:root {
            --bg: #f5f6fb;
            --pn: #fff;
            --tx: #161a2e;
            --mu: #667;
            --ac: #4b45d8;
            --ac2: #f2f4ff;
            --bd: #e2e5f0;
            --cd: #0d1020;
            --ct: #e6e9ff;
            --ok: #16a34a;
            --er: #dc2626;
            --k: #c084fc;
            --s: #86efac;
            --n: #7dd3fc;
            --cm: #7c85ad;
            box-sizing: border-box;
            padding-top: env(safe-area-inset-top, 0px)
        }

        @media(prefers-color-scheme:dark) {
            :root:not([data-theme="light"]) {
                --bg: #0b0e1c;
                --pn: #141831;
                --tx: #e8ebff;
                --mu: #9aa3c9;
                --ac: #8b8bff;
                --ac2: #22264a;
                --bd: #262c50;
                --cd: #070916
            }
        }

        :root[data-theme="dark"] {
            --bg: #0b0e1c;
            --pn: #141831;
            --tx: #e8ebff;
            --mu: #9aa3c9;
            --ac: #8b8bff;
            --ac2: #22264a;
            --bd: #262c50;
            --cd: #070916
        }

        * {
            box-sizing: border-box
        }

        html {
            height: 100%;
            scroll-padding-top: 70px
        }

        body {
            margin: 0;
            background: var(--bg);
            color: var(--tx);
            font: 16px/1.7 Inter, system-ui, sans-serif
        }

        .mono,
        pre,
        textarea,
        code {
            font-family: "JetBrains Mono", ui-monospace, Consolas, monospace
        }

        body > header:not(.site-global-header) {
            position: sticky;
            top: env(safe-area-inset-top, 0px);
            z-index: 6;
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 10px 18px;
            background: color-mix(in srgb, var(--pn) 88%, transparent);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--bd)
        }

        body > header:not(.site-global-header) b {
            font-weight: 800;
            font-size: 1.1rem;
            flex: 1
        }

        body > header:not(.site-global-header) b i {
            font-style: normal;
            background: linear-gradient(90deg, #5b5bf0, #d946ef);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent
        }

        .wrap button,
        #dock button {
            font: inherit;
            font-size: .9rem;
            cursor: pointer;
            border: 1px solid var(--bd);
            background: var(--pn);
            color: var(--tx);
            border-radius: 9px;
            padding: 6px 13px;
            transition: .15s
        }

        .wrap button:hover,
        #dock button:hover {
            border-color: var(--ac);
            color: var(--ac)
        }

        .pr {
            background: var(--ac);
            color: #fff;
            border-color: var(--ac)
        }

        .pr:hover {
            color: #fff;
            filter: brightness(1.1)
        }

        #lesson-menu-toggle {
            display: none
        }

        .wrap {
            display: grid;
            grid-template-columns: 285px 1fr;
            max-width: 1300px;
            margin: 0 auto
        }

        #nav {
            position: sticky;
            top: 76px;
            height: calc(100vh - 76px);
            overflow: auto;
            padding: 16px;
            border-right: 1px solid var(--bd)
        }

        #nav input {
            width: 100%;
            padding: 9px 12px;
            border-radius: 10px;
            border: 1px solid var(--bd);
            background: var(--pn);
            color: var(--tx);
            font: inherit;
            margin-bottom: 8px
        }

        .pg {
            height: 6px;
            background: var(--bd);
            border-radius: 9px;
            overflow: hidden;
            margin: 4px 0 12px
        }

        .pg i {
            display: block;
            height: 100%;
            width: 0;
            background: linear-gradient(90deg, #5b5bf0, #d946ef);
            transition: .3s
        }

        #nav small {
            color: var(--mu)
        }

        #nav h4 {
            margin: 14px 0 4px;
            font-size: .7rem;
            letter-spacing: .1em;
            text-transform: uppercase;
            color: var(--mu)
        }

        #nav a {
            display: flex;
            gap: 8px;
            padding: 6px 10px;
            border-radius: 9px;
            color: var(--tx);
            text-decoration: none;
            font-size: .92rem
        }

        #nav a:hover,
        #nav a.on {
            background: var(--ac2);
            color: var(--ac)
        }

        #nav a.dn::after {
            content: "✓";
            margin-left: auto;
            color: var(--ok)
        }

        main {
            padding: 28px clamp(16px, 4vw, 52px) 60px;
            min-width: 0
        }

        .hero {
            padding: 40px 32px;
            border-radius: 20px;
            color: #fff;
            background: linear-gradient(135deg, #4b45d8, #6d63f5 60%, #8b5cf6);
            margin-bottom: 24px
        }

        .hero h1 {
            margin: 0 0 8px;
            font-size: clamp(1.8rem, 4vw, 2.8rem);
            line-height: 1.15;
            font-weight: 800
        }

        .hero p {
            max-width: 60ch;
            opacity: .92
        }

        .st {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            margin: 16px 0
        }

        .st span {
            background: #ffffff22;
            padding: 5px 14px;
            border-radius: 99px;
            font-size: .88rem
        }

        .grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 14px
        }

        .card {
            background: var(--pn);
            border: 1px solid var(--bd);
            border-radius: 16px;
            padding: 18px
        }

        a.card {
            color: inherit;
            text-decoration: none
        }

        a.card:hover {
            border-color: var(--ac);
            transform: translateY(-2px)
        }

        .tag {
            font-size: .7rem;
            font-weight: 600;
            color: var(--ac);
            background: var(--ac2);
            padding: 2px 10px;
            border-radius: 99px
        }

        h1.t {
            font-size: 2rem;
            margin: 0 0 4px;
            font-weight: 800
        }

        h2 {
            margin: 30px 0 10px;
            font-size: 1.25rem
        }

        .three {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 12px;
            margin: 16px 0
        }

        .three .card h3 {
            margin: 0 0 4px;
            font-size: .95rem;
            color: var(--ac)
        }

        .three p {
            margin: 0;
            font-size: .95rem
        }

        .cb {
            position: relative;
            margin: 12px 0
        }

        pre {
            margin: 0;
            background: var(--cd);
            color: var(--ct);
            padding: 15px 15px 15px;
            border-radius: 12px;
            overflow-x: auto;
            font-size: .86rem;
            line-height: 1.6
        }

        .ac {
            display: flex;
            gap: 6px;
            margin: 6px 0 0;
            flex-wrap: wrap;
            align-items: center
        }

        .ac button {
            font-size: .8rem;
            padding: 4px 10px
        }

        .nr {
            font-size: .75rem;
            color: var(--mu)
        }

        .k {
            color: var(--k);
            font-weight: 600
        }

        .s {
            color: var(--s)
        }

        .n {
            color: var(--n)
        }

        .c {
            color: var(--cm);
            font-style: italic
        }

        .ex {
            border-left: 3px solid var(--ac);
            padding-left: 14px;
            margin: 18px 0
        }

        .ex p {
            margin: 2px 0
        }

        .nota {
            background: var(--ac2);
            border-radius: 12px;
            padding: 12px 16px;
            margin: 14px 0
        }

        table {
            border-collapse: collapse;
            font-size: .85rem
        }

        th,
        td {
            border: 1px solid var(--bd);
            padding: 5px 11px;
            text-align: left;
            white-space: nowrap
        }

        th {
            background: var(--ac2);
            position: sticky;
            top: 0
        }

        .tw {
            overflow: auto;
            max-width: 100%
        }

        .nv {
            display: flex;
            justify-content: space-between;
            margin-top: 30px;
            gap: 10px
        }

        #dock {
            position: fixed;
            left: 0;
            right: 0;
            bottom: 0;
            z-index: 7;
            background: var(--pn);
            border-top: 2px solid var(--ac);
            box-shadow: 0 -10px 30px #0003;
            padding-bottom: env(safe-area-inset-bottom, 0px);
            display: flex;
            flex-direction: column;
            height: 44vh
        }

        #dock.cl {
            height: auto
        }

        #dock.cl .db {
            display: none
        }

        .bar {
            display: flex;
            gap: 8px;
            align-items: center;
            padding: 7px 12px;
            border-bottom: 1px solid var(--bd);
            flex-wrap: wrap
        }

        .bar b {
            flex: 1;
            font-size: .92rem
        }

        .db {
            display: grid;
            grid-template-columns: 1fr 1fr;
            flex: 1;
            min-height: 0
        }

        .ed {
            position: relative;
            border-right: 1px solid var(--bd);
            background: var(--cd)
        }

        .ed pre,
        .ed textarea {
            position: absolute;
            inset: 0;
            margin: 0;
            padding: 12px;
            border: 0;
            border-radius: 0;
            font-size: .86rem;
            line-height: 1.6;
            white-space: pre;
            overflow: auto;
            tab-size: 2
        }

        .ed textarea {
            background: transparent;
            color: transparent;
            caret-color: #fff;
            resize: none;
            outline: 0;
            z-index: 2
        }

        #rs {
            overflow: auto;
            padding: 10px 12px;
            font-size: .9rem
        }

        #msg {
            margin-bottom: 8px;
            font-size: .85rem
        }

        .okc {
            color: var(--ok)
        }

        .erc {
            color: var(--er)
        }

        @media(max-width:860px) {
            .wrap {
                display: block
            }

            #lesson-menu-toggle {
                display: inline-block
            }

            #nav {
                display: none;
                position: fixed;
                inset: 76px 0 0 0;
                height: auto;
                z-index: 5;
                background: var(--bg)
            }

            #nav.op {
                display: block
            }

            .db {
                grid-template-columns: 1fr;
                grid-template-rows: 1fr 1fr
            }

            .ed {
                border-right: 0;
                border-bottom: 1px solid var(--bd)
            }
        }