:root {
    /* Color Palette - Dark Mode (Default) */
    --bg-primary: #0a0a0c;
    --bg-secondary: #16161a;
    --text-primary: #fffffe;
    --text-secondary: #94a1b2;
    --accent-primary: #7f5af0; /* Purple often associated with .NET/Modern dev */
    --accent-secondary: #2cb67d;
    --card-bg: rgba(22, 22, 26, 0.5);
    --border-color: rgba(148, 161, 178, 0.1);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    /* Transition */
    --transition-standard: all 0.3s ease;
}

[data-theme="light"] {
    --bg-primary: #fffffe;
    --bg-secondary: #f2f4f6;
    --text-primary: #2b2c34;
    --text-secondary: #4a5568;
    --accent-primary: #6246ea;
    --card-bg: rgba(255, 255, 255, 0.5);
    --border-color: rgba(0, 0, 0, 0.05);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.5s ease, color 0.5s ease;
    overflow-x: hidden;
    position: relative;
}

/* Background Effect */
.background-globes {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
    background: 
        radial-gradient(circle at 15% 50%, rgba(127, 90, 240, 0.08) 0%, transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(44, 182, 125, 0.05) 0%, transparent 25%);
    pointer-events: none;
}

/* Typography elements */
h1, h2, h3 {
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text-primary) 30%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-md);
    position: relative;
    display: inline-block;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 40px;
    height: 4px;
    background-color: var(--accent-primary);
    border-radius: 2px;
}

p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    max-width: 65ch;
}

strong {
    color: var(--accent-primary);
    font-weight: 600;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-standard);
}

/* Header & Nav */
header {
    position: fixed;
    top: 0;
    width: 100%;
    padding: var(--spacing-md) 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.05em;
}

.theme-toggle button {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-primary);
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition-standard);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle button:hover {
    background-color: var(--bg-secondary);
}

.sun-icon { display: none; }
.moon-icon { display: block; }

[data-theme="light"] .sun-icon { display: block; }
[data-theme="light"] .moon-icon { display: none; }

/* Layout */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    min-height: 80vh; /* changed from 100vh to ensure flow */
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: var(--spacing-xl) 0;
}

/* Hero Section */
#hero {
    min-height: 90vh;
    justify-content: center;
    align-items: flex-start;
}

.greeting {
    font-family: 'Courier New', monospace;
    color: var(--accent-primary);
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    font-size: clamp(1.2rem, 2.5vw, 1.5rem);
    margin-bottom: var(--spacing-md);
}

.cta-container {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.btn {
    padding: 12px 24px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.primary-btn {
    background-color: transparent;
    border: 1px solid var(--accent-primary);
    color: var(--accent-primary);
}

.primary-btn:hover {
    background-color: rgba(127, 90, 240, 0.1);
    transform: translateY(-2px);
}

.secondary-btn {
    color: var(--text-secondary);
}

.secondary-btn:hover {
    color: var(--text-primary);
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.tech-stack {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.tech-stack h3 {
    margin-bottom: var(--spacing-sm);
    font-size: 1.2rem;
}

.tech-list {
    list-style: none;
}

.tech-list li {
    margin-bottom: var(--spacing-xs);
    position: relative;
    padding-left: 1.5rem;
    color: var(--text-secondary);
}

.tech-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
}

/* Contact Section */
#contact {
    text-align: center;
    align-items: center;
}

.contact-text {
    margin: 0 auto var(--spacing-md);
    text-align: center;
}

.email-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    font-weight: 600;
    color: var(--text-primary);
    position: relative;
}

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

.email-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--accent-primary);
    transition: width 0.3s ease;
}

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

/* Footer */
footer {
    padding: var(--spacing-md) 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}

/* Animations */
.fade-in-section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    will-change: opacity, visibility;
}

.fade-in-section.is-visible {
    opacity: 1;
    transform: none;
}

/* Media Queries */
@media (max-width: 768px) {
    :root {
        --spacing-md: 1.5rem;
        --spacing-lg: 3rem;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }

    #hero {
        align-items: center;
        text-align: center;
    }
    
    .cta-container {
        justify-content: center;
    }
}