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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --text: #172033;
    --muted: #5f6f86;
    --border: #dce4ef;
    --surface: #ffffff;
    --surface-muted: #f6f8fb;
    --accent: #0f766e;
    --footer: #0f172a;
}

html {
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: var(--text);
    background: var(--surface);
    font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans CJK SC', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.75;
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.header-inner {
    width: min(1080px, calc(100% - 40px));
    min-height: 64px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 11px;
    min-width: 0;
    font-weight: 700;
}

.brand img {
    width: 40px;
    height: 40px;
    flex: 0 0 40px;
    display: block;
    object-fit: contain;
}

.home-link {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 7px 11px;
    color: var(--muted);
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
}

.home-link:hover,
.home-link:focus-visible {
    color: var(--primary);
    background: #eff6ff;
    outline: none;
}

.page-hero {
    background: var(--surface-muted);
    border-bottom: 1px solid var(--border);
}

.hero-inner {
    width: min(900px, calc(100% - 40px));
    margin: 0 auto;
    padding: 68px 0 54px;
}

.eyebrow {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
    color: var(--primary);
    font-size: 0.88rem;
    font-weight: 700;
}

.page-hero h1 {
    max-width: 760px;
    margin-bottom: 14px;
    font-size: 2.45rem;
    line-height: 1.2;
    letter-spacing: 0;
}

.page-hero p {
    max-width: 760px;
    color: var(--muted);
    font-size: 1.04rem;
}

.updated-at {
    display: block;
    margin-top: 18px;
    color: var(--muted);
    font-size: 0.84rem;
}

.page-main {
    flex: 1;
}

.document {
    width: min(900px, calc(100% - 40px));
    margin: 0 auto;
    padding: 42px 0 72px;
}

.page-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 20px;
    padding-bottom: 22px;
    border-bottom: 1px solid var(--border);
}

.page-nav a {
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 600;
}

.page-nav a:hover,
.page-nav a:focus-visible {
    color: var(--primary);
    outline: none;
}

.content-section {
    padding: 34px 0;
    border-bottom: 1px solid var(--border);
    scroll-margin-top: 84px;
}

.content-section:last-child {
    border-bottom: 0;
}

.content-section h2 {
    margin-bottom: 14px;
    font-size: 1.42rem;
    line-height: 1.35;
    letter-spacing: 0;
}

.content-section h3 {
    margin: 24px 0 8px;
    font-size: 1.05rem;
    line-height: 1.45;
    letter-spacing: 0;
}

.content-section p,
.content-section ul,
.content-section ol,
.content-section dl {
    color: #3f4d63;
}

.content-section p + p {
    margin-top: 14px;
}

.content-section ul,
.content-section ol {
    margin-top: 12px;
    padding-left: 1.35rem;
}

.content-section li + li {
    margin-top: 9px;
}

.content-section strong {
    color: var(--text);
}

.content-section a {
    color: var(--primary-dark);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.definition-list {
    margin-top: 16px;
    border-top: 1px solid var(--border);
}

.definition-row {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 24px;
    padding: 17px 0;
    border-bottom: 1px solid var(--border);
}

.definition-row dt {
    color: var(--text);
    font-weight: 700;
}

.definition-row dd {
    min-width: 0;
    color: #3f4d63;
}

.callout {
    margin-top: 20px;
    padding: 16px 18px;
    border-left: 4px solid var(--accent);
    background: #f0fdfa;
    color: #315d59;
}

.contact-panel {
    margin-top: 20px;
    padding: 24px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface-muted);
}

.contact-address {
    display: block;
    margin: 10px 0 20px;
    color: var(--text);
    font-size: 1.12rem;
    font-weight: 700;
    overflow-wrap: anywhere;
}

.primary-action {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 42px;
    padding: 8px 15px;
    border-radius: 6px;
    color: #fff !important;
    background: var(--primary);
    font-weight: 700;
    text-decoration: none !important;
}

.primary-action:hover,
.primary-action:focus-visible {
    background: var(--primary-dark);
    outline: none;
}

.site-footer {
    padding: 26px 20px;
    color: #a8b5c9;
    background: var(--footer);
    text-align: center;
    font-size: 0.84rem;
}

@media (max-width: 640px) {
    .header-inner,
    .hero-inner,
    .document {
        width: min(calc(100% - 28px), 900px);
    }

    .brand span {
        font-size: 0.95rem;
    }

    .home-link span {
        display: none;
    }

    .page-hero h1 {
        font-size: 2rem;
    }

    .hero-inner {
        padding: 50px 0 40px;
    }

    .document {
        padding-top: 30px;
    }

    .definition-row {
        grid-template-columns: 1fr;
        gap: 5px;
    }

    .contact-panel {
        padding: 18px;
    }
}