:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --light-bg: #f3f4f6;
    --card-bg: #ffffff;
    --footer-bg: #1f2937;
    --footer-text: #ffffff;
}

[data-theme="dark"] {
    --primary-color: #60a5fa;
    --secondary-color: #3b82f6;
    --text-color: #f3f4f6;
    --bg-color: #1f2937;
    --light-bg: #111827;
    --card-bg: #374151;
    --footer-bg: #111827;
    --footer-text: #f3f4f6;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    background-color: var(--bg-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-links a {
    margin-left: 2rem;
    text-decoration: none;
    color: var(--text-color);
}

.hero {
    text-align: center;
    padding: 4rem 1rem;
    background-color: var(--light-bg);
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    padding: 4rem 5%;
}

.app-card {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s;
}

.app-card:hover {
    transform: translateY(-5px);
}

.app-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.2s;
}

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

.about, .contact {
    padding: 4rem 5%;
    text-align: center;
    background-color: var(--light-bg);
}

footer {
    text-align: center;
    padding: 2rem;
    background-color: var(--footer-bg);
    color: var(--footer-text);
    margin-top: auto;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
}

.dark-mode-toggle {
    background: none;
    border: none;
    padding: 0.5rem;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.dark-mode-toggle:hover {
    background-color: var(--light-bg);
}

.dark-mode-toggle svg {
    fill: var(--text-color);
}

.sun-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

.app-card.coming-soon {
    opacity: 0.7;
}

.btn.disabled {
    cursor: not-allowed;
    background-color: #ccc;
    pointer-events: none;
}

/* Optional hover effect for app cards */
.app-card:not(.coming-soon):hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

main {
    flex: 1;
}