/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

/* Variables */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-brand .logo {
    height: 64px;
    width: 64px;
    object-fit: contain;
    flex-shrink: 0;
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0 2rem;
    position: relative;
    overflow: hidden;
}

.hero-content {
    flex: 1;
    max-width: 600px;
    z-index: 2;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    line-height: 1.6;
}

.cta-button {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.cta-button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.hero-visual {
    flex: 1;
    position: relative;
    height: 400px;
}

.floating-cards {
    position: relative;
    width: 100%;
    height: 100%;
}

.floating-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--border-radius);
    padding: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    animation: float 6s ease-in-out infinite;
}

.card-1 {
    top: 10%;
    right: 20%;
    animation-delay: 0s;
}

.card-2 {
    top: 50%;
    right: 10%;
    animation-delay: 2s;
}

.card-3 {
    top: 80%;
    right: 30%;
    animation-delay: 4s;
}

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

/* Apps Section */
.apps-section {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 4rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.apps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.app-card {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    opacity: 1;
    transform: scale(1);
}

.app-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.app-card.hidden {
    opacity: 0;
    transform: scale(0.8);
    height: 0;
    padding: 0;
    margin: 0;
    overflow: hidden;
}

.app-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    margin-bottom: 1.5rem;
}

.app-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.app-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.app-tags {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.tag {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.app-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.app-link {
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

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

.app-link.primary:hover {
    background: #4f46e5;
}

.app-link.secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.app-link.secondary:hover {
    background: var(--border-color);
}

.app-link.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.web-only-note {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: 0.5rem;
    display: block;
}

/* Filter Buttons */
.filter-buttons {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.filter-btn {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* About Section */
.about-section {
    padding: 6rem 0;
    background: var(--bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: top;
}

.about-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.stats {
    display: flex;
    gap: 2rem;
}

.stat {
    text-align: center;
}

.stat h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat p {
    color: var(--text-secondary);
    font-weight: 500;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section p {
    color: #d1d5db;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #d1d5db;
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #374151;
    color: #9ca3af;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        border-top: 1px solid var(--border-color);
    }

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

    .nav-toggle {
        display: flex;
    }

    .hero {
        flex-direction: column;
        text-align: center;
        padding: 2rem 1rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-visual {
        margin-top: 2rem;
        height: 300px;
    }

    .apps-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .stats {
        justify-content: center;
    }

    .tech-stack {
        grid-template-columns: 1fr 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .filter-buttons {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 1rem;
    }

    .filter-btn {
        white-space: nowrap;
        flex-shrink: 0;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .app-card {
        padding: 1.5rem;
    }

    .nav {
        padding: 1rem;
    }

    .container {
        padding: 0 15px;
    }

    .stats {
        flex-direction: column;
        gap: 1rem;
    }

    .tech-stack {
        grid-template-columns: 1fr;
    }
}

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

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading and Transition States */
.app-card {
    transition: all 0.3s ease;
}

.app-card.filtering {
    pointer-events: none;
}

/* Utility Classes */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus States for Accessibility */
.nav-link:focus,
.cta-button:focus,
.app-link:focus,
.filter-btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Smooth Scrolling Enhancement */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}