.article-hero {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 50%, #1e3a5f 100%);
    padding: 120px 20px 60px;
    text-align: center;
    margin-top: 70px;
}
body.light-mode .article-hero {
    background: linear-gradient(135deg, #f8f9fa 0%, #e3e7f1 50%, #c9d6f0 100%);
}
.article-hero h1 {
    font-size: 3.2rem;
    font-weight: 800;
    margin-bottom: 20px;
    letter-spacing: -1px;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}
.article-meta {
    display: flex;
    justify-content: center;
    gap: 20px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 20px;
}
.article-category {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
    display: inline-block;
}
.article-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 20px;
    background: var(--bg-primary);
}
.article-content h2 {
    font-size: 2.2rem;
    font-weight: 700;
    margin: 50px 0 20px;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}
.article-content h3 {
    font-size: 1.6rem;
    font-weight: 600;
    margin: 30px 0 15px;
    color: var(--text-primary);
}
.article-content p {
    font-size: 1.15rem;
    line-height: 1.9;
    margin-bottom: 25px;
    color: var(--text-secondary);
}
.article-content ul {
    margin: 20px 0;
    padding-left: 25px;
    list-style: none;
}
.article-content li {
    font-size: 1.15rem;
    line-height: 1.8;
    margin-bottom: 12px;
    color: var(--text-secondary);
    position: relative;
}
.article-content li:last-child {
    margin-bottom: 0;
}
.article-content li:before {
    content: "•";
    color: var(--accent-start);
    font-weight: bold;
    font-size: 1.2rem;
    position: absolute;
    left: -20px;
    top: 2px;
}
.article-content strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* Principles Grid */
.principles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin: 40px 0;
}
.principle-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 25px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
body.light-mode .principle-card {
    background: #ffffff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}
.principle-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}
.principle-card h3 {
    color: #667eea;
    font-size: 1.3rem;
    margin-bottom: 12px;
    font-weight: 700;
}
.principle-card p {
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 0;
    color: var(--text-secondary);
}

/* Case Study */
.case-study {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-left: 4px solid #667eea;
    border-radius: 8px;
    padding: 25px;
    margin: 30px 0;
}
body.light-mode .case-study {
    background: #f8fafc;
}
.case-study h3 {
    color: #1e40af;
    font-size: 1.4rem;
    margin-bottom: 15px;
}
.case-study p {
    font-size: 1.05rem;
    margin-bottom: 12px;
}
.case-study p:last-child {
    margin-bottom: 0;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin: 40px 0;
}
.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 30px 20px;
    text-align: center;
    transition: transform 0.2s ease;
}
body.light-mode .stat-card {
    background: #ffffff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}
.stat-card:hover {
    transform: scale(1.03);
}
.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}
.stat-label {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.stat-card p {
    font-size: 0.95rem;
    margin-bottom: 0;
    line-height: 1.5;
}

/* Exercise Table */
.exercise-table {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 30px;
    margin: 40px 0;
    overflow-x: auto;
}
.exercise-table table {
    width: 100%;
    border-collapse: collapse;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 8px;
    overflow: hidden;
}
.exercise-table th {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 15px;
    text-align: left;
    font-weight: 700;
    border-bottom: 2px solid var(--card-border);
    font-size: 1rem;
}
.exercise-table td {
    padding: 15px;
    border-bottom: 1px solid var(--card-border);
    vertical-align: top;
    font-size: 0.95rem;
    line-height: 1.6;
}
.exercise-table tr:last-child td {
    border-bottom: none;
}
.exercise-table tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.02);
}

/* Highlight Box */
.highlight-box {
    background: var(--card-bg);
    border-left: 4px solid var(--accent-start);
    padding: 25px;
    margin: 40px 0;
    border-radius: 8px;
}
body.light-mode .highlight-box {
    background: #f8f9fa;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}
.highlight-box h3 {
    color: var(--accent-start);
    margin-bottom: 15px;
}
.highlight-box p {
    margin-bottom: 0;
}

/* CTA Box */
.cta-box {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    margin: 60px 0;
}
.cta-box h3 {
    font-size: 2rem;
    margin-bottom: 15px;
    color: white;
}
.cta-box p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 25px;
    font-size: 1.1rem;
}
.cta-button {
    display: inline-block;
    background: white;
    color: #667eea;
    padding: 15px 35px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    transition: all 0.3s;
}
.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

@media (max-width: 768px) {
    .article-hero h1 {
        font-size: 2.2rem;
    }
    .article-content h2 {
        font-size: 1.8rem;
    }
    .article-content h3 {
        font-size: 1.4rem;
    }
    .article-content p {
        font-size: 1.05rem;
    }
    .article-meta {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }
    .principles-grid {
        grid-template-columns: 1fr;
    }
    .stats-grid {
        grid-template-columns: 1fr;
    }
    .stat-number {
        font-size: 2.5rem;
    }
    .case-study {
        padding: 20px;
    }
    .exercise-table {
        font-size: 0.85rem;
    }
    .exercise-table th,
    .exercise-table td {
        padding: 10px 8px;
    }
    .cta-box {
        padding: 30px 20px;
    }
    .cta-box h3 {
        font-size: 1.6rem;
    }
}