

    .timeline::before {
        left: 10px;
    }

    .timeline-item {
        padding-left: 40px;
    }

    .timeline-marker {
        left: 2px;
    }

    .about-photo {
        float: none;
        margin: 0 auto 20px;
        width: 150px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .section {
        padding: 60px 0;
    }

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

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }

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

    .hobby-card {
        padding: 20px;
    }

    .contact-link {
        padding: 15px;
    }

    .contact-icon {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
.nav-link:focus,
.btn:focus,
.contact-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.3);
        --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.4);
        --border-color: #000;
    }
}