/* 使用 TinyImage 的紫蓝色语义色；正文和目录在窄屏下自然排版，不依赖脚本。 */
:root {
    color-scheme: light dark;
    --background: #f7f8fc;
    --surface: #ffffff;
    --text: #171923;
    --muted: #5e6475;
    --primary: #4853ce;
    --tint: #eceeff;
    --border: #dee2ef;
    --subtle: #f1f3f8;
    --shadow: 0 12px 40px rgb(34 43 89 / 4%);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    font-synthesis: none;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 2rem; }
body { margin: 0; background: var(--background); color: var(--text); font-size: 1rem; line-height: 1.75; }
a { color: var(--primary); text-decoration-thickness: 1px; text-underline-offset: 0.2em; overflow-wrap: anywhere; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible { outline: 3px solid var(--primary); outline-offset: 5px; border-radius: 3px; }
strong { font-weight: 650; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { text-wrap: balance; }
.skip-link { position: absolute; top: -6rem; left: 1rem; padding: 0.6rem 1rem; background: var(--surface); z-index: 5; }
.skip-link:focus { top: 1rem; }
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.header-inner, .page-shell, .site-footer > div { width: min(1120px, calc(100% - 4rem)); margin-inline: auto; }
.header-inner { min-height: 86px; display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; }
.brand { display: inline-flex; align-items: center; gap: 0.7rem; color: var(--text); text-decoration: none; font-size: 1.25rem; font-weight: 750; letter-spacing: -0.04em; }
.brand-mark { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; background: #5965e8; color: #fff; font-weight: 800; font-size: 1.1rem; letter-spacing: -0.05em; }
.header-contact { font-size: 0.9rem; text-decoration: none; font-weight: 600; }
.header-contact span { margin-left: 0.35rem; }
.hero { padding: 4.5rem 0 2.5rem; max-width: 850px; }
.eyebrow, .section-number, .contents-label { text-transform: uppercase; font-size: 0.72rem; font-weight: 750; letter-spacing: 0.13em; }
.eyebrow { color: var(--primary); display: flex; align-items: center; gap: 0.6rem; margin-bottom: 1.1rem; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--primary); }
h1 { font-size: clamp(2.5rem, 5.5vw, 4rem); line-height: 1.13; letter-spacing: -0.055em; font-weight: 750; margin-bottom: 1.35rem; }
.heading-dot { color: var(--primary); }
.hero-copy { max-width: 720px; font-size: 1.16rem; line-height: 1.75; color: var(--muted); margin-bottom: 1.8rem; }
.policy-meta { display: flex; flex-wrap: wrap; gap: 1rem 2.8rem; margin: 0; }
.policy-meta dt { font-size: 0.75rem; color: var(--muted); margin-bottom: 0.15rem; }
.policy-meta dd { margin: 0; font-size: 0.88rem; font-weight: 600; }
.overview { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border: 1px solid var(--border); border-radius: 18px; background: var(--surface); box-shadow: var(--shadow); margin: 0 0 4rem; }
.overview-item { padding: 1.65rem 1.8rem; }
.overview-item + .overview-item { border-left: 1px solid var(--border); }
.item-number { color: var(--primary); font-size: 0.75rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.overview h2 { font-size: 1rem; line-height: 1.45; margin: 0.55rem 0 0.4rem; letter-spacing: -0.02em; }
.overview p { font-size: 0.87rem; line-height: 1.65; color: var(--muted); margin: 0; }
.policy-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 3.6rem; align-items: start; }
.contents { position: sticky; top: 2rem; }
.contents-label { color: var(--muted); margin-bottom: 0.8rem; }
.contents ol { margin: 0; padding: 0; list-style: none; counter-reset: sections; border-top: 1px solid var(--border); }
.contents li { counter-increment: sections; border-bottom: 1px solid var(--border); }
.contents a { display: flex; align-items: baseline; gap: 0.65rem; font-size: 0.79rem; line-height: 1.45; padding: 0.72rem 0; text-decoration: none; color: var(--muted); }
.contents a::before { content: counter(sections, decimal-leading-zero); color: var(--primary); font-size: 0.68rem; font-variant-numeric: tabular-nums; }
.contents a:hover { color: var(--primary); }
.policy { min-width: 0; font-size: 1.01rem; }
.policy section { padding: 0 0 2.6rem; margin-bottom: 2.6rem; border-bottom: 1px solid var(--border); scroll-margin-top: 1.5rem; }
.section-number { color: var(--primary); margin-bottom: 0.6rem; }
.policy h2 { font-size: clamp(1.5rem, 2.5vw, 1.85rem); line-height: 1.3; letter-spacing: -0.035em; margin-bottom: 1rem; }
.policy h3 { font-size: 1.12rem; line-height: 1.5; margin: 1.65rem 0 0.6rem; letter-spacing: -0.015em; }
.policy p { margin-bottom: 1rem; }
.policy p:last-child { margin-bottom: 0; }
code { font-family: ui-monospace, "Cascadia Code", Consolas, monospace; font-size: 0.8em; background: var(--subtle); padding: 0.15em 0.35em; border-radius: 4px; overflow-wrap: anywhere; }
.retention-list { margin: 0; }
.retention-list > div { border-left: 2px solid var(--border); padding-left: 1.15rem; margin-bottom: 1.4rem; }
.retention-list dt { font-weight: 650; margin-bottom: 0.35rem; }
.retention-list dd { margin: 0; }
.choice-list { padding-left: 1.2rem; margin: 0; }
.choice-list li { padding-left: 0.35rem; margin-bottom: 1rem; }
.choice-list li::marker { color: var(--primary); }
.policy .contact-section { padding: 2rem; border: 1px solid var(--border); background: var(--tint); border-radius: 18px; margin-bottom: 4rem; }
.contact-email { display: inline-block; font-size: 1.12rem; font-weight: 650; }
.contact-email span { margin-left: 0.3rem; }
.site-footer { border-top: 1px solid var(--border); padding: 1.7rem 0; }
.site-footer > div { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.8rem 1.5rem; font-size: 0.78rem; color: var(--muted); }
.site-footer a { text-decoration: none; }

/* 浅深色分别定义正文与边框对比度，跟随系统偏好，无需存储用户选择。 */
@media (prefers-color-scheme: dark) {
    :root {
        --background: #11131b;
        --surface: #1a1d28;
        --text: #edf0fa;
        --muted: #acb3c8;
        --primary: #a8afff;
        --tint: #222641;
        --border: #34394d;
        --subtle: #252a3b;
        --shadow: none;
    }
}
@media (max-width: 900px) {
    .policy-layout { grid-template-columns: minmax(0, 1fr); gap: 2.5rem; }
    .contents { position: static; }
    .contents ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 1.8rem; }
    .overview { margin-bottom: 2.5rem; }
    .overview-item { padding: 1.4rem; }
    .hero { padding-top: 3rem; }
}
@media (max-width: 560px) {
    .header-inner, .page-shell, .site-footer > div { width: calc(100% - 2.25rem); }
    .header-inner { min-height: 72px; }
    .hero { padding: 2.5rem 0 2rem; }
    .hero-copy { font-size: 1.05rem; }
    .policy-meta { gap: 0.8rem 1.8rem; }
    .overview { grid-template-columns: minmax(0, 1fr); border-radius: 14px; }
    .overview-item { padding: 1.05rem 1.25rem; }
    .overview-item + .overview-item { border-left: 0; border-top: 1px solid var(--border); }
    .overview h2 { margin-top: 0.15rem; }
    .overview p { font-size: 0.87rem; }
    .contents ol { column-gap: 1rem; }
    .contents a { gap: 0.4rem; }
    .policy { font-size: 0.97rem; }
    .policy section { padding-bottom: 2rem; margin-bottom: 2rem; }
    .policy .contact-section { padding: 1.35rem; }
}
@media (max-width: 350px) {
    .header-contact { font-size: 0.78rem; }
    .contents ol { grid-template-columns: minmax(0, 1fr); }
}

/* 打印保留完整正文；移除导航装饰，避免目录和粘性定位占据纸面。 */
@media print {
    :root { --background: #fff; --surface: #fff; --text: #000; --muted: #333; --primary: #000; --tint: #fff; --border: #ccc; --subtle: #fff; }
    body { font-size: 10pt; }
    .page-shell { width: 100%; }
    .site-header, .contents, .overview, .site-footer, .skip-link, .eyebrow { display: none; }
    .hero { max-width: none; padding: 0 0 1.5rem; }
    h1 { font-size: 28pt; }
    .hero-copy { font-size: 11pt; }
    .policy-layout { display: block; }
    .policy { font-size: 10pt; }
    .policy h2 { font-size: 15pt; }
    .policy h3 { font-size: 11pt; }
    .policy h2, .policy h3, .section-number { break-after: avoid; }
    .policy section { padding-bottom: 1rem; margin-bottom: 1rem; }
    .policy .contact-section { border: 0; border-radius: 0; padding: 0; margin: 0; }
    p, li { orphans: 3; widows: 3; }
    a { color: #000; }
}