/* Website công khai — nhẹ, không phụ thuộc thư viện; nhận diện: xanh #1677ff, cam #f7941d, phẳng, bo 5px */
:root{--blue:#1677ff;--blue-d:#0958d9;--accent:#f7941d;--ink:#1f2328;--muted:#5b6573;--line:#e3e8f0;--bg:#f5f8ff;--card:#fff;--r:5px;--w:1120px;--read:720px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 -apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;text-rendering:optimizeLegibility}
a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.wrap{max-width:var(--w);margin:0 auto;padding:0 16px}
.skip{position:absolute;left:-999px}.skip:focus{left:8px;top:8px;background:#fff;padding:6px 10px;z-index:9}
.muted{color:var(--muted)}
.site-header{background:var(--blue);color:#fff;border-bottom:3px solid var(--accent)}
.header-row{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:56px}
.brand{display:inline-flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:20px}
.brand:hover{text-decoration:none}.brand img{background:#fff;border-radius:var(--r);padding:2px;height:32px;width:auto}
.search input{width:220px;max-width:46vw;border:0;border-radius:var(--r);padding:7px 10px;font:inherit;font-size:14px}
.site-nav{background:var(--blue-d)}
.site-nav ul{list-style:none;margin:0;padding:0;display:flex;gap:2px;overflow-x:auto;scrollbar-width:none}
.site-nav a{display:block;color:#fff;padding:8px 12px;white-space:nowrap;font-size:15px}
.site-nav a:hover,.site-nav a[aria-current]{background:rgba(255,255,255,.14);text-decoration:none;box-shadow:inset 0 -3px 0 var(--accent)}
main{padding-top:20px;padding-bottom:32px;min-height:60vh}
.breadcrumbs ol{list-style:none;padding:0;margin:0 0 14px;display:flex;flex-wrap:wrap;gap:6px;font-size:14px;color:var(--muted)}
.breadcrumbs li+li:before{content:"›";margin-right:6px;color:#a0a8b5}
h1,h2,h3,h4{line-height:1.3;color:#10151c}
.page-head{margin:0 0 18px}.page-head h1{margin:0 0 6px;font-size:28px}.page-head p{margin:0;color:var(--muted)}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px}
@media (max-width:900px){.layout{grid-template-columns:1fr}}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;display:flex;flex-direction:column}
.card .thumb{display:block;aspect-ratio:16/9;background:#e9eef7;overflow:hidden}
.card .thumb img{width:100%;height:100%;object-fit:cover;display:block}
.card .body{padding:12px 14px 14px;display:flex;flex-direction:column;gap:6px;flex:1}
.card h2,.card h3{font-size:18px;margin:0}.card h2 a,.card h3 a{color:var(--ink)}
.card p{margin:0;color:var(--muted);font-size:15px}
.meta{font-size:13px;color:var(--muted);display:flex;flex-wrap:wrap;gap:4px 10px;align-items:center}
.cat{display:inline-block;font-size:12px;font-weight:600;color:var(--accent);text-transform:uppercase;letter-spacing:.3px}
.feature{grid-column:1/-1;display:grid;grid-template-columns:1.3fr 1fr}
.feature .thumb{aspect-ratio:auto;min-height:260px}.feature h2{font-size:24px}
@media (max-width:700px){.feature{grid-template-columns:1fr}.feature .thumb{min-height:0;aspect-ratio:16/9}}
.pager{display:flex;gap:6px;justify-content:center;margin:24px 0 0;flex-wrap:wrap}
.pager a,.pager span{min-width:36px;text-align:center;padding:6px 10px;border:1px solid var(--line);border-radius:var(--r);background:#fff}
.pager span[aria-current]{background:var(--blue);color:#fff;border-color:var(--blue)}
.article{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:24px clamp(16px,4vw,40px)}
.article header h1{font-size:clamp(26px,4vw,36px);margin:6px 0 10px}
.article .lead{font-size:18px;color:#3a4250;margin:0 0 16px}
.article .cover{margin:0 0 20px}.article .cover img{width:100%;border-radius:var(--r);display:block}
.article .cover figcaption{font-size:13px;color:var(--muted);margin-top:6px;text-align:center}
.content{max-width:var(--read);font-size:17px;overflow-wrap:break-word}
.content h2{font-size:24px;margin:1.6em 0 .6em;scroll-margin-top:12px}.content h3{font-size:20px;margin:1.4em 0 .5em;scroll-margin-top:12px}
.content p{margin:0 0 1.1em}
.content img{border-radius:var(--r)}
.content figure{margin:1.4em 0}.content figcaption{font-size:14px;color:var(--muted);text-align:center;margin-top:6px}
.content blockquote{margin:1.2em 0;padding:8px 16px;border-left:4px solid var(--accent);background:#fff8ef;color:#3a4250}
.content pre{background:#0b1a33;color:#d6e4ff;padding:12px 14px;border-radius:var(--r);overflow:auto;font-size:14px}
.content code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.92em}
.content :not(pre)>code{background:#eef2f8;padding:1px 5px;border-radius:4px}
.content table{border-collapse:collapse;width:100%;display:block;overflow-x:auto;margin:1.2em 0}
.content th,.content td{border:1px solid var(--line);padding:6px 10px;text-align:left}.content th{background:#f5f8ff}
.content iframe{width:100%;aspect-ratio:16/9;height:auto;border:0;border-radius:var(--r)}
.toc{border:1px solid var(--line);background:#fafcff;border-radius:var(--r);padding:10px 16px;margin:0 0 20px;max-width:var(--read)}
.toc summary{font-weight:600;cursor:pointer}.toc ol{margin:8px 0 0;padding-left:20px}.toc ul{margin:2px 0;padding-left:18px;list-style:circle}
.tags{display:flex;flex-wrap:wrap;gap:6px;margin:20px 0 0}
.tags a{font-size:13px;background:#eef3ff;border-radius:var(--r);padding:3px 10px}
.author-box{margin:24px 0 0;padding:14px 16px;border:1px solid var(--line);border-radius:var(--r);background:#fafcff}
.side h2{font-size:16px;margin:0 0 10px;padding-bottom:6px;border-bottom:2px solid var(--accent)}
.side section{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:14px;margin-bottom:18px}
.side ul{list-style:none;margin:0;padding:0}.side li{padding:6px 0;border-bottom:1px dashed var(--line)}.side li:last-child{border:0}
.related{margin-top:28px}.related .cards{grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}.related h2{font-size:20px}
.prevnext{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:24px}
.prevnext a{display:block;border:1px solid var(--line);border-radius:var(--r);padding:10px 12px;background:#fff}
.prevnext small{display:block;color:var(--muted)}.prevnext .next{text-align:right}
.hero{padding:28px 0}.hero h1{margin:0;font-size:32px}
.empty{text-align:center;padding:48px 16px}
.btn{display:inline-block;background:var(--blue);color:#fff;padding:8px 16px;border-radius:var(--r)}.btn:hover{background:var(--blue-d);text-decoration:none}
.site-footer{background:#0b1a33;color:#c3cfe3;font-size:14px;padding:22px 0}.site-footer p{margin:4px 0}.site-footer .muted{color:#8b99b3}
.preview-bar{background:#fff3cd;border:1px solid #ffe08a;padding:8px 12px;border-radius:var(--r);margin-bottom:12px;font-size:14px}
.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}