* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.card {
    background: #fff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 500px;
}

.hidden {
    display: none !important;
}

/* Formulario de Login */
#username-page h2 { margin-bottom: 10px; color: #333; }
#username-page p { font-size: 14px; color: #666; margin-bottom: 20px; }
input {
    width: 100%;
    padding: 12px;
    margin-bottom: 15px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 14px;
}
button {
    width: 100%;
    padding: 12px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    font-weight: bold;
}
button:hover { background-color: #0056b3; }

/* Contenedor del Chat */
#chat-page {
    height: 80vh;
    display: flex;
    flex-direction: column;
    padding: 0;
}
.chat-header {
    background: #007bff;
    color: white;
    padding: 15px;
    border-radius: 12px 12px 0 0;
    display: flex;
    justify-content: space-between;
}
#message-area {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
    list-style-type: none;
    background: #f9f9f9;
}
#message-area li {
    margin-bottom: 12px;
    padding: 10px 14px;
    border-radius: 8px;
    max-width: 80%;
    word-wrap: break-word;
}
/* Estilos de mensajes dinámicos */
.event-message { background: #e2e3e5; color: #383d41; text-align: center; margin: 10px auto; max-width: 100% !important; font-size: 13px; }
.chat-message { background: #fff; border: 1px solid #e0e0e0; align-self: flex-start; }
.chat-message strong { color: #007bff; display: block; margin-bottom: 4px; }

.chat-footer {
    display: flex;
    padding: 15px;
    border-top: 1px solid #eee;
}
.chat-footer input { flex-grow: 1; margin-bottom: 0; margin-right: 10px; }
.chat-footer button { width: auto; padding: 0 20px; }