/* Nullprint 官网共用样式(首页 + 条款 / 隐私 / 退款页)。品牌色:深蓝 #13263A,点缀青绿 #5FD4BC。 */
:root {
  --navy: #13263A;
  --navy-2: #1B3350;
  --teal: #5FD4BC;
  --teal-ink: #1E8A76;
  --bg: #F5F7FA;
  --surface: #FFFFFF;
  --surface-2: #EEF2F6;
  --line: #DCE3EA;
  --ink: #13263A;
  --body: #34475B;
  --muted: #5E7084;
  --faint: #8A99A8;
  --on-navy: #F4F6FA;
  --on-navy-muted: #A9B8C8;
  --maxw: 72rem;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0E1A27;
    --surface: #13222F;
    --surface-2: #182A3A;
    --line: #23384B;
    --ink: #EEF2F6;
    --body: #C5D0DB;
    --muted: #93A3B4;
    --faint: #6B7D8F;
    --teal-ink: #5FD4BC;
    --navy: #0A1520;
    --navy-2: #13222F;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--body);
  font-family: var(--sans); font-size: 16px; line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--teal-ink); }
h1, h2, h3 { color: var(--ink); margin: 0; font-weight: 650; letter-spacing: -.01em; line-height: 1.25; text-wrap: balance; }
p { margin: 0; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

/* 导航 */
.top { position: sticky; top: 0; z-index: 30; background: var(--navy); border-bottom: 1px solid rgba(255,255,255,.06); }
.top-in { display: flex; align-items: center; justify-content: space-between; height: 3.75rem; gap: 1rem; }
.brand { display: flex; align-items: center; gap: .6rem; color: var(--on-navy); text-decoration: none; font-weight: 650; font-size: 1.05rem; letter-spacing: -.01em; }
.brand img { width: 28px; height: 28px; border-radius: 7px; display: block; }
.links { display: flex; align-items: center; gap: 1.5rem; font-size: .92rem; }
.links a { color: var(--on-navy-muted); text-decoration: none; }
.links a:hover { color: var(--on-navy); }
@media (max-width: 760px) { .links .opt { display: none; } .links { gap: 1rem; } }

.btn { display: inline-block; padding: .62rem 1.15rem; border-radius: 8px; font-size: .95rem; font-weight: 600; text-decoration: none;
       border: 1px solid transparent; cursor: pointer; transition: background .15s, border-color .15s; white-space: nowrap; }
.btn-primary { background: var(--teal); color: #0B1B29; }
.btn-primary:hover { background: #79DEC9; }
.btn-line { border-color: rgba(244,246,250,.28); color: var(--on-navy); }
.btn-line:hover { border-color: var(--on-navy); }
.btn-sm { padding: .42rem .85rem; font-size: .88rem; }
.links a.btn-primary { color: #0B1B29; }
.links a.btn-line { color: var(--on-navy); }

/* 首屏 */
.hero { background: var(--navy); color: var(--on-navy); padding: 4.5rem 0 5rem; }
.hero-grid { display: grid; grid-template-columns: 1fr 1.05fr; gap: 3rem; align-items: center; }
@media (max-width: 920px) { .hero-grid { grid-template-columns: 1fr; gap: 2.5rem; } .hero { padding: 3rem 0 3.5rem; } }
.kicker { font-size: .85rem; color: var(--teal); font-weight: 600; letter-spacing: .02em; }
.hero h1 { color: #fff; font-size: clamp(1.9rem, 4.4vw, 2.9rem); margin-top: .9rem; }
.hero .lede { color: var(--on-navy-muted); font-size: 1.08rem; margin-top: 1.2rem; max-width: 33rem; }
.hero-cta { display: flex; gap: .75rem; margin-top: 2rem; flex-wrap: wrap; }
.hero-note { margin-top: 1.4rem; font-size: .88rem; color: var(--on-navy-muted); }
.hero-note b { color: var(--on-navy); font-weight: 600; }

/* 首屏右侧:身份列表示意 */
.mock { background: #0D1C2B; border: 1px solid rgba(255,255,255,.08); border-radius: 12px; overflow: hidden; box-shadow: 0 24px 60px rgba(0,0,0,.35); font-size: .82rem; }
.mock-bar { display: flex; align-items: center; gap: .4rem; padding: .65rem .9rem; border-bottom: 1px solid rgba(255,255,255,.07); color: var(--on-navy-muted); }
.mock-bar i { width: 9px; height: 9px; border-radius: 50%; background: #2A3D51; display: inline-block; }
.mock-bar span { margin-left: .6rem; }
.mock table { width: 100%; border-collapse: collapse; }
.mock th, .mock td { text-align: left; padding: .6rem .9rem; border-bottom: 1px solid rgba(255,255,255,.05); white-space: nowrap; }
.mock th { color: #7F93A8; font-weight: 500; font-size: .76rem; }
.mock td { color: #DCE4EC; }
.mock td small { display: block; color: #7F93A8; font-size: .72rem; }
.mock .num { font-family: var(--mono); font-size: .76rem; color: #B9C6D3; }
.tag { display: inline-block; padding: .08rem .5rem; border-radius: 99px; font-size: .72rem; font-weight: 600; }
.tag.ok { background: rgba(95,212,188,.14); color: var(--teal); }
.tag.run { background: rgba(120,170,255,.14); color: #9CC0FF; }
.tag.idle { background: rgba(255,255,255,.07); color: #9AACBE; }
.tag.warn { background: rgba(240,180,80,.14); color: #F0C070; }
@media (max-width: 520px) { .mock .hide-xs { display: none; } }

/* 区块 */
.sec { padding: 4.5rem 0; scroll-margin-top: 3.75rem; }
.sec + .sec { border-top: 1px solid var(--line); }
.sec-alt { background: var(--surface); }
.head { max-width: 42rem; margin-bottom: 2.5rem; }
.head .kicker { color: var(--teal-ink); }
.head h2 { font-size: clamp(1.45rem, 3vw, 2rem); margin-top: .5rem; }
.head p { margin-top: .8rem; color: var(--muted); }

/* 问题陈述 */
.pain { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
@media (max-width: 800px) { .pain { grid-template-columns: 1fr; } }
.pain div { background: var(--surface); padding: 1.4rem 1.5rem; }
.pain h3 { font-size: 1rem; }
.pain p { color: var(--muted); font-size: .93rem; margin-top: .4rem; }

/* 功能 */
.feat { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2.2rem 2.5rem; }
@media (max-width: 900px) { .feat { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .feat { grid-template-columns: 1fr; gap: 1.8rem; } }
.feat h3 { font-size: 1.05rem; display: flex; align-items: center; gap: .55rem; }
.feat h3::before { content: ""; width: 4px; height: 1.05rem; border-radius: 2px; background: var(--teal); flex: none; }
.feat p { margin-top: .5rem; color: var(--muted); font-size: .94rem; }
.feat ul { margin: .6rem 0 0; padding-left: 1.1rem; color: var(--muted); font-size: .92rem; }
.feat li { margin: .15rem 0; }

/* 步骤 */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; counter-reset: s; }
@media (max-width: 800px) { .steps { grid-template-columns: 1fr; } }
.step { border-top: 2px solid var(--ink); padding-top: 1rem; }
.step::before { counter-increment: s; content: "0" counter(s); font-family: var(--mono); font-size: .82rem; color: var(--teal-ink); font-weight: 600; }
.step h3 { font-size: 1.05rem; margin-top: .4rem; }
.step p { color: var(--muted); font-size: .93rem; margin-top: .4rem; }

/* 数据与安全 */
.trust { display: grid; grid-template-columns: 1fr 1.3fr; gap: 3rem; align-items: start; }
@media (max-width: 860px) { .trust { grid-template-columns: 1fr; gap: 1.5rem; } }
.trust dl { margin: 0; display: grid; gap: 1.1rem; }
.trust dt { color: var(--ink); font-weight: 600; }
.trust dd { margin: .2rem 0 0; color: var(--muted); font-size: .94rem; }

/* 价格 */
.billing { display: inline-flex; border: 1px solid var(--line); border-radius: 9px; padding: 3px; background: var(--surface); margin-bottom: 1.6rem; }
.billing button { font: inherit; font-size: .9rem; border: 0; background: transparent; color: var(--muted); padding: .4rem .95rem; border-radius: 6px; cursor: pointer; }
.billing button[aria-pressed="true"] { background: var(--navy); color: #fff; }
@media (prefers-color-scheme: dark) { .billing button[aria-pressed="true"] { background: var(--teal); color: #0B1B29; } }
.billing em { font-style: normal; color: var(--teal-ink); font-size: .8rem; margin-left: .25rem; }
.billing button[aria-pressed="true"] em { color: inherit; opacity: .8; }
.plans { display: grid; grid-template-columns: repeat(6, 1fr); gap: .75rem; }
@media (max-width: 1100px) { .plans { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 620px) { .plans { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 400px) { .plans { grid-template-columns: 1fr; } }
.plan { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 1.25rem 1.1rem; display: flex; flex-direction: column; position: relative; }
.plan.hl { border-color: var(--teal-ink); box-shadow: 0 0 0 1px var(--teal-ink) inset; }
.plan .badge { position: absolute; top: -.7rem; left: 1rem; background: var(--teal); color: #0B1B29; font-size: .72rem; font-weight: 700; padding: .1rem .55rem; border-radius: 99px; }
.plan h3 { font-size: 1rem; }
.plan .price { margin-top: .6rem; font-size: 1.75rem; font-weight: 700; color: var(--ink); font-variant-numeric: tabular-nums; letter-spacing: -.02em; line-height: 1.1; }
.plan .price small { font-size: .8rem; font-weight: 500; color: var(--faint); letter-spacing: 0; }
.plan .bill { font-size: .78rem; color: var(--faint); min-height: 1.3em; margin-top: .3rem; font-variant-numeric: tabular-nums; }
.plan ul { list-style: none; margin: 1rem 0 0; padding: .9rem 0 0; border-top: 1px solid var(--line); font-size: .9rem; display: grid; gap: .3rem; }
.plan ul b { color: var(--ink); font-variant-numeric: tabular-nums; }
.plan-notes { margin-top: 1.75rem; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem 2rem; }
@media (max-width: 860px) { .plan-notes { grid-template-columns: 1fr; } }
.plan-notes h3 { font-size: .98rem; }
.plan-notes p { color: var(--muted); font-size: .9rem; margin-top: .3rem; }
.plan-cta { margin-top: 2rem; display: flex; gap: .75rem; flex-wrap: wrap; align-items: center; }
.plan-cta .btn-dark { background: var(--navy); color: #fff; }
.plan-cta .btn-dark:hover { background: var(--navy-2); }
@media (prefers-color-scheme: dark) { .plan-cta .btn-dark { background: var(--teal); color: #0B1B29; } }
.plan-cta span { color: var(--muted); font-size: .9rem; }

/* 下载 */
.dl { display: grid; grid-template-columns: 1.1fr 1fr; gap: 2.5rem; align-items: start; }
@media (max-width: 860px) { .dl { grid-template-columns: 1fr; gap: 1.5rem; } }
.dl-card { display: block; padding: 1.5rem 1.6rem; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; text-decoration: none; color: inherit; transition: border-color .15s; }
.dl-card:hover { border-color: var(--teal-ink); }
.dl-os { font-size: 1.3rem; font-weight: 700; color: var(--ink); }
.dl-ver { font-size: .88rem; color: var(--muted); margin-top: .35rem; }
.dl-go { color: var(--teal-ink); font-weight: 650; margin-top: 1rem; }
.dl-hash { font-family: var(--mono); font-size: .7rem; color: var(--faint); word-break: break-all; margin-top: .8rem; line-height: 1.5; }
.dl-notes { font-size: .93rem; color: var(--muted); display: grid; gap: .7rem; }
.dl-notes b { color: var(--ink); font-weight: 600; }

/* 常见问题 */
.faq { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 3rem; }
@media (max-width: 800px) { .faq { grid-template-columns: 1fr; } }
.faq details { border-bottom: 1px solid var(--line); padding: 1rem 0; }
.faq summary { cursor: pointer; color: var(--ink); font-weight: 600; list-style: none; display: flex; justify-content: space-between; gap: 1rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--faint); font-weight: 400; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin-top: .55rem; color: var(--muted); font-size: .93rem; }

/* 页脚 */
.foot { background: var(--navy); color: var(--on-navy-muted); padding: 2.75rem 0 2.25rem; font-size: .88rem; }
.foot-in { display: flex; justify-content: space-between; gap: 2rem; flex-wrap: wrap; }
.foot .brand { font-size: .98rem; }
.foot nav { display: flex; gap: 1.4rem; flex-wrap: wrap; }
.foot a { color: var(--on-navy-muted); text-decoration: none; }
.foot a:hover { color: var(--on-navy); }
.foot .legal { margin-top: 1.5rem; padding-top: 1.25rem; border-top: 1px solid rgba(255,255,255,.08); display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; font-size: .8rem; }

/* 法律文档页 */
.doc-hero { background: var(--navy); padding: 3rem 0 2.5rem; }
.doc-hero h1 { color: #fff; font-size: clamp(1.6rem, 3.5vw, 2.2rem); }
.doc-hero p { color: var(--on-navy-muted); margin-top: .6rem; font-size: .9rem; }
.doc { max-width: 46rem; padding: 2.5rem 1.25rem 4rem; margin: 0 auto; }
.doc h2 { font-size: 1.12rem; margin: 2.2rem 0 .6rem; }
.doc h2:first-child { margin-top: 0; }
.doc p, .doc li { font-size: .97rem; }
.doc p + p { margin-top: .7rem; }
.doc ul, .doc ol { padding-left: 1.3rem; margin: .5rem 0 0; }
.doc li { margin: .3rem 0; }
.doc .lead { color: var(--muted); }
.doc .box { background: var(--surface); border: 1px solid var(--line); border-left: 3px solid var(--teal-ink); border-radius: 8px; padding: .9rem 1.1rem; margin-top: .8rem; }