:root {
    /* Dark theme */
    --bg-primary: linear-gradient(135deg, #181818 0%, #232526 100%);
    --bg-secondary: rgba(34, 34, 34, 0.95);
    --bg-navbar: rgba(30, 30, 30, 0.98);
    --bg-footer: #1e1e1e;
    --text-primary: #e0e0e0;
    --text-secondary: #888;
    --accent-primary: #bb86fc;
    --accent-secondary: #6200ea;
    --border-color: #232526;
    --shadow: 0 4px 24px rgba(0,0,0,0.15);
    
    /* Light theme */
    --light-bg-primary: linear-gradient(135deg, #f5f5f5 0%, #e0e0e0 100%);
    --light-bg-secondary: rgba(255,255,255,0.95);
    --light-bg-navbar: rgba(255,255,255,0.98);
    --light-bg-footer: #ececec;
    --light-text-primary: #232526;
    --light-text-secondary: #888;
    --light-accent-primary: #6200ee;
    --light-border-color: #ddd;
    --light-shadow: 0 4px 24px rgba(0,0,0,0.1);
    
    /* Spacing & Typography */
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --transition: 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    background: var(--bg-primary);
    min-height: 100vh;
    color: var(--text-primary);
    font-family: var(--font-family);
    margin: 0;
    padding: 0;
    transition: background var(--transition), color var(--transition);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--bg-navbar);
    box-shadow: var(--shadow);
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.navbar-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 900px;
    margin: 0 auto;
    padding: var(--space-sm) var(--space-lg);
}

.navbar-title {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--accent-primary);
}

.navbar-links {
    list-style: none;
    display: flex;
    gap: var(--space-lg);
    margin: 0;
    padding: 0;
}

.navbar-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition);
    padding: 4px 8px;
    border-radius: 4px;
    position: relative;
}

.navbar-links a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: width var(--transition);
}

.navbar-links a:hover,
.navbar-links a.active {
    color: var(--accent-primary);
}

.navbar-links a:hover::before,
.navbar-links a.active::before {
    width: 100%;
}

/* Dark mode toggle */
#darkmode-toggle {
    background: none;
    border: none;
    color: var(--accent-primary);
    font-size: 1.25rem;
    cursor: pointer;
    margin-left: var(--space-md);
    transition: color var(--transition), transform var(--transition);
    padding: 4px;
    border-radius: 4px;
}

#darkmode-toggle:hover {
    color: var(--text-primary);
    transform: rotate(180deg) scale(1.1);
}

#darkmode-toggle:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Dark mode toggle - Mobile */
#darkmode-toggle-mobile {
    display: none !important;
}

/* Main content */
main {
    max-width: 900px;
    margin: 90px auto 40px;
    padding: var(--space-xl);
    background: var(--bg-secondary);
    border-radius: 16px;
    box-shadow: var(--shadow);
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--accent-primary);
    margin-top: 0;
    font-weight: 600;
}

h1 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

h2 {
    font-size: 1.875rem;
    margin-bottom: var(--space-md);
}

h3 {
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
}

p {
    margin-bottom: var(--space-md);
    line-height: 1.6;
}

/* Buttons */
button {
    background-color: var(--accent-secondary);
    color: white;
    border: none;
    padding: var(--space-sm) var(--space-md);
    cursor: pointer;
    border-radius: 8px;
    font-weight: 500;
    transition: background-color var(--transition), transform var(--transition);
}

button:hover {
    background-color: #3700b3;
    transform: translateY(-1px);
}

/* Footer */
footer {
    background: var(--bg-footer);
    color: var(--text-secondary);
    padding: var(--space-lg) 0 var(--space-sm);
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: var(--space-2xl);
    border-radius: 0 0 16px 16px;
}

.social-links {
    list-style: none;
    padding: 0;
    margin: var(--space-sm) 0 0;
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
}

.social-links a {
    color: var(--accent-primary);
    text-decoration: underline;
}

.social-links a:hover {
    text-decoration: none;
}

.social-links a:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Hero Section */
.hero-section {
    position: relative;
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    margin-bottom: var(--space-2xl);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 700px;
}

.hero-title {
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-greeting {
    display: block;
    font-size: 1.125rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 4px;
    opacity: 0.8;
}

.hero-name {
    display: block;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
    line-height: 1.6;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-cta {
    display: flex;
    gap: var(--space-lg);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    padding: var(--space-md) var(--space-xl);
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition);
}

.cta-button.primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: var(--shadow);
}

.cta-button.primary:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 32px rgba(98, 0, 234, 0.4);
}

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

.cta-button.secondary:hover {
    background: var(--accent-primary);
    color: white;
    transform: translateY(-3px);
}

/* Floating elements */
.hero-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.floating-element {
    position: absolute;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0.1;
    animation: float 6s ease-in-out infinite;
}

.element-1 {
    width: 60px;
    height: 60px;
    top: 20%;
    left: 10%;
}

.element-2 {
    width: 40px;
    height: 40px;
    top: 60%;
    right: 15%;
    animation-delay: 2s;
}

.element-3 {
    width: 80px;
    height: 80px;
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(180deg);
    }
}

/* Intro Section */
.intro-section {
    margin-top: var(--space-2xl);
}

.intro-section h2 {
    text-align: center;
    margin-bottom: var(--space-2xl);
    font-size: 1.875rem;
}

.intro-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
    margin-top: var(--space-xl);
}

.intro-card {
    background: var(--bg-navbar);
    border-radius: 12px;
    padding: var(--space-xl);
    text-align: center;
    transition: transform var(--transition), box-shadow var(--transition);
    border: 1px solid var(--border-color);
}

.intro-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.2);
}

.intro-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
    display: block;
}

.intro-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--accent-primary);
}

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

/* Projects */
.projects-list {
    display: grid;
    gap: var(--space-xl);
    margin-top: var(--space-xl);
}

.project-card {
    background: var(--bg-navbar);
    border-radius: 12px;
    padding: var(--space-xl);
    transition: transform var(--transition), box-shadow var(--transition);
    border: 1px solid var(--border-color);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.2);
}

/* Scroll to top button */
.scroll-to-top {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    width: 50px;
    height: 50px;
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition);
    z-index: 1000;
    box-shadow: var(--shadow);
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-to-top:hover {
    background: var(--accent-secondary);
    transform: translateY(-3px) scale(1.1);
}

/* Page transitions */
.page-transition {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.5s ease;
}

.page-transition.active {
    opacity: 1;
    visibility: visible;
}

.page-transition .spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Light mode */
html.lightmode,
body.lightmode {
    --bg-primary: var(--light-bg-primary);
    --bg-secondary: var(--light-bg-secondary);
    --bg-navbar: var(--light-bg-navbar);
    --bg-footer: var(--light-bg-footer);
    --text-primary: var(--light-text-primary);
    --text-secondary: var(--light-text-secondary);
    --accent-primary: var(--light-accent-primary);
    --border-color: var(--light-border-color);
    --shadow: var(--light-shadow);
    
    background: var(--bg-primary);
    color: var(--text-primary);
}

/* Mobile styles */
@media (max-width: 768px) {
    #darkmode-toggle {
        display: none;
    }
    
    #darkmode-toggle-mobile {
        display: flex !important;
        position: fixed;
        top: 10px;
        right: 10px;
        background: none;
        color: var(--accent-primary);
        border: 2px solid var(--accent-primary);
        border-radius: 50%;
        width: 36px;
        height: 36px;
        font-size: 18px;
        cursor: pointer;
        z-index: 1001;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        transition: all var(--transition);
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    #darkmode-toggle-mobile:hover {
        background: var(--accent-primary);
        color: white;
        transform: scale(1.05);
    }
    
    .navbar-container {
        padding: 12px 20px;
        flex-direction: column;
        gap: 8px;
    }
    
    .navbar-title {
        font-size: 18px;
        text-align: center;
    }
    
    .navbar-links {
        gap: 12px;
        font-size: 14px;
        flex-wrap: wrap;
        justify-content: center;
        margin: 0;
    }
    
    .navbar-links a {
        padding: 6px 10px;
        font-size: 14px;
    }
    
    main {
        margin: 110px 8px 32px 8px;
        padding: 16px;
        border-radius: 12px;
    }
    
    .hero-section {
        min-height: 50vh;
        padding: 16px 0;
    }
    
    .hero-cta {
        gap: 12px;
    }
    
    .cta-button {
        padding: 8px 16px;
        font-size: 14px;
    }
    
    .intro-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .floating-element {
        display: none;
    }
    
    .social-links {
        gap: 12px;
        flex-direction: column;
        align-items: center;
    }
    
    .scroll-to-top {
        bottom: 16px;
        right: 16px;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 480px) {
    #darkmode-toggle-mobile {
        width: 32px;
        height: 32px;
        font-size: 16px;
        top: 8px;
        right: 8px;
    }
    
    .navbar-container {
        padding: 10px 16px;
        gap: 6px;
    }
    
    .navbar-title {
        font-size: 16px;
    }
    
    .navbar-links a {
        padding: 4px 8px;
        font-size: 13px;
    }
    
    main {
        margin: 90px 4px 16px 4px;
        padding: 12px;
        border-radius: 8px;
    }
    
    h1 {
        font-size: 1.5rem;
        text-align: center;
    }
    
    .social-links {
        gap: 8px;
        flex-direction: column;
        align-items: center;
    }
    
    .scroll-to-top {
        bottom: 12px;
        right: 12px;
        width: 36px;
        height: 36px;
        font-size: 14px;
    }
    
    .hero-section {
        min-height: 40vh;
        padding: 12px 0;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }
    
    .cta-button {
        width: 100%;
        max-width: 200px;
        justify-content: center;
        padding: 8px 16px;
        font-size: 13px;
    }
    
    .intro-icon {
        font-size: 2rem;
    }
    
    .intro-card {
        padding: 12px;
    }
}

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

:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--accent-primary);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 10000;
    transition: top var(--transition);
}

.skip-link:focus {
    top: 6px;
}