/* Modern Formules Page Styles */
.formules-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

.formules-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.formules-header h1 {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.formules-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Collapsible Sections */
.collapsible-section {
    margin-bottom: var(--spacing-lg);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.collapsible-section:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-card));
    border: none;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.section-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left var(--transition-slow);
}

.section-header:hover::before {
    left: 100%;
}

.section-header:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
}

.section-header h2 {
    margin: 0;
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 600;
    transition: color var(--transition-normal);
}

.section-header:hover h2 {
    color: white;
}

.toggle-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.toggle-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

.toggle-btn svg {
    width: 24px;
    height: 24px;
    transition: transform var(--transition-normal);
}

.toggle-btn.collapsed svg {
    transform: rotate(180deg);
}

.section-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow) ease-out;
}

.section-content.expanded {
    max-height: 10000px;
}

.content-wrapper {
    padding: var(--spacing-xl);
}

.formule-page {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.formule-page:hover {
    box-shadow: var(--shadow-lg);
}

.formule-page p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-lg);
}

.formula-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    justify-items: center;
}

.formula-item {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    text-align: center;
    width: 100%;
}

.formula-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.formula-item img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    background: white;
    padding: var(--spacing-sm);
}

.formula-text {
    margin: var(--spacing-lg) 0;
    line-height: 1.7;
}

.formula-text h6 {
    color: var(--primary-color);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
    font-weight: 600;
}

.key-points {
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-card));
    border-left: 4px solid var(--primary-color);
    padding: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.key-points::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.key-points ul {
    margin: var(--spacing-md) 0;
    padding-left: var(--spacing-xl);
}

.key-points li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    line-height: 1.6;
}

.key-points li strong {
    color: var(--text-primary);
}

/* Inline formula images */
.formule-page img:not(.formula-item img) {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    background: white;
    padding: var(--spacing-sm);
    margin: var(--spacing-md) 0;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

/* Responsive Design */
@media (max-width: 768px) {
    .formules-container {
        padding: var(--spacing-md);
    }
    
    .formules-header h1 {
        font-size: 2rem;
    }
    
    .section-header {
        padding: var(--spacing-lg);
    }
    
    .section-header h2 {
        font-size: 1.25rem;
    }
    
    .content-wrapper {
        padding: var(--spacing-lg);
    }
    
    .formule-page {
        padding: var(--spacing-lg);
    }
    
    .formula-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .key-points {
        padding: var(--spacing-lg);
    }
}

/* Animation for section expansion */
@keyframes expandSection {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-content.expanded .content-wrapper {
    animation: expandSection 0.3s ease-out;
}

/* Special styling for mathematical content */
.formula-text p {
    text-align: justify;
}

.formula-text ul {
    margin: var(--spacing-md) 0;
    padding-left: var(--spacing-xl);
}

.formula-text li {
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

.formula-text li strong {
    color: var(--text-primary);
}