/* Kho bài cộng đồng — dùng chung bảng màu với trang chủ (index.html). */
:root{
  --brand:#3F4FD9;--brand-dark:#2F3DB5;--brand-soft:#E8EAFB;--brand-ink:#2B349E;
  --acc:#F2A33C;--acc-soft:#FDF0DC;--acc-ink:#8A5A12;
  --bg:#FFFFFF;--bg-alt:#F6F7FC;--card:#FFFFFF;--text:#1B1B2F;--muted:#5B5F7A;--line:#E3E5F0;
  --shadow:0 8px 24px rgba(31,39,120,.08);--radius:18px;
}
@media (prefers-color-scheme:dark){
  :root{
    --brand:#7C88F5;--brand-dark:#5F6CEB;--brand-soft:#242A52;--brand-ink:#C9CEFF;
    --acc:#F2A33C;--acc-soft:#3A2E1B;--acc-ink:#F3C583;
    --bg:#0F1120;--bg-alt:#161A2E;--card:#1B2036;--text:#F1F2FA;--muted:#A6AAC6;--line:#2A2F4A;
    --shadow:0 8px 24px rgba(0,0,0,.35);
  }
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);line-height:1.6;
  font-family:"Be Vietnam Pro",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:var(--brand)}
.wrap{width:100%;max-width:860px;margin:0 auto;padding:0 20px}
h1{font-size:clamp(1.6rem,4vw,2.3rem);font-weight:800;letter-spacing:-.02em;line-height:1.2;margin:.4em 0 .3em}
h2{font-size:1.15rem;font-weight:800;letter-spacing:-.01em;margin:2em 0 .6em}
h3{font-size:1.02rem;font-weight:700;margin:0 0 .35em;letter-spacing:-.01em}
p{margin:0 0 1em}
.lead{font-size:1.05rem;color:var(--muted);max-width:62ch}

header.site{border-bottom:1px solid var(--line);background:var(--bg);position:sticky;top:0;z-index:5}
header.site .bar{display:flex;align-items:center;justify-content:space-between;gap:14px;min-height:60px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;color:var(--text);text-decoration:none}
.langs{display:flex;gap:12px;flex-wrap:wrap;font-size:.85rem}
.langs a{color:var(--muted);text-decoration:none}
.langs a.on{color:var(--brand);font-weight:700}

.filters{display:flex;flex-direction:column;gap:10px;margin:18px 0 6px}
.filter{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.flabel{font-size:.72rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-right:2px}
.pill{font:inherit;font-size:.88rem;font-weight:700;color:var(--muted);background:var(--card);
  border:1px solid var(--line);border-radius:11px;padding:7px 13px;cursor:pointer}
.pill.on{background:var(--brand);border-color:var(--brand);color:#fff}
.count{color:var(--muted);font-size:.9rem;margin:14px 0 10px}

.grid{display:grid;gap:12px;grid-template-columns:1fr}
@media(min-width:640px){.grid{grid-template-columns:1fr 1fr}}
.card{display:block;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:16px;text-decoration:none;color:inherit;box-shadow:var(--shadow)}
.card:hover{border-color:var(--brand)}
.card p{color:var(--muted);font-size:.92rem;margin:0 0 10px}
.cell.hide{display:none}

.chips{display:flex;flex-wrap:wrap;gap:7px;margin:0 0 4px}
.chip{display:inline-flex;align-items:center;gap:7px;background:var(--bg-alt);color:var(--muted);
  border-radius:9px;padding:4px 10px;font-size:.79rem;font-weight:700}
.chip.pri{background:var(--brand-soft);color:var(--brand-ink)}
.chip.acc{background:var(--acc-soft);color:var(--acc-ink)}
.dots{display:inline-flex;gap:3px}
.dots i{width:5px;height:5px;border-radius:50%;background:currentColor;opacity:.28}
.dots i.on{opacity:1}

.article .crumbs{font-size:.85rem;color:var(--muted);margin-top:16px}
.article .crumbs a{color:var(--muted);text-decoration:none}
.box{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;box-shadow:var(--shadow)}
.statement{font-size:1.05rem}
ol.steps{list-style:none;counter-reset:s;padding:0;margin:0}
ol.steps li{counter-increment:s;position:relative;padding:0 0 14px 40px}
ol.steps li::before{content:counter(s);position:absolute;left:0;top:0;width:26px;height:26px;border-radius:9px;
  background:var(--brand-soft);color:var(--brand-ink);font-size:.8rem;font-weight:800;display:grid;place-items:center}
ol.steps li b{display:block;font-weight:700}
ol.steps li span{display:block;color:var(--muted);font-size:.94rem}
.note{color:var(--muted);font-size:.88rem;border-left:3px solid var(--line);padding-left:12px}
.empty{color:var(--muted)}

.cta{background:var(--brand-soft);border-radius:22px;padding:22px;margin:34px 0 8px}
.cta h2{margin-top:0;color:var(--brand-ink)}
.cta p{color:var(--brand-ink);opacity:.85;max-width:52ch}
.btns{display:flex;flex-wrap:wrap;gap:10px}
.btn{font:inherit;font-weight:700;font-size:.95rem;border-radius:13px;padding:12px 18px;text-decoration:none;
  border:1px solid transparent;cursor:pointer;display:inline-block}
.btn.primary{background:var(--brand);color:#fff}
.btn.ghost{background:var(--card);color:var(--text);border-color:var(--line)}

footer.site{border-top:1px solid var(--line);margin-top:40px;padding:26px 0 40px;color:var(--muted);font-size:.87rem}
footer.site .links{display:flex;gap:16px;flex-wrap:wrap;margin-bottom:8px}
footer.site a{color:var(--muted);text-decoration:none}

/* Hình minh hoạ do AI vẽ lại (SVG tĩnh, không cần JavaScript) */
.box.figure{margin-top:12px;padding:14px 16px 10px}
.visual{margin:0}
.visual svg{width:100%;height:auto;max-width:420px;margin:0 auto;display:block}
.figcap{margin:8px 0 0;color:var(--muted);font-size:.8rem;text-align:center}
@media (prefers-color-scheme:dark){
  /* Hình vẽ nền sáng để nét mực đen vẫn rõ trong nền tối */
  .box.figure{background:#F8F9FF}
  .figcap{color:#5B5F7A}
}

/* Sơ đồ trang (HTML sitemap) */
ul.links{list-style:none;padding:0;margin:0 0 6px;display:grid;gap:7px}
ul.links li{padding-left:14px;position:relative}
ul.links li::before{content:"›";position:absolute;left:0;color:var(--muted)}
ul.links a{text-decoration:none;font-weight:600}
ul.links a:hover{text-decoration:underline}
.dim{color:var(--muted);font-weight:500;font-size:.85em}