* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #1d1d1f;
    background: #fff;
    overflow-y: scroll;
    margin: 0;
}

.back-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    padding: 14px 24px;
    background: #fff;
    border-bottom: 1px solid #eee;
}

.back-nav-left {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.back-btn {
    display: inline-block;
    padding: 10px 18px;
    background-color: #000;
    color: #fff;
    text-decoration: none;
    font-family: Helvetica, Arial, sans-serif;
    font-weight: 600;
    font-size: 14px;
    border-radius: 30px;
}

.back-btn:hover {
    background-color: #333;
    color: #fff;
    text-decoration: none;
}

.main-layout {
    display: flex;
    max-width: 1200px;
    margin: 88px auto 50px;
    gap: 40px;
    padding: 0 20px;
}

.vignette-toc {
    flex: 0 0 280px;
    position: sticky;
    top: 96px;
    height: calc(100vh - 120px);
    overflow: auto;
    border-right: 1px solid #ddd;
    padding-right: 20px;
    font-family: Helvetica, Arial, sans-serif;
}

.vignette-toc h3 {
    font-size: 0.95rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: #6e6e73;
    margin: 0 0 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid #ddd;
}

.vignette-toc ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.vignette-toc li {
    margin: 0 0 6px;
}

.vignette-toc a {
    text-decoration: none;
    color: #3a3a3c;
    display: block;
    font-size: 0.95rem;
    font-weight: 400;
    line-height: 1.35;
    padding: 3px 0;
}

.vignette-toc a:hover,
.vignette-toc a:focus-visible {
    color: #000;
    text-decoration: underline;
}

.vignette-toc li.h2 > a {
    font-weight: 500;
    color: #1d1d1f;
}

.vignette-toc li.h2 > ul {
    margin: 4px 0 10px 12px;
}

.vignette-toc li.h3 > a {
    font-weight: 400;
    font-size: 0.88rem;
    color: #6e6e73;
}

.vignette-toc a.is-current {
    font-weight: 600;
    color: #000;
}

.main-layout .tutorial {
    flex: 1;
    min-width: 0;
    max-width: none;
    margin: 0;
    padding: 0 0 48px;
}

@media (max-width: 800px) {
    .main-layout {
        flex-direction: column;
        margin-top: 72px;
        gap: 16px;
    }

    .vignette-toc {
        flex: none;
        position: relative;
        top: 0;
        height: auto;
        max-height: 40vh;
        border-right: none;
        border-bottom: 1px solid #ddd;
        padding-right: 0;
        padding-bottom: 12px;
    }
}

.tutorial {
    max-width: 820px;
    margin: 88px auto 64px;
    padding: 0 20px 48px;
}

.tutorial h1 {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 600;
    margin-bottom: 8px;
}

.tutorial h2 {
    font-size: 22px;
    font-weight: 600;
    margin: 28px 0 10px;
}

.tutorial h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 24px 0 12px;
    color: #1d1d1f;
}

.tutorial h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 16px 0 6px;
}

.tutorial h4 code {
    font-size: 15px;
}

.io-count {
    font-size: 14px;
    color: #6e6e73;
    margin-bottom: 8px;
}

.io-req {
    font-weight: 700;
    color: #0b6e4f;
}

.io-opt {
    font-weight: 700;
    color: #6e6e73;
}

.lede,
.meta {
    color: #6e6e73;
    font-size: 16px;
    margin-bottom: 16px;
}

.tutorial p,
.tutorial li {
    font-size: 16px;
    color: #424245;
    margin-bottom: 10px;
}

.tutorial ol,
.tutorial ul {
    padding-left: 22px;
    margin-bottom: 16px;
}

.tutorial img {
    width: 100%;
    height: auto;
    border: 1px solid #e8e8ed;
    border-radius: 12px;
    margin: 8px 0 20px;
}

.tutorial img[src$="-io.svg"] {
    width: 100%;
    max-width: 100%;
    height: auto;
}

.tutorial figcaption {
    font-size: 13px;
    color: #6e6e73;
    margin-top: -12px;
    margin-bottom: 20px;
}

.tutorial pre {
    background: #f5f5f7;
    border: 1px solid #e8e8ed;
    border-radius: 10px;
    padding: 14px 16px;
    overflow-x: auto;
    font-size: 13px;
    line-height: 1.45;
    margin-bottom: 16px;
}

.tutorial a {
    color: #0071e3;
}

.tutorial-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 24px 0 8px;
}

.tutorial-nav a {
    display: inline-block;
    padding: 8px 16px;
    background: #0071e3;
    color: #fff;
    text-decoration: none;
    border-radius: 999px;
    font-size: 14px;
    font-weight: 600;
}

.tutorial-nav a:hover,
.tutorial-nav a:focus-visible {
    background: #005bb5;
}

.grid-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 12px;
    margin: 20px 0;
}

.grid-list a {
    display: block;
    padding: 16px;
    background: #f5f5f7;
    border: 1px solid #e8e8ed;
    border-radius: 12px;
    text-decoration: none;
    color: #1d1d1f;
    font-weight: 600;
}

.grid-list a:hover {
    border-color: #0071e3;
}

.tutorial h2 {
    scroll-margin-top: 88px;
}

.toc {
    background: #f5f5f7;
    border: 1px solid #e8e8ed;
    border-radius: 12px;
    padding: 16px 20px 8px;
    margin: 8px 0 24px;
}

.toc h2 {
    font-size: 15px;
    margin: 0 0 8px;
}

.toc ol {
    margin-bottom: 8px;
}

.note {
    background: #f5f5f7;
    border-left: 3px solid #0071e3;
    border-radius: 0 10px 10px 0;
    padding: 12px 16px;
    margin: 12px 0 20px;
}

.note p {
    margin-bottom: 0;
}

.tutorial table {
    width: 100%;
    border-collapse: collapse;
    margin: 8px 0 20px;
    font-size: 15px;
}

.tutorial th,
.tutorial td {
    text-align: left;
    padding: 8px 10px;
    border-bottom: 1px solid #e8e8ed;
    vertical-align: top;
}

.tutorial th {
    color: #1d1d1f;
    font-weight: 600;
}