.article-h1 {
    color: #1eaffd;
    border-left: 6px solid #1976d2;
    padding-left: 1rem;
    margin-bottom: 1rem;
}
.article-h2 {
    color: #51c6fc;
    margin-top: 1.8rem;
    margin-bottom: 1rem;
    border-bottom: 2px solid #c4e8fb;
    padding-bottom: 0.3rem;
}
.article-h3 {
    color: #3eacff;
    margin-top: 1.2rem;
    margin-bottom: 0.5rem;
}
.article-meta {
    background: #e8f5e9;
    padding: 0.8rem 1.2rem;
    border-radius: 12px;
    margin: 1rem 0 1.5rem;
    font-size: 0.85rem;
    color: #2e5c2e;
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
}
.info-box {
    background: #d0ecfb;
    padding: 1rem 1.2rem;
    border-radius: 12px;
    margin: 1.2rem 0;
    border-left: 5px solid #1976d2;
}
.example-box {
    background: #fff8e1;
    padding: 1rem 1.2rem;
    border-radius: 12px;
    margin: 1.2rem 0;
    border-left: 5px solid #ffa000;
}
.warning-box {
    background: #ffebee;
    padding: 1rem 1.2rem;
    border-radius: 12px;
    margin: 1.2rem 0;
    border-left: 5px solid #e53935;
}
.formula {
    background: #f5f5f5;
    padding: 0.8rem 1.2rem;
    border-radius: 8px;
    font-family: monospace;
    font-size: 1.1rem;
    text-align: center;
    margin: 1rem 0;
}
.practice-questions {
    background: #f9fbe7;
    padding: 1.2rem;
    border-radius: 12px;
    margin: 1.5rem 0;
}
.answers {
    background: #e0f2f1;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
}
.btn {
    display: inline-block;
    background: #2e7d32;
    color: white;
    padding: 8px 20px;
    border-radius: 40px;
    text-decoration: none;
    font-weight: 500;
    margin-top: 0.5rem;
}
.article-hr {
    margin: 2rem 0;
    border: none;
    border-top: 1px solid #d4e2ce;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}
th, td {
    border: 1px solid #d4e2ce;
    padding: 8px 12px;
    text-align: left;
}
th {
    background: #e8f5e9;
}