:root {
    --primary: #003399;
    --secondary: #ffcc00;
    --bg-color: #f4f7f6;
    --text-color: #333;
}

body {
    background-color: var(--bg-color);
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    color: var(--text-color);
    overflow-x: hidden;
}

.navbar-custom {
    background-color: var(--primary);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.navbar-brand, .nav-link {
    color: white !important;
    font-weight: 500;
    transition: opacity 0.3s;
}

.nav-link:hover {
    opacity: 0.8;
}

.btn-custom {
    background-color: var(--secondary);
    color: #000;
    font-weight: bold;
    border: none;
    transition: transform 0.2s;
}

.btn-custom:hover {
    transform: scale(1.05);
    background-color: #e6b800;
}

.fade-in {
    animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.card-custom {
    border: none;
    border-radius: 12px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.05);
    background: white;
    transition: transform 0.3s, box-shadow 0.3s;
    margin-bottom: 20px;
}

.card-custom:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.topic-item {
    cursor: pointer;
    padding: 15px;
    border-bottom: 1px solid #eee;
    transition: background 0.2s;
}

.topic-item:hover {
    background-color: #f8f9fa;
    padding-left: 20px;
}

.footer-custom {
    background-color: #fff;
    border-top: 1px solid #eee;
    padding: 20px 0;
    margin-top: 40px;
    font-size: 0.9rem;
    color: #666;
}

.loader {
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

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

.app-icon {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 10px;
}