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

        :root {
            --font-sans: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
            --primary: #114473;
            --primary-dark: #0c3357;
            --accent: #16625d;
            --secondary: #5f7183;
            --success: #138a6b;
            --danger: #c7504a;
            --warning: #b7791f;
            --bg: #f3f7fb;
            --card: #ffffff;
            --border: #d7e2ea;
            --text: #132033;
            --text-light: #617286;
            --space-1: 0.25rem;
            --space-2: 0.5rem;
            --space-3: 0.75rem;
            --space-4: 1rem;
            --space-5: 1.25rem;
            --space-6: 1.5rem;
            --space-7: 1.75rem;
            --space-8: 2rem;
            --space-9: 2.25rem;
            --space-10: 2.5rem;
            --space-11: 2.75rem;
            --space-12: 3rem;
            --space-13: 3.25rem;
            --space-14: 3.5rem;
            --space-15: 3.75rem;
            --space-16: 4rem;
            --radius-sm: 6px;
            --radius-md: 10px;
            --radius-lg: 16px;
            --container-max: 1600px;
            --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);

            /* Dark mode variables */
            --dark-bg: #0f172a;
            --dark-card: #1e293b;
            --dark-border: #334155;
            --dark-text: #f1f5f9;
            --dark-text-light: #cbd5e1;
        }

        /* Dark mode support - TAM THOI TAT */
        /*
        @media (prefers-color-scheme: dark) {
            :root {
                --bg: var(--dark-bg);
                --card: var(--dark-card);
                --border: var(--dark-border);
                --text: var(--dark-text);
                --text-light: var(--dark-text-light);
            }
            
            body {
                background: var(--dark-bg);
                color: var(--dark-text);
            }
            
            .navbar {
                background: linear-gradient(135deg, var(--dark-card) 0%, #1e293b 100%);
                border-bottom-color: var(--dark-border);
            }
            
            .card {
                background: var(--dark-card);
                border-color: var(--dark-border);
            }
            
            .form-input,
            .form-textarea {
                background: var(--dark-card);
                border-color: var(--dark-border);
                color: var(--dark-text);
            }
            
            .modal-content {
                background: var(--dark-card);
                color: var(--dark-text);
            }
            
            .navbar-link {
                color: var(--dark-text);
            }
            
            .navbar-link:hover {
                background: rgba(17, 68, 115, 0.2);
            }
            
            .navbar-user {
                background: rgba(30, 41, 59, 0.5);
                border-color: var(--dark-border);
            }
        }
        */

        body {
            font-family: var(--font-sans);
            background: var(--bg);
            color: var(--text);
            line-height: 1.6;
        }

        .skip-link {
            position: absolute;
            left: var(--space-4);
            top: 0;
            transform: translateY(-140%);
            padding: var(--space-3) var(--space-4);
            border-radius: var(--radius-md);
            background: var(--primary);
            color: white;
            text-decoration: none;
            z-index: 1000;
            transition: transform 0.2s ease;
        }

        .skip-link:focus {
            transform: translateY(var(--space-3));
        }

        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }

        /* Accessibility - Focus States */
        *:focus-visible {
            outline: 2px solid var(--primary);
            outline-offset: 2px;
            border-radius: var(--radius-sm);
        }

        button:focus-visible,
        a:focus-visible,
        input:focus-visible,
        textarea:focus-visible,
        select:focus-visible {
            outline: 2px solid var(--primary);
            outline-offset: 2px;
        }

        /* Tooltip Styles - TAM THOI TAT */
        /*
        [data-tooltip] {
            position: relative;
            cursor: help;
        }
        
        [data-tooltip]:hover::after {
            content: attr(data-tooltip);
            position: absolute;
            bottom: 100%;
            left: 50%;
            transform: translateX(-50%);
            padding: 0.5rem 0.75rem;
            background: rgba(15, 23, 42, 0.95);
            color: white;
            border-radius: 0.5rem;
            font-size: 0.75rem;
            white-space: nowrap;
            z-index: 1000;
            margin-bottom: 0.5rem;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
            animation: tooltipFadeIn 0.2s ease-out;
            pointer-events: none;
        }
        
        [data-tooltip]:hover::before {
            content: '';
            position: absolute;
            bottom: 100%;
            left: 50%;
            transform: translateX(-50%);
            border: 5px solid transparent;
            border-top-color: rgba(15, 23, 42, 0.95);
            margin-bottom: -5px;
            z-index: 1000;
            animation: tooltipFadeIn 0.2s ease-out;
            pointer-events: none;
        }
        
        @keyframes tooltipFadeIn {
            from {
                opacity: 0;
                transform: translateX(-50%) translateY(4px);
            }
            to {
                opacity: 1;
                transform: translateX(-50%) translateY(0);
            }
        }
        */

        /* Micro-interactions */
        .btn,
        .filter-btn,
        .conversation-item,
        .label-item {
            position: relative;
            overflow: hidden;
        }

        .btn::after,
        .filter-btn::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 0;
            height: 0;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.3);
            transform: translate(-50%, -50%);
            transition: width 0.6s, height 0.6s;
        }

        .btn:active::after,
        .filter-btn:active::after {
            width: 300px;
            height: 300px;
        }

        /* Pulse animation for unread badges */
        @keyframes pulse-badge {

            0%,
            100% {
                transform: scale(1);
                box-shadow: 0 0 0 0 rgba(17, 68, 115, 0.4);
            }

            50% {
                transform: scale(1.05);
                box-shadow: 0 0 0 4px rgba(17, 68, 115, 0);
            }
        }

        .conversations-count.pulse {
            animation: pulse-badge 2s ease-in-out infinite;
        }

        /* Bounce animation for new messages */
        @keyframes message-bounce {

            0%,
            100% {
                transform: translateY(0);
            }

            25% {
                transform: translateY(-4px);
            }

            75% {
                transform: translateY(2px);
            }
        }

        .message.new-message {
            animation: message-bounce 0.5s ease-out, messageSlideIn 0.3s ease-out;
        }

        /* Improved color contrast */
        .conversation-preview {
            color: #475569;
        }

        .thread-preview {
            color: #475569;
        }

        .header-subtitle {
            color: #64748b;
        }

        .info-label {
            color: #64748b;
        }

        /* Navbar */
        .navbar {
            background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
            border-bottom: 2px solid var(--border);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            position: sticky;
            top: 0;
            z-index: 100;
            backdrop-filter: blur(10px);
        }

        .navbar-container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: var(--space-3) var(--space-8);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .navbar-brand {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--text);
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: var(--space-3);
            transition: all 0.3s ease;
            position: relative;
        }

        .navbar-brand:hover {
            transform: translateY(-2px);
        }

        .navbar-logo {
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, var(--primary) 0%, #1c5a5e 100%);
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 12px rgba(17, 68, 115, 0.3);
            transition: all 0.3s ease;
        }

        .navbar-brand:hover .navbar-logo {
            transform: rotate(-5deg) scale(1.1);
            box-shadow: 0 6px 16px rgba(17, 68, 115, 0.4);
        }

        .navbar-logo svg {
            width: 24px;
            height: 24px;
            fill: white;
        }

        .navbar-brand-text {
            display: flex;
            flex-direction: column;
            gap: 0.125rem;
        }

        .navbar-brand-title {
            font-size: 1rem;
            font-weight: 700;
            background: linear-gradient(135deg, var(--primary) 0%, #1c5a5e 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .navbar-brand-subtitle {
            font-size: 0.75rem;
            color: var(--text-light);
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .navbar-nav {
            display: flex;
            gap: var(--space-2);
            align-items: center;
        }

        .navbar-link {
            color: var(--text);
            text-decoration: none;
            padding: 0.625rem var(--space-4);
            border-radius: var(--radius-md);
            transition: all 0.3s ease;
            font-weight: 500;
            font-size: 0.9rem;
            position: relative;
            overflow: hidden;
        }

        .nav-icon {
            display: inline-flex;
            width: 1rem;
            height: 1rem;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .nav-icon svg {
            width: 100%;
            height: 100%;
            fill: currentColor;
        }

        .navbar-link::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(17, 68, 115, 0.1), transparent);
            transition: left 0.5s;
        }

        .navbar-link:hover::before {
            left: 100%;
        }

        .navbar-link:hover {
            background: linear-gradient(135deg, rgba(17, 68, 115, 0.1) 0%, rgba(28, 90, 94, 0.1) 100%);
            color: var(--primary);
            transform: translateY(-2px);
        }

        .navbar-link.active {
            background: linear-gradient(135deg, var(--primary) 0%, #1c5a5e 100%);
            color: white;
            box-shadow: 0 4px 12px rgba(17, 68, 115, 0.3);
        }

        .navbar-divider {
            width: 1px;
            height: 24px;
            background: var(--border);
            margin: 0 0.5rem;
        }

        .navbar-user {
            display: flex;
            align-items: center;
            gap: var(--space-3);
            padding: var(--space-2) var(--space-4);
            background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
            border-radius: var(--radius-md);
            border: 1px solid var(--border);
            transition: all 0.3s ease;
        }

        .navbar-user:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        }

        .navbar-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary) 0%, #1c5a5e 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 600;
            font-size: 0.875rem;
        }

        .navbar-user-info {
            display: flex;
            flex-direction: column;
            gap: 0.125rem;
        }

        .navbar-user-name {
            font-size: 0.875rem;
            font-weight: 600;
            color: var(--text);
        }

        .navbar-user-role {
            font-size: 0.75rem;
            color: var(--text-light);
        }

        .navbar-logout-form {
            margin: 0 0 0 0.5rem;
            display: inline-flex;
        }

        .navbar-logout-form .btn {
            white-space: nowrap;
        }

        /* Main content */
        .container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: var(--space-4) var(--space-8);
        }

        .page-header {
            margin-bottom: var(--space-8);
        }

        .page-title {
            font-size: 1.15rem;
            font-weight: 700;
            margin-bottom: var(--space-2);
        }

        .page-subtitle {
            color: var(--text-light);
        }

/* Utilities */
        .mt-1 {
            margin-top: var(--space-2);
        }

        .mt-2 {
            margin-top: var(--space-4);
        }

        .mt-3 {
            margin-top: var(--space-6);
        }

        .mb-1 {
            margin-bottom: var(--space-2);
        }

        .mb-2 {
            margin-bottom: var(--space-4);
        }

        .mb-3 {
            margin-bottom: var(--space-6);
        }

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

        .text-muted {
            color: var(--text-light);
        }

        .d-flex {
            display: flex;
        }

        .gap-1 {
            gap: var(--space-2);
        }

        .gap-2 {
            gap: var(--space-4);
        }

        .justify-between {
            justify-content: space-between;
        }

        .align-center {
            align-items: center;
        }

        /* Responsive */
        @media (max-width: 1024px) {
            .navbar-brand-text {
                display: none;
            }

            .navbar-link span:not(.nav-icon) {
                display: none;
            }

            .navbar-user-info {
                display: none;
            }
        }

        @media (max-width: 768px) {
            .container {
                padding: var(--space-2) var(--space-5);
            }

            .navbar-container {
                padding: 0.65rem var(--space-4);
            }

            .navbar-logo {
                width: 36px;
                height: 36px;
            }

            .navbar-logo svg {
                width: 20px;
                height: 20px;
            }

            .navbar-nav {
                gap: 0.25rem;
                flex-wrap: wrap;
            }

            .navbar-link {
                padding: var(--space-2) var(--space-3);
                font-size: 0.85rem;
            }

            .navbar-avatar {
                width: 28px;
                height: 28px;
                font-size: 0.75rem;
            }

            .navbar-user {
                padding: 0.375rem var(--space-3);
            }

            .navbar-divider {
                display: none;
            }
        }

        /* Shared polish pass */
        body {
            min-height: 100vh;
            background:
                radial-gradient(circle at top, rgba(255, 255, 255, 0.95) 0%, rgba(248, 250, 252, 0.96) 34%, #eef4fb 100%);
        }

        main {
            padding-bottom: var(--space-6);
        }

        .navbar {
            border-bottom: 1px solid rgba(226, 232, 240, 0.9);
            box-shadow: 0 12px 30px rgba(15, 23, 42, 0.07);
        }

        .navbar-container {
            gap: 1rem;
            padding: 0.85rem 1.5rem;
        }

        .navbar-nav {
            gap: 0.35rem;
            justify-content: flex-end;
            flex-wrap: wrap;
        }

        .navbar-link {
            display: inline-flex;
            align-items: center;
            gap: 0.55rem;
            padding: 0.58rem 0.9rem;
            border: 1px solid transparent;
            font-size: 0.92rem;
        }

        .navbar-link:hover {
            transform: translateY(-1px);
            border-color: rgba(17, 68, 115, 0.14);
            box-shadow: 0 8px 18px rgba(17, 68, 115, 0.08);
        }

        .navbar-link.active {
            box-shadow: 0 10px 22px rgba(17, 68, 115, 0.22);
        }

        .navbar-divider {
            margin: 0 0.65rem;
            height: 30px;
        }

        .navbar-user {
            gap: 0.7rem;
            padding: 0.45rem 0.8rem;
            box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7);
        }

        .navbar .btn {
            padding: 0.82rem 1.15rem;
            border-radius: 0.95rem;
            font-size: 0.88rem;
        }

        .container {
            padding-top: 1rem;
            padding-bottom: 1.25rem;
        }

        @media (max-width: 1024px) {
            .navbar-container {
                padding: 0.75rem 1rem;
            }

            .navbar-nav {
                gap: 0.3rem;
            }

            .navbar-link {
                padding: 0.5rem 0.75rem;
            }

            .navbar .btn {
                padding: 0.75rem 0.95rem;
            }
        }

        /* Brand refresh */
        body {
            background:
                radial-gradient(circle at top left, rgba(17, 68, 115, 0.05), transparent 28%),
                linear-gradient(180deg, #f7fafc 0%, #f3f7fb 100%);
        }

        .btn {
            border-radius: 0.9rem;
            font-weight: 700;
            letter-spacing: 0.01em;
        }

        .btn::before,
        .btn::after {
            display: none;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            box-shadow: 0 10px 20px rgba(17, 68, 115, 0.18);
        }

        .btn-primary:hover {
            background: linear-gradient(135deg, var(--primary-dark) 0%, #082640 100%);
            box-shadow: 0 14px 28px rgba(17, 68, 115, 0.2);
        }

        .btn-secondary {
            background: #ffffff;
            color: var(--primary-dark);
            border: 1px solid rgba(17, 68, 115, 0.14);
            box-shadow: 0 8px 18px rgba(15, 23, 42, 0.04);
        }

        .btn-secondary:hover {
            background: #f8fbfe;
            color: var(--primary-dark);
            border-color: rgba(17, 68, 115, 0.2);
            box-shadow: 0 12px 24px rgba(15, 23, 42, 0.06);
        }

        .navbar {
            background: rgba(255, 255, 255, 0.88);
            border-bottom: 1px solid rgba(215, 226, 234, 0.95);
            box-shadow: 0 14px 32px rgba(15, 23, 42, 0.06);
            backdrop-filter: blur(14px);
        }

        .navbar-logo {
            background: linear-gradient(145deg, #102845 0%, #17395f 65%, #1c5a5e 100%);
            box-shadow: 0 10px 22px rgba(15, 23, 42, 0.16);
        }

        .navbar-brand:hover {
            transform: none;
        }

        .navbar-brand:hover .navbar-logo {
            transform: none;
            box-shadow: 0 12px 24px rgba(15, 23, 42, 0.18);
        }

        .navbar-brand-title {
            background: none;
            -webkit-text-fill-color: initial;
            color: var(--text);
        }

        .navbar-brand-subtitle {
            color: var(--text-light);
        }

        .navbar-link {
            border: 1px solid transparent;
            border-radius: 999px;
            font-weight: 600;
        }

        .navbar-link::before {
            display: none;
        }

        .navbar-link:hover {
            transform: none;
            color: var(--primary-dark);
            background: rgba(17, 68, 115, 0.06);
            border-color: rgba(17, 68, 115, 0.08);
            box-shadow: none;
        }

        .navbar-link.active {
            background: rgba(17, 68, 115, 0.1);
            color: var(--primary-dark);
            border-color: rgba(17, 68, 115, 0.12);
            box-shadow: none;
        }

        .navbar-user {
            background: rgba(248, 251, 254, 0.92);
            border-color: rgba(19, 32, 51, 0.08);
            box-shadow: none;
        }

        .navbar-user:hover {
            transform: none;
            box-shadow: none;
        }

        .navbar-avatar {
            background: linear-gradient(145deg, var(--primary) 0%, var(--accent) 100%);
        }