/* Mobile First Design */
@media screen and (max-width: 480px) {
    .app-container {
        padding: 0.5rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    nav {
        flex-direction: column;
        gap: 0.5rem;
    }

    .card {
        height: 250px;
    }

    .button-container button {
        padding: 0.6rem 1.2rem;
    }
}

/* Tablet */
@media screen and (min-width: 481px) and (max-width: 768px) {
    .app-container {
        padding: 0.75rem;
    }

    .card {
        height: 275px;
    }
}

/* Desktop */
@media screen and (min-width: 769px) {
    .app-container {
        max-width: 1200px;
        padding: 2rem;
    }

    .deck-list {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

/* Landscape Mode */
@media screen and (orientation: landscape) and (max-height: 500px) {
    .card {
        height: 200px;
    }

    .button-container {
        flex-direction: row;
        justify-content: center;
    }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #121212;
        --text-color: #ffffff;
    }

    .card-front, .card-back, .deck-card, #preview {
        background-color: #1e1e1e;
        color: var(--text-color);
    }

    .file-input-area {
        border-color: var(--primary-color);
    }
}