/* General Body & Font Styles */
body {
    font-family: 'Inter', sans-serif;
    background-color: #f3f4f6; /* bg-gray-100 */
    color: #1f2937; /* text-gray-800 */
    margin: 0;
    padding: 1rem; /* p-4 */
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 56rem; /* max-w-4xl */
    margin: 0 auto;
}

/* View Containers (Setup & Chat) */
.view-container {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem; /* rounded-lg */
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); /* shadow-xl */
}

.setup-view {
    text-align: center;
}

/* Typography */
h1 {
    font-size: 1.875rem; /* text-3xl */
    font-weight: 700; /* font-bold */
    margin-bottom: 0.5rem; /* mb-2 */
}

h2 {
    font-size: 1.25rem; /* text-xl */
    font-weight: 700; /* font-bold */
    margin-bottom: 1rem; /* mb-4 */
    padding-bottom: 0.5rem; /* pb-2 */
    border-bottom: 1px solid #e5e7eb; /* border-b */
}

p.subtitle {
    color: #4b5563; /* text-gray-600 */
    margin-bottom: 1.5rem; /* mb-6 */
}

/* Video & Canvas */
#videoContainer, #modalVideoContainer {
    position: relative;
    width: 100%;
    max-width: 500px;
    aspect-ratio: 4 / 3;
    margin: 0 auto 1rem auto; /* mb-4 */
    background-color: #111;
    border-radius: 0.5rem;
    overflow: hidden;
}

video, canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem; /* py-3 px-6 */
    font-weight: 700; /* font-bold */
    color: white;
    border: none;
    border-radius: 0.5rem; /* rounded-lg */
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}

.btn:hover {
    transform: scale(1.05);
}

.btn:disabled {
    background-color: #9ca3af; /* disabled:bg-gray-400 */
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background-color: #4f46e5; /* bg-indigo-600 */
}
.btn-primary:hover {
    background-color: #4338ca; /* hover:bg-indigo-700 */
}

.btn-secondary {
    width: 100%;
    background-color: #6b7280; /* bg-gray-500 */
    margin-top: 1rem;
}
.btn-secondary:hover {
    background-color: #4b5563;
}


#register-btn {
    width: 100%;
    max-width: 20rem; /* max-w-xs */
    background-color: #2563eb; /* bg-blue-600 */
}
#register-btn:hover {
    background-color: #1d4ed8; /* hover:bg-blue-700 */
}

/* Chat View Layout */
.chat-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem; /* gap-6 */
}

.info-panel {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.chat-panel {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    display: flex;
    flex-direction: column;
}

#my-uuid {
    font-size: 0.75rem; /* text-xs */
    background-color: #f3f4f6; /* bg-gray-100 */
    padding: 0.5rem;
    border-radius: 0.25rem;
    word-break: break-all;
    cursor: pointer;
}

#user-list {
    max-height: 24rem; /* max-h-96 */
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem; /* space-y-2 */
}

#user-list > div {
    padding: 0.5rem;
    border: 1px solid #e5e7eb;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: background-color 0.2s;
}
#user-list > div:hover {
    background-color: #f9fafb; /* hover:bg-gray-100 */
}

#chat-window {
    flex-grow: 1;
    background-color: #f9fafb; /* bg-gray-50 */
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-y: auto;
    height: 24rem; /* h-96 */
    margin-bottom: 1rem; /* mb-4 */
    border: 1px solid #e5e7eb;
    display: flex;
    flex-direction: column;
}

.chat-placeholder {
    margin: auto;
    color: #9ca3af;
}

.chat-input-area {
    display: flex;
    gap: 1rem; /* gap-4 */
}

#message-input {
    flex-grow: 1;
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
}
#message-input:focus {
    outline: none;
    box-shadow: 0 0 0 2px #60a5fa; /* focus:ring-2 focus:ring-blue-500 */
}

/* Message Bubbles */
.message {
    padding: 0.75rem;
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    max-width: 80%;
    transition: background-color 0.3s;
}
.message p {
    font-size: 0.875rem; /* text-sm */
    word-break: break-word;
    margin: 0;
}
.message.sent {
    background-color: #dbeafe; /* bg-blue-100 */
    margin-left: auto;
    align-self: flex-end;
}
.message.received {
    background-color: #e5e7eb; /* bg-gray-200 */
    margin-right: auto;
    align-self: flex-start;
}
.message.decrypted {
    background-color: #d1fae5; /* bg-green-100 */
}
.message.clickable {
    cursor: pointer;
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.75);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    z-index: 50;
}

.modal-content {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    text-align: center;
    max-width: 32rem; /* max-w-lg */
    width: 100%;
}

.modal-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}
.modal-buttons .btn-success { background-color: #16a34a; }
.modal-buttons .btn-success:hover { background-color: #15803d; }
.modal-buttons .btn-cancel { background-color: #6b7280; }
.modal-buttons .btn-cancel:hover { background-color: #4b5563; }


/* Status Message */
#status-container {
    position: fixed;
    top: 1.25rem; /* top-5 */
    right: 1.25rem; /* right-5 */
    z-index: 100;
}
#statusMessage {
    color: black;
    font-weight: 500;
    padding: 0.75rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    opacity: 0;
    transition: opacity 0.5s;
    visibility: hidden;
}
#statusMessage.visible {
    opacity: 1;
    visibility: visible;
}

/* Utility */
.hidden {
    display: none !important;
}

/* Responsive Design */
@media (min-width: 768px) { /* md: prefix */
    .chat-layout {
        grid-template-columns: repeat(3, 1fr);
    }
    .info-panel {
        grid-column: span 1 / span 1;
    }
    .chat-panel {
        grid-column: span 2 / span 2;
    }
}