/* ===== DESIGN.md tokens ================================================
   配色、圆角、字阶、间距严格取自根目录 DESIGN.md 的「ai」领域 token
   集，勿在本文件内新增规范外的色值、圆角或字号。字体按 DESIGN.md 的四大
   角色（display / serif / sans / mono）承担，全部带系统字体兜底栈。
   ===================================================================== */
:root[data-domain="ai"], .theme-neural {
    /* colors */
    --wd-primary: #8b5cf6;
    --wd-on-primary: #ffffff;
    --wd-ink: #e6edf3;
    --wd-ink-soft: #c9d1d9;
    --wd-body: #8b949e;
    --wd-hairline: #21262d;
    --wd-canvas: #0d1117;
    --wd-canvas-soft: #161b22;
    --wd-link: #a3e635;
    --wd-footer-bg: #161b22;
    --wd-footer-ink: #e6edf3;
    /* spacing — 4px 基数 */
    --wd-xxs: 2px;
    --wd-xs: 4px;
    --wd-sm: 8px;
    --wd-md: 12px;
    --wd-lg: 16px;
    --wd-xl: 20px;
    --wd-2xl: 24px;
    --wd-3xl: 32px;
    --wd-4xl: 48px;
    --wd-5xl: 64px;
    /* rounded — 领域自适应圆角 */
    --wd-radius: 4px;
    --wd-radius-card: 10px;
    --wd-r-full: 9999px;
    /* type roles */
    --wd-display: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
    --wd-serif: Georgia, "Times New Roman", Times, serif;
    --wd-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Helvetica, Arial, sans-serif;
    --wd-mono: ui-monospace, "Cascadia Code", "JetBrains Mono", "SFMono-Regular", Menlo, monospace;
}

/* ===== 页面底与基础排版 ===== */
*, *::before, *::after {
    box-sizing: border-box;
}

.theme-neural {
    margin: 0;
    background: var(--wd-canvas);
    color: var(--wd-ink);
    font-family: var(--wd-sans);
    font-size: 17px;
    line-height: 1.45;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.na-main {
    min-height: 80vh;
}

/* ===== masthead-band / nav-bar ===== */
.na-header {
    position: sticky;
    top: 0;
    z-index: 40;
    background: color-mix(in srgb, var(--wd-canvas) 92%, transparent);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--wd-hairline);
}

.na-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--wd-lg);
    padding: var(--wd-md) var(--wd-xl);
    position: relative;
    max-width: 1400px;
    margin: 0 auto;
}

.na-brand {
    font-family: var(--wd-display);
    font-weight: 700;
    color: var(--wd-ink);
    text-decoration: none;
    font-size: 32px;
    line-height: 35.2px;
    letter-spacing: -0.3px;
    display: inline-flex;
    align-items: center;
    gap: var(--wd-sm);
    min-width: 0;
}

.na-brand:hover {
    opacity: 0.85;
}

.na-nav {
    display: flex;
    align-items: center;
    gap: var(--wd-xl);
}

.na-nav a {
    color: var(--wd-ink);
    text-decoration: none;
    font-family: var(--wd-sans);
    font-size: 14px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.4px;
    text-transform: uppercase;
    padding: var(--wd-xs) 0;
    transition: color 0.15s ease;
}

.na-nav a:hover {
    color: var(--wd-link);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.na-menu-toggle {
    display: none;
    text-decoration: none;
    color: inherit;
}

/* ===== category-eyebrow ===== */
.na-kicker {
    color: var(--wd-link);
    text-transform: uppercase;
    margin-bottom: var(--wd-sm);
    font-family: var(--wd-mono);
    font-size: 13px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.4px;
}

/* ===== 广告位：与正文保持 24px 以上视觉隔离 ===== */
.na-ad:has(.ad) {
    margin: var(--wd-4xl) 0;
    padding: var(--wd-2xl) 0;
    border-top: 1px solid var(--wd-hairline);
    border-bottom: 1px solid var(--wd-hairline);
    text-align: center;
    background: var(--wd-canvas);
}

/* ===== 通用页头 ===== */
.na-page-head {
    padding-bottom: var(--wd-lg);
    margin-bottom: var(--wd-3xl);
    border-bottom: 1px solid var(--wd-hairline);
}

.na-page-head h1 {
    font-family: var(--wd-display);
    font-weight: 700;
    margin: var(--wd-sm) 0;
    overflow-wrap: break-word;
    font-size: 48px;
    line-height: 52.8px;
    letter-spacing: -0.4px;
}

.na-page-head p {
    color: var(--wd-body);
    margin: 0;
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

.na-page-head a {
    color: var(--wd-link);
    font-weight: 700;
    text-decoration: underline;
}

/* ===== 列表 / 卡片 ===== */
.na-wrap {
    max-width: 1400px;
    margin: auto;
    padding: var(--wd-3xl) var(--wd-xl) var(--wd-4xl);
}

.na-with-side {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: var(--wd-4xl);
}

.na-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--wd-3xl) var(--wd-2xl);
}

.na-card {
    display: flex;
    flex-direction: column;
    background: var(--wd-canvas-soft);
    color: var(--wd-ink);
    border: 1px solid var(--wd-hairline);
    border-radius: var(--wd-radius-card);
    overflow: hidden;
    text-decoration: none;
    padding: 0 0 var(--wd-lg);
    transition: border-color 0.15s ease, transform 0.15s ease;
}

.na-card:hover {
    border-color: var(--wd-primary);
    transform: translateY(-1px);
}

.na-card img {
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
    display: block;
    margin-bottom: var(--wd-md);
    background: var(--wd-hairline);
}

.na-card .na-kicker, .na-card h2, .na-card p {
    padding: 0 var(--wd-lg);
}

.na-card h2 {
    font-family: var(--wd-sans);
    font-weight: 700;
    margin: 0 0 var(--wd-sm);
    font-size: 20px;
    line-height: 26px;
    letter-spacing: -0.28px;
}

.na-card:hover h2 {
    text-decoration: underline;
}

.na-card p {
    color: var(--wd-body);
    margin: 0;
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

.na-card-plain {
    padding: var(--wd-xl);
}

.na-card-plain .na-kicker, .na-card-plain h2, .na-card-plain p {
    padding: 0;
}

.na-empty {
    grid-column: 1 / -1;
    text-align: center;
    padding: var(--wd-4xl) 0;
    color: var(--wd-body);
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

.na-pager {
    margin-top: var(--wd-3xl);
    padding-top: var(--wd-2xl);
    border-top: 1px solid var(--wd-hairline);
}

.na-pager nav {
    display: flex;
    justify-content: center;
    gap: var(--wd-sm);
    flex-wrap: wrap;
}

/* ===== 侧栏 ===== */
.na-side {
    display: flex;
    flex-direction: column;
    gap: var(--wd-3xl);
    min-width: 0;
}

.na-side-box {
    display: flex;
    flex-direction: column;
    background: var(--wd-canvas);
    border-radius: var(--wd-radius);
}

.na-side-box h3 {
    margin: 0 0 var(--wd-sm);
    padding-bottom: var(--wd-sm);
    border-bottom: 2px solid var(--wd-primary);
    text-transform: uppercase;
    color: var(--wd-ink);
    font-family: var(--wd-mono);
    font-size: 13px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.4px;
}

.na-side-box a {
    display: block;
    color: var(--wd-ink);
    text-decoration: none;
    padding: var(--wd-lg) 0;
    border-bottom: 1px solid var(--wd-hairline);
    font-family: var(--wd-sans);
    font-size: 17px;
    font-weight: 700;
    line-height: 22px;
    letter-spacing: -0.144px;
    transition: background-color 0.15s ease, padding-left 0.15s ease;
}

.na-side-box a:hover {
    text-decoration: underline;
    background: var(--wd-canvas-soft);
    padding-left: var(--wd-xs);
}

/* ===== 长文型页面（about / contact） ===== */
.na-prose-wrap {
    max-width: 760px;
    margin: auto;
}

.na-panel {
    background: var(--wd-canvas);
    border-radius: var(--wd-radius);
}

.na-panel h2 {
    font-family: var(--wd-display);
    font-weight: 700;
    margin: var(--wd-3xl) 0 var(--wd-md);
    font-size: 26px;
    line-height: 30px;
}

.na-panel h2:first-child {
    margin-top: 0;
}

.na-panel p {
    color: var(--wd-ink);
    margin: 0 0 var(--wd-lg);
    font-family: var(--wd-serif);
    font-size: 19px;
    line-height: 31.35px;
    letter-spacing: 0.108px;
}

.na-source-list {
    list-style: none;
    padding: 0;
    margin: var(--wd-lg) 0 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
    gap: 0;
}

.na-source-list li {
    padding: var(--wd-md) 0;
    border-bottom: 1px solid var(--wd-hairline);
    color: var(--wd-body);
    font-family: var(--wd-mono);
    font-size: 13px;
    line-height: 18px;
    letter-spacing: 0.4px;
    overflow-wrap: anywhere;
}

.na-flash {
    padding: var(--wd-md) var(--wd-lg);
    margin-bottom: var(--wd-2xl);
    border: 1px solid var(--wd-primary);
    border-radius: var(--wd-radius);
    color: var(--wd-ink);
    font-family: var(--wd-sans);
    font-size: 14px;
    line-height: 18px;
    letter-spacing: 0.4px;
}

/* ===== 表单：触控高度 >= 44px ===== */
.na-form {
    display: flex;
    flex-direction: column;
    gap: var(--wd-2xl);
}

.na-form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--wd-2xl);
}

.na-form label {
    display: flex;
    flex-direction: column;
    gap: var(--wd-sm);
}

.na-form span {
    color: var(--wd-ink);
    text-transform: uppercase;
    font-family: var(--wd-mono);
    font-size: 13px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.4px;
}

.na-form input, .na-form textarea {
    width: 100%;
    box-sizing: border-box;
    background: var(--wd-canvas-soft);
    color: var(--wd-ink);
    border: 1px solid var(--wd-hairline);
    border-radius: var(--wd-radius);
    padding: var(--wd-md) var(--wd-lg);
    min-height: 44px;
    font-family: var(--wd-sans);
    font-size: 17px;
    line-height: 20px;
}

.na-form input:focus, .na-form textarea:focus {
    outline: 2px solid var(--wd-primary);
    outline-offset: 1px;
}

.na-form button {
    align-self: flex-start;
    background: var(--wd-primary);
    color: var(--wd-on-primary);
    border: none;
    border-radius: var(--wd-radius);
    padding: 10px var(--wd-2xl);
    cursor: pointer;
    font-family: var(--wd-sans);
    font-size: 16px;
    font-weight: 700;
    line-height: 20px;
    letter-spacing: 0.3px;
    min-height: 44px;
    transition: transform 0.15s ease, opacity 0.15s ease;
}

.na-form button:hover {
    transform: translateY(-1px);
    opacity: 0.9;
}

/* ===== footer ===== */
.na-footer {
    background: var(--wd-footer-bg);
    color: var(--wd-footer-ink);
    padding: var(--wd-4xl) var(--wd-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--wd-2xl);
    font-family: var(--wd-sans);
    font-size: 14px;
    line-height: 18px;
    letter-spacing: 0.4px;
}

.na-footer nav {
    display: flex;
    gap: var(--wd-2xl);
}

.na-footer a {
    color: var(--wd-footer-ink);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    min-height: 44px;
}

.na-footer a:hover {
    text-decoration: underline;
}

/* ===== 合规页（privacy / terms） ===== */
.na-breadcrumb {
    color: var(--wd-body);
    margin-bottom: var(--wd-2xl);
    font-family: var(--wd-sans);
    font-size: 14px;
    line-height: 18px;
    letter-spacing: 0.4px;
}

.na-breadcrumb a {
    color: var(--wd-body);
    text-decoration: none;
    display: inline-block;
    padding: var(--wd-sm) 0;
}

.na-breadcrumb a:hover {
    color: var(--wd-link);
    text-decoration: underline;
}

.na-breadcrumb .is-current {
    color: var(--wd-ink);
}

.na-legal {
    max-width: 760px;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.na-legal h1 {
    font-family: var(--wd-display);
    font-weight: 700;
    margin: 0 0 var(--wd-2xl);
    padding-bottom: var(--wd-lg);
    border-bottom: 2px solid var(--wd-primary);
    font-size: 48px;
    line-height: 52.8px;
    letter-spacing: -0.4px;
}

.na-legal h2 {
    font-family: var(--wd-display);
    font-weight: 700;
    margin: var(--wd-4xl) 0 var(--wd-lg);
    font-size: 26px;
    line-height: 30px;
}

.na-legal h3 {
    font-family: var(--wd-sans);
    font-weight: 700;
    margin: var(--wd-3xl) 0 var(--wd-md);
    font-size: 20px;
    line-height: 24px;
    letter-spacing: -0.28px;
}

.na-legal h4 {
    font-family: var(--wd-sans);
    font-weight: 700;
    margin: var(--wd-2xl) 0 var(--wd-sm);
    font-size: 17px;
    line-height: 22px;
    letter-spacing: -0.144px;
}

.na-legal p {
    color: var(--wd-ink);
    margin: var(--wd-lg) 0;
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

.na-legal p.is-strong {
    font-weight: 700;
}

.na-legal a {
    color: var(--wd-link);
    text-decoration: underline;
}

.na-legal ul {
    margin: var(--wd-lg) 0;
    padding-left: var(--wd-xl);
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

.na-legal li {
    margin: var(--wd-sm) 0;
}

.na-legal-updated {
    margin-top: var(--wd-4xl);
    padding-top: var(--wd-2xl);
    border-top: 1px solid var(--wd-hairline);
}

.na-legal-updated p {
    color: var(--wd-body);
    font-family: var(--wd-mono);
    font-size: 13px;
    line-height: 18px;
    letter-spacing: 0.4px;
}

/* ===== 通用响应式 ===== */
@media (max-width: 1023px) {
    .na-with-side {
        grid-template-columns: minmax(0, 1fr);
    }
    .na-page-head h1 {
        font-size: 36px;
        line-height: 40px;
        letter-spacing: -0.3px;
    }
    .na-legal h1 {
        font-size: 36px;
        line-height: 40px;
        letter-spacing: -0.3px;
    }
}

@media (max-width: 767px) {
    .na-wrap {
        padding: var(--wd-2xl) var(--wd-lg) var(--wd-3xl);
    }
    .na-form-row {
        grid-template-columns: 1fr;
    }
    .na-page-head h1, .na-legal h1 {
        font-size: 28px;
        line-height: 32px;
        letter-spacing: 0;
    }
    .na-menu-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
        min-width: 44px;
        min-height: 44px;
        cursor: pointer;
        font-family: var(--wd-sans);
        font-size: 22px;
        line-height: 24px;
        color: var(--wd-ink);
        user-select: none;
    }
    .na-nav {
        display: none;
        flex-direction: column;
        gap: var(--wd-xs);
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--wd-canvas);
        border-bottom: 1px solid var(--wd-primary);
        padding: var(--wd-md) var(--wd-xl);
        z-index: 50;
    }
    .na-nav a {
        display: flex;
        align-items: center;
        min-height: 44px;
        font-size: 15px;
        border-bottom: 1px solid var(--wd-hairline);
    }
    .na-nav a:last-child {
        border-bottom: none;
    }
    .na-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--wd-xl);
    }
    .na-footer nav {
        flex-wrap: wrap;
        gap: var(--wd-lg);
    }
    .na-brand {
        font-size: 24px;
        line-height: 28px;
    }
}

/* ===== 骨架：左侧层级刻度轴 + 右侧分层节点流 =========================
   本主题不使用任何网格卡片墙或分屏舞台：内容被拆成若干「层」(layer)，
   每层的条目是等级一致的节点 (node)，节点通过发丝连接线挂在层脊上，
   左侧是 sticky 的层级刻度轴，用单色号标出当前深度。
   ================================================================= */
.na-atlas {
    display: grid;
    grid-template-columns: 128px minmax(0, 1fr);
    gap: var(--wd-4xl);
    align-items: start;
}

.na-axis {
    position: sticky;
    top: 96px;
    display: flex;
    flex-direction: column;
    gap: var(--wd-3xl);
    padding-top: var(--wd-sm);
}

.na-axis-item {
    position: relative;
    padding-left: var(--wd-xl);
    color: var(--wd-body);
    font-family: var(--wd-mono);
    font-size: 13px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.4px;
    text-transform: uppercase;
}

.na-axis-item::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 5px;
    width: 8px;
    height: 8px;
    border-radius: var(--wd-r-full);
    background: var(--wd-primary);
}

.na-axis-item::after {
    content: "";
    position: absolute;
    left: 6px;
    top: 17px;
    bottom: calc(var(--wd-3xl) * -1);
    width: 1px;
    background: var(--wd-hairline);
}

.na-axis-item:last-child::after {
    display: none;
}

.na-axis-item b {
    display: block;
    color: var(--wd-ink);
    font-family: var(--wd-sans);
    font-size: 14px;
    line-height: 20px;
    letter-spacing: -0.1px;
}

.na-flow {
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: var(--wd-4xl);
}

/* 根节点：整幅横向节点，左图右文 */
.na-root {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    gap: var(--wd-3xl);
    align-items: center;
    text-decoration: none;
    color: var(--wd-ink);
    background: var(--wd-canvas-soft);
    border: 1px solid var(--wd-hairline);
    border-left: 4px solid var(--wd-primary);
    border-radius: var(--wd-radius-card);
    overflow: hidden;
    transition: border-color 0.15s ease;
}

.na-root:hover {
    border-color: var(--wd-primary);
}

.na-root img {
    width: 100%;
    aspect-ratio: 16/9;
    object-fit: cover;
    display: block;
    background: var(--wd-hairline);
}

.na-root-body {
    padding: var(--wd-3xl) var(--wd-3xl) var(--wd-3xl) 0;
    min-width: 0;
}

.na-root h1 {
    font-family: var(--wd-display);
    font-weight: 700;
    margin: 0 0 var(--wd-lg);
    overflow-wrap: break-word;
    font-size: 48px;
    line-height: 52.8px;
    letter-spacing: -0.4px;
}

.na-root:hover h1 {
    text-decoration: underline;
}

.na-root p {
    color: var(--wd-body);
    margin: 0;
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

/* 层：一条层脊 + 挂在脊上的等级节点 */
.na-layer {
    position: relative;
    padding-top: var(--wd-3xl);
    border-top: 1px solid var(--wd-hairline);
}

.na-layer-label {
    position: absolute;
    top: calc(var(--wd-md) * -1);
    left: 0;
    background: var(--wd-canvas);
    padding-right: var(--wd-md);
    color: var(--wd-link);
    font-family: var(--wd-mono);
    font-size: 13px;
    font-weight: 700;
    line-height: 18px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.na-nodes {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--wd-2xl);
}

.na-node {
    position: relative;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: var(--wd-ink);
    background: var(--wd-canvas-soft);
    border: 1px solid var(--wd-hairline);
    border-radius: var(--wd-radius-card);
    overflow: hidden;
    padding-bottom: var(--wd-lg);
    transition: border-color 0.15s ease, transform 0.15s ease;
}

/* 节点连接线：把节点挂回上方层脊 */
.na-node::before {
    content: "";
    position: absolute;
    top: calc(var(--wd-3xl) * -1);
    left: var(--wd-2xl);
    width: 1px;
    height: var(--wd-3xl);
    background: var(--wd-hairline);
}

.na-node:hover {
    border-color: var(--wd-primary);
    transform: translateY(-1px);
}

.na-node img {
    width: 100%;
    aspect-ratio: 3/2;
    object-fit: cover;
    display: block;
    margin-bottom: var(--wd-md);
    background: var(--wd-hairline);
}

.na-node-body {
    padding: 0 var(--wd-lg);
    min-width: 0;
}

.na-node h2 {
    font-family: var(--wd-sans);
    font-weight: 700;
    margin: 0 0 var(--wd-sm);
    font-size: 20px;
    line-height: 26px;
    letter-spacing: -0.28px;
}

.na-node:hover h2 {
    text-decoration: underline;
}

.na-node p {
    color: var(--wd-body);
    margin: 0;
    font-family: var(--wd-serif);
    font-size: 16px;
    line-height: 24px;
    letter-spacing: 0.09px;
}

@media (max-width: 1023px) {
    .na-atlas {
        grid-template-columns: minmax(0, 1fr);
        gap: var(--wd-3xl);
    }
    .na-axis {
        position: static;
        flex-direction: row;
        flex-wrap: wrap;
        gap: var(--wd-xl);
    }
    .na-axis-item::after {
        display: none;
    }
    .na-root {
        grid-template-columns: minmax(0, 1fr);
    }
    .na-root-body {
        padding: 0 var(--wd-2xl) var(--wd-2xl);
    }
    .na-root h1 {
        font-size: 32px;
        line-height: 36px;
        letter-spacing: -0.3px;
    }
}

@media (max-width: 767px) {
    .na-node::before {
        display: none;
    }
    .na-root h1 {
        font-size: 26px;
        line-height: 30px;
    }
}


/* 分类页 category_banner2 插在文章列表内部：grid 布局下必须跨满整行，
   否则广告会被当成一张卡片挤进某一列（AGENTS.md §4.2）。 */
.cat-ad-row {
    grid-column: 1 / -1;
    width: 100%;
}