:root {
            --primary: #1e3a8a;
            --primary-light: #3b82f6;
            --accent: #f59e0b;
            --bg: #f8fafc;
            --card-bg: #ffffff;
            --text: #0f172a;
            --text-muted: #64748b;
            --border: #e2e8f0;
            --danger: #ef4444;
            --success: #10b981;
            --whatsapp: #25d366;
            --font-scale: 1;
        }

        body.dark-mode {
            --bg: #0f172a;
            --card-bg: #1e293b;
            --text: #f8fafc;
            --text-muted: #94a3b8;
            --border: #334155;
        }

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

        html {
            font-size: calc(16px * var(--font-scale));
        }

        body {
            background-color: var(--bg);
            color: var(--text);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            transition: background-color 0.2s, color 0.2s;
        }

        /* Login Screen */
        #login-screen {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
        }

        .login-card {
            background: white;
            padding: 2.5rem;
            border-radius: 1rem;
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
            width: 100%;
            max-width: 400px;
            text-align: center;
            color: #0f172a;
        }

        .login-card h2 {
            color: var(--primary);
            margin-bottom: 0.5rem;
            font-size: 1.8rem;
        }

        .login-card p {
            color: #64748b;
            margin-bottom: 1.5rem;
            font-size: 0.9rem;
        }

        .form-group {
            margin-bottom: 1.25rem;
            text-align: left;
        }

        .form-group label {
            display: block;
            margin-bottom: 0.4rem;
            font-weight: 600;
            color: var(--text);
            font-size: 0.9rem;
        }

        .form-control {
            width: 100%;
            padding: 0.75rem 1rem;
            border: 1px solid var(--border);
            border-radius: 0.5rem;
            font-size: 1rem;
            outline: none;
            background: var(--card-bg);
            color: var(--text);
            transition: border-color 0.2s;
        }

        .form-control:focus {
            border-color: var(--primary-light);
        }

        .editor-box {
            min-height: 120px;
            max-height: 220px;
            overflow-y: auto;
            padding: 0.75rem 1rem;
            border: 1px solid var(--border);
            border-radius: 0.5rem;
        }

        .toolbar {
            display: flex;
            gap: 0.3rem;
            margin-bottom: 0.4rem;
            background: rgba(0,0,0,0.05);
            padding: 0.4rem;
            border-radius: 0.4rem;
            border: 1px solid var(--border);
            flex-wrap: wrap;
        }

        .toolbar-btn {
            background: var(--card-bg);
            border: 1px solid var(--border);
            color: var(--text);
            padding: 0.2rem 0.6rem;
            border-radius: 0.25rem;
            font-weight: bold;
            cursor: pointer;
            font-size: 0.85rem;
        }

        .btn {
            background-color: var(--primary);
            color: white;
            border: none;
            padding: 0.75rem 1.5rem;
            border-radius: 0.5rem;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            width: 100%;
            transition: background 0.2s;
        }

        .btn:hover {
            background-color: var(--primary-light);
        }

        .btn-sm {
            padding: 0.4rem 0.8rem;
            font-size: 0.85rem;
            width: auto;
        }

        .btn-success { background-color: var(--success); }
        .btn-danger { background-color: var(--danger); }
        .btn-warning { background-color: var(--accent); }
        .btn-whatsapp { background-color: var(--whatsapp); color: white; }

        /* Top Navbar */
        header {
            background-color: var(--primary);
            color: white;
            padding: 1rem 1.5rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            flex-wrap: wrap;
            gap: 0.5rem;
        }

        .nav-controls {
            display: flex;
            gap: 0.4rem;
            align-items: center;
            flex-wrap: wrap;
        }

        .accessibility-btn {
            background: rgba(255, 255, 255, 0.2);
            border: 1px solid rgba(255, 255, 255, 0.3);
            color: white;
            padding: 0.3rem 0.6rem;
            border-radius: 0.4rem;
            font-weight: bold;
            cursor: pointer;
        }

        /* Nav Tabs & Combination Bar */
        .portal-tabs {
            background: var(--card-bg);
            padding: 0.5rem 1rem 0;
            border-bottom: 1px solid var(--border);
            display: flex;
            gap: 0.5rem;
            overflow-x: auto;
        }

        .tab-btn {
            background: none;
            border: none;
            border-bottom: 3px solid transparent;
            padding: 0.6rem 0.8rem;
            font-weight: bold;
            color: var(--text-muted);
            cursor: pointer;
            white-space: nowrap;
            font-size: 0.9rem;
        }

        .tab-btn.active {
            color: var(--primary-light);
            border-bottom-color: var(--primary-light);
        }

        .combo-bar {
            background: var(--card-bg);
            padding: 0.75rem 1rem;
            border-bottom: 1px solid var(--border);
            display: flex;
            gap: 0.75rem;
            overflow-x: auto;
            align-items: center;
        }

        .combo-btn {
            position: relative;
            background: rgba(0,0,0,0.05);
            border: 1px solid var(--border);
            padding: 0.5rem 1rem;
            border-radius: 0.5rem;
            font-weight: 600;
            cursor: pointer;
            white-space: nowrap;
            color: var(--text);
            font-size: 0.9rem;
        }

        .combo-btn.active {
            background: var(--primary);
            color: white;
        }

        .combo-btn .badge-dot {
            position: absolute;
            top: -4px;
            right: -4px;
            width: 12px;
            height: 12px;
            background-color: var(--danger);
            border: 2px solid white;
            border-radius: 50%;
            display: none;
        }

        .combo-btn.has-unread .badge-dot { display: block; }

        /* Container Layout (Responsive for Android & Desktop) */
        .container {
            display: flex;
            flex: 1;
            padding: 1rem;
            gap: 1rem;
            flex-direction: column;
        }

        @media (min-width: 900px) {
            .container {
                flex-direction: row;
                padding: 1.5rem 2rem;
                gap: 1.5rem;
            }
        }

        .main-content {
            flex: 3;
            display: flex;
            flex-direction: column;
            gap: 1.5rem;
        }

        .card {
            background: var(--card-bg);
            border: 1px solid var(--border);
            border-radius: 0.75rem;
            padding: 1.25rem;
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
        }

        .subject-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1rem;
            margin-top: 1rem;
        }

        .subject-card {
            border: 1px solid var(--border);
            border-radius: 0.5rem;
            padding: 1rem;
            background: rgba(0,0,0,0.02);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .subject-filter {
            display: flex;
            gap: 0.5rem;
            margin-top: 1rem;
            flex-wrap: wrap;
        }

        .sub-pill {
            background: rgba(0,0,0,0.08);
            padding: 0.3rem 0.8rem;
            border-radius: 15px;
            font-size: 0.85rem;
            font-weight: 600;
            cursor: pointer;
            color: var(--text);
        }

        .sub-pill.active {
            background: var(--primary-light);
            color: white;
        }

        /* Work Items & Attachments */
        .resource-item {
            border: 1px solid var(--border);
            border-radius: 0.5rem;
            padding: 1.25rem;
            margin-bottom: 1rem;
            background: var(--card-bg);
        }

        .resource-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 0.5rem;
            flex-wrap: wrap;
            gap: 0.5rem;
        }

        .subject-tag {
            background: #dbeafe;
            color: #1e40af;
            font-weight: bold;
            padding: 0.2rem 0.6rem;
            border-radius: 4px;
            font-size: 0.75rem;
        }

        .file-attachment {
            background: rgba(59, 130, 246, 0.1);
            border: 1px solid var(--border);
            padding: 0.6rem 0.8rem;
            border-radius: 0.4rem;
            margin-top: 0.75rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 0.5rem;
            font-size: 0.85rem;
            flex-wrap: wrap;
        }

        .web-link-attachment {
            background: #fef3c7;
            border: 1px solid #fde68a;
            padding: 0.5rem 0.8rem;
            border-radius: 0.4rem;
            margin-top: 0.5rem;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 0.85rem;
            color: #92400e;
        }

        /* Communication Sidebar */
        .sidebar {
            flex: 1.2;
            display: flex;
            flex-direction: column;
            gap: 1.5rem;
            min-width: 280px;
        }

        .chat-messages {
            height: 240px;
            overflow-y: auto;
            border: 1px solid var(--border);
            border-radius: 0.5rem;
            padding: 1rem;
            margin-bottom: 0.75rem;
            background: rgba(0,0,0,0.02);
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
        }

        .msg {
            max-width: 85%;
            padding: 0.6rem 0.9rem;
            border-radius: 0.5rem;
            font-size: 0.9rem;
        }

        .msg.sent { align-self: flex-end; background: var(--primary-light); color: white; }
        .msg.received { align-self: flex-start; background: var(--border); color: var(--text); }

        .media-controls {
            display: flex;
            gap: 0.5rem;
            margin-top: 0.5rem;
            align-items: center;
            flex-wrap: wrap;
        }

        .icon-btn {
            background: var(--card-bg);
            border: 1px solid var(--border);
            border-radius: 50%;
            width: 38px;
            height: 38px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            color: var(--text);
        }

        .icon-btn.recording {
            background: var(--danger);
            color: white;
            animation: pulse 1s infinite;
        }

        @keyframes pulse {
            0% { opacity: 1; }
            50% { opacity: 0.5; }
            100% { opacity: 1; }
        }

        /* Modals */
        .modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.7);
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 2000;
            padding: 1rem;
        }

        .modal-card {
            background: var(--card-bg);
            color: var(--text);
            padding: 1.5rem;
            border-radius: 0.75rem;
            width: 100%;
            max-width: 550px;
            max-height: 90vh;
            overflow-y: auto;
        }

        .pdf-modal-card {
            max-width: 850px;
            height: 85vh;
            display: flex;
            flex-direction: column;
        }

        .video-box {
            background: #000;
            width: 100%;
            max-width: 700px;
            height: 400px;
            border-radius: 1rem;
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            flex-direction: column;
            padding: 1rem;
            text-align: center;
        }


/* Production setup and status elements */
[hidden] { display: none !important; }
.setup-screen {
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1200;
    padding: 1rem;
    overflow-y: auto;
}
.setup-screen .login-card { margin: auto; }
.form-error { color: var(--danger); margin: 0.75rem 0; font-size: 0.9rem; }
.portal-toast {
    position: fixed;
    z-index: 3000;
    right: 1rem;
    bottom: 1rem;
    max-width: min(28rem, calc(100vw - 2rem));
    background: var(--primary);
    color: #fff;
    padding: 0.8rem 1rem;
    border-radius: 0.5rem;
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.25);
}
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible,
textarea:focus-visible, [contenteditable="true"]:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 2px;
}
button:disabled { opacity: 0.6; cursor: not-allowed; }
.resource-item .grade-panel { margin-top: 0.8rem; padding: 0.8rem; border: 1px solid var(--border); border-radius: 0.5rem; }
.grade-panel textarea { min-height: 4rem; }
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; scroll-behavior: auto !important; }
}