/* Physics Subject - Color Variables */
:root {
    --physics-primary: #0077B6;
    --physics-secondary: #00B4D8;
    --physics-accent: #90E0EF;
    --physics-light: #E6F7FF;
    --physics-dark: #023E8A;
}

/* Hero Section Styling */
.subject-hero {
    background: linear-gradient(135deg, var(--physics-light) 0%, rgba(230, 247, 255, 0.8) 100%);
    padding: var(--spacing-xxl) 0;
}

.subject-hero-content h1 {
    color: var(--physics-dark);
}

.subject-hero-content .gradient-text {
    background: linear-gradient(90deg, var(--physics-primary), var(--physics-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subject-description {
    color: var(--text-light);
    max-width: 600px;
    margin-bottom: var(--spacing-lg);
}

.section-header .gradient-text {
    background: linear-gradient(90deg, var(--physics-primary), var(--physics-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* Topics Section Styling */
.topic-card {
    transition: all 0.3s ease;
}

.topic-card:hover {
    border-color: var(--physics-secondary);
}

.topic-icon {
    background-color: rgba(0, 119, 182, 0.1);
}

/* AI Assistant Section */
.ai-assistant-section {
    background-color: var(--bg-color);
    padding: var(--spacing-xxl) 0;
}

.chat-header {
    background-color: var(--physics-primary);
}

/* Simulator Section */
.simulator-section {
    padding: var(--spacing-xxl) 0;
}

.simulator-container {
    background-color: var(--bg-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.simulator-controls {
    margin-bottom: var(--spacing-lg);
}

.simulation-display {
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--bg-dark);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
}

/* Formula Section */
.formula-section {
    padding: var(--spacing-xxl) 0;
}

.formula-container {
    margin-bottom: var(--spacing-xl);
}

.formula-category {
    display: none;
}

.formula-category.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

.formula-category h3 {
    margin-bottom: var(--spacing-lg);
    color: var(--physics-dark);
}

.formula-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.formula-card {
    background-color: white;
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.formula-card h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--physics-primary);
}

.formula-notation {
    background-color: var(--physics-light);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-sm);
    display: flex;
    justify-content: center;
    align-items: center;
}

.formula-description {
    font-size: 0.9rem;
    color: var(--text-light);
}

.formula-selector {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    justify-content: center;
}

.formula-category-btn {
    padding: 0.5rem 1rem;
    background-color: var(--bg-color);
    border: 1px solid var(--bg-dark);
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
}

.formula-category-btn.active {
    background-color: var(--physics-primary);
    color: white;
    border-color: var(--physics-primary);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Custom button styles */
.btn-primary {
    background-color: var(--physics-primary);
    border-color: var(--physics-primary);
}

.btn-primary:hover {
    background-color: var(--physics-dark);
    border-color: var(--physics-dark);
}

/* Quiz section customization */
.quiz-section .btn-primary {
    background-color: var(--physics-primary);
    border-color: var(--physics-primary);
}

.quiz-option.selected {
    background-color: var(--physics-secondary);
    border-color: var(--physics-secondary);
}

/* Testing Section Styling */
.testing-section {
    padding: 3rem 0;
    background: linear-gradient(135deg, #E6F7FF 0%, rgba(230, 247, 255, 0.5) 100%);
    position: relative;
    overflow: hidden;
}

.testing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.testing-card {
    background: white;
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(0, 119, 182, 0.1);
}

.testing-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #0077B6, #00B4D8);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.testing-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 119, 182, 0.15);
}

.testing-card:hover::before {
    transform: scaleX(1);
}

.testing-card-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    background: linear-gradient(135deg, #0077B6, #00B4D8);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.testing-card-icon i {
    font-size: 2.5rem;
    color: white;
}

.testing-card-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: #023E8A;
    margin-bottom: 1rem;
}

.testing-card-description {
    font-size: 1rem;
    color: #666666;
    line-height: 1.6;
    margin-bottom: 2rem;
}

.testing-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: rgba(0, 119, 182, 0.05);
    border-radius: 10px;
    transition: all 0.3s ease;
}

.feature-item:hover {
    background: rgba(0, 119, 182, 0.1);
    transform: translateY(-2px);
}

.feature-item i {
    font-size: 1.2rem;
    color: #0077B6;
    width: 20px;
    text-align: center;
}

.feature-item span {
    font-weight: 600;
    color: #333333;
    font-size: 0.9rem;
}

.testing-cta {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid rgba(0, 119, 182, 0.1);
}

.cta-text {
    background: linear-gradient(135deg, #0077B6, #00B4D8);
    color: white;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    transition: all 0.3s ease;
    margin-bottom: 0.75rem;
}

.cta-text:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 119, 182, 0.3);
}

.cta-text i {
    font-size: 1rem;
}

.cta-description {
    color: #666666;
    font-size: 0.9rem;
    margin: 0;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .formula-selector {
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: var(--spacing-sm);
    }
    
    .formula-list {
        grid-template-columns: 1fr;
    }
    
    .simulation-display {
        min-height: 300px;
    }
    
    /* Testing section mobile styles */
    .testing-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 0 0.5rem;
    }
    
    .testing-card {
        padding: 2rem;
    }
    
    .testing-card-title {
        font-size: 1.5rem;
    }
    
    .testing-card-description {
        font-size: 0.95rem;
    }
    
    .testing-features {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .feature-item {
        padding: 0.75rem;
    }
    
    .cta-text {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
}

/* Physics visualization elements */
.particle {
    position: absolute;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--physics-secondary);
    opacity: 0.7;
    animation: float 3s infinite ease-in-out alternate;
}

.wave {
    stroke: var(--physics-primary);
    stroke-width: 2;
    fill: none;
    animation: wave 4s infinite linear;
}

@keyframes wave {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-100%);
    }
}

@keyframes float {
    0% {
        transform: translateY(0) translateX(0);
    }
    100% {
        transform: translateY(-20px) translateX(10px);
    }
}

/* Physics-specific clickable card styles */
.topic-card.clickable {
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.topic-card.clickable:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(67, 97, 238, 0.2);
    border-color: #4361ee;
}

.preview-badge {
    display: inline-block;
    background: linear-gradient(135deg, #4361ee, #7209b7);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-top: 1rem;
}