* {
    box-sizing: border-box;
}

body {
    font-family: "Poppins", sans-serif;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

/* Layout */
.main-container {
    display: flex;
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
    align-items: flex-start;
    overflow: visible;
    /* IMPORTANT */
}

/* Left Content */
.content-area {
    flex: 3;
    background: #ffffff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
}

.content-area h1 {
    font-size: 42px;
    margin-bottom: 8px;
    font-weight: 400;
    line-height: 1.2;
}

.meta-info {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 30px;
}

.meta-info span {
    background-color: #e5e7eb;
    padding: 3px 12px;
    font-size: 12px;
    border-radius: 5px;
}

.article-content h2 {
    font-size: 22px;
    margin-bottom: 14px;
    font-weight: 600;
}

.article-content p {
    font-size: 14px;
    line-height: 1.6;
    color: #334155;
    margin-bottom: 16px;
}

.article-content ul {
    padding-left: 20px;
}

.article-content a {
    color: #2563eb;
    text-decoration: none;
}

.article-content ul li {
    margin-bottom: 8px;
    color: #475569;
    font-size: 14px;
}

/* Sidebar */
.sidebar {
    flex: 1;
    position: relative;
    /* IMPORTANT */
}

.sticky-content {
    position: sticky;
    top: 40px;
    background: #ffffff;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
    height: fit-content;
}

/* TOC */
.toc h3 {
    margin-top: 0;
    font-size: 18px;
    margin-bottom: 16px;
}

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

.toc li {
    padding: 10px 0;
    border-bottom: 1px solid #e5e7eb;
}

.toc a {
    text-decoration: none;
    color: #475569;
    font-size: 14.5px;
    transition: color 0.2s ease;
}

.toc a:hover {
    color: #2563eb;
}

.img-fluid {
    max-width: 100%;
    height: auto;
}

.btn_primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;

    padding: 14px 26px;
    background: #000000;
    color: #ffffff !important;

    font-family: "Poppins", sans-serif;
    font-size: 15px;
    font-weight: 600;

    border-radius: 999px;
    text-decoration: none;

    transition: all 0.25s ease;
}

/* Hover */
.btn_primary:hover {
    transform: translateY(-2px);
    background: #0d4dd6;
}

/* Active / Click */
.btn_primary:active {
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 992px) {
    .main-container {
        flex-direction: column;
    }

    .sticky-content {
        position: relative;
        top: 0;
    }
}