body {
    background-color: #f4f6f9;
    padding-top: 40px;
    font-family: 'Segoe UI', sans-serif;
    transition: background-color 0.3s, color 0.3s;
}

.dropdown-toggle {
    padding: 12px 24px;
    font-size: 1.1rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.dropdown-menu {
    border-radius: 12px;
    padding: 10px;
}

.dropdown-item {
    border-radius: 8px;
    padding: 10px 16px;
    transition: background 0.2s ease, color 0.2s ease;
    color: #0d6efd;
    background-color: transparent;
}

.dropdown-item:hover,
.dropdown-item.active {
    background-color: #0d6efd !important;
    color: #ffffff !important;
}

.iframe-container {
    margin-top: 20px;
    border-radius: 12px;
    background: #ffffff;
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    height: 70vh;
    overflow: hidden;
}

iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.welcome-message {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    padding: 40px;
    text-align: center;
    color: #343a40;
}

.welcome-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    color: #4e73df;
}

.developer-credit {
    position: absolute;
    bottom: 20px;
    right: 20px;
    font-size: 0.9em;
    color: #6c757d;
}

/* Tema oscuro */
body.dark-theme {
    background-color: #212529;
    color: #f8f9fa;
}

body.dark-theme .iframe-container {
    background: #2c3034;
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

body.dark-theme .welcome-message {
    color: #dee2e6;
}

body.dark-theme .developer-credit {
    color: #adb5bd;
}

body.dark-theme .dropdown-menu {
    background-color: #343a40;
    border-color: #444;
}

body.dark-theme .dropdown-item {
    color: #f8f9fa;
}

body.dark-theme .dropdown-item:hover,
body.dark-theme .dropdown-item.active {
    background-color: #0d6efd !important;
    color: #ffffff !important;
}