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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #06b6d4;
    --success-color: #10b981;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-alternate: #f1f5f9;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 700;
}

.logo img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
}

.nav {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}

.nav a:hover,
.nav a:focus {
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
    padding: 0.5rem;
}

.main {
    flex: 1;
}

.hero {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-alternate) 100%);
    padding: 4rem 0;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.hero-content h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
}

.projects-section {
    padding: 4rem 0;
}

.projects-section.bg-alternate {
    background-color: var(--bg-secondary);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.project-image {
    width: 100%;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    padding: 1rem;
}

.project-image img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.project-icon {
    width: 100%;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.project-icon svg {
    width: 64px;
    height: 64px;
}

.project-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.project-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

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

.project-tagline {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
    font-style: italic;
}

.project-info .btn {
    margin-top: auto;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    border: 2px solid transparent;
    font-size: 1rem;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-outline:hover,
.btn-outline:focus {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1.5rem;
    margin-top: 4rem;
}

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

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

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

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-section a:hover,
.footer-section a:focus {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }

    .nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--bg-primary);
        border-bottom: 1px solid var(--border-color);
        flex-direction: column;
        padding: 1rem;
        display: none;
        box-shadow: var(--shadow-md);
    }

    .nav.active {
        display: flex;
    }

    .nav a {
        width: 100%;
        text-align: center;
        padding: 0.75rem;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

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

.legacy-badge {
background-color: var(--text-muted);
color: white;
font-size: 0.75rem;
padding: 0.25rem 0.5rem;
border-radius: var(--radius-sm);
vertical-align: middle;
margin-left: 0.5rem;
}

.legacy-note {
text-align: center;
color: var(--text-secondary);
margin-bottom: 2rem;
font-style: italic;
}

.legacy-list {
    max-width: 600px;
    margin: 0 auto;
}

.projects-grid + .legacy-list {
    margin-top: 2.5rem;
}

.legacy-item {
padding: 1rem 0;
border-bottom: 1px solid var(--border-color);
display: flex;
align-items: center;
flex-wrap: wrap;
gap: 0.5rem;
}

.legacy-item:last-child {
border-bottom: none;
}

.legacy-link {
color: var(--primary-color);
text-decoration: none;
font-weight: 600;
transition: color 0.2s;
}

.legacy-link:hover {
color: var(--primary-hover);
text-decoration: underline;
}

.download-link {
display: inline-flex;
align-items: center;
gap: 0.5rem;
text-decoration: none;
}

.download-link:hover {
text-decoration: none;
}

.download-link .legacy-link-text {
text-decoration: none;
}

.download-link:hover .legacy-link-text {
color: var(--primary-hover);
text-decoration: underline;
}

.download-badge {
display: inline-flex;
align-items: center;
gap: 0.25rem;
font-size: 0.75rem;
font-weight: 500;
color: var(--primary-color);
background-color: var(--bg-alternate);
border: 1px solid var(--border-color);
padding: 0.15rem 0.5rem;
border-radius: var(--radius-sm);
text-decoration: none;
line-height: 1.2;
transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

.download-link:hover .download-badge {
background-color: var(--primary-color);
color: var(--bg-primary);
border-color: var(--primary-color);
}

.download-icon {
width: 12px;
height: 12px;
flex-shrink: 0;
}

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

.external-icon {
    display: inline-block;
    width: 0.85em;
    height: 0.85em;
    vertical-align: -0.1em;
    margin-left: 0.3rem;
    flex-shrink: 0;
    transition: transform 0.2s ease;
}

.btn .external-icon {
    margin-left: 0;
    width: 1em;
    height: 1em;
}

a:hover .external-icon {
    transform: translate(2px, -2px);
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .header-content {
        flex-wrap: wrap;
    }

    .logo {
        font-size: 1.25rem;
    }

    .logo img {
        width: 32px;
        height: 32px;
    }

    .hero {
        padding: 3rem 0;
    }

    .hero-content h1 {
        font-size: 1.75rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

}