:root {
  --ink: #20242b;
  --muted: #7a828d;
  --line: #e8eaed;
  --accent: #0173e5;
  --accent-deep: #075fae;
  --accent-soft: #f1f7fd;
  --paper: #ffffff;
}

* { box-sizing: border-box; }

html { background: var(--paper); }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Sans CJK SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  line-height: 1.82;
  letter-spacing: .008em;
  -webkit-font-smoothing: antialiased;
  text-size-adjust: 100%;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: 44px 1fr 44px;
  align-items: center;
  min-height: 54px;
  padding-top: env(safe-area-inset-top);
  border-bottom: 1px solid rgba(229, 232, 236, .9);
  background: rgba(255, 255, 255, .96);
  backdrop-filter: blur(12px);
}

.topbar button {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-left: 4px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  color: #394252;
  background: transparent;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: color .18s ease, background-color .18s ease, transform .18s ease;
}

.topbar button svg {
  width: 23px;
  height: 23px;
  overflow: visible;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.topbar button:active {
  color: var(--accent);
  background: #eef5ff;
  transform: scale(.92);
}

@media (hover: hover) {
  .topbar button:hover { color: var(--accent); background: #f1f6fd; }
}

.topbar span { color: #183b60; text-align: center; font-size: 16px; font-weight: 600; letter-spacing: .015em; }

main { width: min(100%, 720px); margin: 0 auto; padding: 36px 21px calc(64px + env(safe-area-inset-bottom)); }

.eyebrow { display: none; }

h1 { margin: 0; color: #173e66; font-size: clamp(27px, 7.5vw, 36px); font-weight: 700; line-height: 1.26; letter-spacing: -.025em; }

.meta { margin: 14px 0 0; color: var(--muted); font-size: 12px; line-height: 1.75; }

.lead { margin: 27px 0 0; color: #3f4650; font-size: 15px; line-height: 1.88; }

.notice { margin: 24px 0 8px; padding: 16px 17px; border: 1px solid #dceaf7; border-radius: 8px; background: var(--accent-soft); color: #3f4d5d; line-height: 1.75; }

.toc { display: flex; gap: 8px; overflow-x: auto; margin: 25px -21px 2px; padding: 0 21px 10px; scrollbar-width: none; }
.toc::-webkit-scrollbar { display: none; }
.toc a { flex: none; padding: 7px 1px 4px; border-bottom: 1px solid #a9c8e5; color: var(--accent-deep); background: transparent; font-size: 12px; text-decoration: none; }
.toc a + a { margin-left: 12px; }

section { padding: 31px 0; border-bottom: 1px solid var(--line); scroll-margin-top: 72px; }
section:last-of-type { border-bottom: 0; }
h2 { position: relative; margin: 0 0 18px; padding-bottom: 10px; color: #1d2127; font-size: 20px; font-weight: 650; line-height: 1.42; letter-spacing: -.01em; }
h2::after { position: absolute; bottom: 0; left: 0; width: 24px; height: 2px; background: var(--accent); content: ""; }
h3 { margin: 23px 0 9px; color: #2a2f36; font-size: 16px; font-weight: 650; }
p { margin: 0 0 13px; }
section > p, section > ul { color: #414851; }
ul { margin: 8px 0 12px; padding-left: 1.25em; }
li { margin: 9px 0; padding-left: .25em; }
li::marker { color: #8c939c; }
strong { color: #111923; font-weight: 700; }
a { color: var(--accent); }

.section-tip { margin: -5px 0 12px; color: var(--muted); font-size: 12px; }

.sdk-list { margin-top: 18px; border-top: 1px solid var(--line); }
.sdk-list details { border-bottom: 1px solid var(--line); }
.sdk-list summary {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
  min-height: 72px;
  padding: 13px 28px 13px 0;
  color: #252a31;
  cursor: pointer;
  list-style: none;
  -webkit-tap-highlight-color: transparent;
}
.sdk-list summary::-webkit-details-marker { display: none; }
.sdk-list summary::after {
  position: absolute;
  top: 50%;
  right: 3px;
  width: 7px;
  height: 7px;
  border-right: 1.5px solid #8a919a;
  border-bottom: 1.5px solid #8a919a;
  content: "";
  transform: translateY(-70%) rotate(45deg);
  transition: transform .18s ease;
}
.sdk-list details[open] summary { color: var(--accent-deep); }
.sdk-list details[open] summary::after { border-color: var(--accent); transform: translateY(-35%) rotate(225deg); }
.sdk-list summary span { min-width: 0; }
.sdk-list summary strong { display: block; font-size: 15px; font-weight: 600; }
.sdk-list summary small { display: block; overflow: hidden; margin-top: 2px; color: var(--muted); font-size: 11px; font-weight: 400; text-overflow: ellipsis; white-space: nowrap; }
.sdk-list summary em { color: #68717c; font-size: 12px; font-style: normal; white-space: nowrap; }
.sdk-content { margin: 0 0 14px; padding: 14px 15px 5px; border-radius: 6px; background: #f7f7f8; }
.sdk-content p { margin-bottom: 9px; color: #4a515a; font-size: 13px; line-height: 1.72; }
.sdk-content b { display: inline-block; margin-right: 8px; color: #292e35; font-weight: 600; }
.sdk-note { margin-top: 18px; padding: 14px 15px; border: 1px solid var(--line); border-radius: 6px; color: #5a626d !important; font-size: 12px; line-height: 1.75; }

.permission-list { display: grid; gap: 0; margin-top: 22px; border-top: 1px solid var(--line); }
.permission { padding: 20px 0; border-bottom: 1px solid var(--line); background: #fff; }
.permission h2 { display: flex; align-items: center; gap: 10px; margin-bottom: 7px; font-size: 17px; }
.permission h2::after { display: none; }
.permission .icon { display: inline-grid; width: 27px; height: 27px; place-items: center; border-radius: 50%; color: var(--accent-deep); background: #edf5fc; font-size: 14px; }
.permission p { margin: 0; color: #536071; font-size: 14px; }
.permission small { display: block; margin-top: 9px; color: var(--muted); font-size: 12px; }

footer { margin-top: 10px; padding-top: 26px; border-top: 1px solid var(--line); color: var(--muted); text-align: center; font-size: 12px; }
footer .copyright-note { margin: 0 auto 8px; max-width: 560px; line-height: 1.65; }
footer .copyright-mark { margin: 0; color: #8a94a2; letter-spacing: .02em; }
footer .icp { margin: 6px 0 0; }
footer .icp a { color: inherit; text-decoration: none; }
footer .icp a:active { color: var(--accent); }
footer .icp a:hover { color: var(--accent-deep); }

@media (min-width: 700px) {
  main { padding-top: 52px; }
}

@media (max-width: 360px) {
  main { padding-right: 17px; padding-left: 17px; }
  h1 { font-size: 26px; }
  .toc { margin-right: -17px; margin-left: -17px; padding-right: 17px; padding-left: 17px; }
}