/* ============================================
   MODERN WEBSITE DESIGN - FosSoftware Studio
   ============================================ */

/* CSS Custom Properties for consistent theming */
:root {
    /* Color palette - dark theme with vibrant accents */
    --color-primary: #3da9fc;
    --color-primary-dark: #1d8fe9;
    --color-secondary: #90b4ce;
    --color-accent: #ef4565;
    --color-success: #2cb67d;
    
    --color-bg-dark: #0f172a;
    --color-bg-card: #1e293b;
    --color-bg-surface: #334155;
    
    --color-text-primary: #f8fafc;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #94a3b8;
    
    --color-border: #475569;
    --color-shadow: rgba(0, 0, 0, 0.3);
    
    /* Typography */
    --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    --font-family-heading: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    
    --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;
    
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 var(--color-shadow);
    --shadow-md: 0 4px 6px -1px var(--color-shadow);
    --shadow-lg: 0 10px 15px -3px var(--color-shadow);
    --shadow-xl: 0 20px 25px -5px var(--color-shadow);
    
    /* Container widths */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1400px;
}

/* Reset and base styles */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

body.menu-open {
    overflow: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
    font-weight: var(--font-weight-bold);
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--font-size-5xl);
}

h2 {
    font-size: var(--font-size-4xl);
}

h3 {
    font-size: var(--font-size-2xl);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.highlight {
    color: var(--color-primary);
}

/* Utility classes */
.container {
    width: 100%;
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Button styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-base);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all var(--transition-normal);
    border: 2px solid transparent;
    cursor: pointer;
}

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

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

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

.btn-secondary:hover {
    background-color: rgba(61, 169, 252, 0.1);
    transform: translateY(-2px);
}

/* Header and Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding: var(--spacing-sm) 0;
    transition: all var(--transition-normal);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-xl);
    color: var(--color-text-primary);
    text-decoration: none;
    z-index: 1001;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    border-radius: var(--radius-md);
    color: white;
    font-weight: var(--font-weight-bold);
}

.main-nav {
    transition: transform var(--transition-normal) ease;
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.main-nav a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast);
    position: relative;
}

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

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: all var(--transition-normal);
    transform: translateX(-50%);
}

.main-nav a:hover::after {
    width: 80%;
}

/* Mobile Menu Toggle Button */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    flex-direction: column;
    justify-content: space-between;
    width: 40px;
    height: 30px;
    z-index: 1001;
    position: relative;
}

.mobile-menu-toggle .hamburger-line {
    display: block;
    width: 100%;
    height: 3px;
    background-color: var(--color-text-primary);
    border-radius: 2px;
    transition: all 0.3s ease;
    transform-origin: center;
}

/* Hamburger to X animation */
.mobile-menu-toggle.active .hamburger-line:nth-child(1) {
    transform: translateY(11px) rotate(45deg);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(3) {
    transform: translateY(-11px) rotate(-45deg);
}

/* Hero Section */
.hero {
    padding: calc(var(--spacing-2xl) * 2) 0 var(--spacing-2xl);
    margin-top: 4rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 200%;
    background: radial-gradient(circle, rgba(61, 169, 252, 0.1) 0%, transparent 70%);
    z-index: -1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, var(--font-size-5xl));
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 90%;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.visual-placeholder {
    position: relative;
    width: 100%;
    max-width: 400px;
    height: 300px;
}

.code-block {
    position: absolute;
    top: 0;
    left: 0;
    width: 60%;
    height: 70%;
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    z-index: 2;
}

.code-line {
    height: 12px;
    background-color: var(--color-bg-surface);
    margin-bottom: var(--spacing-sm);
    border-radius: var(--radius-sm);
    animation: pulse 2s infinite ease-in-out;
}

.code-line:nth-child(1) { width: 80%; animation-delay: 0s; }
.code-line:nth-child(2) { width: 60%; animation-delay: 0.2s; }
.code-line:nth-child(3) { width: 70%; animation-delay: 0.4s; }
.code-line:nth-child(4) { width: 50%; animation-delay: 0.6s; }

.device-mockup {
    position: absolute;
    bottom: 0;
    right: 0;
    width: 70%;
    height: 80%;
    background-color: var(--color-bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    z-index: 1;
}

.screen {
    width: 100%;
    height: 100%;
    background-color: var(--color-bg-surface);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
}

.app-preview {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, var(--color-primary), var(--color-accent));
    opacity: 0.3;
    border-radius: var(--radius-md);
}

@keyframes pulse {
    0%, 100% { opacity: 0.7; }
    50% { opacity: 1; }
}

/* Section common styles */
section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Features Section */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.feature-card {
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-normal);
    border: 1px solid var(--color-border);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.feature-title {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
}

.feature-description {
    color: var(--color-text-muted);
    font-size: var(--font-size-base);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--color-border);
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.project-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-xl);
}

.project-header {
    margin-bottom: var(--spacing-md);
}

.project-title {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
}

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

.project-tag {
    background-color: var(--color-bg-surface);
    color: var(--color-text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
}

.project-description {
    flex-grow: 1;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.project-link {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: gap var(--transition-fast);
}

.project-link:hover {
    gap: 1rem;
}

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

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.stat {
    text-align: center;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}

.stat-number {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

/* Contact Section */
.contact {
    background-color: var(--color-bg-card);
    border-radius: var(--radius-xl);
    margin: var(--spacing-2xl) auto;
    max-width: var(--container-lg);
}

.contact-content {
    padding: var(--spacing-2xl);
    text-align: center;
}

.contact-subtitle {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xl);
    color: var(--color-text-secondary);
}

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

.contact-method {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background-color: var(--color-bg-surface);
    border-radius: var(--radius-lg);
}

.contact-icon {
    font-size: 2.5rem;
}

.contact-details h3 {
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-lg);
}

.contact-details a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.contact-details a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

.cta {
    background: linear-gradient(135deg, var(--color-bg-surface), var(--color-bg-card));
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.cta-text {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--color-text-primary);
}

/* Footer */
.footer {
    background-color: var(--color-bg-card);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

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

.footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
}

.footer-link-group h4 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.footer-link-group ul {
    list-style: none;
}

.footer-link-group li {
    margin-bottom: var(--spacing-xs);
}

.footer-link-group a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    text-align: center;
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.footer-note {
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-xs);
    opacity: 0.7;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

/* Tablet and Desktop - default styles are for desktop */

/* Mobile Menu Styles (for screens <= 768px) */
@media (max-width: 768px) {
    /* Hide desktop navigation on mobile */
    .main-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--color-bg-dark);
        backdrop-filter: blur(20px);
        padding: var(--spacing-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-xl);
        z-index: 999;
        transition: all var(--transition-normal) ease;
    }
    
    .main-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .main-nav ul {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-md);
        padding: 0;
    }
    
    .main-nav li {
        width: 100%;
        text-align: center;
    }
    
    .main-nav a {
        display: block;
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-lg);
        border-radius: var(--radius-md);
        transition: all var(--transition-fast);
    }
    
    .main-nav a:hover {
        background-color: rgba(61, 169, 252, 0.1);
    }
    
    /* Show mobile menu toggle button */
    .mobile-menu-toggle {
        display: flex;
    }
    
    /* Adjust hero section for mobile */
    .hero {
        padding-top: calc(var(--spacing-2xl) + 2rem);
        padding-bottom: var(--spacing-xl);
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-xl);
    }
    
    .hero-subtitle {
        max-width: 100%;
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .visual-placeholder {
        margin: 0 auto;
        max-width: 300px;
        height: 250px;
    }
    
    /* Adjust features and projects grid for mobile */
    .features-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    /* Adjust about section for mobile */
    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .about-stats {
        grid-template-columns: repeat(2, 1fr);
        margin-top: var(--spacing-xl);
    }
    
    /* Adjust footer for mobile */
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    /* Adjust container padding for mobile */
    .container {
        padding: 0 var(--spacing-md);
    }
    
    /* Adjust contact section for mobile */
    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        padding: var(--spacing-lg);
    }
}

/* Small mobile devices (<= 480px) */
@media (max-width: 480px) {
    /* Adjust typography for small screens */
    h1 {
        font-size: var(--font-size-3xl);
    }
    
    h2 {
        font-size: var(--font-size-2xl);
    }
    
    .hero-title {
        font-size: var(--font-size-3xl);
    }
    
    /* Adjust button layout for small screens */
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    /* Adjust stats grid for small screens */
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    /* Adjust visual elements for small screens */
    .visual-placeholder {
        max-width: 250px;
        height: 200px;
    }
    
    /* Adjust feature and project cards */
    .feature-card,
    .project-card {
        padding: var(--spacing-lg);
    }
    
    /* Adjust contact method cards */
    .contact-method {
        padding: var(--spacing-md);
    }
    
    /* Adjust footer text sizes */
    .footer-link-group h4 {
        font-size: var(--font-size-base);
    }
    
    .footer-link-group a {
        font-size: var(--font-size-xs);
    }
}

/* Large desktop screens (> 1400px) */
@media (min-width: 1400px) {
    .container {
        max-width: var(--container-2xl);
    }
    
    .hero-content {
        gap: var(--spacing-2xl);
    }
    
    .features-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Animation for mobile menu backdrop */
@media (max-width: 768px) {
    body.menu-open::after {
        content: '';
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background-color: rgba(0, 0, 0, 0.5);
        z-index: 998;
        animation: fadeIn 0.3s ease;
    }
    
    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }
}