:root {
    color-scheme: light;
    --ink: #202124;
    --muted: #62636a;
    --line: #dedfe3;
    --surface: #ffffff;
    --page: #f7f8fa;
    --accent: #0f766e;
    --accent-soft: #e7f6f3;
    --warm: #c15337;
}

* {
    box-sizing: border-box;
    letter-spacing: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--page);
    color: var(--ink);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.85;
}

a {
    color: var(--accent);
    text-underline-offset: 3px;
}

a:hover {
    color: #0b5f59;
}

.site-header {
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.94);
}

.site-nav {
    display: flex;
    min-height: 62px;
    max-width: 1040px;
    margin: 0 auto;
    padding: 0 24px;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    color: var(--ink);
    font-size: 17px;
    font-weight: 800;
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 18px;
    font-size: 14px;
    font-weight: 650;
}

.nav-links a {
    color: var(--muted);
    text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
    color: var(--accent);
}

.page-shell {
    max-width: 820px;
    min-height: calc(100vh - 250px);
    margin: 0 auto;
    padding: 56px 28px 72px;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--warm);
    font-size: 13px;
    font-weight: 750;
}

h1,
h2,
h3 {
    color: var(--ink);
    line-height: 1.42;
}

h1 {
    margin: 0;
    font-size: 34px;
}

h2 {
    margin: 44px 0 10px;
    padding-top: 4px;
    font-size: 23px;
}

h3 {
    margin: 26px 0 6px;
    font-size: 18px;
}

.lede {
    margin: 16px 0 0;
    color: var(--muted);
    font-size: 17px;
}

.meta {
    margin: 12px 0 0;
    color: #85868c;
    font-size: 13px;
}

.content {
    margin-top: 38px;
}

.content p {
    margin: 12px 0;
}

.content ul,
.content ol {
    margin: 12px 0;
    padding-left: 24px;
}

.content li {
    margin: 6px 0;
}

.callout {
    margin: 26px 0;
    border-left: 4px solid var(--accent);
    border-radius: 0 6px 6px 0;
    background: var(--accent-soft);
    padding: 16px 18px;
}

.callout strong {
    display: block;
    margin-bottom: 3px;
}

.note {
    color: var(--muted);
    font-size: 14px;
}

.checklist {
    padding-left: 0 !important;
    list-style: none;
}

.checklist li {
    position: relative;
    padding-left: 26px;
}

.checklist li::before {
    position: absolute;
    left: 0;
    color: var(--accent);
    content: "✓";
    font-weight: 800;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    margin-top: 24px;
}

.article-link {
    display: block;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: var(--surface);
    padding: 18px;
    color: var(--ink);
    text-decoration: none;
}

.article-link:hover {
    border-color: var(--accent);
    color: var(--ink);
}

.article-link strong {
    display: block;
    line-height: 1.55;
}

.article-link span {
    display: block;
    margin-top: 6px;
    color: var(--muted);
    font-size: 14px;
    line-height: 1.65;
}

.primary-link {
    display: inline-flex;
    margin-top: 24px;
    border-radius: 6px;
    background: var(--ink);
    padding: 11px 18px;
    color: #fff;
    font-weight: 750;
    text-decoration: none;
}

.primary-link:hover {
    background: #34363a;
    color: #fff;
}

.site-footer {
    border-top: 1px solid var(--line);
    background: var(--surface);
}

.footer-inner {
    display: flex;
    max-width: 1040px;
    margin: 0 auto;
    padding: 28px 24px 36px;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
}

.footer-copy {
    color: var(--muted);
    font-size: 13px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 10px 18px;
    font-size: 13px;
}

.footer-links a,
.footer-links button {
    border: 0;
    background: none;
    color: var(--muted);
    font: inherit;
    padding: 0;
    cursor: pointer;
    text-decoration: none;
}

.footer-links a:hover,
.footer-links button:hover {
    color: var(--accent);
}

@media (max-width: 680px) {
    .site-nav {
        min-height: 56px;
        padding: 0 18px;
    }

    .nav-links {
        gap: 12px;
        font-size: 13px;
    }

    .nav-links .nav-optional {
        display: none;
    }

    .page-shell {
        padding: 38px 20px 54px;
    }

    h1 {
        font-size: 28px;
    }

    h2 {
        margin-top: 36px;
        font-size: 21px;
    }

    .article-grid {
        grid-template-columns: 1fr;
    }

    .footer-inner {
        display: block;
        padding: 24px 20px 32px;
    }

    .footer-links {
        justify-content: flex-start;
        margin-top: 14px;
    }
}