@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-latin-400-normal.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-latin-ext-400-normal.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-400-normal.woff2) format('woff2');unicode-range:U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/be-vietnam-pro-latin-500-normal.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/be-vietnam-pro-latin-ext-500-normal.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-500-normal.woff2) format('woff2');unicode-range:U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/be-vietnam-pro-latin-600-normal.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/be-vietnam-pro-latin-ext-600-normal.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-600-normal.woff2) format('woff2');unicode-range:U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:700;font-display:swap;src:url(fonts/be-vietnam-pro-latin-700-normal.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:700;font-display:swap;src:url(fonts/be-vietnam-pro-latin-ext-700-normal.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;}@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:700;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-700-normal.woff2) format('woff2');unicode-range:U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;}@font-face{font-family:'Be Vietnam Pro';font-style:italic;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-latin-400-italic.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'Be Vietnam Pro';font-style:italic;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-400-italic.woff2) format('woff2');unicode-range:U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;}@font-face{font-family:'JetBrains Mono';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/jetbrains-mono-latin-400-normal.woff2) format('woff2');unicode-range:U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;}@font-face{font-family:'JetBrains Mono';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/jetbrains-mono-latin-ext-400-normal.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;}

/* ==========================================================================
   Dedy theme v3 "Giấy mềm" cho AI Learn. Claude viết ngày 11/11/2026.
   Nền sáng, ô bo tròn mềm, chữ đen, đúng một dải nhấn xanh lá. Gần như không dùng bóng đổ.
   Mặc định sáng; công tắc sáng/tối ở chân trang (site.js). Mọi hook giữ theo README "Theme hooks".
   Bản gốc tối giản nằm ở theme.goc-20261111/.
   ========================================================================== */
:root{
 --bg:#f6f6f3;--tile:#ededea;--track:#e1e1dd;--surface:#fff;--ink:#121214;--bone:#f1f1ee;
 --fg:#121214;--muted:#5b5b60;--faint:#85858a;--line:rgba(18,18,20,.08);--line-2:rgba(18,18,20,.17);
 --go:#2ccb5c;--go-2:#b9f03f;--grad:linear-gradient(90deg,var(--go),var(--go-2));--on-go:#08240f;--ok:#17803a;--ok-soft:#dff5e3;--warn:#8a5a00;--warn-soft:#fbefd0;--bad:#b3261e;--bad-soft:#fbe4e2;
 --inv:var(--ink);--on-inv:var(--bone);--code-bg:#121214;--code-fg:#dcdcd6;
 --shadow:0 1px 2px rgba(18,18,20,.05);--pop:inset 0 0 0 1px var(--line),0 22px 44px -24px rgba(18,18,20,.2);
 --font:'Be Vietnam Pro',system-ui,sans-serif;--display:'Newsreader','Times New Roman',serif;--mono:'JetBrains Mono',ui-monospace,monospace;
 --r-tile:clamp(1.375rem,2.1vw,1.875rem);--r-xl:clamp(1.5rem,2.6vw,2.25rem);--r-in:1rem;--side-w:19rem;
}
:root[data-theme=dark]{color-scheme:dark;
 --bg:#0f0f11;--tile:#18181b;--track:#2a2a2f;--surface:#202024;--fg:#f1f1ee;--muted:#a6a6ab;--faint:#78787e;--line:rgba(255,255,255,.08);--line-2:rgba(255,255,255,.18);
 --ok:#6fe08a;--ok-soft:rgba(72,214,110,.14);--warn:#f0c869;--warn-soft:rgba(240,200,105,.14);--bad:#ff8a80;--bad-soft:rgba(255,138,128,.14);
 --inv:var(--bone);--on-inv:var(--ink);--code-bg:#0b0b0d;--shadow:inset 0 0 0 1px rgba(255,255,255,.06);--pop:inset 0 0 0 1px rgba(255,255,255,.1),0 22px 44px -24px rgba(0,0,0,.7)}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:5.75rem}
body{margin:0;background:var(--bg);color:var(--fg);font:400 1rem/1.7 var(--font);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit}
img{max-width:100%;height:auto}
figure{margin:0}
:focus-visible{outline:2px solid var(--fg);outline-offset:3px;border-radius:.375rem}
::selection{background:var(--go-2);color:var(--on-go)}
.muted{color:var(--muted)}
.read-progress{position:fixed;inset:0 0 auto 0;z-index:40;height:2px;background:var(--grad);transform-origin:left;transform:scaleX(var(--p,0))}

/* ── Thanh trên: viên thuốc nổi, viền mảnh ── */
.site-header{position:sticky;top:.75rem;z-index:30;display:flex;align-items:center;gap:.75rem;width:min(100% - 1.5rem,96rem);height:3.5rem;margin:.75rem auto 0;padding:0 .5rem 0 1.25rem;border-radius:999px;background:color-mix(in srgb,var(--surface) 88%,transparent);-webkit-backdrop-filter:saturate(160%) blur(18px);backdrop-filter:saturate(160%) blur(18px);box-shadow:inset 0 0 0 1px var(--line)}
.site-brand{display:inline-flex;align-items:center;gap:.5rem;font:500 1.5rem/1 var(--display);letter-spacing:-.02em;text-decoration:none;white-space:nowrap}
.site-brand::before{content:"";width:1.125rem;aspect-ratio:1;border-radius:50%;background:conic-gradient(from 200deg,var(--go),var(--go-2),var(--go));-webkit-mask:radial-gradient(farthest-side,transparent 50%,#000 53%);mask:radial-gradient(farthest-side,transparent 50%,#000 53%)}
.course-switcher,.site-links{display:flex;gap:.125rem;min-width:0;margin-left:.75rem;overflow-x:auto;scrollbar-width:none}
.course-switcher::-webkit-scrollbar,.site-links::-webkit-scrollbar{display:none}
.course-switcher a,.site-links a{display:inline-flex;align-items:center;height:2.25rem;padding:0 .875rem;border-radius:999px;font-size:.875rem;font-weight:500;color:var(--muted);text-decoration:none;white-space:nowrap;transition:color .2s,background-color .2s}
.course-switcher a:hover,.site-links a:hover{color:var(--fg)}
.course-switcher a[aria-current]{background:var(--tile);color:var(--fg);font-weight:600}
.site-links a[aria-current]{color:var(--fg);font-weight:600}
.site-search{display:inline-flex;align-items:center;gap:.5rem;flex:0 1 15rem;min-width:0;height:2.25rem;margin-left:auto;padding:0 .5rem 0 2.25rem;border:0;border-radius:999px;background:var(--tile) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2385858a' stroke-width='2' stroke-linecap='round'%3E%3Ccircle cx='11' cy='11' r='7'/%3E%3Cpath d='m20 20-3.5-3.5'/%3E%3C/svg%3E") no-repeat .75rem 50%/1rem;color:var(--faint);font:400 .875rem var(--font);text-align:left;cursor:pointer;transition:background-color .2s,color .2s}
.site-search:hover{color:var(--fg)}
.site-search span{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.site-search kbd{display:inline-grid;place-items:center;min-width:1.375rem;height:1.375rem;border-radius:.4375rem;background:var(--surface);font:400 .6875rem/1 var(--mono);color:var(--muted)}
.lang-switch,.mode-switch{display:inline-flex;padding:3px;border-radius:999px;background:var(--track)}
.lang-switch a,.mode-switch button{display:inline-flex;align-items:center;justify-content:center;min-width:2.5rem;height:1.875rem;padding:0 .75rem;border:0;border-radius:999px;background:none;font:600 .75rem var(--font);color:var(--muted);text-decoration:none;cursor:pointer;transition:color .2s,background-color .2s}
.lang-switch a[aria-current],.mode-switch button[aria-pressed=true]{background:var(--surface);color:var(--fg);box-shadow:var(--shadow)}
.nav-toggle{display:none;align-items:center;height:2.25rem;padding:0 .875rem;border:0;border-radius:999px;background:var(--tile);color:var(--fg);font:600 .8125rem var(--font);cursor:pointer}

/* ── Khung trang: mục lục bên trái trên nền sáng, phần đọc là một ô xám lớn bo góc ── */
.site-body{display:grid;grid-template-columns:var(--side-w) minmax(0,1fr);align-items:start;width:min(100%,97.5rem);margin:0 auto;padding:.75rem .75rem .75rem 0}
.site-nav{position:sticky;top:5rem;max-height:calc(100dvh - 5.75rem);overflow-y:auto;overscroll-behavior:contain;padding:.75rem .75rem 2rem 1rem;font-size:.875rem;scrollbar-width:thin}
.site-nav:empty{display:none}
.site-body:has(.site-nav:empty){grid-template-columns:minmax(0,1fr);padding-left:.75rem}
.nav-course{margin:0 0 .25rem;padding:0 .75rem;font:500 1.375rem/1.2 var(--display);letter-spacing:-.015em}
.nav-course a{text-decoration:none}
.site-nav>h2:not(.nav-course){margin:0 0 .5rem;padding:0 .75rem;font:500 1.375rem/1.2 var(--display);letter-spacing:-.015em}
.site-nav h3{margin:1.25rem 0 .375rem;padding:0 .75rem;font:500 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--faint)}
.site-nav ul{list-style:none;margin:0;padding:0;display:grid;gap:.125rem}
.site-nav li a{display:block;padding:.5rem .75rem;border-radius:.875rem;line-height:1.4;color:var(--muted);text-decoration:none;transition:background-color .2s,color .2s}
.site-nav li a:hover{background:var(--tile);color:var(--fg)}
.site-nav li a[aria-current]{background:var(--surface);color:var(--fg);font-weight:600;box-shadow:var(--shadow)}
.content{min-width:0;padding:clamp(.75rem,2vw,1.75rem);border-radius:var(--r-xl);background:var(--tile)}

/* ── Trang giấy ── */
.page{width:min(100%,70rem);margin:0 auto;padding:clamp(1.5rem,4.4vw,3.75rem);border-radius:var(--r-tile);background:var(--surface);box-shadow:var(--shadow);font-size:1.0625rem;line-height:1.78}
.page>*{margin:0;min-width:0}
.page>*+*{margin-top:1.125rem}
.page-header{padding-bottom:1.75rem;border-bottom:1px solid var(--line)}
.page-header h1{margin:0;font:400 clamp(2rem,1.3rem + 2.4vw,3.25rem)/1.06 var(--display);letter-spacing:-.028em;text-wrap:balance}
.page-summary{margin:.875rem 0 0;max-width:42rem;font-size:1.125rem;line-height:1.55;color:var(--muted)}
.page-meta{margin:.75rem 0 0;font:400 .75rem/1.6 var(--mono);color:var(--muted)}
.page h2{margin-top:3.25rem;font:500 clamp(1.5rem,1.2rem + .9vw,1.875rem)/1.18 var(--display);letter-spacing:-.018em;scroll-margin-top:6rem;text-wrap:balance}
.page h3{margin-top:2.25rem;font-size:1.125rem;font-weight:600;line-height:1.35;letter-spacing:-.01em;scroll-margin-top:6rem}
.page h4{margin-top:1.75rem;font-size:1rem;font-weight:600}
.page h2+*,.page h3+*,.page h4+*{margin-top:.875rem}
.page :is(ul,ol){padding-left:1.375rem}
.page li+li{margin-top:.5rem}
.page li>:is(ul,ol){margin:.5rem 0 0}
.page ul>li::marker{color:var(--go)}
.page ol>li::marker{font:400 .875em var(--mono);color:var(--faint)}
.page a{text-decoration:underline;text-decoration-color:var(--line-2);text-decoration-thickness:1.5px;text-underline-offset:.3em;overflow-wrap:anywhere;transition:text-decoration-color .2s}
.page a:hover{text-decoration-color:var(--go)}
.page strong{font-weight:600}
.page hr{height:1px;border:0;background:var(--line);margin-top:2.5rem}
.page blockquote{padding:.25rem 0 .25rem 1.25rem;border-left:2px solid var(--line-2);color:var(--muted)}
.page code{padding:.125em .375em;border-radius:.375rem;background:var(--tile);font:400 .875em var(--mono);overflow-wrap:anywhere}
.page pre{padding:1.125rem 1.25rem;border-radius:var(--r-in);background:var(--code-bg);color:var(--code-fg);font:400 .8125rem/1.7 var(--mono);overflow-x:auto;tab-size:2}
.page pre code,.page pre code.hljs{display:block;padding:0;border-radius:0;background:none;color:inherit;font:inherit;overflow:visible;overflow-wrap:normal}
.page pre :is(.hljs-keyword,.hljs-literal,.hljs-built_in,.hljs-type,.hljs-doctag){color:#8fe28a}
.page pre :is(.hljs-string,.hljs-attr,.hljs-symbol,.hljs-regexp,.hljs-meta .hljs-string){color:#d6f58a}
.page pre :is(.hljs-number,.hljs-title,.hljs-title.function_,.hljs-title.class_,.hljs-name,.hljs-section){color:#f4f4f0}
.page pre :is(.hljs-comment,.hljs-quote){color:#8a8a8f;font-style:italic}
.page pre :is(.hljs-params,.hljs-variable,.hljs-subst,.hljs-meta,.hljs-operator,.hljs-punctuation,.hljs-attribute,.hljs-selector-class,.hljs-selector-id,.hljs-tag){color:#dcdcd6}
.page table{width:100%;border-collapse:separate;border-spacing:0;border-radius:var(--r-in);box-shadow:inset 0 0 0 1px var(--line);font-size:.9375rem;line-height:1.55}
.page th{padding:.75rem 1rem;background:var(--tile);font:400 .6875rem/1.4 var(--mono);letter-spacing:.06em;text-transform:uppercase;text-align:left;color:var(--muted);vertical-align:bottom}
.page th:first-child{border-top-left-radius:var(--r-in)}.page th:last-child{border-top-right-radius:var(--r-in)}
.page td{padding:.75rem 1rem;border-top:1px solid var(--line);vertical-align:top}
.page td:first-child{font-weight:500}

/* "Trong trang này": ô xám ở đầu bài; màn hình rộng thì đứng yên bên phải và sáng mục đang đọc */
.toc{padding:1rem 1.125rem;border-radius:var(--r-in);background:var(--tile);font-size:.875rem;line-height:1.45}
.page .toc h2{margin:0 0 .5rem;padding:0 .5rem;font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--faint)}
.toc ol{list-style:none;margin:0;padding:0;display:grid;gap:.125rem}
.toc li+li{margin-top:0}
.toc ol ol{margin:.125rem 0 .25rem .75rem}
.page .toc a{display:block;padding:.3125rem .5rem;border-radius:.5rem;color:var(--muted);text-decoration:none;transition:background-color .2s,color .2s}
.page .toc a:hover,.page .toc a.is-active{background:var(--surface);color:var(--fg)}
@media (min-width:84rem){
 .page:has(>.toc){display:grid;grid-template-columns:minmax(0,1fr) 13.5rem;column-gap:clamp(2rem,3.6vw,3.5rem);align-content:start}
 .page:has(>.toc)>*{grid-column:1}
 .page>.toc{grid-column:2;grid-row:1/span 600;align-self:start;position:sticky;top:5.75rem;margin:0;padding:0;background:none;max-height:calc(100dvh - 7rem);overflow-y:auto}
 .page .toc a:hover,.page .toc a.is-active{background:var(--tile)}
 .page .toc a.is-active{font-weight:600}
}

/* Khối nhấn */
.brief,.note,.notice{padding:1.25rem 1.5rem;border-radius:var(--r-in);background:var(--tile)}
.brief-label,.note::before{display:flex;align-items:center;gap:.5rem;margin:0 0 .5rem;font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.brief-label::before{content:"";width:.5rem;aspect-ratio:1;border-radius:50%;background:var(--grad)}
.brief-text>*,.note>*{margin:0}.brief-text>*+*,.note>*+*{margin-top:.75rem}
.brief-text p{font:400 1.25rem/1.5 var(--display);letter-spacing:-.005em}
.brief figure{margin-top:1rem}
.note::before{content:"Lưu ý"}html[lang=en] .note::before{content:"Note"}
.translator-note{padding:.0625rem .375rem;border-radius:.375rem;background:var(--tile);font:400 .75em var(--mono);color:var(--muted)}

/* Dòng thông tin đầu bài (cấp độ, thời lượng, đầu ra) của khoá Dedy AI Engineer */
body[data-course="dedy-ai-engineer"] .page-chapter>.toc+p,.page .lesson-meta{padding:.875rem 1.125rem;border-radius:var(--r-in);background:var(--tile);font-size:.875rem;line-height:1.7;color:var(--muted)}
body[data-course="dedy-ai-engineer"] .page-chapter>.toc+p strong,.page .lesson-meta strong{font:400 .6875rem/1 var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--faint)}

/* Ba thử thách: mỗi thử thách một ô, số điểm nằm trong vòng tròn, Boss là vòng đen */
:is(#thu-thach,#challenges)+p,:is(#thu-thach,#challenges)+p+p,:is(#thu-thach,#challenges)+p+p+p{position:relative;min-height:4.75rem;padding:1.125rem 1.25rem 1.125rem 4.5rem;border-radius:var(--r-in);background:var(--tile);font-size:1rem;line-height:1.65}
:is(#thu-thach,#challenges)+p+p,:is(#thu-thach,#challenges)+p+p+p{margin-top:.5rem}
:is(#thu-thach,#challenges)+p::before,:is(#thu-thach,#challenges)+p+p::before,:is(#thu-thach,#challenges)+p+p+p::before{content:"10";position:absolute;left:1rem;top:1.125rem;display:grid;place-items:center;width:2.5rem;height:2.5rem;border-radius:50%;background:var(--surface);box-shadow:var(--shadow);font:600 .875rem/1 var(--font);font-variant-numeric:tabular-nums}
:is(#thu-thach,#challenges)+p+p::before{content:"20"}
:is(#thu-thach,#challenges)+p+p+p::before{content:"40";background:var(--inv);color:var(--on-inv);box-shadow:none}

/* Đáp án: gập lại cho tới khi người học bấm xem */
.answers{padding:0 1.25rem;border-radius:var(--r-in);background:var(--tile)}
.answers summary{display:flex;align-items:center;justify-content:space-between;min-height:3.25rem;cursor:pointer;list-style:none;font-size:.9375rem;font-weight:600}
.answers summary::-webkit-details-marker{display:none}
.answers summary::after{content:"+";font:400 1.25rem/1 var(--mono);color:var(--muted);transition:transform .3s}
.answers[open] summary::after{transform:rotate(45deg)}
.answers>*+*{margin:0}.answers>:is(ol,ul){padding:0 0 1.25rem 1.375rem}

/* Bài trước / bài tiếp */
.pager{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;margin-top:3.5rem}
.page .pager a{display:grid;gap:.25rem;padding:1.125rem 1.25rem;border-radius:var(--r-in);background:var(--tile);text-decoration:none;transition:background-color .2s}
.page .pager a:hover{background:var(--track)}
.pager small{font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.pager span{font-size:1rem;font-weight:600;line-height:1.35}
.pager .next{text-align:right}.pager .next:only-child{grid-column:2}

/* Thẻ bài học và thẻ khoá học */
.course-cards,.lesson-cards,.source-cards{list-style:none;padding:0;display:grid;gap:.75rem}
.page :is(.course-cards,.lesson-cards,.source-cards) li+li{margin-top:0}
.page :is(.course-cards,.lesson-cards,.source-cards){padding:0}
.lesson-cards{grid-template-columns:repeat(auto-fill,minmax(min(100%,17.5rem),1fr))}
.page .lesson-card a{position:relative;display:flex;flex-direction:column;gap:.375rem;height:100%;padding:1.125rem 3.75rem 1.125rem 1.25rem;border-radius:var(--r-in);background:var(--tile);text-decoration:none;transition:background-color .2s}
.page .lesson-card a:hover{background:var(--track)}
.lesson-card a::before{content:"";position:absolute;right:1rem;top:1rem;width:1.875rem;height:1.875rem;border-radius:50%;background:var(--inv);transition:background-color .2s}
.lesson-card a::after{content:"";position:absolute;right:1rem;top:1rem;width:1.875rem;height:1.875rem;background:var(--on-inv);-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M8 16 16 8M9 8h7v7'/%3E%3C/svg%3E") center/.9375rem no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M8 16 16 8M9 8h7v7'/%3E%3C/svg%3E") center/.9375rem no-repeat;transition:transform .3s,background-color .2s}
.lesson-card a:hover::before{background:var(--go)}.lesson-card a:hover::after{background:var(--on-go);transform:rotate(45deg)}
.lesson-title{font-weight:600;line-height:1.35}
.lesson-summary{font-size:.875rem;line-height:1.5;color:var(--muted)}
.page-portal .page-header{border:0;padding-bottom:.5rem}
.page-portal .page-header h1{font-size:clamp(3.5rem,11vw,7.5rem);line-height:.95;letter-spacing:-.045em}
.course-cards{grid-template-columns:repeat(auto-fit,minmax(min(100%,19rem),1fr))}
.page .course-card a{position:relative;isolation:isolate;display:flex;flex-direction:column;justify-content:flex-end;height:100%;min-height:23rem;padding:1.5rem;border-radius:var(--r-tile);background:var(--tile);text-decoration:none;overflow:hidden;transition:background-color .2s}
.course-card a::before{content:"";position:absolute;z-index:-1;top:.25rem;right:.25rem;width:11.5rem;aspect-ratio:1;background:var(--toy,none) center/contain no-repeat;rotate:-6deg;transition:rotate .6s cubic-bezier(.3,1.3,.5,1),scale .6s cubic-bezier(.3,1.3,.5,1)}
.course-card a:hover::before{rotate:2deg;scale:1.06}
.course-card a[href*="dedy-ai-engineer"]{--toy:url(img/toy-sub.png)}
.course-card a[href*="dive-into-llms"]{--toy:url(img/toy-globe.png)}
.course-card a[href*="claude-cloudexam"]{--toy:url(img/toy-chat.png)}
.course-card:has(a[href*="dedy-ai-engineer"]){order:-1}
.course-card h2{margin:0;font:400 1.75rem/1.1 var(--display);letter-spacing:-.02em;text-wrap:balance}
.course-card p{margin:.625rem 0 0;font-size:.9375rem;line-height:1.55;color:var(--muted)}
.course-card p.muted{font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase}

/* Hình, slide, nguồn (hai khoá cũ) */
.figure img,.slide-image img,.brief figure img{display:block;width:100%;border-radius:var(--r-in);background:var(--tile);cursor:zoom-in}
figcaption{margin-top:.5rem;font-size:.8125rem;line-height:1.5;color:var(--muted)}
.figure-text,.slide-text{margin-top:.75rem;padding:1rem 1.125rem;border-radius:var(--r-in);background:var(--tile);font-size:.9375rem;line-height:1.65}
.figure-text>:first-child,.slide-text>:first-child{margin-top:0}.figure-text>:last-child,.slide-text>:last-child{margin-bottom:0}
details.original-image{margin-top:.5rem;font-size:.875rem}
details.ocr{display:none} /* chữ gốc trong ảnh là tiếng Trung: không hiện trên giao diện */
details.original-image>summary,details.ocr>summary{cursor:pointer;color:var(--muted)}
details.original-image img{margin-top:.5rem;border-radius:var(--r-in)}
.ocr pre{margin-top:.5rem;background:var(--tile);color:var(--fg);white-space:pre-wrap}
.slides{display:grid;gap:1rem}
.slide{padding:.75rem;border-radius:var(--r-tile);background:var(--tile)}
.slide .slide-text{background:var(--surface)}
.slide-number{margin:.5rem .25rem 0;font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.page .source-card a{display:block;padding:.875rem 1rem;border-radius:var(--r-in);background:var(--tile);text-decoration:none}
.source-title{display:block;font-weight:600;line-height:1.4}
.source-url{display:block;font:400 .75rem/1.5 var(--mono);color:var(--muted);overflow-wrap:anywhere}
.status{display:inline-flex;align-items:center;height:1.5rem;padding:0 .625rem;border-radius:999px;background:var(--track);font-size:.75rem;font-weight:500}
.status-ok{background:var(--ok-soft);color:var(--ok)}.status-partial{background:var(--warn-soft);color:var(--warn)}.status-unreachable{background:var(--bad-soft);color:var(--bad)}
dialog.zoom{max-width:96vw;max-height:96vh;padding:0;border:0;border-radius:var(--r-in);background:var(--surface);cursor:zoom-out}
dialog.zoom::backdrop{background:rgba(18,18,20,.7)}
dialog.zoom img{display:block;max-width:96vw;max-height:96vh}

/* Chân trang */
.site-footer{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:1rem 2rem;width:min(100%,70rem);margin:1.25rem auto 0;padding:.25rem .75rem;font-size:.75rem;line-height:1.6;color:var(--muted)}
.site-legal{margin:0;flex:1 1 24rem;max-width:46rem}
.site-prefs{display:inline-flex;align-items:center;gap:.75rem}
.pref-label{font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase}

/* ── v4: tiến độ, học tiếp, bài chưa mở, cài ra màn hình chính ── */
@view-transition{navigation:auto}
::view-transition-old(root),::view-transition-new(root){animation-duration:.2s}
a,button,summary,input{-webkit-tap-highlight-color:transparent}
a,button,summary{touch-action:manipulation}
.level-chip{display:inline-flex;align-items:center;height:1.5rem;padding:0 .625rem;border-radius:999px;background:var(--tile);font:400 .6875rem/1 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.page-header>.level-chip{margin-bottom:.875rem}
.lesson-summary .level-chip{height:1.25rem;margin-right:.375rem;padding:0 .5rem;background:var(--surface);font-size:.625rem;vertical-align:.1em}
.nav-progress{display:grid;grid-template-columns:auto 1fr;align-items:baseline;gap:.375rem .5rem;margin:.5rem 0 0;padding:0 .75rem;font-size:.75rem;color:var(--muted)}
.nav-progress b{font-weight:600;color:var(--fg);font-variant-numeric:tabular-nums}
.nav-progress i{position:relative;grid-column:1/-1;height:.375rem;border-radius:999px;background:var(--track);overflow:hidden}
.nav-progress i::before{content:"";position:absolute;inset:0;border-radius:inherit;background:var(--grad);transform-origin:left;transform:scaleX(var(--p,0));transition:transform .6s cubic-bezier(.2,.8,.2,1)}
.site-nav li a{position:relative;padding-right:2.125rem}
.site-nav li a.is-done::after,.site-nav li a[data-locked]::after{content:"";position:absolute;right:.625rem;top:50%;width:1.125rem;height:1.125rem;margin-top:-.5625rem}
.site-nav li a.is-done::after{border-radius:50%;background:var(--go) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2308240f' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12.5 4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/.6875rem no-repeat}
.site-nav li a[data-locked]::after,.lesson-card a[data-locked]::after{background:var(--faint);-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='5' y='11' width='14' height='9' rx='2'/%3E%3Cpath d='M8 11V8a4 4 0 0 1 8 0v3'/%3E%3C/svg%3E") center/.9375rem no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='5' y='11' width='14' height='9' rx='2'/%3E%3Cpath d='M8 11V8a4 4 0 0 1 8 0v3'/%3E%3C/svg%3E") center/.9375rem no-repeat}
.lesson-card a[data-locked]::before{background:var(--track)}
.lesson-card a[data-locked]:hover::before{background:var(--track)}.lesson-card a[data-locked]:hover::after{background:var(--faint);transform:none}
.lesson-card a.is-done::before,.lesson-card a.is-done:hover::before{background:var(--go)}
.lesson-card a.is-done::after,.lesson-card a.is-done:hover::after{background:var(--on-go);transform:none;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12.5 4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/.9375rem no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12.5 4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/.9375rem no-repeat}
.done-btn{display:inline-flex;align-items:center;justify-self:start;gap:.5rem;height:3rem;margin-top:3rem;padding:0 1.375rem 0 1.125rem;border:0;border-radius:999px;background:var(--inv);color:var(--on-inv);font:600 .9375rem var(--font);cursor:pointer;transition:transform .1s}
.done-btn:active{transform:scale(.97)}
.done-btn svg{width:1.125rem;height:1.125rem}
.done-btn[aria-pressed=true]{background:var(--grad);color:var(--on-go)}
.page>.done-btn+.pager{margin-top:1.25rem}
.page .resume{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:.125rem 1rem;padding:1rem 1.25rem;border-radius:var(--r-in);background:var(--inv);color:var(--on-inv);text-decoration:none}
.resume small{font:400 .6875rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;opacity:.7}
.resume span{grid-column:1;font-weight:600;line-height:1.35}
.resume i{grid-column:2;grid-row:1/span 2;display:grid;place-items:center;width:2.5rem;height:2.5rem;border-radius:50%;background:var(--grad);color:var(--on-go)}
.resume svg{width:1.125rem;height:1.125rem}
.locked-panel{display:grid;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:1rem 1.25rem;padding:1.5rem;border-radius:var(--r-in);background:var(--tile)}
.locked-panel__ic{display:grid;place-items:center;width:3rem;height:3rem;border-radius:50%;background:var(--surface);box-shadow:var(--shadow);color:var(--fg)}
.locked-panel__ic svg{width:1.25rem;height:1.25rem}
.locked-panel strong{display:block;font:500 1.375rem/1.2 var(--display);letter-spacing:-.015em}
.locked-panel p{margin:.25rem 0 0;font-size:.9375rem;line-height:1.55;color:var(--muted)}
.page .locked-panel__cta{grid-column:1/-1;justify-self:start;display:inline-flex;align-items:center;height:2.75rem;padding:0 1.25rem;border-radius:999px;background:var(--inv);color:var(--on-inv);font-size:.9375rem;font-weight:600;text-decoration:none}
.install{display:none;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:.75rem;position:relative;margin-top:1.25rem;padding:.875rem 2.25rem .875rem .875rem;border-radius:var(--r-in);background:var(--tile)}
.install[hidden]{display:none!important}
.install__ic{display:grid;place-items:center;width:2.25rem;height:2.25rem;border-radius:.75rem;background:var(--inv);color:var(--on-inv)}
.install__ic svg{width:1.125rem;height:1.125rem}
.install strong{display:block;font-size:.875rem;font-weight:600;line-height:1.3}
.install small{display:none;margin-top:.125rem;font-size:.75rem;line-height:1.45;color:var(--muted)}
.install.is-ios small{display:block}.install.is-ios .install__go{display:none}
.install__go{grid-column:1/-1;height:2.5rem;border:0;border-radius:999px;background:var(--inv);color:var(--on-inv);font:600 .8125rem var(--font);cursor:pointer}
.install__x{position:absolute;right:.375rem;top:.375rem;width:1.75rem;height:1.75rem;border:0;border-radius:50%;background:none;color:var(--muted);font-size:1.125rem;line-height:1;cursor:pointer}
.app-bar,.sheet-backdrop{display:none}
@media (display-mode:standalone){
 html,body{overscroll-behavior-y:none}
 .site-header{top:calc(.5rem + env(safe-area-inset-top))}
 .install{display:none!important}
}
@media (max-width:62rem){
 .site-header{gap:.5rem;padding-left:1rem}
 .nav-toggle,.course-switcher,.site-links{display:none}
 .site-search{flex:1 1 auto;min-width:0}
 .site-body{grid-template-columns:minmax(0,1fr);padding:.75rem}
 body{padding-bottom:calc(5.5rem + env(safe-area-inset-bottom))}
 /* Mục lục thành tấm kéo lên từ đáy */
 .site-nav{position:fixed;inset:auto 0 0 0;z-index:45;max-height:min(84dvh,46rem);padding:1.125rem 1rem calc(1.25rem + env(safe-area-inset-bottom));border-radius:var(--r-xl) var(--r-xl) 0 0;background:var(--surface);box-shadow:var(--pop);visibility:hidden;transform:translateY(104%);transition:transform .34s cubic-bezier(.2,.8,.2,1),visibility .34s}
 .site-nav::before{content:"";display:block;width:2.5rem;height:.25rem;margin:-.375rem auto .875rem;border-radius:999px;background:var(--track)}
 .site-nav.is-open{visibility:visible;transform:none}
 .site-nav li a{padding-block:.6875rem}
 .site-nav li a[aria-current]{background:var(--tile);box-shadow:none}
 .sheet-backdrop{display:block;position:fixed;inset:0;z-index:44;background:rgba(18,18,20,.36);opacity:0;visibility:hidden;transition:opacity .25s,visibility .25s}
 .sheet-backdrop.is-on{opacity:1;visibility:visible}
 html.has-sheet{overflow:hidden}
 /* Thanh điều hướng nổi dưới đáy */
 .app-bar{position:fixed;left:50%;bottom:calc(.75rem + env(safe-area-inset-bottom));z-index:40;display:grid;grid-auto-flow:column;grid-auto-columns:minmax(0,1fr);gap:.125rem;width:min(100% - 1.5rem,28rem);height:4rem;padding:.3125rem;border-radius:1.5rem;transform:translateX(-50%);background:color-mix(in srgb,var(--surface) 92%,transparent);-webkit-backdrop-filter:saturate(160%) blur(18px);backdrop-filter:saturate(160%) blur(18px);box-shadow:inset 0 0 0 1px var(--line),0 12px 28px -20px rgba(18,18,20,.45)}
 .app-bar__item{display:grid;justify-items:center;align-content:center;gap:.1875rem;min-width:0;border:0;border-radius:1.1875rem;background:none;color:var(--muted);font:500 .6875rem/1 var(--font);text-decoration:none;cursor:pointer;transition:background-color .2s,color .2s,transform .1s}
 .app-bar__item:active{transform:scale(.95)}
 .app-bar__item svg{width:1.375rem;height:1.375rem}
 .app-bar__item span{max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
 .app-bar__item[aria-current],.app-bar__item[aria-expanded=true]{background:var(--tile);color:var(--fg)}
 .app-bar__item.is-primary{background:var(--inv);color:var(--on-inv)}
 .install{display:grid}
 /* "Trong trang này" thành một hàng nhãn vuốt ngang, không chiếm cả màn hình */
 .toc{padding:.625rem;border-radius:999px;overflow:hidden}
 .page .toc h2{display:none}
 .toc ol{display:flex;gap:.25rem;overflow-x:auto;scrollbar-width:none;scroll-snap-type:x proximity;-webkit-overflow-scrolling:touch}
 .toc ol::-webkit-scrollbar{display:none}
 .toc ol ol{display:none}
 .page .toc a{padding:.4375rem .75rem;border-radius:999px;background:var(--surface);white-space:nowrap;scroll-snap-align:start}
 .page .toc a.is-active{background:var(--inv);color:var(--on-inv)}
 .site-footer{padding-bottom:.5rem}
}
@media (max-width:44rem){
 .page{font-size:1rem}
 .page table{display:block;overflow-x:auto}
 .page :is(th,td){min-width:9.5rem}
 .pager{grid-template-columns:minmax(0,1fr)}.pager .next:only-child{grid-column:1}
 .site-brand{font-size:1.25rem}
 .site-search kbd{display:none}
}

@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}
@media print{.site-header,.site-nav,.site-footer,.toc,.pager,.read-progress{display:none!important}.site-body{display:block;padding:0}.content,.page{padding:0;background:none;box-shadow:none}.answers{background:none;padding:0}}