* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow-x: hidden;
        }

        .lightBackground {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(20px);
            border: 1px solid rgba(255, 255, 255, 0.2);
            width: min(600px, 95vw);
            height: 80vh;
            border-radius: 20px;
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.2);
            animation: slideIn 0.8s ease-out;
            position: relative;
            overflow: hidden;
        }

        .messageBackground {
            background: rgba(255, 255, 255, 0.95);
            width: calc(100% - 30px);
            margin: 15px auto;
            height: calc(100% - 30px);
            border-radius: 15px;
            display: flex;
            flex-direction: column;
            overflow: hidden;
            box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.1);
        }

        .heading {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 25px;
            background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
            color: white;
            position: relative;
        }

        .heading::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
        }

        .heading h3 {
            font-size: 1.5em;
            font-weight: 600;
            animation: fadeInLeft 0.6s ease-out 0.2s both;
        }

        .close-btn {
            cursor: pointer;
            padding: 8px;
            border-radius: 50%;
            transition: all 0.3s ease;
            animation: fadeInRight 0.6s ease-out 0.4s both;
        }

        .close-btn:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: rotate(90deg);
        }

        .searchBar {
            display: flex;
            align-items: center;
            margin: 25px;
            position: relative;
            animation: fadeInUp 0.6s ease-out 0.6s both;
        }

        .searchBar label {
            position: absolute;
            left: 15px;
            z-index: 2;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .searchBar label svg {
            fill: #666;
            transition: all 0.3s ease;
        }

        .searchBar input {
            width: 100%;
            padding: 15px 15px 15px 55px;
            border: 2px solid #e0e0e0;
            border-radius: 25px;
            font-size: 16px;
            outline: none;
            transition: all 0.3s ease;
            background: rgba(255, 255, 255, 0.9);
        }

        .searchBar input:focus {
            border-color: #4facfe;
            box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.1);
            transform: translateY(-2px);
        }

        .searchBar input:focus + label svg,
        .searchBar:hover label svg {
            fill: #4facfe;
            transform: scale(1.1);
        }

        .contacts {
            flex: 1;
            padding: 0 25px;
            overflow-y: auto;
            animation: fadeInUp 0.6s ease-out 0.8s both;
        }

        .contacts h4 {
            color: #333;
            margin-bottom: 20px;
            font-size: 1.1em;
            font-weight: 600;
        }

        .contact-item {
            display: flex;
            align-items: center;
            padding: 15px 20px;
            margin-bottom: 10px;
            border-radius: 15px;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 2px solid transparent;
            position: relative;
            overflow: hidden;
            animation: slideInContact 0.5s ease-out both;
        }

        .contact-item:nth-child(2) { animation-delay: 0.9s; }
        .contact-item:nth-child(3) { animation-delay: 1.0s; }
        .contact-item:nth-child(4) { animation-delay: 1.1s; }
        .contact-item:nth-child(5) { animation-delay: 1.2s; }
        .contact-item:nth-child(6) { animation-delay: 1.3s; }

        .contact-item::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(79, 172, 254, 0.1), transparent);
            transition: left 0.5s ease;
        }

        .contact-item:hover {
            background: linear-gradient(135deg, rgba(79, 172, 254, 0.1), rgba(0, 242, 254, 0.1));
            transform: translateX(10px);
            border-color: rgba(79, 172, 254, 0.3);
            box-shadow: 0 5px 15px rgba(79, 172, 254, 0.2);
        }

        .contact-item:hover::before {
            left: 100%;
        }

        .contact-item.selected {
            background: linear-gradient(135deg, #4facfe, #00f2fe);
            color: white;
            transform: translateX(15px);
            box-shadow: 0 8px 25px rgba(79, 172, 254, 0.4);
        }

        .contact-item.selected .name p {
            color: white;
        }

        .avatar {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: linear-gradient(135deg, #667eea, #764ba2);
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
            font-size: 1.2em;
            margin-right: 15px;
            position: relative;
            overflow: hidden;
        }

        .avatar::after {
            content: '';
            position: absolute;
            width: 12px;
            height: 12px;
            background: #4ade80;
            border: 2px solid white;
            border-radius: 50%;
            bottom: 2px;
            right: 2px;
            animation: pulse 2s infinite;
        }

        .name {
            flex: 1;
        }

        .name p:first-child {
            font-weight: 600;
            color: #333;
            margin-bottom: 2px;
        }

        .name p:last-child {
            color: #666;
            font-size: 0.9em;
        }

        .checkbox-wrapper {
            position: relative;
        }

        .checkbox-wrapper input[type="checkbox"] {
            width: 20px;
            height: 20px;
            cursor: pointer;
            opacity: 0;
            position: relative;
            z-index: 2;
        }

        .checkbox-wrapper::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 20px;
            height: 20px;
            border: 2px solid #ccc;
            border-radius: 4px;
            background: white;
            transition: all 0.3s ease;
        }

        .checkbox-wrapper input[type="checkbox"]:checked + ::before,
        .contact-item.selected .checkbox-wrapper::before {
            background: #4facfe;
            border-color: #4facfe;
        }

        .checkbox-wrapper::after {
            content: '✓';
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%) scale(0);
            color: white;
            font-weight: bold;
            transition: transform 0.2s ease;
        }

        .checkbox-wrapper input[type="checkbox"]:checked ~ ::after,
        .contact-item.selected .checkbox-wrapper::after {
            transform: translate(-50%, -50%) scale(1);
        }

        .action-buttons {
            padding: 20px 25px;
            display: flex;
            gap: 15px;
            background: rgba(247, 250, 252, 0.8);
            border-top: 1px solid rgba(0, 0, 0, 0.1);
        }

        .btn {
            flex: 1;
            padding: 12px 20px;
            border: none;
            border-radius: 25px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 14px;
        }

        .btn-primary {
            background: linear-gradient(135deg, #4facfe, #00f2fe);
            color: white;
            box-shadow: 0 4px 15px rgba(79, 172, 254, 0.3);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(79, 172, 254, 0.4);
        }

        .btn-secondary {
            background: rgba(255, 255, 255, 0.8);
            color: #666;
            border: 1px solid #e0e0e0;
        }

        .btn-secondary:hover {
            background: white;
            transform: translateY(-2px);
        }

        .selected-count {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background: linear-gradient(135deg, #4facfe, #00f2fe);
            color: white;
            padding: 12px 20px;
            border-radius: 25px;
            font-weight: 600;
            box-shadow: 0 8px 25px rgba(79, 172, 254, 0.4);
            transform: translateY(100px);
            transition: transform 0.3s ease;
            z-index: 1000;
        }

        .selected-count.show {
            transform: translateY(0);
        }

        /* Animations */
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(50px) scale(0.9);
            }
            to {
                opacity: 1;
                transform: translateY(0) scale(1);
            }
        }

        @keyframes fadeInLeft {
            from {
                opacity: 0;
                transform: translateX(-30px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        @keyframes fadeInRight {
            from {
                opacity: 0;
                transform: translateX(30px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes slideInContact {
            from {
                opacity: 0;
                transform: translateX(-50px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        @keyframes pulse {
            0%, 100% {
                transform: scale(1);
                opacity: 1;
            }
            50% {
                transform: scale(1.2);
                opacity: 0.7;
            }
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            .lightBackground {
                width: 95vw;
                height: 90vh;
            }
            
            .heading {
                padding: 15px 20px;
            }
            
            .searchBar {
                margin: 20px;
            }
            
            .contacts {
                padding: 0 20px;
            }
            
            .contact-item {
                padding: 12px 15px;
            }
            
            .action-buttons {
                padding: 15px 20px;
            }
        }