body {
    background-color: #212121; /* Nội dung chính */
    color: #e0e0e0;
    font-family: 'Inter', sans-serif;
}

/* Ẩn scrollbar nhưng vẫn scroll được */
.hide-scrollbar::-webkit-scrollbar { display: none; }
.hide-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }

/* Tab Style */
.tab-btn { color: #666; }
.tab-btn.active {
    background-color: #212121;
    color: #fff;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

/* Sidebar Titles */
.sidebar-item {
    color: #888;
    cursor: pointer;
    transition: all 0.3s;
    position: relative;
}
.sidebar-item:hover, .sidebar-item.active {
    color: #fff;
}

/* Grid so sánh 3 nền tảng */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 2rem;
}
.platform-card {
    background: #171717;
    padding: 1.5rem;
    border-radius: 1.5rem;
    font-size: 0.9rem;
    line-height: 1.6;
}
.platform-card h4 {
    font-size: 0.7rem;
    font-weight: 800;
    text-transform: uppercase;
    margin-bottom: 1rem;
    letter-spacing: 0.1em;
}

/* Markdown styling */
#mainContent h1 { font-size: 2rem; font-weight: 600; margin-bottom: 2rem; }
#mainContent strong { color: #3b82f6; }

/* Định dạng nội dung bên trong các cột so sánh */
.platform-card div {
    color: #b3b3b3;
    font-size: 0.85rem;
}

.platform-card ul {
    list-style-type: none;
    padding-left: 0;
}

.platform-card li::before {
    content: "→";
    color: #3b82f6;
    margin-right: 8px;
    font-size: 10px;
}

/* Hiệu ứng xuất hiện mượt mà */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}