:root{color-scheme:light;--blue:#0071e3;--blue-dark:#005bb5;--ink:#1d1d1f;--muted:#6e6e73;--line:#e4e9f0;--soft:#f5f5f7;--tint:#f8fbff}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;padding:16px;background:var(--soft);color:var(--ink);font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif}
a{color:var(--blue);text-decoration:none}
a:hover{color:var(--blue-dark)}
button,input{font:inherit}
button{cursor:pointer}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.site-header,.container,.site-footer{max-width:1000px;margin-left:auto;margin-right:auto;background:#fff;border-radius:12px;box-shadow:0 2px 15px rgba(25,42,70,.07)}
.site-header{margin-bottom:22px;padding:13px 24px}
.nav-container{display:flex;align-items:center;justify-content:space-between;gap:28px}
.nav-top-row{display:flex;align-items:center;gap:24px;min-width:0}
.logo{white-space:nowrap;color:var(--ink);font-size:21px;font-weight:700;letter-spacing:-.5px}
.logo:hover{color:var(--blue)}
.logo-domain{font-size:10px;font-weight:700;letter-spacing:1.3px;color:var(--blue);vertical-align:middle}
.nav-links{display:flex;align-items:center;gap:22px;list-style:none;margin:0;padding:0}
.nav-links a{display:block;white-space:nowrap;color:#34353b;font-size:14px;padding:8px 0;border-bottom:2px solid transparent;transition:color .18s,border-color .18s}
.nav-links a:hover,.nav-links a:focus-visible{color:var(--blue);border-color:var(--blue)}
.header-search{display:flex;align-items:center;gap:6px;background:var(--soft);border-radius:22px;padding:4px 5px 4px 14px;min-width:0}
.header-search:focus-within{outline:2px solid #b9d7f7;background:#fff}
.header-search input{width:170px;min-width:0;border:0;outline:0;background:transparent;font-size:13px}
.header-search button{border:0;border-radius:17px;background:var(--blue);color:#fff;padding:7px 14px;font-size:12px}
.header-search button:hover,.hero-form button:hover,.download-card a:hover{background:var(--blue-dark);color:#fff}
.container{padding:30px;margin-bottom:26px;min-height:350px}
.hero-search{padding:31px 26px;border:1px solid #e1edfa;background:var(--tint);border-radius:12px;text-align:center;margin-bottom:30px}
.hero-search h1{font-size:23px;line-height:1.3;letter-spacing:-.4px;margin:0 0 5px}
.hero-search p{margin:0 0 22px;color:var(--muted);font-size:14px}
.hero-form{max-width:700px;margin:auto;display:flex;align-items:center;gap:12px}
.hero-form input{flex:1;min-width:0;height:48px;border:1px solid #d1e1f3;border-radius:25px;padding:0 20px;background:#fff;outline:0;font-size:15px;transition:border-color .18s,box-shadow .18s}
.hero-form input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(0,113,227,.11)}
.hero-form button{height:48px;white-space:nowrap;border:0;border-radius:25px;background:var(--blue);color:#fff;padding:0 27px;font-size:15px;font-weight:600;transition:background .18s}
.hot-words{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:4px 16px;max-width:700px;margin:16px auto 0;font-size:13px}
.hot-words span{color:var(--muted)}
.hot-words a{white-space:nowrap}
.section-heading,.page-title-row{display:flex;align-items:baseline;gap:12px;justify-content:space-between;margin:0 0 16px}
.section-heading h2,.page-title-row h1,.page-title-row h2{font-size:19px;line-height:1.35;margin:0}
.section-heading span,.page-title-row span{font-size:13px;color:var(--muted)}
.latest-section{margin-bottom:34px}
.collapse-card{border:1px solid #e1edfa;border-radius:12px;overflow:hidden;margin-bottom:16px}
.collapse-heading{display:flex;justify-content:space-between;align-items:center;background:var(--tint);padding:13px 18px}
.collapse-heading>a{color:var(--ink);font-size:16px;font-weight:650}
.collapse-heading>a:hover{color:var(--blue)}
.collapse-toggle{width:30px;height:30px;border:0;background:transparent;color:var(--blue);display:grid;place-items:center;border-radius:50%}
.collapse-toggle:hover{background:#e6f1ff}
.collapse-toggle svg{width:19px;height:19px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;transition:transform .2s}
.collapse-toggle[aria-expanded="false"] svg{transform:rotate(-90deg)}
.collapse-content[hidden]{display:none}
.table-wrap{overflow-x:auto}
.table-wrap.bordered{border:1px solid var(--line);border-radius:12px;overflow:hidden}
.standards-table{width:100%;border-collapse:collapse;table-layout:fixed}
.standards-table th,.standards-table td{padding:13px 12px;text-align:left;border-bottom:1px solid #eff1f4;font-size:14px}
.standards-table th{background:var(--soft);color:var(--muted);font-weight:700;font-size:13px}
.standards-table tr:last-child td{border-bottom:0}
.standards-table th:first-child,.standards-table td:first-child{width:22%}
.standards-table th:nth-child(2),.standards-table td:nth-child(2){width:38%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.standards-table th:nth-child(3),.standards-table td:nth-child(3){width:12%;text-align:center}
.standards-table th:nth-child(4),.standards-table td:nth-child(4),.standards-table th:nth-child(5),.standards-table td:nth-child(5){width:14%;text-align:center}
.standards-table td a{font-weight:650}
.clickable-row{cursor:pointer;transition:background .18s}
.clickable-row:hover{background:#f5faff}
.browse-section .section-heading{margin-bottom:15px}
.category-card{background:var(--tint);border:1px solid #e1edfa;border-radius:12px;padding:22px;margin-bottom:18px}
.category-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px;gap:14px}
.category-heading h2,.category-heading h3{margin:0;font-size:18px;line-height:1.35}
.category-heading h2 a{color:var(--ink)}
.category-heading>a{font-size:13px}
.tag-list{display:flex;flex-wrap:wrap;gap:10px}
.category-tag,.filter-tag{display:inline-block;padding:7px 14px;border:1px solid #e1edfa;border-radius:16px;background:#fff;color:#34353b;font-size:13px;line-height:1.4;transition:background .18s,color .18s,border-color .18s,transform .18s}
.category-tag:hover,.filter-tag:hover{color:var(--blue);border-color:#c1d9f0;background:#f0f7ff;transform:translateY(-1px)}
.filter-tag.active{border-color:var(--blue);background:#eaf4ff;color:var(--blue);font-weight:700}
.breadcrumb{margin:0 0 15px;color:var(--muted);font-size:13px}
.breadcrumb span{margin:0 8px;color:#c7c7cc}
.filter-card{display:flex;flex-wrap:wrap;gap:9px;padding:18px;margin-bottom:21px;border:1px solid #e1edfa;border-radius:12px;background:var(--tint);max-height:190px;overflow:auto}
.empty-state{padding:46px 20px;text-align:center;color:var(--muted);font-size:14px}
.pagination{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:7px;margin:28px 0 4px}
.pagination a{min-width:36px;height:36px;display:grid;place-items:center;padding:0 10px;border:1px solid var(--line);border-radius:18px;color:#34353b;font-size:13px}
.pagination a:hover{border-color:var(--blue);color:var(--blue);background:#f5faff}
.pagination a.active{background:var(--blue);border-color:var(--blue);color:#fff;pointer-events:none}
.hero-search.compact{padding:25px;margin-bottom:25px}
.hero-search.compact h1{font-size:20px;margin-bottom:18px}
.detail-title{border-bottom:1px solid var(--line);padding:5px 0 24px;margin-bottom:25px}
.eyebrow{font-size:12px;font-weight:700;letter-spacing:2px;color:var(--blue);margin:0 0 8px}
.detail-title h1{font-size:27px;line-height:1.35;margin:0 0 8px}
.english-name{color:var(--muted);font-size:14px;margin:0 0 17px}
.standard-badges{display:flex;flex-wrap:wrap;gap:9px;margin-top:17px}
.standard-badges span{padding:5px 12px;border-radius:20px;font-size:13px;font-weight:650;background:#f0f5fa;color:#4e5967}
.standard-badges .code-badge{background:#eaf4ff;color:var(--blue)}
.standard-badges .status-badge{background:#e9f8ef;color:#21824b}
.detail-section{margin:0 0 28px}
.detail-section h2{font-size:18px;margin:0 0 15px}
.info-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.info-item{padding:14px 17px;background:var(--tint);border:1px solid #e9f1fa;border-radius:10px;min-width:0}
.info-item h3{margin:0 0 5px;color:var(--muted);font-size:12px;font-weight:600}
.info-item p{margin:0;font-size:14px;overflow-wrap:anywhere}
.summary{margin:0;padding:18px;background:var(--tint);border:1px solid #e9f1fa;border-radius:10px;white-space:pre-wrap;font-size:14px}
.preview-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.preview-grid img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:9px;background:#fff}
.download-card{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:21px 23px;border-radius:12px;background:#f1f8ff;border:1px solid #dcecfb;margin:30px 0}
.download-card h2{font-size:17px;margin:0 0 3px}
.download-card p{font-size:13px;color:var(--muted);margin:0}
.download-card a{display:inline-block;white-space:nowrap;padding:10px 20px;background:var(--blue);color:#fff;border-radius:22px;font-size:14px;font-weight:650}
.sitemap-top{display:flex;gap:12px;flex-wrap:wrap;margin:0 0 22px}
.sitemap-top a{padding:9px 17px;border-radius:20px;background:#eaf4ff;font-size:14px}
.site-footer{padding:25px;text-align:center;margin-bottom:16px}
.footer-inner p{margin:0 0 5px;color:var(--muted);font-size:13px}
.footer-inner strong{color:var(--ink)}
.footer-inner nav{display:flex;justify-content:center;gap:22px;margin-top:13px;font-size:13px}
@media(max-width:800px){.nav-container{display:block}.nav-top-row{justify-content:space-between}.nav-links{overflow-x:auto;gap:20px;padding-top:7px;scrollbar-width:none}.nav-links::-webkit-scrollbar{display:none}.site-header{padding:12px 20px}}
@media(max-width:640px){body{padding:9px;font-size:15px}.container{padding:19px}.site-header{margin-bottom:12px;padding:9px 16px}.logo{font-size:19px}.logo-domain{display:none}.header-search{max-width:58vw}.header-search input{width:100px}.header-search button{padding:6px 9px}.hero-search{padding:23px 17px;margin-bottom:25px}.hero-search h1{font-size:20px}.hero-form{display:block}.hero-form input,.hero-form button{width:100%}.hero-form button{margin-top:9px}.hot-words{justify-content:flex-start;text-align:left}.section-heading span{display:none}.standards-table th,.standards-table td{padding:11px 8px;font-size:13px}.standards-table th:nth-child(n+3),.standards-table td:nth-child(n+3){display:none}.standards-table th:first-child,.standards-table td:first-child{width:41%;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.standards-table th:nth-child(2),.standards-table td:nth-child(2){width:59%}.category-card{padding:18px}.tag-list{gap:8px}.category-tag{padding:6px 11px}.info-grid,.preview-grid{grid-template-columns:1fr}.detail-title h1{font-size:23px}.download-card{display:block}.download-card a{margin-top:15px}.filter-card{max-height:155px}.site-footer{padding:19px}}
.not-found-container{min-height:55vh;display:grid;place-items:center;padding-top:50px;padding-bottom:70px}.not-found-card{max-width:590px;text-align:center;background:#fff;border:1px solid var(--line);border-radius:16px;padding:48px 36px;box-shadow:0 12px 32px rgba(27,95,160,.06)}.not-found-code{display:block;color:var(--blue);font-size:76px;font-weight:800;line-height:1}.not-found-card h1{margin:18px 0 12px;font-size:25px}.not-found-card p{color:var(--muted);line-height:1.8}.not-found-actions{display:flex;justify-content:center;gap:12px;margin-top:25px}.not-found-actions a{padding:10px 20px;border-radius:8px;font-weight:650}.not-found-primary{background:var(--blue);color:#fff}.not-found-primary:hover{color:#fff;opacity:.9}.not-found-secondary{border:1px solid var(--line);color:var(--ink)}
.purchase-card{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:24px;background:var(--tint);border:1px solid #dceafa;border-radius:12px;margin:24px 0}.purchase-card h2{margin:0;font-size:20px}.purchase-card p{margin:6px 0;color:var(--muted);font-size:14px}.purchase-action{display:flex;flex-direction:column;align-items:center;gap:10px;flex-shrink:0}.purchase-price{color:var(--blue);font-size:26px;font-weight:700}.cha-button{display:inline-flex;justify-content:center;align-items:center;background:var(--blue);color:#fff;border:1px solid var(--blue);border-radius:8px;padding:10px 20px;font-weight:650;font-size:15px;cursor:pointer}.cha-button:hover{background:var(--blue-dark);color:#fff}.cha-button.secondary{background:#fff;color:var(--blue);border-color:#c9dcf2}.cha-button:disabled{opacity:.55;cursor:wait}.cha-button[hidden],.payment-qr[hidden]{display:none}.purchase-orders,.purchase-unavailable{font-size:14px}.purchase-dialog{border:1px solid var(--line);border-radius:16px;width:min(520px,calc(100% - 28px));max-height:85vh;overflow:auto;padding:30px;color:var(--ink);text-align:center}.purchase-dialog::backdrop{background:rgba(17,30,48,.45)}.purchase-dialog h2{margin:0 30px 12px}.purchase-dialog>p{overflow-wrap:anywhere}.dialog-close{position:absolute;right:12px;top:8px;border:0;background:transparent;font-size:30px;color:var(--muted)}.purchase-methods{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin:18px 0}.payment-qr{margin:20px auto}.payment-qr img{background:white;border:1px solid var(--line);padding:8px}.purchase-feedback{font-size:14px;color:var(--muted);min-height:24px;white-space:pre-line}.account-container{display:grid;place-items:center;min-height:65vh}.account-card{width:100%;max-width:430px}.account-card h1{text-align:center}.account-card p{color:var(--muted);font-size:14px}.account-card form{display:grid;gap:10px;margin-top:24px}.account-card label{font-size:14px;font-weight:650}.account-card input{width:100%;border:1px solid var(--line);border-radius:8px;padding:11px 12px;margin-bottom:8px}.login-alternative{text-align:center;border-top:1px solid var(--line);padding-top:20px}.order-note{color:var(--muted);font-size:14px}.order-card{display:flex;justify-content:space-between;align-items:center;gap:18px;padding:22px 0;border-bottom:1px solid var(--line)}.order-card h2{font-size:16px;margin:0 0 8px}.order-card p{font-size:13px;color:var(--muted);margin:0}.order-actions{display:flex;align-items:center;gap:16px;flex-shrink:0}@media(max-width:640px){.purchase-card,.order-card{display:block;padding:20px}.purchase-action{align-items:stretch;margin-top:16px}.purchase-action .purchase-price{align-self:flex-start}.order-actions{margin-top:16px;justify-content:space-between}.purchase-dialog{padding:25px 18px}}
.purchase-card{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:24px;background:var(--tint);border:1px solid #dceafa;border-radius:12px;margin:24px 0}.purchase-card h2{margin:0;font-size:20px}.purchase-card p{margin:6px 0;color:var(--muted);font-size:14px}.purchase-action{display:flex;flex-direction:column;align-items:center;gap:10px;flex-shrink:0}.purchase-price{color:var(--blue);font-size:26px;font-weight:700}.cha-button{display:inline-flex;justify-content:center;align-items:center;background:var(--blue);color:#fff;border:1px solid var(--blue);border-radius:8px;padding:10px 20px;font-weight:650;font-size:15px;cursor:pointer}.cha-button:hover{background:var(--blue-dark);color:#fff}.cha-button.secondary{background:#fff;color:var(--blue);border-color:#c9dcf2}.cha-button:disabled{opacity:.55;cursor:wait}.cha-button[hidden],.payment-qr[hidden]{display:none}.purchase-orders,.purchase-unavailable{font-size:14px}.purchase-dialog{border:1px solid var(--line);border-radius:16px;width:min(520px,calc(100% - 28px));max-height:85vh;overflow:auto;padding:30px;color:var(--ink);text-align:center}.purchase-dialog::backdrop{background:rgba(17,30,48,.45)}.purchase-dialog h2{margin:0 30px 12px}.purchase-dialog>p{overflow-wrap:anywhere}.dialog-close{position:absolute;right:12px;top:8px;border:0;background:transparent;font-size:30px;color:var(--muted)}.purchase-methods{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin:18px 0}.payment-qr{margin:20px auto}.payment-qr img{background:white;border:1px solid var(--line);padding:8px}.purchase-feedback{font-size:14px;color:var(--muted);min-height:24px;white-space:pre-line}.account-container{display:grid;place-items:center;min-height:65vh}.account-card{width:100%;max-width:430px}.account-card h1{text-align:center}.account-card p{color:var(--muted);font-size:14px}.account-card form{display:grid;gap:10px;margin-top:24px}.account-card label{font-size:14px;font-weight:650}.account-card input{width:100%;border:1px solid var(--line);border-radius:8px;padding:11px 12px;margin-bottom:8px}.login-alternative{text-align:center;border-top:1px solid var(--line);padding-top:20px}.order-note{color:var(--muted);font-size:14px}.order-card{display:flex;justify-content:space-between;align-items:center;gap:18px;padding:22px 0;border-bottom:1px solid var(--line)}.order-card h2{font-size:16px;margin:0 0 8px}.order-card p{font-size:13px;color:var(--muted);margin:0}.order-actions{display:flex;align-items:center;gap:16px;flex-shrink:0}@media(max-width:640px){.purchase-card,.order-card{display:block;padding:20px}.purchase-action{align-items:stretch;margin-top:16px}.purchase-action .purchase-price{align-self:flex-start}.order-actions{margin-top:16px;justify-content:space-between}.purchase-dialog{padding:25px 18px}}
.wechat-login-dialog{width:min(400px,calc(100% - 24px));max-height:90vh;overflow:auto;padding:28px 24px;border:1px solid var(--line);border-radius:16px;text-align:center;color:var(--ink)}.wechat-login-dialog::backdrop{background:rgba(17,30,48,.45)}.wechat-login-dialog h2{margin:0 20px 8px;font-size:22px}.wechat-login-dialog>p{color:var(--muted);font-size:14px}.wechat-login-dialog iframe{display:block;width:300px;max-width:100%;height:400px;border:0;margin:0 auto}.wechat-login-dialog .purchase-feedback{margin:8px 0 14px}