:root {
            --bg: #0a0e1a;
            --panel-bg: #0d1424;
            --row-bg: #0a0f1d;
            --border: #1c2438;
            --text: #e7ecf7;
            --text-2: #8892ab;
            --text-dim: #4c5573;
            --accent: #f2a65a;
            --accent-soft: rgba(242, 166, 90, 0.10);
            --easy: #5ec98f;
            --keyword: #7fb0f2;
            --string: #9fd88d;
            --comment: #5b6483;
            --danger: #f2705a;
            --purple: #c792ea;
        }

        * {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            background: var(--bg);
            color: var(--text);
            font-family: 'JetBrains Mono', monospace;
        }

        .header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 20px 40px;
            border-bottom: 1px solid var(--border);
        }

        .logo {
            font-family: 'Space Grotesk', sans-serif;
            font-weight: 700;
            font-size: 19px;
            color: var(--text);
            text-decoration: none;
        }

        .navbar {
            display: flex;
            gap: 26px;
        }

        .navbar a {
            color: var(--text-2);
            text-decoration: none;
            font-size: 14px;
        }

        .navbar a:hover {
            color: var(--text);
        }

        .navbar a.active {
            color: var(--accent);
        }

        .wrap {
            max-width: 1100px;
            margin: 0 auto;
            padding: 48px 24px 100px;
        }

        .crumb {
            font-size: 12.5px;
            color: var(--text-dim);
            margin-bottom: 18px;
        }

        .crumb a {
            color: var(--text-dim);
            text-decoration: none;
        }

        .crumb a:hover {
            color: var(--accent);
        }

        .ptitle-row {
            display: flex;
            align-items: center;
            gap: 14px;
            flex-wrap: wrap;
            margin-bottom: 10px;
        }

        .ptitle-row h1 {
            font-family: 'Space Grotesk', sans-serif;
            font-weight: 700;
            font-size: clamp(26px, 4.5vw, 36px);
            margin: 0;
        }

        .diff-badge {
            font-size: 12px;
            font-weight: 600;
            padding: 5px 11px;
            border-radius: 6px;
            color: var(--easy);
            background: rgba(94, 201, 143, .12);
        }

        .topic-badges {
            display: flex;
            gap: 8px;
            margin-bottom: 24px;
            flex-wrap: wrap;
        }

        .topic-badges span {
            font-size: 11.5px;
            color: var(--text-2);
            border: 1px solid var(--border);
            padding: 4px 9px;
            border-radius: 5px;
        }

        .card {
            border: 1px solid var(--border);
            border-radius: 12px;
            background: var(--panel-bg);
            margin-bottom: 28px;
            overflow: hidden;
        }

        .card-title {
            padding: 16px 22px;
            border-bottom: 1px solid var(--border);
            font-family: 'Space Grotesk', sans-serif;
            font-weight: 700;
            font-size: 15px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .card-title::before {
            content: "";
            width: 7px;
            height: 7px;
            border-radius: 50%;
            background: var(--accent);
        }

        .card-body {
            padding: 20px 22px;
            font-size: 13.5px;
            line-height: 1.75;
            color: var(--text-2);
        }

        .card-body code {
            background: rgba(255, 255, 255, .06);
            padding: 1px 6px;
            border-radius: 4px;
            color: var(--text);
            font-size: 12.5px;
        }

        .example {
            margin-top: 12px;
            padding: 12px 14px;
            background: var(--row-bg);
            border: 1px solid var(--border);
            border-radius: 8px;
            font-size: 12.5px;
            color: var(--text-2);
        }

        /* High-level steps */
        .steps-list {
            margin: 0;
            padding-left: 20px;
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

        .steps-list li {
            color: var(--text-2);
            font-size: 13px;
            line-height: 1.6;
        }

        .steps-list strong {
            color: var(--text);
        }

        /* Control bars */
        .switch-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 12px;
            padding: 14px 22px;
            border-bottom: 1px solid var(--border);
            background: var(--row-bg);
        }

        .seg {
            display: flex;
            background: var(--panel-bg);
            border: 1px solid var(--border);
            border-radius: 8px;
            padding: 3px;
            gap: 2px;
        }

        .seg button {
            background: transparent;
            border: none;
            color: var(--text-2);
            font-family: inherit;
            font-size: 12px;
            padding: 6px 12px;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.15s ease;
        }

        .seg button.active {
            background: var(--accent-soft);
            color: var(--accent);
            font-weight: 600;
        }

        .seg-title {
            font-size: 11px;
            color: var(--text-dim);
            letter-spacing: 0.05em;
            margin-right: 6px;
            text-transform: uppercase;
            align-self: center;
        }

        /* Multi-language selection toggles */
        .lang-toggle-group {
            display: flex;
            gap: 6px;
            align-items: center;
        }

        .lang-btn {
            background: var(--panel-bg);
            border: 1px solid var(--border);
            color: var(--text-2);
            font-size: 12px;
            padding: 5px 11px;
            border-radius: 6px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .lang-btn.selected {
            border-color: var(--accent);
            color: var(--accent);
            background: var(--accent-soft);
        }

        .lang-btn input {
            display: none;
        }

        /* Code split container */
        .code-comparison-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 0;
            border-bottom: 1px solid var(--border);
        }

        .code-pane {
            border-right: 1px solid var(--border);
            background: var(--panel-bg);
        }

        .code-pane:last-child {
            border-right: none;
        }

        .code-pane-header {
            padding: 8px 16px;
            background: var(--row-bg);
            border-bottom: 1px solid var(--border);
            font-size: 11px;
            font-weight: 600;
            color: var(--accent);
            text-transform: uppercase;
        }

        .code-lines {
            padding: 14px 0;
        }

        .code-line {
            display: flex;
            gap: 12px;
            padding: 2px 16px;
            font-size: 12.5px;
            line-height: 1.8;
            white-space: pre;
            overflow-x: auto;
        }

        .code-line .ln {
            color: var(--text-dim);
            min-width: 18px;
            text-align: right;
            user-select: none;
        }

        .code-line.active-line {
            background: var(--accent-soft);
            border-left: 3px solid var(--accent);
        }

        /* Simulation area */
        .sim-visual {
            padding: 20px 22px;
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .arr-row {
            display: flex;
            gap: 8px;
            justify-content: center;
            flex-wrap: wrap;
        }

        .arr-box {
            position: relative;
            width: 50px;
            height: 50px;
            border: 1px solid var(--border);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 15px;
            font-weight: 600;
            background: var(--row-bg);
            transition: all .2s ease;
        }

        .arr-box .idx {
            position: absolute;
            bottom: -19px;
            font-size: 10px;
            color: var(--text-dim);
        }

        .arr-box.ptr-i {
            border-color: var(--keyword);
            box-shadow: 0 0 0 3px rgba(127, 176, 242, .15);
        }

        .arr-box.ptr-j {
            border-color: var(--purple);
            box-shadow: 0 0 0 3px rgba(199, 146, 234, .15);
        }

        .arr-box.found {
            border-color: var(--easy);
            background: rgba(94, 201, 143, .12);
            box-shadow: 0 0 0 3px rgba(94, 201, 143, .2);
        }

        .map-panel {
            min-height: 50px;
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            align-items: center;
            padding: 10px 14px;
            background: var(--row-bg);
            border: 1px dashed var(--border);
            border-radius: 8px;
        }

        .map-panel .empty {
            color: var(--text-dim);
            font-size: 12px;
        }

        .map-chip {
            font-size: 12px;
            padding: 4px 8px;
            border-radius: 6px;
            background: var(--accent-soft);
            color: var(--accent);
            border: 1px solid rgba(242, 166, 90, .3);
        }

        .desc-line {
            min-height: 38px;
            font-size: 13px;
            color: var(--text);
            padding: 10px 14px;
            background: var(--row-bg);
            border-radius: 8px;
            border: 1px solid var(--border);
        }

        .desc-line.win {
            border-color: var(--easy);
            color: var(--easy);
            background: rgba(94, 201, 143, .08);
        }

        .controls-row {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 14px 22px;
            border-top: 1px solid var(--border);
            background: var(--row-bg);
            flex-wrap: wrap;
        }

        .controls-row button {
            width: 34px;
            height: 34px;
            border-radius: 8px;
            border: 1px solid var(--border);
            background: var(--panel-bg);
            color: var(--text);
            cursor: pointer;
            font-family: inherit;
            font-size: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .controls-row button:hover {
            border-color: var(--accent);
            color: var(--accent);
        }

        .controls-row button.play {
            background: var(--accent-soft);
            border-color: var(--accent);
            color: var(--accent);
        }

        .step-count {
            font-size: 12px;
            color: var(--text-dim);
            margin-left: auto;
        }

        .progress-track {
            flex: 1;
            min-width: 100px;
            height: 4px;
            background: var(--border);
            border-radius: 2px;
            position: relative;
            margin: 0 8px;
        }

        .progress-fill {
            height: 100%;
            background: var(--accent);
            border-radius: 2px;
            transition: width .2s ease;
        }

        /* Complexity Chart */
        .complexity-body {
            padding: 22px;
        }

        .complexity-badges {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
            margin-bottom: 20px;
        }

        .cbadge {
            flex: 1;
            min-width: 150px;
            padding: 12px 16px;
            background: var(--row-bg);
            border: 1px solid var(--border);
            border-radius: 10px;
        }

        .cbadge .label {
            font-size: 11px;
            color: var(--text-dim);
            letter-spacing: .06em;
            margin-bottom: 4px;
        }

        .cbadge .value {
            font-family: 'Space Grotesk', sans-serif;
            font-size: 20px;
            font-weight: 700;
            color: var(--accent);
        }

        .chart-wrap {
            background: var(--row-bg);
            border: 1px solid var(--border);
            border-radius: 10px;
            padding: 18px;
        }

        .chart-legend {
            display: flex;
            gap: 18px;
            font-size: 11.5px;
            color: var(--text-2);
            margin-top: 12px;
            flex-wrap: wrap;
        }

        .chart-legend span {
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .swatch {
            width: 10px;
            height: 10px;
            border-radius: 2px;
        }

        table.compare {
            width: 100%;
            border-collapse: collapse;
            font-size: 13px;
        }

        table.compare th,
        table.compare td {
            padding: 12px 16px;
            text-align: left;
            border-bottom: 1px solid var(--border);
        }

        table.compare th {
            color: var(--text-dim);
            font-size: 11px;
            letter-spacing: .06em;
            font-weight: 600;
        }

        table.compare td {
            color: var(--text-2);
        }

        table.compare td.hl {
            color: var(--accent);
            font-weight: 600;
        }

        table.compare tr:last-child td {
            border-bottom: none;
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            background: none;
            border: none;
            cursor: pointer;
            z-index: 1001;
            padding: 5px;
        }
        .hamburger span {
            width: 24px;
            height: 2px;
            background: var(--text);
            transition: all 0.3s ease;
        }
        .hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
        .hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
        .hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

        @media (max-width:760px) {
            .hamburger { display: flex; }
            .navbar {
                position: fixed;
                top: 0;
                right: -100%;
                width: 240px;
                height: 100vh;
                background: var(--panel-bg);
                border-left: 1px solid var(--border);
                flex-direction: column;
                justify-content: center;
                align-items: flex-start;
                padding: 40px 30px;
                gap: 16px;
                transition: right 0.35s ease;
                z-index: 999;
            }
            .navbar.nav-open { right: 0; }
            
            .header {
                padding: 16px 20px;
            }
            .wrap {
                padding: 80px 16px 100px;
            }

            .code-comparison-grid {
                grid-template-columns: 1fr;
            }

            .code-pane {
                border-right: none;
                border-bottom: 1px solid var(--border);
            }

            .complexity-badges {
                flex-direction: column;
            }
            .code-line {
                font-size: 11px;
                white-space: pre-wrap;
                word-break: break-all;
            }
            .desc-line, .example {
                word-wrap: break-word;
            }
        }

        /* Graph Visual Area */
        .chart-stage {
            position: relative;
            height: 240px;
            display: flex;
            align-items: flex-end;
            justify-content: center;
            gap: 12px;
            margin: 30px 0 10px 0;
            padding-bottom: 40px;
            border-bottom: 1px solid var(--border);
            overflow-x: auto;
        }

        .bar-wrapper {
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
            flex: 1;
            max-width: 48px;
            min-width: 24px;
        }

        .bar {
            width: 100%;
            background-color: var(--row-bg);
            border: 1px solid var(--border);
            border-radius: 4px 4px 0 0;
            transition: background-color 0.3s ease, height 0.3s ease, border-color 0.3s ease;
        }

        .bar-value {
            margin-top: 8px;
            font-size: 0.85rem;
            font-weight: bold;
            color: var(--text);
        }

        .pointer-marker {
            position: absolute;
            bottom: -32px;
            font-size: 0.8rem;
            font-weight: bold;
            display: flex;
            flex-direction: column;
            align-items: center;
            opacity: 0;
            transition: opacity 0.2s ease;
        }

        .pointer-marker.visible {
            opacity: 1;
        }

        .pointer-marker.left {
            color: #ff0055;
        }

        .pointer-marker.right {
            color: #ff0055;
        }

        .pointer-marker.match {
            color: #ccff00;
        }

        .bar.active {
            background-color: rgba(255, 0, 85, 0.18) !important;
            border-color: #ff0055 !important;
        }

        .bar.match {
            background-color: rgba(204, 255, 0, 0.18) !important;
            border-color: #ccff00 !important;
        }