/* ---------------------------------------------------------------
   Bản tiếng Việt - Cẩm nang SDLC AI-native
   Thiết kế riêng, dùng font Google có tiếng Việt.
   Không dùng font, logo hay tài sản thương hiệu của Anthropic.
   --------------------------------------------------------------- */

:root{
  --paper:#faf9f5;
  --ink:#141413;
  --body:#3b3a36;
  --muted:#6b6a64;
  --line:rgba(20,20,19,.16);
  --clay:#d97757;
  --clay-dark:#b4553a;
  --old:#f1efe8;
  --new:#f3e3dc;
  --cell:#fbf1ec;
  --nd:#8a5a2b;            /* màu chú thích của người dịch */
  --nd-bg:rgba(217,119,87,.10);
  --sans:"Be Vietnam Pro",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  --serif:"Newsreader",Georgia,"Times New Roman",serif;
  --mono:"JetBrains Mono",Menlo,Consolas,"SF Mono",monospace;
  --wrap:720px;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; background:var(--paper); color:var(--body);
  font-family:var(--sans); font-size:17px; line-height:1.65;
  font-weight:400; -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto}

/* ---------- khối dẫn nguồn + disclaimer đầu trang ---------- */
.topbar{
  background:var(--ink); color:#e8e6dc;
  font-size:13.5px; line-height:1.6;
}
.topbar .in{max-width:var(--wrap);margin:0 auto;padding:18px 22px}
.topbar b{color:#faf9f5;font-weight:600}
.topbar a{color:#f0b49a;text-decoration:underline;text-underline-offset:2px}
.topbar .row{display:flex;gap:10px;flex-wrap:wrap;align-items:baseline}
.topbar .tag{
  font-size:10.5px;letter-spacing:.13em;text-transform:uppercase;
  font-weight:600;color:var(--clay);
}
.topbar p{margin:8px 0 0}
.topbar .fine{color:#b0aea5;font-size:12.5px;margin-top:10px}

/* ---------- đầu bài ---------- */
header.doc{max-width:var(--wrap);margin:0 auto;padding:56px 22px 8px}
header.doc h1{
  font-family:var(--serif);font-weight:400;font-size:46px;line-height:1.08;
  color:var(--ink);margin:0 0 16px;letter-spacing:-.01em;
}
header.doc .sub{font-size:19px;line-height:1.5;color:var(--muted);margin:0 0 26px}
header.doc .meta{
  border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  padding:16px 0;display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));
  gap:14px;font-size:13.5px;line-height:1.45;
}
header.doc .meta b{
  display:block;font-size:10.5px;letter-spacing:.12em;text-transform:uppercase;
  color:var(--muted);font-weight:600;margin-bottom:4px;
}
header.doc .meta a{color:inherit}

/* ---------- thân bài ---------- */
main{max-width:var(--wrap);margin:0 auto;padding:0 22px 40px}
main h2{
  font-family:var(--serif);font-weight:400;font-size:32px;line-height:1.15;
  color:var(--ink);margin:56px 0 16px;letter-spacing:-.005em;scroll-margin-top:20px;
}
main h3{
  font-family:var(--serif);font-weight:400;font-size:25px;line-height:1.2;
  color:var(--ink);margin:44px 0 14px;scroll-margin-top:20px;
}
main h4{font-size:1.06em;font-weight:600;line-height:1.35;color:var(--ink);margin:36px 0 12px}
main p{margin:0 0 20px}
main ul,main ol{margin:0 0 22px;padding-left:22px}
main li{margin:0 0 9px}
main a{color:inherit;text-decoration:underline;text-underline-offset:2.5px;
  text-decoration-color:rgba(20,20,19,.35)}
main a:hover{text-decoration-color:currentColor}
code{
  font-family:var(--mono);font-size:.855em;background:rgba(127,127,127,.16);
  padding:1px 5px;border-radius:4px;
}

/* chú thích của người dịch */
.nd{
  color:var(--nd);background:var(--nd-bg);
  font-size:.85em;line-height:1.4;
  padding:1px 6px;border-radius:4px;
  border-bottom:1px dotted rgba(217,119,87,.6);
}
.nd::before{content:"ND: ";font-weight:600;letter-spacing:.02em}

/* khối code */
pre{
  font-family:var(--mono);font-size:12.5px;line-height:1.55;
  background:var(--ink);color:#e8e6dc;
  padding:16px 18px;border-radius:10px;margin:0 0 28px;
  white-space:pre;overflow-x:auto;tab-size:2;position:relative;
}
pre code{background:none;padding:0;font-size:inherit;color:inherit}
.codewrap{position:relative;margin:0 0 28px}
.codewrap pre{margin:0}
.copy{
  position:absolute;top:10px;right:10px;
  font-family:var(--sans);font-size:11px;font-weight:500;
  background:rgba(250,249,245,.12);color:#e8e6dc;
  border:1px solid rgba(250,249,245,.25);border-radius:6px;
  padding:4px 9px;cursor:pointer;opacity:0;transition:opacity .15s;
}
.codewrap:hover .copy,.copy:focus{opacity:1}
.copy.done{background:var(--clay);border-color:var(--clay);color:#fff}

/* ---------- mục lục ---------- */
.toc{
  border:1px solid var(--line);border-radius:14px;
  padding:22px 26px;margin:0 0 32px;
}
.toc .k{
  font-size:11px;letter-spacing:.12em;text-transform:uppercase;
  color:var(--clay);font-weight:600;margin:0 0 12px;
}
.toc ol{margin:0;padding:0;list-style:none;counter-reset:r;columns:2;column-gap:28px}
.toc li{
  counter-increment:r;font-size:15px;line-height:1.4;margin:0 0 9px;padding:0;
  display:flex;gap:12px;break-inside:avoid;
}
.toc li::before{
  content:'0' counter(r);font-size:13px;color:var(--clay);
  min-width:24px;font-variant-numeric:tabular-nums;padding-top:2px;
}
.toc a{text-decoration:none;border-bottom:1px solid rgba(20,20,19,.25);color:inherit}
.toc a:hover{border-color:currentColor}

/* ---------- dải giai đoạn ---------- */
.band{
  border-radius:16px;padding:36px 36px 38px;
  display:grid;grid-template-columns:auto 1fr;gap:28px;align-items:start;
  margin:64px 0 36px;color:var(--ink);scroll-margin-top:20px;
}
.band .num{font-size:76px;line-height:.9;font-weight:400;color:var(--ink);opacity:.28;
  font-family:var(--serif);font-variant-numeric:tabular-nums}
.band h2{font-family:var(--serif);font-weight:400;font-size:34px;line-height:1.1;
  margin:0 0 10px;color:var(--ink)}
.band p{margin:0;font-size:16px;line-height:1.5;color:#3b3a36}

/* ---------- Truyền thống / AI-native ---------- */
.vs{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:0 0 32px}
.vs>div{border-radius:12px;padding:20px 20px 22px;font-size:15.5px;line-height:1.55;color:var(--body)}
.vs .old{background:var(--old)}
.vs .new{background:var(--new)}
.vs small{
  display:block;font-size:11px;letter-spacing:.12em;text-transform:uppercase;
  font-weight:600;margin-bottom:8px;color:var(--muted);
}
.vs .new small{color:var(--clay-dark)}
.vs p{margin:0}

/* ---------- khối cặp nhãn - nội dung ---------- */
.kv{border-top:1px solid var(--line);margin:0 0 28px;font-size:15.5px;line-height:1.55}
.kv>div{display:grid;grid-template-columns:170px 1fr;gap:16px;padding:14px 0;
  border-bottom:1px solid var(--line)}
.kv>div>b{font-size:13.5px;font-weight:600;opacity:.7;padding-top:2px}
.kv>div>div{opacity:.9}
.kv p{margin:0}

/* ---------- bảng ---------- */
.tbl{overflow-x:auto;margin:0 0 32px}
.tbl table{width:100%;border-collapse:collapse;font-size:14px;line-height:1.45;min-width:560px}
.tbl th{background:var(--ink);color:var(--paper);text-align:left;padding:10px 12px;
  font-size:11px;letter-spacing:.1em;text-transform:uppercase;font-weight:600}
.tbl th:first-child{border-radius:8px 0 0 0}
.tbl th:last-child{border-radius:0 8px 0 0}
.tbl td{padding:12px;border-bottom:1px solid var(--line);vertical-align:top}
.tbl td:first-child{font-weight:600;white-space:nowrap}
.tbl td:last-child{background:var(--cell)}

/* ---------- khối chốt ---------- */
.key{
  border-radius:14px;padding:24px 28px;margin:0 0 32px;
  display:grid;grid-template-columns:auto 1fr;gap:22px;align-items:center;
  font-size:17px;line-height:1.5;color:var(--ink);background:var(--clay);
}
.key.sand{background:#ece7da}
.key .mark{width:38px;height:38px;flex:0 0 38px}
.key p{margin:0}

/* ---------- ghi chú bên lề ---------- */
.side{
  background:var(--ink);color:#faf9f5;border-radius:14px;padding:26px 28px;margin:0 0 32px;
  display:grid;grid-template-columns:170px minmax(0,1fr);gap:28px;
  font-size:14.5px;line-height:1.55;
}
.side small{display:block;font-size:11px;letter-spacing:.12em;text-transform:uppercase;
  font-weight:600;color:var(--clay);margin-bottom:10px}
.side h3{font-family:var(--serif);font-weight:400;font-size:22px;line-height:1.2;
  margin:0 0 8px;color:#faf9f5}
.side .note{font-size:12.5px;color:#b0aea5;display:block}
.side p{margin:0 0 12px;color:#e8e6dc}
.side p:last-child{margin-bottom:0}
.side b{color:#faf9f5;font-weight:600}
.side a{color:#f0b49a}
.side code{background:rgba(250,249,245,.16);color:inherit}
.side pre{background:#000;margin:0 0 14px}
.side .nd{color:#f0b49a;background:rgba(240,180,154,.14);border-bottom-color:rgba(240,180,154,.5)}

/* ---------- danh sách tài liệu ---------- */
.res{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:0 0 32px}
.res a{
  display:block;border:1px solid var(--line);border-radius:10px;padding:12px 14px;
  text-decoration:none;color:inherit;font-size:14px;line-height:1.4;
}
.res a:hover{border-color:currentColor}
.res a small{display:block;font-family:var(--mono);font-size:11px;opacity:.6;
  margin-top:4px;word-break:break-all}

/* ---------- hình vẽ lại ---------- */
figure{margin:0 0 32px}
figure .art{background:#f1efe8;border-radius:14px;padding:26px}
figure figcaption{font-size:13.5px;line-height:1.5;color:var(--muted);margin-top:12px}
figure svg{display:block;width:100%;height:auto}
.fignote{
  font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--nd);
  font-weight:600;margin-bottom:10px;
}

/* ---------- sổ tay thuật ngữ ---------- */
.glossary{
  border:1px solid var(--line);border-radius:14px;padding:28px 30px;margin:56px 0 0;
  background:#f5f3ec;
}
.glossary h2{margin:0 0 6px;font-size:27px}
.glossary .note{font-size:13.5px;color:var(--nd);margin:0 0 18px;font-style:italic}
.glossary ul{list-style:none;padding:0;margin:0}
.glossary li{
  margin:0;padding:10px 0;border-bottom:1px solid var(--line);
  font-size:14.5px;line-height:1.5;
}
.glossary li:last-child{border-bottom:0}
.glossary b{color:var(--ink)}

/* ---------- chân trang ---------- */
footer.doc{
  border-top:1px solid var(--line);margin-top:56px;
  background:#f1efe8;
}
footer.doc .in{max-width:var(--wrap);margin:0 auto;padding:34px 22px 46px;
  font-size:13px;line-height:1.65;color:var(--muted)}
footer.doc .k{
  font-size:10.5px;letter-spacing:.13em;text-transform:uppercase;
  color:var(--clay-dark);font-weight:600;margin:0 0 10px;
}
footer.doc a{color:inherit}
footer.doc p{margin:0 0 12px}
footer.doc .credit{margin-top:22px;padding-top:16px;border-top:1px solid var(--line);
  font-size:12px;color:#9a9890}

/* ---------- điện thoại ---------- */
@media (max-width:720px){
  body{font-size:16.5px}
  header.doc{padding-top:38px}
  header.doc h1{font-size:34px}
  header.doc .sub{font-size:17px}
  main h2{font-size:27px}
  main h3{font-size:22px}
  .vs,.res{grid-template-columns:minmax(0,1fr)}
  .toc ol{columns:1}
  .band{grid-template-columns:1fr;gap:8px;padding:28px 24px;margin-top:48px}
  .band .num{font-size:44px}
  .band h2{font-size:28px}
  .kv>div{grid-template-columns:1fr;gap:4px}
  .side{grid-template-columns:minmax(0,1fr);gap:16px}
  .key{grid-template-columns:1fr;gap:14px;font-size:16px}
  .tbl table{min-width:520px}
  figure .art{padding:16px}
}

/* ---------- in ra giấy / xuất PDF ---------- */
@media print{
  body{background:#fff;font-size:11pt}
  .topbar{background:#fff;color:#000;border-bottom:1px solid #999}
  .topbar a,.topbar b,.topbar .fine{color:#000}
  .copy{display:none}
  .band,.vs>div,.key,.side,figure .art,.glossary{break-inside:avoid}
  main h2,main h3{break-after:avoid}
  pre{white-space:pre-wrap;word-break:break-word}
}

/* ================= hình 1: trước / sau khi có agent ================= */
.f1-row{margin-bottom:26px}
.f1-row:last-child{margin-bottom:0}
.f1-lab{font-size:14.5px;color:var(--body);margin-bottom:10px}
.f1-lab b{color:var(--ink);font-weight:600}
.f1-bars{display:flex;gap:8px;align-items:stretch}
.f1-b{
  background:var(--ink);color:var(--paper);border-radius:9px;
  padding:14px 10px;font-size:13.5px;text-align:center;line-height:1.25;
  flex:1 1 0;min-width:0;min-height:56px;
  display:flex;align-items:center;justify-content:center;
}
.f1-big{flex:4 1 0;background:var(--clay);color:#fff}
.f1-c{flex:1 1 0;min-width:0;display:flex;flex-direction:column;gap:6px}
.f1-c .f1-b,.f1-c .f1-ghost{flex:1 1 auto}
.f1-c .f1-b{flex:none}
.f1-c span{font-size:11.5px;color:var(--muted);text-align:center;line-height:1.2}
.f1-c.f1-grow{flex:3 1 0}
.f1-sliver{flex:1 1 auto;padding:0;background:var(--clay);min-width:14px;max-width:14px;margin:0 auto}
.f1-c:has(.f1-sliver){flex:0 0 14px}
.f1-ghost{
  border:1px dashed rgba(20,20,19,.32);border-radius:9px;color:var(--muted);
  padding:14px 10px;font-size:12.5px;text-align:center;line-height:1.25;
  min-height:56px;display:flex;align-items:center;justify-content:center;
}

/* ================= hình 2: đường thẳng / vòng lặp ================= */
.f2{display:grid;grid-template-columns:1fr 1.15fr;gap:30px;align-items:start}
.f2-line{display:flex;flex-direction:column;gap:0}
.f2-bar{
  background:var(--ink);color:var(--paper);border-radius:9px;
  padding:13px 10px;font-size:15px;text-align:center;
}
.f2-arw{text-align:center;color:var(--ink);font-size:15px;line-height:1;padding:6px 0}
.f2-ring{max-width:400px;margin:0 auto}
.f2-cap{font-size:13.5px;line-height:1.5;color:var(--muted);margin:16px 0 0}
.f2-cap b{color:var(--ink);font-weight:600}

/* ================= hình 3: sơ đồ thứ tự áp dụng ================= */
.f3{overflow-x:auto}
.f3 svg{min-width:660px}

/* ================= hình 4: kênh sự cố ================= */
.f4{background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:20px 22px}
.f4-head{
  display:flex;gap:12px;align-items:baseline;flex-wrap:wrap;
  border-bottom:1px solid var(--line);padding-bottom:14px;margin-bottom:16px;
}
.f4-head b{font-family:var(--mono);font-size:15px;color:var(--ink);font-weight:500}
.f4-head span{font-size:12.5px;color:var(--muted)}
.f4-msg{display:grid;grid-template-columns:38px 1fr;gap:12px;margin-bottom:16px}
.f4-msg:last-child{margin-bottom:0}
.f4-av{
  width:38px;height:38px;border-radius:50%;display:flex;align-items:center;
  justify-content:center;font-size:12px;font-weight:600;
}
.f4-av-p{background:#e3e0d6;color:#6b6a64}
.f4-av-c{background:var(--clay);color:#fff;font-size:15px}
.f4-who{font-size:14px;font-weight:600;color:var(--ink);margin-bottom:3px}
.f4-who span{font-family:var(--mono);font-size:11.5px;font-weight:400;color:var(--muted);margin-left:8px}
.f4-txt{font-size:14.5px;line-height:1.5;color:var(--body)}
.f4-txt a{color:var(--clay-dark)}
.f4-txt code{font-size:.9em}

@media (max-width:720px){
  .f2{grid-template-columns:minmax(0,1fr);gap:26px}
  .f1-bars{gap:5px}
  .f1-b{font-size:11.5px;padding:11px 5px}
  .f1-ghost{font-size:11px;padding:11px 5px}
  .f4{padding:16px}
  .f4-msg{grid-template-columns:30px 1fr;gap:9px}
  .f4-av{width:30px;height:30px;font-size:11px}
}