:root {
    --primary: #0366d6;
    --secondary: #6c757d;
    --success: #28a745;
    --info: #17a2b8;
    --warning: #ffc107;
    --danger: #dc3545;
    --light: #f8f9fa;
    --dark: #343a40;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    color: #333;
    background-color: #f7f9fc;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: linear-gradient(135deg, #0366d6, #17a2b8);
    color: white;
    padding: 2rem 0;
    text-align: center;
    border-bottom: 5px solid #0366d6;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

h2 {
    font-size: 1.8rem;
    margin-top: 0;
    color: #0366d6;
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.4rem;
    color: #0366d6;
}

h4 {
    font-size: 1.2rem;
    color: #17a2b8;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

.lead {
    font-size: 1.2rem;
    font-weight: 300;
}

.card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
    overflow: hidden;
}

.card-header {
    background-color: #f1f8ff;
    padding: 1rem;
    border-bottom: 1px solid #e1e4e8;
}

.card-body {
    padding: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: inline-block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

input[type="range"] {
    display: block;
    width: 100%;
    margin-top: 0.5rem;
}

.btn {
    display: inline-block;
    font-weight: 400;
    text-align: center;
    vertical-align: middle;
    user-select: none;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.25rem;
    transition: all 0.15s ease-in-out;
    cursor: pointer;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

.btn-primary {
    color: #fff;
    background-color: var(--primary);
    border: 1px solid var(--primary);
}

.btn-primary:hover {
    background-color: #0353a8;
}

#video-container {
    width: 100%;
    margin-bottom: 1rem;
}

#simulation-video {
    width: 100%;
    max-height: 500px;
    border-radius: 4px;
}

.tags {
    margin-top: 1rem;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    line-height: 1;
    color: #fff;
    text-align: center;
    white-space: nowrap;
    vertical-align: baseline;
    border-radius: 0.25rem;
    margin-right: 0.5rem;
}

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

.tag.chemistry {
    background-color: var(--success);
}

.tag.computation {
    background-color: var(--warning);
    color: #212529;
}

footer {
    background-color: #f1f8ff;
    padding: 2rem 0;
    text-align: center;
    margin-top: 2rem;
    border-top: 1px solid #e1e4e8;
}

#loading-indicator {
    text-align: center;
    padding: 20px;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #0366d6;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 2s linear infinite;
    margin: 0 auto 15px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.hidden {
    display: none;
}

#status-message {
    margin: 10px 0;
    padding: 10px;
    border-radius: 4px;
}

.success {
    background-color: #d4edda;
    color: #155724;
}

.error {
    background-color: #f8d7da;
    color: #721c24;
}

.info {
    background-color: #d1ecf1;
    color: #0c5460;
}

/* New styles for equation boxes */
.equation-box {
    background-color: #f8f9fa;
    border-left: 4px solid #0366d6;
    padding: 1rem;
    margin: 1rem 0;
    overflow-x: auto;
}

.equation-box h4 {
    margin-top: 0;
    color: #0366d6;
}

/* Make equations slightly larger and centered */
.equation-box .MathJax {
    font-size: 110%;
    margin: 0.5rem 0;
}

/* Additional styles for better responsive behavior */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .equation-box {
        padding: 0.75rem;
    }
}