:root {
    --primary-color: #4a6fa5;
    --secondary-color: #166088;
    --accent-color: #4fc3f7;
    --background-color: #f8f9fa;
    --card-color: #ffffff;
    --text-color: #333333;
    --border-color: #e0e0e0;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
}

.card {
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border: none;
    margin-bottom: 20px;
}

.text-primary {
    color: var(--primary-color) !important;
}

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

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

.btn-secondary-custom {
    background-color: var(--border-color);
    color: var(--text-color);
    border-color: #d0d0d0;
}

.btn-secondary-custom:hover {
    background-color: #d0d0d0;
    border-color: #d0d0d0;
}

.btn-donate {
    background-color: #ffc439;
    color: #111;
    font-weight: bold;
    border-color: #e6b035;
}

.btn-donate:hover {
    background-color: #e6b035;
    border-color: #e6b035;
}

.header {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
    margin-bottom: 30px;
}

.main-content {
    background-color: var(--card-color);
    border-radius: 10px;
    padding: 25px;
}

canvas {
    border: 1px solid var(--border-color);
    border-radius: 5px;
    background-color: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    max-width: 100%;
}

.form-range::-webkit-slider-thumb {
    background: var(--primary-color);
}

.form-check-label {
    cursor: pointer;
}

.book-cover,

.sponsor-img {
    width: 120px;
    height: auto;
    border-radius: 5px;
    object-fit: cover;
}

.link-custom {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.link-custom:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Utils */

.hidden {
    display: none !important;
}

/* Mobile */
@media (max-width: 768px) {
    .slider-group {
        margin-bottom: 15px;
    }

    .radio-group-compact {
        margin-bottom: 15px;
    }

}