:root {
            --primary-color: #4f46e5;
            --primary-hover: #4338ca;
            --success-color: #10b981;
            --success-hover: #059669;
            --danger-color: #ef4444;
            --danger-hover: #dc2626;
            --bg-color: #f8fafc;
            --card-bg: #ffffff;
            --text-main: #1e293b;
            --text-muted: #64748b;
            --border-color: #e2e8f0;
            --radius: 12px;
            --transition: all 0.2s ease-in-out;
            --menu-bg-color: #e0e7ff; 
            --menu-bg-hover: #c7d2fe;
        }

        body {
            font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            background-color: var(--bg-color);
            color: var(--text-main);
            margin: 0;
            padding: 0;
            min-height: 100vh;
            box-sizing: border-box;
            display: flex;
        }

        /* Responsive Layout Container Wrapper */
        .app-layout {
            display: flex;
            width: 100%;
            min-height: 100vh;
        }

        /* Modernized Responsive Sidebar */
        .sidebar {
            width: 320px;
            background: var(--card-bg);
            border-right: 1px solid var(--border-color);
            display: flex;
            flex-direction: column;
            padding: 24px;
            box-sizing: border-box;
            flex-shrink: 0;
        }

        .sidebar-logo {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 24px;
            display: flex;
            align-items: center;
            gap: 8px;
        }


         .email-login-box {
            display: flex;
            flex-direction: column;
            gap: 10px;
            background: #f8fafc;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 12px;
        }

        .email-login-title {
            font-size: 0.82rem;
            font-weight: 600;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .email-login-input {
            width: 100%;
            box-sizing: border-box;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 11px 12px;
            font-size: 0.92rem;
            outline: none;
            transition: var(--transition);
            background: #fff;
            color: var(--text-main);
        }

        .email-login-input:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
        }

        .email-login-btn {
            width: 100%;
        }

        .auth-container {
            margin-bottom: 24px;
            padding-bottom: 20px;
            border-bottom: 1px solid var(--border-color);
            display: flex;
            flex-direction: column;
            gap: 14px;
        }

        .profile-card {
            display: flex;
            align-items: center;
            justify-content: space-between;
            background: #f8fafc;
            padding: 12px;
            border-radius: 8px;
            border: 1px solid var(--border-color);
        }

        .profile-info {
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .profile-info img {
            width: 36px;
            height: 36px;
            border-radius: 50%;
        }

        .profile-name {
            font-size: 0.9rem;
            font-weight: 600;
        }

        .btn-logout {
            background: none;
            border: none;
            color: var(--danger-color);
            cursor: pointer;
            font-size: 0.85rem;
            font-weight: 500;
        }
        .btn-logout:hover {
            text-decoration: underline;
        }

        .sidebar-info-box {
            font-size: 0.8rem;
            color: var(--text-muted);
            line-height: 1.4;
            background-color: #f0fdf4;
            border: 1px solid #bbf7d0;
            padding: 12px;
            border-radius: 8px;
            margin-bottom: 20px;
        }
        .sidebar-info-box.warning {
            background-color: #fffaf0;
            border: 1px solid #feebc8;
            color: #c05621;
        }

        .saved-list-container {
            flex-grow: 1;
            overflow-y: auto;
            margin-bottom: 16px;
        }

        .saved-list-title {
            font-size: 0.85rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--text-muted);
            margin-bottom: 12px;
        }

        .equation-item {
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 12px;
            margin-bottom: 10px;
            cursor: pointer;
            position: relative;
            transition: var(--transition);
        }
        .equation-item:hover {
            border-color: var(--primary-color);
            background: #fafafa;
        }

        .equation-preview {
            font-size: 0.9rem;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
            margin-bottom: 6px;
            padding-right: 24px;
        }

        .equation-meta {
            font-size: 0.75rem;
            color: var(--text-muted);
        }

        .btn-delete-eq {
            position: absolute;
            top: 10px;
            right: 10px;
            background: transparent;
            border: none;
            color: var(--text-muted);
            cursor: pointer;
            border-radius: 4px;
            padding: 2px;
        }
        .btn-delete-eq:hover {
            color: var(--danger-color);
            background: #fee2e2;
        }

        /* Workspace View Styles */
        .main-content {
            flex-grow: 1;
            padding: 40px;
            display: flex;
            flex-direction: column; /* Allow children to expand vertically */
            box-sizing: border-box;
            height: 100vh;
            overflow: hidden;
        }

        .editor-container {
            width: 100%;
            flex-grow: 1; /* Stretch to fill available space */
            background: var(--card-bg);
            border-radius: var(--radius);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05);
            border: 1px solid var(--border-color);
            overflow: hidden;
            display: flex;
            flex-direction: column;
        }

        .toolbar {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            padding: 16px;
            background-color: #fafafa;
            border-bottom: 1px solid var(--border-color);
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 10px 16px;
            font-size: 0.875rem;
            font-weight: 500;
            border-radius: 8px;
            border: 1px solid transparent;
            cursor: pointer;
            transition: var(--transition);
        }

        .btn-primary { background-color: var(--primary-color); color: white; }
        .btn-primary:hover { background-color: var(--primary-hover); }
        .btn-success { background-color: var(--success-color); color: white; }
        .btn-success:hover { background-color: var(--success-hover); }
        .btn-secondary { background-color: #f1f5f9; color: var(--text-main); border: 1px solid var(--border-color); }
        .btn-secondary:hover { background-color: #e2e8f0; }

        #mathfield-wrapper {
            padding: 24px;
            background: #fff;
            box-sizing: border-box;
            flex-grow: 1; /* Expand wrapper */
            display: flex;
            flex-direction: column;
        }

        math-field {
            width: 100%; 
            flex-grow: 1; /* Expand actual typing area */
            margin: 0;
            min-height: 70px;
            overflow-y: auto;
            overflow-x: auto;
            display: block;
            border: 2px solid var(--border-color);
            border-radius: 8px;
            padding: 10px;
            font-size: 1.6em;
            outline: none;
            transition: var(--transition);
            background: #fff;
            box-sizing: border-box;
            --caret-color: red;
        }

        math-field:focus-within {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
        }

        math-field::part(virtual-keyboard-toggle) { display: none; }
        math-field::part(menu-toggle) {
            color: var(--primary-color);
            background-color: var(--menu-bg-color); 
            border-radius: 6px;
            font-size: 16px;
            padding: 4px;
            width: 24px;
            height: 24px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition);
        }
        math-field::part(menu-toggle):hover { background-color: var(--menu-bg-hover); transform: scale(1.05); }

        .latex-panel {
            border-top: 1px solid var(--border-color);
            background-color: #f8fafc;
            padding: 16px 24px;
        }

        .panel-label {
            font-size: 0.75rem;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--text-muted);
            margin-bottom: 8px;
            font-weight: 600;
        }

        .latex-input-wrapper {
            display: flex;
            position: relative;
            align-items: stretch;
            gap: 12px;
        }

        .latex-input-wrapper textarea {
            flex-grow: 1;
            font-family: "Fira Code", Consolas, Monaco, monospace;
            font-size: 0.9rem;
            padding: 12px;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            resize: vertical;
            min-height: 54px;
            height: 54px;
            background: #fff;
            color: #0f172a;
            box-sizing: border-box;
            outline: none;
            transition: var(--transition);
        }

        .btn-copy { height: 54px; white-space: nowrap; align-self: center;}


/* Sidebar collapse controls */
.sidebar {
    transition: width 0.25s ease, padding 0.25s ease, transform 0.28s ease, box-shadow 0.25s ease;
    position: relative;
}

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

.sidebar-logo-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
}

.sidebar-title {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-left: 50px;
}

.sidebar-fab,
.sidebar-toggle {
    border: none;
    background: var(--bg-color);
    color: var(--primary-color);
    width: 40px;
    height: 40px;
    border-radius: 10px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
}

.sidebar-fab:hover,
.sidebar-toggle:hover {
    background: var(--menu-bg-color);
}

.sidebar-fab {
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 80;
}

.sidebar.collapsed {
    width: 92px;
    padding: 24px 12px;
}

.sidebar.collapsed .sidebar-title,
.sidebar.collapsed .auth-container,
.sidebar.collapsed .sidebar-info-box,
.sidebar.collapsed .saved-list-container,
.sidebar.collapsed .sidebar-footer {
    display: none;
}

.sidebar.collapsed .sidebar-logo {
    justify-content: center;
}

.sidebar.collapsed .sidebar-logo-brand {
    justify-content: center;
}

.sidebar.collapsed .sidebar-toggle svg {
    transform: rotate(180deg);
}

.sidebar.collapsed .sidebar-fab {
    left: 110px;
}

@media (max-width: 900px) {
    .app-layout {
        display: block;
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: min(320px, 88vw);
        z-index: 70;
        transform: translateX(-100%);
        box-shadow: 18px 0 40px rgba(15, 23, 42, 0.12);
        border-right: 1px solid var(--border-color);
        border-bottom: none;
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

    .sidebar.collapsed {
        width: min(320px, 88vw);
        padding: 24px;
    }

    .sidebar.collapsed .sidebar-title,
    .sidebar.collapsed .auth-container,
    .sidebar.collapsed .sidebar-info-box,
    .sidebar.collapsed .saved-list-container,
    .sidebar.collapsed .sidebar-footer {
        display: block;
    }

    .main-content {
        padding: 72px 16px 16px;
        height: auto;
    }

    .sidebar-fab {
        top: 14px;
        left: 14px;
        z-index: 90;
    }
}