/* 
 * Modern CSS for Lakshay Sharma Portfolio
 * Created: February 8, 2026
 */

/* CSS Variables (Custom Properties) */
:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --danger-color: #ef4444;
    
    /* Dark Theme */
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #16213e;
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    
    /* Light Theme */
    --bg-primary-light: #ffffff;
    --bg-secondary-light: #f8fafc;
    --bg-tertiary-light: #f1f5f9;
    --text-primary-light: #1e293b;
    --text-secondary-light: #475569;
    --text-muted-light: #64748b;
    --border-color-light: #e2e8f0;
    
    /* Typography */
    --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-family-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal: 1040;
    --z-popover: 1050;
    --z-tooltip: 1060;
}

/* Light theme variables */
[data-theme="light"] {
    --bg-primary: var(--bg-primary-light);
    --bg-secondary: var(--bg-secondary-light);
    --bg-tertiary: var(--bg-tertiary-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --text-muted: var(--text-muted-light);
    --border-color: var(--border-color-light);
}

/* Reset & Base Styles */
*,
*::before,
*::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 4rem;
}

body {
    font-family: var(--font-family-primary);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: var(--radius-md);
    z-index: 1000;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-primary) / 0.95;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: var(--z-fixed);
    transition: all var(--transition-normal);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: var(--font-size-xl);
}

.logo-text {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

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

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
    border-radius: var(--radius-full);
}

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

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('../images/hero-pattern.svg') no-repeat center center;
    background-size: cover;
    opacity: 0.03;
    z-index: 1;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    text-align: center;
    position: relative;
    z-index: 2;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-greeting {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    opacity: 0;
    animation: fadeInUp 0.8s ease-out forwards;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 0.2s forwards;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 0.4s forwards;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-lg);
    justify-content: center;
    flex-wrap: wrap;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 0.6s forwards;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-full);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    font-size: var(--font-size-base);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

/* Projects Section */
.projects-preview {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.project-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color) / 0.5;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.project-tag {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.project-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

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

/* Flash Messages */
.flash-message {
    position: fixed;
    top: 4rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-modal);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-md);
    max-width: 400px;
    width: calc(100% - 2rem);
    animation: slideDown 0.3s ease-out;
}

.flash-info { background: var(--primary-color); color: white; }
.flash-success { background: var(--accent-color); color: white; }
.flash-error { background: var(--danger-color); color: white; }
.flash-warning { background: var(--secondary-color); color: white; }

.flash-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
}

.flash-close {
    background: none;
    border: none;
    color: inherit;
    font-size: var(--font-size-xl);
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-subtitle {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

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

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

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.footer-social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--bg-primary);
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.footer-social-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.cv-download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-full);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.cv-download-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-copyright,
.footer-credits {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.footer-credits i {
    color: var(--danger-color);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: var(--z-fixed);
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary) / 0.9;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.loading-overlay.visible {
    opacity: 1;
    visibility: visible;
}

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

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

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 1.25rem;
        --spacing-xl: 1.5rem;
        --spacing-2xl: 2rem;
        --spacing-3xl: 2.5rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background: var(--bg-primary) / 0.98;
        backdrop-filter: blur(10px);
        border-top: 1px solid var(--border-color);
        padding: var(--spacing-lg);
        flex-direction: column;
        gap: var(--spacing-lg);
        transform: translateY(-100vh);
        transition: transform var(--transition-normal);
    }
    
    .nav-menu.active {
        transform: translateY(0);
    }
    
    .nav-links {
        flex-direction: column;
        gap: var(--spacing-lg);
        width: 100%;
    }
    
    .nav-link {
        padding: var(--spacing-sm) 0;
        text-align: center;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 var(--spacing-sm);
    }
    
    .section-container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-container {
        padding: 0 var(--spacing-sm);
    }
    
    .footer-container {
        padding: 0 var(--spacing-sm);
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --border-color: #ffffff40;
        --text-secondary: #ffffff90;
    }
}

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

/* Print styles */
@media print {
    .navbar,
    .footer,
    .back-to-top,
    .theme-toggle,
    .nav-toggle {
        display: none !important;
    }
    
    .hero {
        min-height: auto;
        padding: 2rem 0;
    }
    
    * {
        box-shadow: none !important;
        text-shadow: none !important;
    }
}