:root {
  --brand: #0d71fc;
  --brand-strong: #0858d6;
  --green: #16b38a;
  --bg: #f5f8fe;
  --bg-tint: #eaf1fd;
  --surface: #ffffff;
  --text: #13213a;
  --muted: #5a6884;
  --line: #dbe4f3;
  --code-bg: #eef3fb;
  --shadow: 0 10px 30px rgba(20, 60, 140, 0.08);
  --radius: 16px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand: #4c95ff;
    --brand-strong: #77aeff;
    --green: #35c99f;
    --bg: #0d1420;
    --bg-tint: #111b2b;
    --surface: #162235;
    --text: #e6edf8;
    --muted: #9aa8c0;
    --line: #26354d;
    --code-bg: #0f1a2a;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}

a { color: var(--brand); }

.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 32px; } }

/* 顶栏 */
.topbar {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 12px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 650; font-size: 18px; }
.brand img { border-radius: 8px; }
.nav { display: flex; align-items: center; gap: 4px; }
.nav a { color: var(--muted); text-decoration: none; padding: 6px 10px; border-radius: 8px; font-size: 15px; }
.nav a:hover { color: var(--text); background: var(--bg-tint); }
.nav a.nav-cta { color: #fff; background: var(--brand); }
.nav a.nav-cta:hover { background: var(--brand-strong); color: #fff; }
@media (max-width: 560px) { .nav a:not(.nav-cta) { display: none; } }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 46px; padding: 0 22px; border-radius: 12px;
  font-weight: 600; font-size: 16px; text-decoration: none;
  border: 1px solid transparent; transition: background-color .15s, border-color .15s;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-strong); }
.btn-ghost { background: var(--surface); color: var(--text); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--brand); }
.btn:focus-visible, .nav a:focus-visible, summary:focus-visible { outline: 3px solid color-mix(in srgb, var(--brand) 45%, transparent); outline-offset: 2px; }

/* 首屏 */
.hero { padding: 56px 0 64px; background: radial-gradient(1000px 420px at 85% 0%, var(--bg-tint), transparent 70%); }
.hero-grid { display: grid; gap: 40px; align-items: center; }
@media (min-width: 920px) { .hero { padding: 88px 0 96px; } .hero-grid { grid-template-columns: 1.05fr 1fr; gap: 56px; } }
.eyebrow { margin: 0 0 12px; color: var(--brand); font-weight: 600; font-size: 15px; }
h1 { margin: 0; font-size: clamp(32px, 6vw, 50px); line-height: 1.2; letter-spacing: -0.01em; }
.lead { margin: 20px 0 0; color: var(--muted); font-size: 18px; max-width: 34em; }
.lead strong { color: var(--text); font-weight: 600; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.hero-meta { margin: 16px 0 0; color: var(--muted); font-size: 14px; }

/* 界面示意 */
.mock { margin: 0; min-width: 0; }
.mock-window { background: var(--surface); border: 1px solid var(--line); border-radius: 20px; box-shadow: var(--shadow); overflow: hidden; }
.mock-bar { display: flex; gap: 6px; padding: 12px 16px; border-bottom: 1px solid var(--line); }
.mock-bar span { width: 10px; height: 10px; border-radius: 50%; background: var(--line); }
.mock-body { padding: 20px; }
.mock-title { margin: 0 0 16px; font-weight: 650; font-size: 18px; }
.mock-cards { display: grid; gap: 14px; }
@media (min-width: 480px) { .mock-cards { grid-template-columns: 1fr 1fr; } }
.mock-card { border: 1px solid var(--line); border-radius: 14px; padding: 16px; background: var(--bg); }
.mock-head { display: flex; gap: 10px; align-items: center; margin-bottom: 14px; }
.mock-head b { display: block; font-size: 15px; line-height: 1.3; }
.mock-head small { display: block; color: var(--muted); font-size: 12px; line-height: 1.4; }
.mock-icon { flex: none; width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center; }
.mock-icon svg { width: 18px; height: 18px; fill: none; stroke: #fff; stroke-width: 2; stroke-linejoin: round; }
.mock-icon-blue { background: var(--brand); }
.mock-icon-green { background: var(--green); }
.mock-label { margin: 0; color: var(--muted); font-size: 12px; }
.mock-code { margin: 2px 0 0; font-size: 28px; font-weight: 700; letter-spacing: 0.04em; font-variant-numeric: tabular-nums; }
.mock-input { margin: 0 0 10px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; color: var(--muted); font-size: 13px; background: var(--surface); }
.mock-button { margin: 0; padding: 8px; border-radius: 8px; background: var(--brand); color: #fff; text-align: center; font-size: 14px; font-weight: 600; }
.mock figcaption { margin-top: 10px; text-align: center; color: var(--muted); font-size: 13px; }

/* 通用区块 */
.section { padding: 64px 0; }
@media (min-width: 920px) { .section { padding: 88px 0; } }
.section-tint { background: var(--bg-tint); }
h2 { margin: 0; font-size: clamp(26px, 4vw, 34px); line-height: 1.3; }
.section-lead { margin: 12px 0 0; color: var(--muted); max-width: 40em; }

/* 怎么用 */
.roles { display: grid; gap: 20px; margin-top: 36px; }
@media (min-width: 820px) { .roles { grid-template-columns: 1fr 1fr; gap: 24px; } }
.role { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.role h3 { margin: 0 0 18px; font-size: 18px; display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.tag { font-size: 13px; font-weight: 600; padding: 2px 10px; border-radius: 999px; }
.tag-blue { color: var(--brand); background: color-mix(in srgb, var(--brand) 12%, transparent); }
.tag-green { color: var(--green); background: color-mix(in srgb, var(--green) 14%, transparent); }
.steps { list-style: none; margin: 0; padding: 0; counter-reset: step; display: grid; gap: 16px; }
.steps li { counter-increment: step; position: relative; padding-left: 44px; color: var(--muted); }
.steps li::before {
  content: counter(step); position: absolute; left: 0; top: 2px;
  width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center;
  background: var(--bg-tint); color: var(--brand); font-weight: 700; font-size: 14px;
}
.steps b { display: block; color: var(--text); font-weight: 600; }

/* 能做什么 / 安全 */
.features, .safety, .reqs { list-style: none; margin: 36px 0 0; padding: 0; display: grid; gap: 16px; }
@media (min-width: 640px) { .features, .safety { grid-template-columns: 1fr 1fr; } }
@media (min-width: 960px) { .features, .safety { grid-template-columns: repeat(3, 1fr); } }
.features li, .safety li { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.features b, .safety b { display: block; font-size: 17px; margin-bottom: 4px; }
.features span { color: var(--muted); }
.safety li { color: var(--muted); border-left: 3px solid var(--green); }
.safety b { color: var(--text); }
.note { margin: 24px 0 0; padding: 14px 16px; border-radius: 12px; background: var(--bg-tint); color: var(--muted); font-size: 15px; }

/* 下载 */
.downloads { display: grid; gap: 20px; margin-top: 36px; }
@media (min-width: 820px) { .downloads { grid-template-columns: 1.6fr 1fr; } }
.dl-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); min-width: 0; }
.dl-card-muted { box-shadow: none; background: transparent; }
.dl-head h3 { margin: 0; font-size: 22px; }
.dl-head p { margin: 4px 0 0; color: var(--muted); }
.dl-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 20px; }
.dl-extra { margin: 14px 0 0; color: var(--muted); font-size: 15px; }
code { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: 0.92em; background: var(--code-bg); padding: 2px 6px; border-radius: 6px; color: var(--text); }
.hash { margin-top: 16px; border-top: 1px solid var(--line); padding-top: 14px; }
.hash summary { cursor: pointer; color: var(--muted); font-size: 15px; }
.hash p { margin: 10px 0 6px; color: var(--muted); font-size: 14px; }
.hash-value, .hash-cmd { display: block; margin-top: 10px; padding: 10px 12px; overflow-wrap: anywhere; font-size: 13px; line-height: 1.6; }
.reqs { gap: 10px; margin-top: 28px; }
@media (min-width: 640px) { .reqs { grid-template-columns: 1fr 1fr; } }
.reqs li { color: var(--muted); font-size: 15px; }
.reqs b { color: var(--text); margin-right: 8px; }
.more { margin: 20px 0 0; color: var(--muted); font-size: 15px; }

/* 页脚 */
.footer { border-top: 1px solid var(--line); padding: 28px 0; color: var(--muted); font-size: 14px; }
.footer-inner { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.footer a { color: var(--muted); }