* { margin: 0; padding: 0; box-sizing: border-box; }
        body { background: #ffffff; font-family: system-ui, 'Segoe UI', 'Noto Sans', sans-serif; color: #1a6b3b; min-height: 100vh; display: flex; flex-direction: column; }
        button, input, textarea, .card, .message-item, .loading-bar-container, .invite-box, .online-users-panel, .nickname-panel { border-radius: 0px !important; }
        .app-wrapper { display: flex; flex-direction: column; min-height: 100vh; }
        .app-header { background: white; border-bottom: 1px solid #d4e9dd; padding: 12px 24px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; position: relative; }
        .offline-banner { position: absolute; top: 100%; left: 0; right: 0; background: #dc3545; color: white; text-align: center; padding: 4px; font-size: 0.75rem; display: none; z-index: 100; }
        .offline-banner.show { display: block; }
        .logo-area h1 { font-size: 1.5rem; font-weight: 600; color: #1a6b3b; }
        .logo-area p { font-size: 0.7rem; color: #2e7d32; margin-top: 4px; }
        .lang-selector { display: flex; gap: 8px; }
        .lang-btn { background: transparent; border: 1px solid #c8e6df; padding: 4px 10px; font-size: 0.75rem; font-weight: 500; color: #1a6b3b; cursor: pointer; transition: all 0.2s; }
        .lang-btn.active { background: #1a6b3b; color: white; border-color: #1a6b3b; }
        .lang-btn:hover:not(.active) { background: #e0f2e9; }
        .btn { background: white; border: 1px solid #c8e6df; padding: 6px 16px; font-size: 0.85rem; font-weight: 500; color: #1a6b3b; cursor: pointer; transition: background 0.2s; }
        .btn:hover { background: #e0f2e9; border-color: #2e7d32; }
        .btn-primary { border-color: #1a6b3b; background: #f0f8f2; }
        .btn-sm { padding: 4px 12px; font-size: 0.75rem; }
        .loading-area { width: 100%; padding: 0 24px; margin-top: 6px; height: 6px; }
        .loading-bar-container { width: 100%; background: #e0f2e9; height: 6px; overflow: hidden; display: none; }
        .loading-bar-container.active { display: block; }
        .loading-slider { width: 20%; height: 100%; background: #1a8c4a; animation: slideMove 0.7s ease-in-out infinite; }
        @keyframes slideMove { 0% { transform: translateX(0%); } 50% { transform: translateX(400%); } 100% { transform: translateX(0%); } }
        .main-content { flex: 1; padding: 20px 24px; display: flex; gap: 24px; }
        .chat-area { flex: 3; display: flex; flex-direction: column; }
        .room-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; flex-wrap: wrap; gap: 8px; }
        .status-badge { font-size: 0.7rem; padding: 4px 10px; background: #f9fbf9; border: 1px solid #d4e9dd; display: inline-flex; align-items: center; gap: 6px; cursor: pointer; }
        .status-badge:hover { background: #e0f2e9; }
        .invite-box { background: #f9fbf9; border: 1px solid #d4e9dd; padding: 10px 14px; margin-bottom: 12px; display: none; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; }
        .key-container { display: flex; align-items: center; gap: 8px; flex: 1; font-family: monospace; background: white; padding: 6px 8px; border: 1px solid #c8e6df; font-size: 0.7rem; word-break: break-all; }
        .key-text { flex: 1; font-family: monospace; font-size: 0.65rem; letter-spacing: 1px; font-weight: bold; word-break: break-all; }
        .key-eye { cursor: pointer; font-size: 0.9rem; padding: 0 4px; background: #e0f2e9; user-select: none; }
        .chat-container { border: 1px solid #d4e9dd; background: white; display: flex; flex-direction: column; height: 520px; position: relative; }
        .messages-area { flex: 1; overflow-y: auto; padding: 12px; display: flex; flex-direction: column; gap: 10px; background: #fefefe; }
        .message-item { border: 1px solid #e0f2e9; background: white; padding: 8px 12px; max-width: 85%; width: fit-content; }
        .message-self { align-self: flex-end; background: #f0f8f2; border-color: #c8e6df; }
        .message-meta { font-size: 0.65rem; color: #2e7d32; margin-bottom: 4px; display: flex; gap: 12px; border-bottom: 1px dotted #e0f2e9; padding-bottom: 3px; }
        .message-sender { font-weight: bold; cursor: pointer; }
        .message-body { font-size: 0.85rem; word-wrap: break-word; white-space: pre-wrap; }
        .message-body img { max-width: 200px; max-height: 150px; border: 1px solid #c8e6df; margin-top: 4px; }
        .input-area { display: flex; border-top: 1px solid #d4e9dd; padding: 10px; gap: 8px; align-items: flex-end; background: white; }
        .input-area textarea { flex: 1; padding: 10px; border: 1px solid #c8e6df; background: white; font-family: inherit; font-size: 0.85rem; resize: vertical; min-height: 60px; max-height: 120px; }
        .toolbar { display: flex; gap: 6px; align-items: center; }
        .online-sidebar { flex: 1; border: 1px solid #d4e9dd; background: white; display: flex; flex-direction: column; max-width: 260px; }
        .sidebar-header { padding: 12px; border-bottom: 1px solid #d4e9dd; font-weight: bold; background: #fefefe; }
        .users-list { flex: 1; overflow-y: auto; padding: 8px; }
        .user-item { display: flex; justify-content: space-between; align-items: center; padding: 8px 10px; border-bottom: 1px solid #e0f2e9; cursor: pointer; }
        .user-item:hover { background: #e0f2e9; }
        .user-name { font-size: 0.8rem; font-weight: 500; word-break: break-word; }
        .fingerprint-icon { font-size: 0.7rem; opacity: 0.8; margin-left: 4px; }
        .nickname-panel, .modal-dialog { background: white; border: 1px solid #1a6b3b; padding: 20px; position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); z-index: 1000; width: 380px; max-width: 90vw; box-shadow: 0 4px 20px rgba(0,0,0,0.15); }
        .nickname-panel input, .nickname-panel .file-input-wrapper, .modal-dialog input { width: 100%; padding: 10px; margin: 8px 0; border: 1px solid #c8e6df; background: white; }
        .nickname-panel .file-input-wrapper { background: #f9fbf9; cursor: pointer; text-align: center; }
        .overlay { position: fixed; top:0;left:0;width:100%;height:100%; background: rgba(0,0,0,0.3); z-index: 999; }
        .app-footer { background: white; border-top: 1px solid #d4e9dd; padding: 14px; text-align: center; font-size: 0.7rem; color: #9bc4a5; }
        .identity-row { display: flex; gap: 8px; flex-wrap: wrap; }
        .fingerprint-dialog { background: white; border: 1px solid #1a6b3b; padding: 20px; position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); z-index: 1000; width: 400px; max-width: 90vw; }
        .fingerprint-dialog .full-hash { font-family: monospace; word-break: break-all; background: #f9fbf9; padding: 12px; margin: 16px 0; border: 1px solid #c8e6df; font-size: 0.7rem; white-space: normal; word-wrap: break-word; }
        .fingerprint-dialog .dialog-buttons { display: flex; gap: 12px; justify-content: flex-end; margin-top: 16px; }
        .history-warning { background: #fff3cd; border: 1px solid #ffecb5; padding: 8px 12px; margin-bottom: 12px; font-size: 0.7rem; color: #856404; display: none; }
        .clear-file-btn { background: #dc3545; color: white; border: none; padding: 4px 8px; font-size: 0.7rem; cursor: pointer; margin-left: 8px; border-radius: 0px; }
        .clear-file-btn:hover { background: #c82333; }
        @media (max-width: 768px) { .online-sidebar { display: none; } .main-content { padding: 16px; } .chat-container { height: calc(100vh - 280px); min-height: 400px; } }
        .loading-text { display: inline-block; margin-left: 8px; font-size: 0.7rem; color: #1a6b3b; }
        .load-more-trigger { text-align: center; padding: 8px; color: #9bc4a5; font-size: 0.7rem; cursor: pointer; }
        .load-more-trigger:hover { background: #e0f2e9; }
        .modal-buttons { display: flex; gap: 12px; margin-top: 16px; justify-content: flex-end; }
        .modal-buttons button { flex: 1; }
        .helper-text { font-size: 0.7rem; color: #9bc4a5; }
        .dot { font-size: 0.5rem; letter-spacing: 2px; }
        .message-sender-name { cursor: pointer; }
        .message-sender-name:hover { text-decoration: underline; }
        .full-hash { word-break: break-all; white-space: normal; overflow-wrap: break-word; max-width: 100%; }
        .message-sender { cursor: pointer; }
        .message-sender:hover { text-decoration: underline; }
        .key-text { word-break: break-all; }
        .modal-dialog .full-hash { max-height: 200px; overflow-y: auto; }