/* sdvn.vn — trang chủ bản nháp "canon" (thử skill impeccable) */
:root {
  --bg: #0C0C0E;
  --surface: #151518;
  --surface-2: #1C1C21;
  --line: rgba(255, 255, 255, .08);
  --line-2: rgba(255, 255, 255, .17);
  --ink: #F4F4F5;
  --ink-2: #B9B9C2;
  --ink-3: #8E8E98;
  --accent: #6D5BE8;
  --accent-hover: #5A48D6;
  --accent-ink: #A79BF8;
  --hot: #FF6B7A;
  --hot-soft: rgba(215, 38, 61, .16);
  --accent-soft: rgba(124, 108, 242, .14);
  --on-accent: #FFFFFF;
  --shadow: 0 1px 0 rgba(255, 255, 255, .04) inset, 0 24px 48px -28px rgba(0, 0, 0, .8);
  --nav-bg: #0C0C0E;
  --r-lg: 20px;
  --r-md: 14px;
  --r-sm: 10px;
  --gutter: clamp(16px, 4vw, 40px);
  --maxw: 1200px;
  --sec-pad: clamp(72px, 10vw, 128px);
  --f-display: 'Bricolage Grotesque', 'Be Vietnam Pro', system-ui, sans-serif;
  --f-body: 'Be Vietnam Pro', system-ui, sans-serif;
  --ease: cubic-bezier(.16, 1, .3, 1);
  --ill-bg: #101013;
  --ill-dot: rgba(255, 255, 255, .07);
  --c-model: #B4A9FF;
  --c-cond: #F5B26B;
  --c-latent: #F28DBB;
  --c-image: #74B7FF;
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #FCFCFB;
  --surface: #FFFFFF;
  --surface-2: #F4F4F2;
  --line: rgba(12, 12, 14, .1);
  --line-2: rgba(12, 12, 14, .18);
  --ink: #0B0B0D;
  --ink-2: #2F2F36;
  --ink-3: #5C5C66;
  --accent-ink: #5A48D6;
  --hot: #C01F35;
  --hot-soft: rgba(215, 38, 61, .09);
  --accent-soft: rgba(109, 91, 232, .1);
  --shadow: 0 1px 2px rgba(12, 12, 14, .04), 0 12px 32px -20px rgba(12, 12, 14, .18);
  --nav-bg: #FCFCFB;
  --ill-bg: #F7F7F5;
  --ill-dot: rgba(12, 12, 14, .08);
  --c-model: #6150E0;
  --c-cond: #C77A1E;
  --c-latent: #C4457F;
  --c-image: #2D7AD6;
  color-scheme: light;
}

/* ---------- base & browser surfaces ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { background: var(--bg); scroll-behavior: smooth; scroll-padding-top: 84px; -webkit-text-size-adjust: 100%; scrollbar-color: var(--line-2) var(--bg); }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 16.5px/1.6 var(--f-body); -webkit-font-smoothing: antialiased; caret-color: var(--accent); }
::selection { background: var(--accent); color: var(--on-accent); }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent-ink); outline-offset: 3px; border-radius: 6px; }
h1, h2, h3 { font-family: var(--f-display); font-weight: 700; margin: 0; text-wrap: balance; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
.ic { width: 18px; height: 18px; flex: none; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.wrap { width: 100%; max-width: calc(var(--maxw) + 2 * var(--gutter)); margin: 0 auto; padding: 0 var(--gutter); }
.skip { position: absolute; left: 12px; top: -60px; z-index: 200; padding: 10px 16px; border-radius: var(--r-sm); background: var(--accent); color: var(--on-accent); font-weight: 600; }
.skip:focus { top: 12px; }

/* ---------- buttons & links ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 9px; min-height: 46px; padding: 0 20px; border-radius: 999px; font: 600 15px/1 var(--f-body); border: 1px solid transparent; cursor: pointer; transition: background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease), transform .2s var(--ease); white-space: nowrap; }
.btn .ic { width: 17px; height: 17px; }
.btn-fill { background: var(--accent); color: var(--on-accent); }
.btn-fill:hover { background: var(--accent-hover); }
.btn-line { border-color: var(--line-2); color: var(--ink); background: transparent; }
.btn-line:hover { border-color: var(--ink-3); background: var(--surface-2); }
.btn-sm { min-height: 40px; padding: 0 16px; font-size: 14px; }
.btn-lg { min-height: 54px; padding: 0 26px; font-size: 16px; }
.btn:active { transform: translateY(1px); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }
.link { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; font-size: 15px; color: var(--accent-ink); }
.link .ic { width: 16px; height: 16px; transition: transform .25s var(--ease); }
.meta { display: flex; align-items: center; gap: 6px; font-size: 14px; font-weight: 500; color: var(--ink-3); }
.meta .ic { width: 15px; height: 15px; }
.desc { color: var(--ink-2); max-width: 46ch; }
.icon-btn { display: inline-grid; place-items: center; width: 44px; height: 44px; border-radius: 999px; border: 1px solid var(--line); background: transparent; color: var(--ink); cursor: pointer; transition: border-color .2s, background .2s; }
.icon-btn:hover { border-color: var(--line-2); background: var(--surface-2); }

/* ---------- nav ---------- */
.nav { position: sticky; top: 0; z-index: 100; background: var(--nav-bg); border-bottom: 1px solid transparent; transition: border-color .25s; }
.nav.scrolled { border-bottom-color: var(--line); }
.nav-in { max-width: calc(var(--maxw) + 2 * var(--gutter)); margin: 0 auto; padding: 0 var(--gutter); height: 68px; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font: 700 19px/1 var(--f-display); letter-spacing: -.02em; }
.brand .tld { color: inherit; }
.nav-links { display: flex; gap: 4px; margin-left: 8px; }
.nav-links a { padding: 10px 14px; border-radius: 999px; font-size: 15px; font-weight: 500; color: var(--ink-2); transition: color .2s, background .2s; }
.nav-links a:hover { color: var(--ink); background: var(--surface-2); }
.nav-links a.active { color: var(--ink); }
.nav-links .nav-cta-m { display: none; }
.nav-right { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.theme .ic-moon, :root[data-theme="light"] .theme .ic-sun { display: none; }
:root[data-theme="light"] .theme .ic-moon { display: block; }
.menu { display: none; }
.menu .ic-close, .nav.open .menu .ic-open { display: none; }
.nav.open .menu .ic-close { display: block; }

/* ---------- hero ---------- */
.hero { padding-top: clamp(56px, 9vh, 104px); overflow: hidden; }
.hero-copy { text-align: center; display: flex; flex-direction: column; align-items: center; }
.hero h1 { font-size: clamp(44px, 6.6vw, 92px); line-height: 1.06; letter-spacing: -.035em; font-weight: 800; max-width: 15ch; }
.nb { white-space: nowrap; }
.lead { margin-top: 22px; font-size: clamp(17px, 1.5vw, 19px); color: var(--ink-2); max-width: 54ch; }
.paths { margin-top: 36px; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; width: 100%; max-width: 1100px; }
.path { display: flex; align-items: center; gap: 14px; min-height: 76px; padding: 14px 18px; text-align: left; border-radius: var(--r-md); background: var(--surface); border: 1px solid var(--line); box-shadow: var(--shadow); transition: border-color .2s var(--ease), transform .25s var(--ease), background .2s; }
.path:hover { border-color: var(--accent); transform: translateY(-2px); }
.path-ic { width: 40px; height: 40px; padding: 9px; border-radius: 11px; background: var(--accent-soft); color: var(--accent-ink); stroke-width: 1.7; }
.path-t { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.path-t b { font: 650 17px/1.25 var(--f-display); font-weight: 650; letter-spacing: -.01em; }
.path-t small { font-size: 13.5px; color: var(--ink-3); line-height: 1.35; }
.path-go { display: none; margin-left: auto; width: 18px; height: 18px; color: var(--ink-3); transition: transform .25s var(--ease), color .2s; }
.path:hover .path-go { transform: translateY(3px); color: var(--accent-ink); }

/* tường ảnh: tín hiệu chính của trang — 6 cột so le, cuộn lệch tốc độ */
.wall { margin: clamp(48px, 7vh, 72px) 0 0; position: relative; }
.wall-cols { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 12px; padding: 0 12px; height: clamp(420px, 64vh, 720px); overflow: hidden; -webkit-mask-image: linear-gradient(to bottom, #000 58%, transparent 98%); mask-image: linear-gradient(to bottom, #000 58%, transparent 98%); }
.col { display: flex; flex-direction: column; gap: 12px; will-change: transform; }
.col:nth-child(2n) { margin-top: 56px; }
.col:nth-child(3n) { margin-top: 24px; }
.col img { width: 100%; border-radius: var(--r-md); background: var(--surface-2); }
.wall figcaption { margin-top: 6px; text-align: center; font-size: 13.5px; color: var(--ink-3); }

/* ---------- sections ---------- */
.sec { padding: var(--sec-pad) 0 0; }
.sec-head { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; margin-bottom: clamp(28px, 4vw, 44px); }
.sec-head h2 { display: flex; align-items: center; gap: 14px; font-size: clamp(34px, 4.2vw, 54px); line-height: 1.08; letter-spacing: -.03em; }
.h-ic { width: 44px; height: 44px; padding: 10px; border-radius: 13px; background: var(--hot-soft); color: var(--hot); stroke-width: 1.7; }
.sec-head p { color: var(--ink-2); font-size: 17.5px; max-width: 60ch; }
h3 { font-size: 23px; line-height: 1.2; letter-spacing: -.02em; }

/* card base (khung chung, nội dung khác nhau) */
.app, .course, .community { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); box-shadow: var(--shadow); overflow: hidden; transition: border-color .25s var(--ease), transform .3s var(--ease); }
a.app:hover { border-color: var(--line-2); transform: translateY(-3px); }
a.app:hover .link .ic { transform: translate(2px, -2px); }
.app img, .course-media img, .mini-wall img, .close-art img { transition: transform .6s var(--ease); }
a.app:hover .app-media img, .course-media:hover img { transform: scale(1.03); }

/* ứng dụng */
.apps { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.app { display: flex; flex-direction: column; }
.app-media { aspect-ratio: 1200 / 630; overflow: hidden; display: grid; place-items: center; }
.app-media img { width: 100%; height: 100%; object-fit: cover; }
.app-lazidi .app-media { background: #1B57D6; }
.app-lazidi .app-media .app-icon-xl { width: 38%; height: auto; object-fit: contain; border-radius: 22%; box-shadow: 0 30px 60px -20px rgba(0, 0, 0, .5); }
a.app-lazidi:hover .app-media img { transform: scale(1.05) rotate(-2deg); }
.app-body { padding: 22px 24px 24px; display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 4px 14px; align-items: center; }
.app-icon { width: 56px; height: 56px; border-radius: 13px; grid-row: span 1; }
.app-body .desc, .app-body .link { grid-column: 1 / -1; }
.app-body .desc { margin-top: 12px; }
.app-body .link { margin-top: 14px; }

/* học */
.learn { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); gap: 16px; }
.course { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); }
.course-media { overflow: hidden; display: grid; place-items: center; background: linear-gradient(#17128A, #3F37A8); }
/* poster có chữ: luôn hiện trọn, không cắt */
.course-media img { width: 100%; height: 100%; object-fit: contain; }
.course-body { padding: clamp(24px, 3vw, 36px); display: flex; flex-direction: column; gap: 14px; }
.course-body h3 { font-size: clamp(26px, 2.6vw, 32px); }
.course-body .btn { align-self: flex-start; margin-top: auto; }
.ticks { display: flex; flex-direction: column; gap: 10px; margin: 4px 0 18px; color: var(--ink-2); }
.ticks li { position: relative; padding-left: 26px; }
.ticks li::before { content: ''; position: absolute; left: 2px; top: .45em; width: 12px; height: 7px; border-left: 2px solid var(--hot); border-bottom: 2px solid var(--hot); transform: rotate(-45deg); }
.community { display: flex; flex-direction: column; }
.mini-wall { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; padding: 8px 8px 0; }
.mini-wall img { width: 100%; aspect-ratio: 3 / 4; height: auto; max-height: 300px; object-fit: cover; object-position: 50% 18%; border-radius: 12px; }
.community-body { padding: 22px 24px 26px; display: flex; flex-direction: column; gap: 12px; flex: 1; }
.community-body .btn-row { margin-top: auto; padding-top: 8px; }

/* ComfyUI + Train model: thẻ chính / thẻ phụ, minh hoạ SVG động tự vẽ */
.pcard { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); box-shadow: var(--shadow); overflow: hidden; transition: border-color .25s var(--ease), transform .3s var(--ease); }
a.pcard:hover { border-color: var(--line-2); transform: translateY(-3px); }
a.pcard:hover .link .ic { transform: translate(2px, -2px); }
.pcard-ill { background: var(--ill-bg); border-bottom: 1px solid var(--line); aspect-ratio: 480 / 270; overflow: hidden; }
.pcard-ill svg { display: block; width: 100%; height: 100%; }
.pcard-body { padding: 22px 24px 24px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.pcard-body .link { margin-top: auto; padding-top: 6px; }
.pcard-main { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); }
.pcard-main .pcard-ill { aspect-ratio: 720 / 400; border-bottom: 0; border-right: 1px solid var(--line); }
.pcard-main.flip { grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); }
.pcard-main.flip .pcard-ill { order: 2; border-right: 0; border-left: 1px solid var(--line); }
.pcard-main .pcard-body { padding: clamp(28px, 3.4vw, 44px); justify-content: center; gap: 14px; }
.pcard-main h3 { font-size: clamp(28px, 2.8vw, 36px); }
.pcard-main .desc { font-size: 17px; }
.pcard-main .link { margin-top: 8px; padding-top: 0; }
.sub-head { display: flex; align-items: center; gap: 16px; margin: 32px 0 16px; }
.sub-head h3 { font: 600 15px/1 var(--f-body); letter-spacing: 0; color: var(--ink-2); white-space: nowrap; }
.sub-head::after { content: ''; flex: 1; height: 1px; background: var(--line); }
.subs { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips li { font-size: 13px; font-weight: 500; color: var(--ink-2); padding: 5px 11px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface-2); }

/* màu minh hoạ (theo quy ước màu dây của ComfyUI) */
.ill-svg text { font-family: var(--f-body); }
.ill-svg .dot { fill: var(--ill-dot); }
.ill-svg .nb { fill: var(--surface); stroke: var(--line-2); stroke-width: 1; }
.ill-svg .nh { fill: var(--surface-2); }
.ill-svg .nh-acc { fill: var(--accent); }
.ill-svg .fld { fill: var(--bg); stroke: var(--line); stroke-width: 1; }
.ill-svg .side { fill: var(--surface-2); }
.ill-svg .ln { fill: none; stroke: var(--line-2); stroke-width: 1.2; }
.ill-svg .tt { font-size: 12px; font-weight: 600; fill: var(--ink); }
.ill-svg .tt-on { font-size: 12px; font-weight: 600; fill: #fff; }
.ill-svg .tl { font-size: 10.5px; font-weight: 500; fill: var(--ink-3); }
.ill-svg .tf { font-size: 10.5px; font-weight: 500; fill: var(--ink-2); }
.ill-svg .tbtn { font-size: 11.5px; font-weight: 600; fill: #fff; }
.ill-svg .wire { fill: none; stroke-width: 2.4; stroke-linecap: round; }
.ill-svg .w-model { stroke: var(--c-model); }
.ill-svg .w-cond { stroke: var(--c-cond); }
.ill-svg .w-latent { stroke: var(--c-latent); }
.ill-svg .w-image { stroke: var(--c-image); }
.ill-svg .s-model { fill: var(--c-model); }
.ill-svg .s-cond { fill: var(--c-cond); }
.ill-svg .s-latent { fill: var(--c-latent); }
.ill-svg .s-image { fill: var(--c-image); }
.ill-svg .trk { fill: var(--line); }
.ill-svg .bar { fill: var(--accent-ink); }
.ill-svg .bar1 { fill: var(--line-2); }
.ill-svg .bar2 { fill: var(--line); }
.ill-svg .act { fill: none; stroke: var(--accent-ink); stroke-width: 2; }
.ill-svg .hl { fill: var(--accent-soft); stroke: var(--accent); stroke-opacity: .5; }
.ill-svg .btnf { fill: var(--accent); }
.ill-svg .chip { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 1.5; }
.ill-svg .tchip { font-family: var(--f-display); font-size: 17px; font-weight: 700; fill: var(--accent-ink); }
.ill-svg .dotc { fill: var(--hot); }
.ill-svg .curve { fill: none; stroke: var(--accent-ink); stroke-width: 2.6; stroke-linecap: round; }
.ill-svg .axis { fill: none; stroke: var(--line-2); stroke-width: 1.2; }
.ill-svg .grid { fill: none; stroke: var(--line); stroke-dasharray: 3 5; }
.ill-svg .pill { fill: rgba(10, 10, 12, .72); }
.ill-svg .tpill { font-size: 8.5px; font-weight: 600; fill: #fff; }
.ill-svg .ico { fill: none; stroke: var(--ink-2); stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.ill-svg .ok { fill: none; stroke: #3FB27F; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }
.ill-svg .mainl { fill: none; stroke: var(--ink-3); stroke-width: 2.4; stroke-linecap: round; }
.ill-svg .brl { fill: none; stroke: var(--accent-ink); stroke-width: 2.4; stroke-linecap: round; }
.ill-svg .cm { fill: var(--surface); stroke: var(--ink-3); stroke-width: 2.4; }
.ill-svg .cb { fill: var(--surface); stroke: var(--accent-ink); stroke-width: 2.4; }
.ill-svg .merge { fill: var(--hot); stroke: var(--surface); stroke-width: 3; }

/* đóng trang: cộng đồng */
.close { margin-top: var(--sec-pad); padding: clamp(64px, 9vw, 112px) 0; background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); overflow: hidden; }
.close-in { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .95fr); gap: clamp(32px, 5vw, 72px); align-items: center; }
.close-copy { display: flex; flex-direction: column; gap: 20px; }
.close h2 { font-size: clamp(34px, 4.4vw, 58px); line-height: 1.08; letter-spacing: -.03em; }
.close-copy > p { color: var(--ink-2); font-size: 17.5px; max-width: 46ch; }
.close .btn-row { margin-top: 6px; }
.small { font-size: 15px; color: var(--ink-3); }
.small a { color: var(--accent-ink); font-weight: 600; text-decoration: underline; text-underline-offset: 4px; text-decoration-thickness: 1px; }
.close-art { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; height: 460px; }
.close-art img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 15%; border-radius: var(--r-md); }
.close-art img:nth-child(1) { grid-row: span 2; }
.close-art img:nth-child(4) { display: none; }

/* footer */
.foot { padding: 36px 0 44px; }
.foot-in { display: flex; align-items: center; gap: 12px 24px; flex-wrap: wrap; }
.foot .brand { font-size: 16px; }
.foot-note { color: var(--ink-3); font-size: 14.5px; }
.foot-links { display: flex; gap: 4px; margin-left: auto; }
.foot-links a { display: inline-flex; align-items: center; min-height: 44px; padding: 0 12px; font-size: 15px; color: var(--ink-2); border-radius: 999px; }
.foot-links a:hover { color: var(--ink); background: var(--surface-2); }

/* ---------- responsive ---------- */
@media (max-width: 1080px) {
  .pcard-main, .pcard-main.flip { grid-template-columns: 1fr; }
  .pcard-main .pcard-ill, .pcard-main.flip .pcard-ill { order: 0; border: 0; border-bottom: 1px solid var(--line); }
  .learn { grid-template-columns: 1fr; }
}
@media (max-width: 900px) {
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; gap: 0; margin: 0; padding: 8px var(--gutter) 16px; background: var(--bg); border-bottom: 1px solid var(--line); box-shadow: 0 24px 40px -24px rgba(0, 0, 0, .5); }
  .nav.open .nav-links { display: flex; }
  .nav-links a { padding: 0 4px; min-height: 52px; display: flex; align-items: center; font-size: 17px; border-radius: 0; border-bottom: 1px solid var(--line); }
  .nav-links a:hover { background: transparent; }
  .nav-links .nav-cta-m { display: flex; border-bottom: 0; color: var(--accent-ink); font-weight: 600; }
  .nav-cta { display: none; }
  .menu { display: inline-grid; }
  .paths { grid-template-columns: repeat(2, minmax(0, 1fr)); max-width: 640px; }
  .wall-cols { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .col:nth-child(n+5) { display: none; }
  .apps, .subs { grid-template-columns: 1fr; }
  .close-in { grid-template-columns: 1fr; }
  .close-art { height: auto; grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .close-art img, .close-art img:nth-child(1) { grid-row: auto; aspect-ratio: 3 / 4; height: auto; }
}
@media (max-width: 600px) {
  body { font-size: 16px; }
  .nav-in { height: 60px; gap: 12px; }
  .hero h1 { font-size: clamp(38px, 11vw, 52px); }
  .paths { gap: 10px; margin-top: 28px; }
  .path { flex-direction: column; align-items: flex-start; gap: 10px; min-height: 0; padding: 14px; }
  .path-go { display: none; }
  .path-t b { font-size: 16px; }
  .path-t small { font-size: 13px; }
  .wall-cols { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; padding: 0 8px; height: 380px; }
  .col { gap: 8px; }
  .col:nth-child(n+4) { display: none; }
  .col:nth-child(2n) { margin-top: 36px; }
  .course { grid-template-columns: 1fr; }
  .course-media { aspect-ratio: 1 / 1; }
  .h-ic { width: 38px; height: 38px; padding: 8px; }
  .app-body, .community-body, .pcard-body { padding: 18px 18px 20px; }
  .pcard-main .pcard-body { padding: 22px 18px 24px; }
  .foot-links { margin-left: -12px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
  .col { transform: none !important; }
}

/* thẻ khoá học: minh hoạ động chép từ trang chủ hungdiffusion.com (thay poster ảnh tĩnh) */
.course-media.hdp { position: relative; overflow: hidden; display: block; min-height: 340px; color: #fff; background: radial-gradient(120% 90% at 85% 0%, rgba(252, 79, 79, .28), transparent 55%), linear-gradient(155deg, #3B30D6 0%, #2419A6 48%, #130E5C 100%); }
.hdp::before { content: ''; position: absolute; inset: 0; background-image: linear-gradient(rgba(255,255,255,.07) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.07) 1px, transparent 1px); background-size: 22px 22px; -webkit-mask-image: radial-gradient(ellipse at 60% 40%, #000 20%, transparent 80%); mask-image: radial-gradient(ellipse at 60% 40%, #000 20%, transparent 80%); }
.hdp .pane-text { position: absolute; left: 28px; top: 26px; z-index: 2; }
.hdp .hp-kicker { display: block; font: italic 700 17px/1 var(--f-body); }
.hdp .hp-title { display: block; margin-top: 8px; font: 800 64px/.92 var(--f-body); letter-spacing: -.035em; background: linear-gradient(180deg, #fff 30%, #C7C0FF); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hdp .hp-sub { display: block; margin-top: 8px; font: 600 14px/1 var(--f-body); letter-spacing: .34em; }
.hdp .ill { position: absolute; left: 0; top: 0; width: 100%; height: 100%; overflow: visible; }
.hdp .ill * { transform-box: fill-box; transform-origin: center; }
.hdp .w1 { fill: none; stroke: rgba(255,255,255,.24); stroke-width: 1.2; stroke-linecap: round; stroke-linejoin: round; }
.hdp .dash { stroke-dasharray: 3 5; }
.hdp .wf { fill: rgba(255,255,255,.16); }
.hdp .rd { fill: #FC4F4F; }
.hdp .vi { fill: #ABA5FF; }
.hdp .gr { fill: #3DDC84; }
.hdp .tx { font-family: ui-monospace, Menlo, monospace; font-size: 8px; fill: rgba(255,255,255,.78); }
.hdp .txb { font-family: ui-monospace, Menlo, monospace; font-size: 8px; font-weight: 600; fill: #fff; }
.hdp .chip { fill: rgba(255,255,255,.1); stroke: rgba(255,255,255,.32); stroke-width: 1; }
.hdp .pop { animation: hdPop 6s cubic-bezier(.34,1.56,.64,1) infinite; animation-delay: var(--d, 0s); }
.hdp .twk { fill: #fff; animation: hdTwinkle 3s ease-in-out infinite; animation-delay: var(--d, 0s); }
.hdp .spin { animation: hdSpin 14s linear infinite; }
.hdp .pulse { animation: hdPulse 2.4s ease-in-out infinite; }
.hdp .sampler { fill: none; stroke: #FC4F4F; stroke-width: 2.2; animation: hdSampler 5s steps(5, end) infinite; filter: url(#hdp-glow); }
.hdp .sprog { transform-origin: left center; animation: hdProg 5s linear infinite; }
.hdp.idle .ill, .hdp.idle .ill * { animation-play-state: paused !important; }
@keyframes hdPop { 0% { transform: scale(0); opacity: 0 } 8%, 60% { transform: scale(1); opacity: 1 } 68%, 100% { transform: scale(.4); opacity: 0 } }
@keyframes hdTwinkle { 0%, 100% { transform: scale(.35) rotate(0); opacity: .25 } 50% { transform: scale(1) rotate(45deg); opacity: 1 } }
@keyframes hdSpin { to { transform: rotate(360deg) } }
@keyframes hdPulse { 0%, 100% { transform: scale(1); opacity: .7 } 50% { transform: scale(1.35); opacity: 1 } }
@keyframes hdSampler { to { transform: translateX(350px) } }
@keyframes hdProg { 0% { transform: scaleX(0) } 100% { transform: scaleX(1) } }
@media (max-width: 600px) { .course-media.hdp { min-height: 0; aspect-ratio: 1 / 1; } .hdp .hp-title { font-size: 52px; } }
@media (prefers-reduced-motion: reduce) { .hdp .ill * { animation: none !important; } }
.ticks b { color: var(--ink); font-weight: 600; }

/* ---------- trang con (contact, gopy, donate) ---------- */
:root {
  /* tên token cũ mà CSS riêng của trang con còn dùng */
  --muted: var(--ink-2);
  --faint: var(--ink-3);
  --chip: var(--surface-2);
  --border: var(--line);
  --border2: var(--line-2);
  --accent-strong: var(--accent-ink);
  --accent-fill: var(--accent);
  --accent-fill-hover: var(--accent-hover);
  --accent-line: color-mix(in srgb, var(--accent) 40%, transparent);
}
@keyframes tlUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
@keyframes tlIn { from { opacity: 0; } to { opacity: 1; } }
body.sub { min-height: 100vh; display: flex; flex-direction: column; }
body.sub .foot { margin-top: auto; border-top: 1px solid var(--line); }
.page-header { width: 100%; max-width: calc(var(--maxw) + 2 * var(--gutter)); margin: 0 auto; padding: clamp(56px, 9vh, 96px) var(--gutter) 40px; text-align: center; }
.page-header h1 { margin: 0 auto; max-width: 18ch; font-size: clamp(36px, 5.4vw, 64px); line-height: 1.06; font-weight: 800; letter-spacing: -.035em; }
.page-header .lead { margin: 18px auto 0; max-width: 60ch; font-size: clamp(16.5px, 1.4vw, 18px); line-height: 1.65; color: var(--ink-2); }
.pill, .pill-ghost, .btn-accent { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 0 18px; border-radius: 999px; font: 600 14.5px/1 var(--f-body); white-space: nowrap; transition: background .2s var(--ease), border-color .2s var(--ease), color .2s; }
.pill, .btn-accent { background: var(--accent); color: var(--on-accent); border: 0; cursor: pointer; }
.pill:hover, .btn-accent:hover { background: var(--accent-hover); color: var(--on-accent); }
.pill-ghost { background: transparent; color: var(--ink); border: 1px solid var(--line-2); }
.pill-ghost:hover { border-color: var(--ink-3); background: var(--surface-2); }
.btn-accent { min-height: 48px; border-radius: 12px; }
@media (prefers-reduced-motion: reduce) { [style*="tlUp"], .page-header *, .collab, .feedback-card { animation: none !important; } }