/* Delu Academy · nền và component dùng chung. Chỉ dùng token từ tokens.css. */

/* ───────── Reset ───────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 1rem); }
body { margin: 0; background: var(--bg); color: var(--text); font: 400 var(--fs-body)/var(--lh-body) var(--font-sans); -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; overflow-x: clip; }
img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4, p, ul, ol, dl, dd, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: 0; padding: 0; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: var(--r-sm); }
::selection { background: var(--accent); color: var(--on-accent); }
[hidden] { display: none !important; }

/* ───────── Chữ ───────── */
.display { font-size: var(--fs-display); line-height: var(--lh-display); letter-spacing: var(--tracking-display); font-weight: 700; text-wrap: balance; }
.h1 { font-size: var(--fs-h1); line-height: 1.12; letter-spacing: -.03em; font-weight: 700; text-wrap: balance; }
.h2 { font-size: var(--fs-h2); line-height: var(--lh-heading); letter-spacing: var(--tracking-heading); font-weight: 700; text-wrap: balance; }
.h3 { font-size: var(--fs-h3); line-height: 1.3; letter-spacing: -.012em; font-weight: 600; }
.lead { font-size: var(--fs-lead); line-height: 1.5; color: var(--text-2); text-wrap: pretty; }
.eyebrow { font-size: var(--fs-sm); font-weight: 600; color: var(--text-2); }
.muted { color: var(--text-2); } .small { font-size: var(--fs-sm); } .xs { font-size: var(--fs-xs); }
.mono { font-family: var(--font-mono); } .tnum { font-variant-numeric: tabular-nums; } .nowrap { white-space: nowrap; }
.grad-text { background: var(--grad-text); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-box-decoration-break: clone; box-decoration-break: clone; padding-block: .14em; }
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: .18em; }

/* ───────── Bố cục ───────── */
.container { width: min(100% - 2 * var(--gutter), var(--container)); margin-inline: auto; }
.container--narrow { width: min(100% - 2 * var(--gutter), var(--container-narrow)); margin-inline: auto; }
.section { padding-block: var(--section-y); }
.section--soft { background: var(--bg-soft); }
.section__head { max-width: 44rem; margin-bottom: clamp(2.5rem, 5vw, 4rem); }
.section__head--center { margin-inline: auto; text-align: center; }
.section__head .eyebrow + * { margin-top: var(--sp-3); }
.section__head .lead { margin-top: var(--sp-4); }
.stack > * + * { margin-top: var(--stack, 1rem); }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--gap, .75rem); }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.ic { width: 1.25em; height: 1.25em; flex: none; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.ic--sm { width: 1em; height: 1em; }

/* ───────── Nút ───────── */
.btn {
  --btn-h: 2.75rem; --btn-px: 1.375rem; --btn-bg: var(--text); --btn-fg: var(--bg); --btn-bd: transparent;
  position: relative; isolation: isolate; display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  min-height: var(--btn-h); padding: 0 var(--btn-px); border-radius: var(--r-pill); border: 1px solid var(--btn-bd);
  background: var(--btn-bg); color: var(--btn-fg); font-size: var(--fs-sm); font-weight: 600; line-height: 1; white-space: nowrap;
  transition: transform var(--dur-1) var(--ease-out), background-color var(--dur-2), border-color var(--dur-2), color var(--dur-2), opacity var(--dur-2);
  -webkit-tap-highlight-color: transparent; user-select: none;
}
.btn:active { transform: scale(.97); }
.btn .ic { transition: transform var(--dur-2) var(--ease-out); }
.btn:hover .ic--go { transform: translateX(3px); }
.btn--primary::before { /* quầng phổ màu: chỉ hiện khi rê chuột, là chữ ký của nút chính */
  content: ""; position: absolute; inset: -3px; z-index: -1; border-radius: inherit; background: var(--grad-spectrum);
  filter: blur(10px); opacity: 0; transition: opacity var(--dur-3) var(--ease-out);
}
.btn--primary::after { content: ""; position: absolute; inset: 0; z-index: -1; border-radius: inherit; background: var(--btn-bg); }
.btn--primary:hover::before, .btn--primary:focus-visible::before { opacity: .7; }
.btn--soft { --btn-bg: var(--bg-soft); --btn-fg: var(--text); }
.btn--soft:hover { --btn-bg: color-mix(in srgb, var(--text) 10%, var(--bg)); }
.btn--ghost { --btn-bg: transparent; --btn-fg: var(--text); --btn-bd: var(--line-strong); }
.btn--ghost:hover { --btn-bg: var(--bg-soft); }
.btn--light { --btn-bg: var(--gray-0); --btn-fg: var(--gray-800); }
.btn--lg { --btn-h: 3.25rem; --btn-px: 1.75rem; font-size: var(--fs-body); }
.btn--sm { --btn-h: 2.25rem; --btn-px: 1rem; font-size: var(--fs-xs); }
.btn--block { width: 100%; }
.btn[disabled], .btn[aria-disabled="true"] { opacity: .45; pointer-events: none; }
.btn.is-loading { color: transparent; pointer-events: none; }
.btn.is-loading .ic { opacity: 0; }
.btn.is-loading > .btn__spin { opacity: 1; }
.btn__spin { position: absolute; width: 1.125rem; height: 1.125rem; border-radius: 50%; border: 2px solid var(--btn-fg); border-right-color: transparent; opacity: 0; animation: spin .7s linear infinite; }
.btn.is-done { --btn-bg: var(--success); --btn-fg: var(--bg); }
@keyframes spin { to { transform: rotate(360deg); } }

.link { display: inline-flex; align-items: center; gap: .3rem; min-height: 2.75rem; color: var(--accent); font-size: var(--fs-sm); font-weight: 600; transition: color var(--dur-2); }
.link:hover { color: var(--accent-hover); }
.link .ic { transition: transform var(--dur-2) var(--ease-out); }
.link:hover .ic { transform: translateX(3px); }
.link--quiet { color: var(--text-2); } .link--quiet:hover { color: var(--text); }

.icon-btn { position: relative; display: inline-grid; place-items: center; width: 2.75rem; height: 2.75rem; border-radius: 50%; color: var(--text-2); transition: background-color var(--dur-2), color var(--dur-2), transform var(--dur-1) var(--ease-out); }
.icon-btn:hover { background: var(--bg-soft); color: var(--text); }
.icon-btn:active { transform: scale(.94); }
.icon-btn[disabled] { opacity: .35; pointer-events: none; }
.icon-btn--line { box-shadow: inset 0 0 0 1px var(--line-strong); background: var(--surface); }

/* ───────── Nhãn ───────── */
.chip { display: inline-flex; align-items: center; gap: .375rem; min-height: 1.75rem; padding: 0 .75rem; border-radius: var(--r-pill); background: var(--bg-soft); color: var(--text-2); font-size: var(--fs-xs); font-weight: 600; white-space: nowrap; }
.chip--course { background: var(--course-soft); color: var(--course-tone); }
.chip--success { background: var(--success-soft); color: var(--success); }
.chip--warning { background: var(--warning-soft); color: var(--warning); }
.chip--line { background: transparent; box-shadow: inset 0 0 0 1px var(--line-strong); }
.chip--inverse { background: var(--surface-inverse); color: var(--text-inverse); }

/* ───────── Nút chọn kiểu phân đoạn (VI | EN, bộ lọc) ───────── */
.seg { --n: 2; --i: 0; position: relative; display: inline-grid; grid-auto-flow: column; grid-auto-columns: 1fr; padding: 3px; border-radius: var(--r-pill); background: var(--bg-soft); box-shadow: inset 0 0 0 1px var(--line); }
.seg__btn { position: relative; z-index: 1; min-width: 2.5rem; height: 1.875rem; padding: 0 .75rem; border-radius: var(--r-pill); font-size: var(--fs-xs); font-weight: 600; color: var(--text-2); transition: color var(--dur-2); }
.seg__btn::after { content: ""; position: absolute; inset: -7px 0; }
.seg__btn[aria-pressed="true"] { color: var(--text); }
.seg__thumb { position: absolute; top: 3px; bottom: 3px; left: 3px; width: calc((100% - 6px) / var(--n)); border-radius: var(--r-pill); background: var(--surface); box-shadow: var(--shadow-1); transform: translateX(calc(var(--i) * 100%)); transition: transform var(--dur-3) var(--ease-soft); }
.seg--lg .seg__btn { height: 2.375rem; padding: 0 1.125rem; font-size: var(--fs-sm); }

/* ───────── Thanh điều hướng ───────── */
.nav { position: sticky; top: 0; z-index: var(--z-nav); height: var(--nav-h); background: var(--glass); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-bottom: 1px solid transparent; transition: border-color var(--dur-2); }
.nav.is-stuck { border-bottom-color: var(--line); }
.nav__in { height: 100%; display: flex; align-items: center; gap: var(--sp-4); }
.brand { display: inline-flex; align-items: center; gap: .5rem; min-height: 2.75rem; font-size: 1.0625rem; font-weight: 700; letter-spacing: -.02em; white-space: nowrap; }
.brand__mark { width: 1.375rem; aspect-ratio: 1; border-radius: 50%; flex: none; background: conic-gradient(from 210deg, var(--iris-500), var(--blue-400), var(--mint-500), var(--sun-400), var(--coral-500), var(--pink-500), var(--iris-500)); -webkit-mask: radial-gradient(farthest-side, transparent 50%, #000 53%); mask: radial-gradient(farthest-side, transparent 50%, #000 53%); }
.nav__links { display: flex; gap: var(--sp-1); margin-left: var(--sp-4); }
.nav__link { display: inline-flex; align-items: center; min-height: 2.75rem; padding: 0 .75rem; border-radius: var(--r-pill); font-size: var(--fs-sm); font-weight: 500; color: var(--text-2); transition: color var(--dur-2); }
.nav__link:hover, .nav__link[aria-current="page"] { color: var(--text); }
.nav__link[aria-current="page"] { font-weight: 600; }
.nav__right { margin-left: auto; display: flex; align-items: center; gap: var(--sp-2); }
.nav__menu-btn { display: none; }
.nav-sheet { position: fixed; inset: var(--nav-h) 0 0; z-index: calc(var(--z-nav) - 1); background: var(--bg); padding: var(--sp-6) var(--gutter) var(--sp-8); display: grid; align-content: start; gap: var(--sp-2); opacity: 0; visibility: hidden; transform: translateY(-.75rem); transition: opacity var(--dur-2), transform var(--dur-3) var(--ease-out), visibility var(--dur-2); }
.nav-sheet.is-open { opacity: 1; visibility: visible; transform: none; }
.nav-sheet a.nav-sheet__link { display: flex; align-items: center; justify-content: space-between; min-height: 3.5rem; font-size: 1.5rem; font-weight: 700; letter-spacing: -.02em; border-bottom: 1px solid var(--line); }
.nav-sheet__tools { display: flex; align-items: center; justify-content: space-between; margin-top: var(--sp-6); }
@media (max-width: 53.75rem) {
  .nav__links, .nav__right .hide-sm { display: none; }
  .nav__menu-btn { display: inline-grid; }
}
@media (min-width: 53.76rem) { .nav-sheet { display: none; } }

/* ───────── Chân trang ───────── */
.footer { padding-block: var(--sp-16) var(--sp-10); border-top: 1px solid var(--line); font-size: var(--fs-sm); color: var(--text-2); }
.footer__grid { display: grid; gap: var(--sp-10); grid-template-columns: minmax(0, 1.6fr) repeat(3, minmax(0, 1fr)); }
.footer__title { color: var(--text); font-weight: 600; margin-bottom: var(--sp-3); }
.footer__list { display: grid; gap: var(--sp-1); }
.footer__list a { display: inline-flex; align-items: center; min-height: 2rem; transition: color var(--dur-2); }
.footer__list a:hover { color: var(--text); }
.footer__note { margin-top: var(--sp-10); padding-top: var(--sp-6); border-top: 1px solid var(--line); font-size: var(--fs-xs); display: flex; flex-wrap: wrap; gap: var(--sp-2) var(--sp-8); justify-content: space-between; }
@media (max-width: 48rem) { .footer__grid { grid-template-columns: 1fr 1fr; } .footer__grid > :first-child { grid-column: 1 / -1; } }

/* ───────── Vòng tiến độ ───────── */
.ring { --size: 2.75rem; --w: 4px; --ring-fill: currentColor; --ring-track: color-mix(in srgb, currentColor 24%, transparent); position: relative; display: inline-grid; place-items: center; flex: none; width: var(--size); aspect-ratio: 1; font-size: calc(var(--size) * .27); font-weight: 700; line-height: 1; font-variant-numeric: tabular-nums; transition: --p var(--dur-5) var(--ease-out); }
.ring::before { content: ""; position: absolute; inset: 0; border-radius: 50%; background: conic-gradient(var(--ring-fill) calc(var(--p) * 1%), var(--ring-track) 0); -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - var(--w) - .5px), #000 calc(100% - var(--w))); mask: radial-gradient(farthest-side, transparent calc(100% - var(--w) - .5px), #000 calc(100% - var(--w))); }
.ring--course { --ring-fill: var(--course-tone); --ring-track: var(--course-soft); color: var(--text); }
.ring--lg { --size: 4.5rem; --w: 6px; }
.ring--sm { --size: 1.5rem; --w: 3px; }

.bar { --p: 0; height: .375rem; border-radius: var(--r-pill); background: var(--bg-soft); overflow: hidden; }
.bar::before { content: ""; display: block; height: 100%; width: 100%; border-radius: inherit; background: var(--course-grad, var(--accent)); transform-origin: left; transform: scaleX(calc(var(--p) / 100)); transition: transform var(--dur-5) var(--ease-out); }

/* ───────── Thẻ khoá học (pass) ───────── */
.pass { --pass-r: 1.5rem; position: relative; isolation: isolate; display: block; text-align: left; container-type: inline-size; aspect-ratio: 1.6; border-radius: var(--pass-r); background: var(--course-grad); color: var(--on-pass); overflow: hidden; box-shadow: inset 0 1px 0 rgba(255, 255, 255, .35), 0 22px 44px -16px var(--course-glow), 0 8px 16px -8px rgba(0, 0, 0, .22); transform: perspective(62rem) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)); transition: transform var(--dur-3) var(--ease-out), box-shadow var(--dur-3) var(--ease-out); }
.pass::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(to top, var(--pass-shade), transparent 72%), var(--course-pattern); }
.pass::after { content: ""; position: absolute; inset: 0; background: radial-gradient(70cqw circle at var(--mx, 82%) var(--my, -12%), rgba(255, 255, 255, .42), transparent 62%); mix-blend-mode: soft-light; pointer-events: none; }
.pass__body { position: absolute; inset: 0; padding: 7cqw; display: flex; flex-direction: column; }
.pass__top { display: flex; align-items: flex-start; justify-content: space-between; }
.pass__kicker { font-size: max(.6875rem, 3.1cqw); font-weight: 600; letter-spacing: .03em; }
.pass__title { margin-top: auto; font-size: max(1.125rem, 8.6cqw); line-height: 1.08; letter-spacing: -.035em; font-weight: 700; text-wrap: balance; }
.pass__sub { margin-top: 1.8cqw; max-width: 24em; font-size: max(.75rem, 3.5cqw); line-height: 1.36; font-weight: 500; }
.pass__meta { margin-top: 4cqw; display: flex; flex-wrap: wrap; gap: 1.6cqw; }
.pass .chip { min-height: max(1.5rem, 6.6cqw); padding-inline: max(.5rem, 2.6cqw); background: var(--pass-chip); color: var(--on-pass); font-size: max(.6875rem, 2.9cqw); -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); }
.pass .ring { --size: max(1.75rem, 11cqw); --w: max(3px, 1.1cqw); }
.pass--sm { --pass-r: .875rem; }
.pass--sm .pass__body { display: none; }
a.pass:hover, .pass.is-lift { box-shadow: inset 0 1px 0 rgba(255, 255, 255, .35), 0 34px 60px -18px var(--course-glow), 0 12px 22px -10px rgba(0, 0, 0, .26); }

/* ───────── Chứng chỉ ───────── */
.cert { position: relative; isolation: isolate; container-type: inline-size; aspect-ratio: 1.414; text-align: left; border-radius: var(--r-lg); background: var(--paper); color: var(--paper-ink); overflow: hidden; box-shadow: 0 0 0 1px var(--paper-line), 0 34px 70px -24px var(--course-glow), 0 14px 30px -12px rgba(0, 0, 0, .24); transform: perspective(75rem) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)); transition: transform var(--dur-3) var(--ease-out); }
.cert__foil { position: absolute; inset: 0 auto 0 0; width: 3.4cqw; background: var(--course-grad); }
.cert__foil::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, transparent 20%, rgba(255, 255, 255, .85) 50%, transparent 80%); background-size: 100% 260%; background-position: 0 var(--foil, 130%); mix-blend-mode: overlay; transition: background-position var(--dur-5) var(--ease-out); }
.cert::after { /* vân chìm: vòng tròn đồng tâm rất nhạt */ content: ""; position: absolute; inset: 0; z-index: -1; background: repeating-radial-gradient(circle at 100% 100%, var(--paper-line) 0 1px, transparent 1px 3.2cqw); opacity: .5; -webkit-mask: linear-gradient(315deg, #000, transparent 46%); mask: linear-gradient(315deg, #000, transparent 46%); }
.cert__body { position: absolute; inset: 0; padding: 6cqw 6.4cqw 5.4cqw 9.6cqw; display: flex; flex-direction: column; }
.cert__head { display: flex; align-items: center; justify-content: space-between; gap: 2cqw; }
.cert__brand { display: flex; align-items: center; gap: 1.2cqw; font-size: max(.625rem, 2.1cqw); font-weight: 700; letter-spacing: -.02em; }
.cert__brand .brand__mark { width: 2.8cqw; }
.cert__type { font-size: max(.5rem, 1.5cqw); font-weight: 600; letter-spacing: .16em; text-transform: uppercase; color: var(--paper-ink-2); }
.cert__label { margin-top: auto; font-size: max(.5625rem, 1.9cqw); color: var(--paper-ink-2); }
.cert__name { margin-top: .4cqw; font-family: var(--font-serif); font-style: italic; font-weight: 500; font-size: max(1.25rem, 6.4cqw); line-height: 1.22; letter-spacing: -.01em; text-wrap: balance; }
.cert__text { margin-top: 1.6cqw; font-size: max(.5625rem, 1.9cqw); color: var(--paper-ink-2); }
.cert__course { margin-top: .5cqw; font-size: max(.875rem, 3.9cqw); line-height: 1.15; font-weight: 700; letter-spacing: -.03em; color: var(--course-ink); }
.cert__foot { margin-top: auto; display: flex; align-items: flex-end; gap: 5cqw; }
.cert__foot dt { font-size: max(.5rem, 1.5cqw); color: var(--paper-ink-2); }
.cert__foot dd { font-size: max(.5625rem, 1.9cqw); font-weight: 600; font-variant-numeric: tabular-nums; }
.cert__seal { margin-left: auto; width: 11cqw; aspect-ratio: 1; border-radius: 50%; display: grid; place-items: center; background: conic-gradient(from 210deg, var(--iris-500), var(--blue-400), var(--mint-500), var(--sun-400), var(--coral-500), var(--pink-500), var(--iris-500)); color: var(--paper-ink); }
.cert__seal::before { content: ""; grid-area: 1 / 1; width: 78%; aspect-ratio: 1; border-radius: 50%; background: var(--paper); }
.cert__seal .ic { grid-area: 1 / 1; position: relative; width: 4.4cqw; height: 4.4cqw; stroke-width: 2.2; }
.cert--mini .cert__type, .cert--mini .cert__text, .cert--mini .cert__label, .cert--mini .cert__foot dl { display: none; }

/* ───────── Bề mặt ───────── */
.card { background: var(--surface); border-radius: var(--r-xl); box-shadow: 0 0 0 1px var(--line); padding: clamp(1.25rem, 3vw, 2rem); }
.card--raised { box-shadow: 0 0 0 1px var(--line), var(--shadow-2); }
.divider { height: 1px; background: var(--line); border: 0; margin: 0; }

/* ───────── Gập mở ───────── */
.acc { border-top: 1px solid var(--line); }
.acc__item { border-bottom: 1px solid var(--line); }
.acc__sum { display: flex; align-items: center; gap: var(--sp-4); min-height: 4rem; padding-block: var(--sp-4); cursor: pointer; list-style: none; font-weight: 600; }
.acc__sum::-webkit-details-marker { display: none; }
.acc__sum:hover { color: var(--accent); }
.acc__chev { margin-left: auto; color: var(--text-2); transition: transform var(--dur-3) var(--ease-out); }
.acc__item[open] .acc__chev { transform: rotate(180deg); }
.acc__panel { padding-bottom: var(--sp-6); color: var(--text-2); max-width: 44rem; }
@supports (interpolate-size: allow-keywords) {
  :root { interpolate-size: allow-keywords; }
  .acc__item::details-content { block-size: 0; overflow: clip; transition: block-size var(--dur-3) var(--ease-out), content-visibility var(--dur-3) allow-discrete; }
  .acc__item[open]::details-content { block-size: auto; }
}

/* ───────── Ô nhập ───────── */
.field { display: grid; gap: .375rem; }
.field__label { font-size: var(--fs-sm); font-weight: 600; }
.input { width: 100%; height: 3rem; padding: 0 1rem; border-radius: var(--r-md); border: 1px solid var(--line-strong); background: var(--surface); transition: border-color var(--dur-2), box-shadow var(--dur-2); }
.input::placeholder { color: var(--text-3); }
.input:hover { border-color: var(--text-3); }
.input:focus-visible { outline: none; border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.input[aria-invalid="true"] { border-color: var(--danger); box-shadow: 0 0 0 4px var(--danger-soft); }
.field__hint { font-size: var(--fs-xs); color: var(--text-2); }
.field__error { display: none; align-items: center; gap: .375rem; font-size: var(--fs-xs); font-weight: 500; color: var(--danger); }
.field.has-error .field__error { display: flex; }
.field.has-error .field__hint { display: none; }

/* ───────── Thông báo nổi ───────── */
.toast-wrap { position: fixed; left: 50%; bottom: max(1.5rem, env(safe-area-inset-bottom)); z-index: var(--z-toast); transform: translateX(-50%); display: grid; justify-items: center; gap: .5rem; pointer-events: none; width: max-content; max-width: calc(100vw - 2rem); }
.toast { display: flex; align-items: center; gap: .5rem; padding: .75rem 1.125rem; border-radius: var(--r-pill); background: var(--surface-inverse); color: var(--text-inverse); font-size: var(--fs-sm); font-weight: 500; box-shadow: var(--shadow-2); animation: toast-in var(--dur-3) var(--ease-soft); }
.toast.is-out { animation: toast-out var(--dur-2) var(--ease-in) forwards; }
@keyframes toast-in { from { opacity: 0; transform: translateY(.75rem) scale(.96); } }
@keyframes toast-out { to { opacity: 0; transform: translateY(.5rem); } }

/* ───────── Hộp thoại ───────── */
.dialog { width: min(100% - 2rem, 36rem); margin-top: 12vh; padding: 0; border: 0; border-radius: var(--r-xl); background: var(--surface); color: var(--text); box-shadow: 0 0 0 1px var(--line), var(--shadow-3); }
.dialog::backdrop { background: var(--scrim); -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px); }
.dialog[open] { animation: dialog-in var(--dur-3) var(--ease-out); }
@keyframes dialog-in { from { opacity: 0; transform: translateY(-.75rem) scale(.98); } }

/* ───────── Xuất hiện khi cuộn tới (chỉ bật khi có .js trên <html>) ───────── */
.js [data-reveal] { opacity: 0; transform: translateY(1.5rem); transition: opacity var(--dur-4) var(--ease-out), transform var(--dur-5) var(--ease-out); transition-delay: calc(var(--i, 0) * 70ms); }
.js [data-reveal="drop"] { transform: translateY(-1.25rem) scale(1.03); transition-timing-function: var(--ease-out), var(--ease-soft); }
.js [data-reveal="mask"] { opacity: 1; transform: none; clip-path: inset(-.22em -5%); }
.js [data-reveal="mask"] > .rv { display: block; transform: translateY(135%); transition: transform var(--dur-5) var(--ease-out); transition-delay: calc(var(--i, 0) * 70ms); }
.js [data-reveal].is-in { opacity: 1; transform: none; }
.js [data-reveal="mask"].is-in > .rv { transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; transition-delay: 0s !important; }
}

/* Chuyển trang: thẻ khoá biến thành đầu trang khoá. Trình duyệt cũ bỏ qua. */
@view-transition { navigation: auto; }
::view-transition-group(pass) { animation-duration: var(--dur-4); animation-timing-function: var(--ease-out); }
::view-transition-old(root), ::view-transition-new(root) { animation-duration: var(--dur-2); }