body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #121212;
    color: #e0e0e0;
    background-image: linear-gradient(45deg, #1a1a1a 25%, transparent 25%),
                      linear-gradient(-45deg, #1a1a1a 25%, transparent 25%),
                      linear-gradient(45deg, transparent 75%, #1a1a1a 75%),
                      linear-gradient(-45deg, transparent 75%, #1a1a1a 75%);
    background-size: 20px 20px;
}

header {
    text-align: center;
    padding: 4rem 1rem;
    background-color: #1a1a1a;
    border-bottom: 1px solid #333;
}

h1 {
    font-size: 3rem;
    color: #4a90e2;
    margin-bottom: 0.5rem;
}

main {
    padding: 2rem 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.about, .features {
    background-color: #1e1e1e;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

h2 {
    font-size: 2rem;
    color: #4a90e2;
    border-bottom: 2px solid #4a90e2;
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

.features ul {
    list-style: none;
    padding: 0;
}

/* Style for top-level list items */
.features > ul > li {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1rem;
}

/* Add checkmark to top-level items */
.features > ul > li::before {
    content: '✓';
    color: #4a90e2;
    font-weight: bold;
    margin-right: 0.8rem;
    font-size: 1.2rem;
    flex-shrink: 0; /* Prevent checkmark from shrinking */
}

/* The parent item of the nested list needs to wrap its content */
.features > ul > li:has(ul) {
    flex-wrap: wrap;
}

/* The nested list itself */
.features ul ul {
    width: 100%; /* Make it take the full width to appear on the next line */
    margin-top: 0.5rem;
    padding-left: 2.2rem; /* Indent past the parent's checkmark */
    list-style: '— ';
}

/* The items within the nested list */
.features ul ul li {
    padding-left: 0.5rem;
    margin-bottom: 0.5rem;
}

/* Remove the checkmark from nested list items */
.features ul ul li::before {
    content: none;
}

.play-store-button {
    display: inline-block;
    margin-top: 1.5rem;
    transition: transform 0.3s ease;
}

.play-store-button:hover {
    transform: scale(1.05);
}

.play-store-button img {
    width: 200px;
    border-radius: 8px;
}

footer {
    text-align: center;
    padding: 2rem 1rem;
    background-color: #1a1a1a;
    border-top: 1px solid #333;
    font-size: 0.9rem;
}

footer a {
    color: #4a90e2;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 600px) {
    h1 {
        font-size: 2.5rem;
    }
    main {
        padding: 1rem;
    }
    .about, .features {
        padding: 1.5rem;
    }
}