/* CSS Variables for Theming */
:root {
    --bg-main: #ffffff;
    --bg-nav: rgba(255, 255, 255, 0.8);
    --bg-card: #ffffff;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --border-color: #e5e7eb;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --tag-bg: #f3f4f6;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] {
    --bg-main: #0a0a0a;
    --bg-nav: rgba(10, 10, 10, 0.8);
    --bg-card: #0a0a0a;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --border-color: #262626;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --tag-bg: #1f2937;
    --shadow-sm: none;
}

/* Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    scroll-behavior: smooth;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--bg-nav);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-weight: 700;
    font-size: 1.2rem;
    letter-spacing: -0.5px;
}

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

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--text-primary);
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.1rem;
    padding: 0.5rem;
}

#theme-toggle:hover {
    color: var(--text-primary);
}

.hamburger {
    display: none;
    cursor: pointer;
    color: var(--text-primary);
}

/* Layout */
main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}


section:last-of-type {
    border-bottom: none;
}

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

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.5px;
}

/* Typography */
h1 {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* Buttons */
.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.6rem 1.2rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
}

.btn.primary {
    background-color: var(--text-primary);
    color: var(--bg-main);
    border: 1px solid var(--text-primary);
}

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

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

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

/* Cards (Projects & Skills) */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
}

.project-grid, .skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.tech-stack {
    margin: auto 0 1rem 0; /* Pushes to bottom */
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-stack span {
    background-color: var(--tag-bg);
    color: var(--text-primary);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
}

.project-details {
    font-size: 0.85rem;
    color: var(--text-secondary);
    border-top: 1px dashed var(--border-color);
    padding-top: 1rem;
    margin-top: 0.5rem;
}

/* Contact & Footer */
.contact-container {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.social-links {
    margin: 2rem 0;
}

.social-links a {
    color: var(--text-secondary);
    font-size: 1.5rem;
    margin: 0 0.8rem;
}

.social-links a:hover {
    color: var(--text-primary);
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-color);
}

/* Hero specific */
#hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center; 
    width: 100%;
    border-bottom: none;
    margin-top: -60px; 
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--bg-main);
        border-bottom: 1px solid var(--border-color);
        padding: 1rem 0;
    }

    .nav-links.active {
        display: flex;
    }

    .hamburger {
        display: block;
    }

    h1 {
        font-size: 2.5rem;
    }
    
}

.profile-img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--border-color);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.profile-img:hover {
    transform: scale(1.05);
    border-color: var(--accent);
}


section {
    padding: 4rem 0; /* Tightened from 6rem */
    border-bottom: 1px solid var(--border-color);
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    width: 100%;
}