/* ===== Coinbase-style article.css ===== */
:root{
  --canvas:#ffffff;
  --surface-soft:#f7f7f7;
  --surface-strong:#eef0f3;
  --surface-dark:#0a0b0d;
  --ink:#0a0b0d;
  --body:#5b616e;
  --muted:#7c828a;
  --muted-soft:#a8acb3;
  --hairline:#dee1e6;
  --hairline-soft:#eef0f3;
  --brand:#C8102E;
  --brand-active:#a00d24;
  --brand-tint:#fdf2f4;
  --up:#05b169;
  --down:#cf202f;
  --warn:#c77800;
  --r-xs:4px;
  --r-sm:8px;
  --r-md:12px;
  --r-lg:16px;
  --r-xl:24px;
  --r-pill:100px;
  --shadow:0 4px 12px rgba(0,0,0,.04);
  /* Aliases */
  --paper:var(--surface-soft);
  --ink-soft:var(--body);
  --border:var(--hairline);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
a,button{-webkit-tap-highlight-color:transparent}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:2px solid var(--brand);outline-offset:2px}
h1,h2,h3{text-wrap:balance}
p,li{text-wrap:pretty}
body{
  font-family:'Inter',-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;
  background:var(--canvas);color:var(--ink);line-height:1.7;
  -webkit-font-smoothing:antialiased;
  font-variant-numeric:tabular-nums;
}
.article-nav{
  background:var(--surface-dark);color:#fff;padding:12px 0;
  display:flex;justify-content:space-between;align-items:center;
  padding-left:16px;padding-right:16px;
}
.article-nav a{color:var(--muted-soft);text-decoration:none;font-size:13px;font-weight:600}
@media(hover:hover){
  .article-nav a:hover{color:#fff}
}
.article{max-width:760px;margin:0 auto;padding:32px 16px 80px}
.article-header{margin-bottom:28px}
.article-header .tag{
  display:inline-block;font-size:11px;font-weight:600;
  padding:3px 10px;border-radius:var(--r-pill);
  background:var(--brand-tint);color:var(--brand);
  margin-bottom:10px;
}
.article-header h1{font-size:28px;font-weight:600;letter-spacing:-.4px;line-height:1.35}
.article-header .meta{font-size:13px;color:var(--body);margin-top:8px}
.article section{margin-bottom:28px}
.article h2{font-size:20px;font-weight:600;margin-bottom:10px;letter-spacing:-.2px}
.article h3{font-size:16px;font-weight:600;margin-bottom:8px;margin-top:16px}
.article p{font-size:15px;color:var(--ink);margin-bottom:10px}
.article ul,.article ol{margin-bottom:12px;padding-inline-start:20px}
.article li{font-size:15px;margin-bottom:6px}
.article a{color:var(--brand);text-decoration:none;font-weight:600}
@media(hover:hover){
  .article a:hover{text-decoration:underline}
}
.article details{
  background:var(--canvas);border:1px solid var(--hairline);border-radius:var(--r-lg);
  padding:14px 16px;margin-bottom:10px;
}
.article summary{font-weight:600;font-size:15px;cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:10px}
.article summary::-webkit-details-marker{display:none}
.article summary::after{content:"+";color:var(--brand);font-size:20px;font-weight:600;line-height:1}
.article details[open] summary::after{content:"–"}
.article details p{font-size:14px;color:var(--body);margin-top:8px}
.data-table{width:100%;border-collapse:collapse;margin:12px 0;font-size:14px}
.data-table th,.data-table td{
  border:1px solid var(--hairline);padding:8px 12px;text-align:start;
}
.data-table th{background:var(--surface-strong);font-weight:600}
.data-table tr:nth-child(even){background:var(--surface-soft)}
.article-footer{
  margin-top:32px;padding-top:16px;border-top:1px solid var(--hairline);
}
.article-footer p{font-size:12px;color:var(--body)}
@media(max-width:680px){
  .article{padding:24px 14px 60px}
  .article-header h1{font-size:24px}
  .article h2{font-size:18px}
  .article p,.article li{font-size:14px}
  .data-table{font-size:12px}
  .data-table th,.data-table td{padding:6px 8px}
}
/* 返回链接箭头由 CSS 供给（文案源保持无箭头），RTL 自动反向 */
.back-link::before{content:"←";margin-inline-end:6px}
[dir="rtl"] .back-link::before{content:"→"}
/* RTL（ar/fa 文章页）：负字距会破坏阿拉伯/波斯字母连写，置零 */
[dir="rtl"] .article-header h1,[dir="rtl"] .article h2,[dir="rtl"] .article h3{letter-spacing:0}
/* 尊重减弱动态偏好 */
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}