:root {
    color-scheme: dark;
    --bg: #0f151d;
    --card: #172029;
    --tx: #e8edf5;
    --mut: #9aa7ba;
    --ac: #4ade80;
    --soft: #173226;
    --bd: #263340;
    --code: #0a1017;
    --grid: #16202a
}

* {
    box-sizing: border-box
}

html {
    scroll-behavior: smooth
}

[hidden] {
    display: none !important
}

body {
    margin: 0;
    font: 16px/1.75 "Be Vietnam Pro", system-ui, "Segoe UI", sans-serif;
    background: var(--bg);
    color: var(--tx)
}

a {
    color: var(--ac);
    text-decoration: none
}

:focus-visible {
    outline: 2px solid var(--ac);
    outline-offset: 2px
}

.top {
    position: sticky;
    top: 0;
    z-index: 9;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 24px;
    background: var(--card);
    border-bottom: 1px solid var(--bd)
}

.brand {
    font-weight: 800;
    font-size: 1.15rem;
    color: var(--tx);
    font-family: "JetBrains Mono", monospace
}

.brand b {
    color: var(--ac)
}

.top nav {
    display: flex;
    gap: 2px;
    margin-left: auto
}

.top nav a {
    padding: 6px 12px;
    border-radius: 8px;
    color: var(--mut);
    font-size: .9rem
}

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

.icon {
    border: 1px solid var(--bd);
    background: var(--card);
    color: var(--tx);
    border-radius: 8px;
    width: 36px;
    height: 36px;
    cursor: pointer
}

#menu {
    display: none
}

.hero {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 40px;
    align-items: center;
    max-width: 1100px;
    margin: 0 auto;
    padding: 64px 20px 40px
}

.hero-bg {
    background: linear-gradient(var(--grid) 1px, transparent 1px) 0 0/28px 28px, linear-gradient(90deg, var(--grid) 1px, transparent 1px) 0 0/28px 28px
}

.hero h1 {
    font-size: clamp(2rem, 4.5vw, 3.1rem);
    line-height: 1.2;
    margin: 12px 0
}

.hero p {
    color: var(--mut);
    max-width: 520px
}

#q {
    width: min(420px, 100%);
    padding: 12px 16px;
    border-radius: 10px;
    border: 1px solid var(--bd);
    background: var(--card);
    color: var(--tx);
    font: inherit;
    margin-top: 8px
}

.judge {
    background: var(--code);
    color: #d8e2ef;
    border-radius: 14px;
    padding: 20px;
    font: .88rem/1.9 "JetBrains Mono", monospace
}

.judge i {
    font-style: normal;
    color: #4ade80
}

.judge s {
    text-decoration: none;
    color: #94a3b8;
    float: right
}

.tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 99px;
    background: var(--soft);
    color: var(--ac);
    font-size: .78rem;
    font-weight: 600
}

main {
    max-width: 1100px;
    margin: 0 auto;
    padding: 16px 20px 60px
}

h2.sec {
    margin: 36px 0 16px;
    font-size: 1.4rem
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px
}

.card {
    display: block;
    padding: 20px;
    border: 1px solid var(--bd);
    border-left: 5px solid var(--ac);
    border-radius: 6px 14px 14px 6px;
    background: var(--card);
    color: var(--tx)
}

a.card:hover {
    background: var(--soft)
}

.card.soon {
    border-left-color: var(--bd);
    opacity: .6
}

.card .ic {
    font-size: 1.7rem
}

.card h3 {
    margin: 6px 0 2px
}

.card p {
    margin: 0 0 10px;
    color: var(--mut);
    font-size: .92rem
}

.steps {
    counter-reset: s;
    list-style: none;
    padding: 0;
    display: grid;
    gap: 10px
}

.steps li {
    counter-increment: s;
    position: relative;
    padding: 12px 16px 12px 56px;
    background: var(--card);
    border: 1px solid var(--bd);
    border-radius: 10px
}

.steps li:before {
    content: counter(s);
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--ac);
    color: var(--card);
    display: grid;
    place-items: center;
    font-weight: 700;
    font-size: .85rem
}

.layout {
    max-width: 1100px;
    margin: 0 auto;
    padding: 24px 20px 50px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) 210px;
    gap: 32px
}

.doc {
    background: var(--card);
    border: 1px solid var(--bd);
    border-radius: 14px;
    padding: 32px 38px
}

.doc h1 {
    margin: 8px 0;
    font-size: 2rem;
    line-height: 1.25
}

.doc h2 {
    margin: 2em 0 .5em;
    padding-top: 1em;
    border-top: 1px solid var(--bd);
    font-size: 1.3rem
}

.toc {
    position: sticky;
    top: 76px;
    align-self: start;
    font-size: .88rem;
    border-left: 2px solid var(--bd);
    padding-left: 14px
}

.toc b {
    display: block;
    margin-bottom: 6px
}

.toc a {
    display: block;
    color: var(--mut);
    padding: 3px 0;
    line-height: 1.4
}

.toc a:hover {
    color: var(--ac)
}

pre {
    position: relative;
    background: var(--code);
    color: #e2e8f0;
    padding: 18px 16px 14px;
    border-radius: 10px;
    overflow-x: auto;
    font-size: .86rem;
    line-height: 1.6
}

code {
    font-family: "JetBrains Mono", ui-monospace, Consolas, monospace
}

p code,
li code,
td code {
    background: var(--soft);
    color: var(--ac);
    padding: 1px 6px;
    border-radius: 5px;
    font-size: .86em
}

.cp {
    position: absolute;
    top: 6px;
    right: 6px;
    background: #ffffff1f;
    color: #fff;
    border: 0;
    border-radius: 6px;
    padding: 3px 10px;
    cursor: pointer;
    font: .72rem "Be Vietnam Pro", sans-serif
}

.note {
    padding: 12px 16px;
    border-left: 4px solid var(--ac);
    background: var(--soft);
    border-radius: 4px 10px 10px 4px;
    margin: 16px 0
}

.tw {
    overflow-x: auto
}

table {
    border-collapse: collapse;
    width: 100%
}

th,
td {
    padding: 8px 12px;
    border: 1px solid var(--bd);
    text-align: left
}

th {
    background: var(--soft)
}

footer {
    text-align: center;
    color: var(--mut);
    padding: 24px;
    font-size: .86rem
}

@media(max-width:1000px) {
    .hero {
        grid-template-columns: 1fr;
        padding-top: 36px
    }

    .layout {
        grid-template-columns: 1fr
    }

    .toc {
        display: none
    }

    .doc {
        padding: 22px 18px
    }

    #menu {
        display: block;
        margin-left: auto
    }

    .top nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--card);
        padding: 10px;
        border-bottom: 1px solid var(--bd)
    }

    .top nav.open {
        display: flex
    }
}

@media(prefers-reduced-motion:reduce) {
    html {
        scroll-behavior: auto
    }
}

#totop {
    position: fixed;
    right: 20px;
    bottom: 20px;
    z-index: 9;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 0;
    background: var(--ac);
    color: var(--code);
    font-size: 1.3rem;
    font-weight: 700;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity .2s, visibility .2s
}

#totop.show {
    opacity: 1;
    visibility: visible
}