/*
        Author: Trent Brown (GitHub: TrentBrownUML)
        File: css/index.css - shared styles for HW4 sliders, tabs, and validation UI
        */

        :root {
            --bg: #f4f7fb;
            --card: #ffffff;
            --accent: #2563eb;
            --accent-dark: #1e3a8a;
            --muted: #5c5c5c;
            --error: #b91c1c;
        }

        html,
        body {
            min-height: 100%;
            margin: 0;
            font-family: system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial;
            background: linear-gradient(180deg, var(--bg), #e9eef6);
            color: #0f172a;
        }

        body {
            display: flex;
            justify-content: center;
            padding: 32px 16px 48px;
            box-sizing: border-box;
        }

        .tabs {
            width: 100%;
            max-width: 1100px;
            background: transparent;
        }

        .card {
            background: var(--card);
            padding: 24px;
            border-radius: 12px;
            box-shadow: 0 6px 18px rgba(15, 23, 42, 0.08);
            margin-bottom: 24px;
        }

        h1,
        h2 {
            margin: 0 0 16px;
        }

        .field {
            display: flex;
            flex-direction: column;
            margin-bottom: 18px;
        }

        label {
            font-size: 14px;
            color: var(--muted);
            margin-bottom: 6px;
        }

        input[type="number"],
        textarea {
            padding: 10px 12px;
            border: 1px solid #5c5c5c;
            border-radius: 8px;
            font-size: 15px;
            outline: none;
            transition: box-shadow .12s, border-color .12s;
            background: #fff;
        }

        input:focus,
        textarea:focus {
            border-color: var(--accent);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
        }

        button {
            width: 100%;
            padding: 12px 14px;
            background: var(--accent);
            color: #fff;
            border: none;
            border-radius: 8px;
            font-size: 15px;
            cursor: pointer;
            margin-top: 8px;
            transition: background .15s ease-in-out;
        }

        button:hover {
            background: var(--accent-dark);
        }

        button.secondary {
            background: transparent;
            color: var(--accent);
            border: 1px solid var(--accent);
        }

        button.secondary:disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .note {
            font-size: 14px;
            color: var(--muted);
            text-align: left;
            margin-top: 12px;
        }

        .slider {
            margin: 10px 4px 0;
        }

        .field-hint {
            font-size: 13px;
            color: var(--muted);
            margin-top: 6px;
        }

        .field-error {
            font-size: 13px;
            color: var(--error);
            margin-top: 6px;
        }

        .has-error {
            border-color: var(--error) !important;
            box-shadow: 0 0 0 2px rgba(185, 28, 28, 0.2) !important;
        }

        .live-preview h2,
        .tab-management h2 {
            font-size: 18px;
        }

        .preview-hint {
            font-size: 14px;
            color: var(--muted);
            margin-bottom: 12px;
        }

        .placeholder {
            color: var(--muted);
            margin: 0;
        }

        .tab-selection-list {
            display: flex;
            flex-direction: column;
            gap: 8px;
            margin-bottom: 12px;
        }

        .tab-selection-item {
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 8px 10px;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            background: #fff;
        }

        .tab-selection-item label {
            flex: 1;
            color: var(--muted);
        }

        .tab-selection-item input[type="checkbox"] {
            width: 18px;
            height: 18px;
        }

        .table-container {
            width: 100%;
            margin: 0 auto;
            max-height: 60vh;
            overflow: auto;
            padding: 4px;
            box-sizing: border-box;
        }

        .multiplicationTable,
        .generatedTable {
            border-collapse: collapse;
            width: 100%;
            min-width: max-content;
            margin: 0 auto;
            font-family: sans-serif;
            background: #fff;
            box-shadow: 0 4px 12px rgba(15, 23, 42, 0.06);
        }

        .generatedTable th,
        .generatedTable td {
            border: 1px solid #ddd;
            padding: 10px;
            text-align: center;
            vertical-align: middle;
        }

        .generatedTable thead th {
            background: #333;
            color: #fff;
            font-weight: 600;
        }

        .generatedTable tbody tr:nth-child(odd) {
            background: #fafafa;
        }

        .generatedTable tbody tr:nth-child(even) {
            background: #ffffff;
        }

        .generatedTable tbody td:nth-child(4n+1) {
            background: #e6f7ff;
        }

        .generatedTable tbody td:nth-child(4n+2) {
            background: #fff0f6;
        }

        .generatedTable tbody td:nth-child(4n+3) {
            background: #f6fff0;
        }

        .generatedTable tbody td:nth-child(4n) {
            background: #fff7e6;
        }

        .generatedTable tbody th[scope="row"] {
            font-weight: 600;
            background: #333;
            color: #fff;
        }

        .generatedTable.compact th,
        .generatedTable.compact td {
            padding: 6px 8px;
        }

        .ui-tabs .ui-tabs-nav {
            margin: 0 0 20px;
            padding: 0;
            border: none;
            background: transparent;
        }

        .ui-tabs .ui-tabs-nav li {
            border: none;
            background: transparent;
            margin-right: 8px;
            position: relative;
        }

        .ui-tabs .ui-tabs-nav li a {
            background: rgba(255, 255, 255, 0.9);
            border-radius: 8px;
            padding: 8px 34px 8px 14px;
            border: 1px solid #cbd5f5;
            color: #0f172a;
        }

        .tab-close {
            position: absolute;
            right: 6px;
            top: 8px;
            border: none;
            background: transparent;
            font-size: 16px;
            line-height: 1;
            color: #475569;
            cursor: pointer;
        }

        .tab-close:hover {
            color: #b91c1c;
        }

        @media (max-width: 720px) {
            body {
                padding: 16px;
            }

            .card {
                padding: 18px;
            }

            .generatedTable th,
            .generatedTable td {
                padding: 8px;
                font-size: 13px;
            }
        }