/* ==========================================================================
   Base stylesheet. Direction: "Firouzeh & Ink" (warm paper, indigo ink, turquoise + saffron); the learner screens
   add the "Kashi" layer in kashi.css (glazed eight-point star tiles, girih lattice).
   Rules: logical properties only (RTL-first), transform/opacity animations,
   motion tiers via html[data-motion="0|1|2|3"], no external requests.
   ========================================================================== */

@font-face {
  font-family: "Vazirmatn NL";
  src: url("../fonts/Vazirmatn-NL-wght.d9a4f66b2ce3.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
}
@font-face {
  font-family: "Inter Var";
  src: url("../fonts/inter-latin-wght-normal.260c81a4759b.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
}
@font-face {
  font-family: "Estedad";
  src: url("../fonts/estedad-arabic-wght.31b4bff49ffc.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
  unicode-range: U+0600-06FF, U+0750-077F, U+08A0-08FF, U+200C-200E, U+2010-2011, U+FB50-FDFF, U+FE70-FEFC;
}
/* Latin for English learning text. ZWNJ/ZWJ/marks (U+200C-200F) are left to the Persian fonts so joining is never split. */
@font-face {
  font-family: "Atkinson Next";
  src: url("../fonts/atkinson-next-latin-wght.825fabef695f.woff2") format("woff2");
  font-weight: 200 800;
  font-style: normal;
  font-display: swap;
  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+2000-200B, U+2010-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FFFD;
}
@font-face {
  font-family: "Atkinson Next";
  src: url("../fonts/atkinson-next-latin-wght-italic.740db8084ae9.woff2") format("woff2");
  font-weight: 200 800;
  font-style: italic;
  font-display: swap;
  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+2000-200B, U+2010-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FFFD;
}

:root {
  /* ---- colour: grouped grey ground, white cards, one accent (docs/DESIGN-APPLE.md §2) ---- */
  --paper: #f5f5f7;
  --paper-2: #ebebf0;
  --card: #ffffff;
  --ink: #1d1d1f;
  --ink-2: #6e6e73;
  --indigo: #4f52e0;
  --on-indigo: #ffffff;
  --teal: #0a7d74;
  --teal-deco: #22b8ab;
  --saffron: #ffb627;
  --ok: #1a7f45;
  --bad: #d1302b;
  --line: #8e8e93;
  --hair: #e3e3e8;
  --sep: rgb(60 60 67 / 0.14);          /* inset list separators (Apple "separator") */
  --brand-a: #6c70f0; --brand-b: #22b8ab; /* logo A gradient */
  --tint: color-mix(in srgb, var(--indigo) 11%, transparent);  /* tinted buttons, selected rows */

  --hero-a: #b9bbff;
  --hero-b: #a6e6df;
  --hero-c: #ffe2a8;
  --hero-bg: #f5f5f7;

  /* Persian: Vazirmatn for reading, Estedad for display. English: Atkinson Hyperlegible Next (clear I/l/1, built for
     low-vision readers, which suits learners decoding a new script). SF Pro is not licensable for the web. */
  --f-body: "Vazirmatn NL", "Atkinson Next", system-ui, sans-serif;
  --f-display: "Atkinson Next", "Estedad", "Vazirmatn NL", system-ui, sans-serif;

  /* ---- motion (docs/DESIGN-APPLE.md §5): critically damped springs by default, overshoot only when earned ---- */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-std: cubic-bezier(0.2, 0, 0, 1);
  --ease-pop: cubic-bezier(0.3, 1.3, 0.5, 1);
  --spring: linear(0, 0.042 1.1%, 0.162 2.4%, 0.517 6.7%, 0.672 9.1%, 0.796 11.7%, 0.882 14.4%, 0.941 17.4%, 0.975 20.4%,
    1.003 25.6%, 1.009 29.6%, 1.005 39.7%, 1);
  --dur-1: 120ms; --dur-2: 240ms; --dur-3: 420ms;

  --gutter: 16px;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 18px 40px -16px rgb(0 0 0 / 0.16);

  /* ---- type (docs/DESIGN-APPLE.md §3). Persian is never letter-spaced; --ls-* apply to Latin runs only. ---- */
  --fs-2xs: 0.75rem;     /* 12  tab-bar labels, ticks, kbd */
  --fs-xs: 0.8125rem;    /* 13  captions, badges: the Persian floor */
  --fs-sm: 0.875rem;     /* 14  meta, help, table cells, small buttons */
  --fs-base: 1rem;       /* 16  body, buttons */
  --fs-md: 1.0625rem;    /* 17  card titles, long reading text (iOS body) */
  --fs-lg: 1.1875rem;    /* 19  section titles, sheet titles */
  --fs-xl: 1.375rem;     /* 22  key numbers, page title on small phones */
  --fs-2xl: 1.75rem;     /* 28  large title on phones */
  --fs-3xl: 2.25rem;     /* 36  marketing section titles, scores */
  --fs-4xl: 3.75rem;     /* 60  landing hero, desktop only */
  --fs-h1: clamp(1.75rem, 1.1vw + 1.4rem, 2.25rem);
  --fs-hero: clamp(2.125rem, 3.4vw + 1.1rem, var(--fs-4xl));
  --fs-h2-mkt: clamp(1.625rem, 2vw + 1rem, 2.75rem);
  --lh-body: 1.75; --lh-title: 1.4; --lh-display: 1.22;
  --ls-display: -0.03em; --ls-title: -0.018em; --ls-small: 0.008em;
  --ls-caps: 0.06em;     /* Latin labels only (IELTS, B2, codes) */
  /* controls: 40 with a pointer, 44 on touch; primary CTAs 52 */
  --ctl-sm: 34px; --ctl: 40px; --ctl-lg: 52px;
  /* radii: continuous-feeling corners, capsules for controls */
  --r-xs: 6px; --r-sm: 10px; --r-md: 14px; --r-lg: 20px; --r-xl: 28px;
  --radius: var(--r-lg);
  /* elevation: resting cards get a soft lift (no outline), floating layers real shadow, sheets the deepest */
  --e1: 0 0 0 0.5px rgb(0 0 0 / 0.03), 0 1px 2px rgb(0 0 0 / 0.04), 0 4px 14px -6px rgb(0 0 0 / 0.07);
  --e2: 0 0 0 0.5px rgb(0 0 0 / 0.05), 0 2px 6px rgb(0 0 0 / 0.05), 0 16px 40px -14px rgb(0 0 0 / 0.22);
  --e3: 0 -1px 0 rgb(0 0 0 / 0.04), 0 -12px 48px -8px rgb(0 0 0 / 0.22);
  --ledge: 0px;          /* the old Kashi "glazed tile" button ledge is retired (flat, pressed = scale) */

  /* ---- materials (chrome only: header, tab bar, sheets, sticky bars) ---- */
  --mat: color-mix(in srgb, var(--paper) 74%, transparent);
  --mat-card: color-mix(in srgb, var(--card) 78%, transparent);
  --mat-blur: saturate(180%) blur(20px);
  --scrim: rgb(0 0 0 / 0.32);
  --header-h: 52px;
  --tabbar-h: 54px;
  /* safe areas: the Android app (Capacitor SystemBars, insetsHandling "css") injects --safe-area-inset-* on <html>; they equal
     env() on WebView 140+ and stay the source of truth on older WebViews (and they zero the bottom while the keyboard is up) */
  --safe-t: var(--safe-area-inset-top, env(safe-area-inset-top, 0px)); --safe-b: var(--safe-area-inset-bottom, env(safe-area-inset-bottom, 0px));
  --safe-l: var(--safe-area-inset-left, env(safe-area-inset-left, 0px)); --safe-r: var(--safe-area-inset-right, env(safe-area-inset-right, 0px));

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #000000;
    --paper-2: #2c2c2e;
    --card: #1c1c1e;
    --ink: #f5f5f7;
    --ink-2: #a1a1a6;
    --indigo: #9a9cff;
    --on-indigo: #0b0b10;
    --teal: #3fd3c6;
    --teal-deco: #3fd3c6;
    --saffron: #ffc84d;
    --ok: #4bd487;
    --bad: #ff7b72;
    --line: #76767e;
    --hair: #2c2c30;
    --sep: rgb(84 84 88 / 0.55);
    --tint: color-mix(in srgb, var(--indigo) 18%, transparent);
    --hero-a: #3a3eb8;
    --hero-b: #0c6f68;
    --hero-c: #6b4a12;
    --hero-bg: #000000;
    --shadow: 0 0 0 0.5px rgb(255 255 255 / 0.06), 0 18px 40px -16px rgb(0 0 0 / 0.8);
    --e1: 0 0 0 0.5px rgb(255 255 255 / 0.05);
    --e2: 0 0 0 0.5px rgb(255 255 255 / 0.08), 0 16px 40px -12px rgb(0 0 0 / 0.75);
    --e3: 0 0 0 0.5px rgb(255 255 255 / 0.08), 0 -12px 48px -8px rgb(0 0 0 / 0.7);
    --mat: color-mix(in srgb, #161618 72%, transparent);
    --mat-card: color-mix(in srgb, #1c1c1e 80%, transparent);
    --scrim: rgb(0 0 0 / 0.55);
  }
}
:root[data-theme="dark"] {
  --paper: #000000;
  --paper-2: #2c2c2e;
  --card: #1c1c1e;
  --ink: #f5f5f7;
  --ink-2: #a1a1a6;
  --indigo: #9a9cff;
  --on-indigo: #0b0b10;
  --teal: #3fd3c6;
  --teal-deco: #3fd3c6;
  --saffron: #ffc84d;
  --ok: #4bd487;
  --bad: #ff7b72;
  --line: #76767e;
  --hair: #2c2c30;
  --sep: rgb(84 84 88 / 0.55);
  --tint: color-mix(in srgb, var(--indigo) 18%, transparent);
  --hero-a: #3a3eb8;
  --hero-b: #0c6f68;
  --hero-c: #6b4a12;
  --hero-bg: #000000;
  --shadow: 0 0 0 0.5px rgb(255 255 255 / 0.06), 0 18px 40px -16px rgb(0 0 0 / 0.8);
  --e1: 0 0 0 0.5px rgb(255 255 255 / 0.05);
  --e2: 0 0 0 0.5px rgb(255 255 255 / 0.08), 0 16px 40px -12px rgb(0 0 0 / 0.75);
  --e3: 0 0 0 0.5px rgb(255 255 255 / 0.08), 0 -12px 48px -8px rgb(0 0 0 / 0.7);
  --mat: color-mix(in srgb, #161618 72%, transparent);
  --mat-card: color-mix(in srgb, #1c1c1e 80%, transparent);
  --scrim: rgb(0 0 0 / 0.55);
}
@media (pointer: coarse) { :root { --ctl-sm: 36px; --ctl: 44px; } }
/* accessibility: solid materials when transparency is reduced or contrast is raised (docs/DESIGN-APPLE.md §5) */
@media (prefers-reduced-transparency: reduce) { :root { --mat: var(--paper); --mat-card: var(--card); --mat-blur: none; } }
@media (prefers-contrast: more) {
  :root { --mat: var(--paper); --mat-card: var(--card); --mat-blur: none; --hair: var(--line); --sep: var(--line); --ink-2: var(--ink); }
}

/* ---- base ---------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth;
  scroll-padding-block-start: calc(var(--header-h) + var(--safe-t) + 16px); background: var(--paper); }
html[data-motion="0"] { scroll-behavior: auto; }
body {
  margin: 0;
  min-block-size: 100dvh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--f-body);
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  letter-spacing: 0;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
  overflow-x: clip;
}
:lang(en) { line-height: 1.5; }
[lang="en"] { font-family: "Atkinson Next", "Vazirmatn NL", system-ui, sans-serif; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { text-wrap: balance; font-family: var(--f-display); font-weight: 700; line-height: var(--lh-title); letter-spacing: 0; }
h1 { font-weight: 750; line-height: 1.3; }
h3 { font-weight: 650; }
/* Latin runs inside titles get size-specific tracking (Persian stays at 0: spacing breaks cursive joining) */
h1 :is(.en, [lang="en"]), h1:lang(en) { letter-spacing: var(--ls-title); }
h2 :is(.en, [lang="en"]) { letter-spacing: -0.01em; }
small :is(.en, [lang="en"]), .small :is(.en, [lang="en"]) { letter-spacing: var(--ls-small); }
p, li { text-wrap: pretty; }
img, svg, canvas { display: block; max-width: 100%; }
button { font: inherit; color: inherit; cursor: pointer; }
a { color: inherit; }
/* touch: no 300ms delay / double-tap zoom on controls, no grey flash (pinch-zoom on content stays) */
a, button, summary, label, input, select, textarea, [role="button"], [role="tab"] { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 2px solid var(--indigo); outline-offset: 2px; border-radius: var(--r-sm); }
::selection { background: color-mix(in srgb, var(--indigo) 24%, transparent); }
/* icons: one stroke family (Lucide), stroke set here so it can thin out at large sizes and thicken at small ones */
.ic { stroke-width: 1.75; fill: currentColor; } /* fill only reaches the few solid glyphs (play, pause, stop, star, flame); the rest set fill="none" */
.sr-only { position: absolute; inline-size: 1px; block-size: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.en { direction: ltr; unicode-bidi: isolate; font-family: var(--f-display); display: inline-block; }
.wrap { inline-size: min(100% - 2 * var(--gutter) - var(--safe-l, 0px) - var(--safe-r, 0px), 1180px); margin-inline: auto; }
@media (min-width: 760px) { :root { --gutter: 24px; } }
.skip { position: absolute; inset-inline-start: 12px; inset-block-start: -80px; background: var(--ink); color: var(--paper); padding: 8px 14px; border-radius: 10px; z-index: 100; }
.skip:focus { inset-block-start: calc(12px + var(--safe-t)); }

/* ---- buttons: capsules; feedback on press (pointer-down), never a hover lift ---------------------------------- */
.btn {
  position: relative; display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-block-size: var(--ctl); padding-inline: 20px; border-radius: 999px; border: 0; background: transparent;
  font-size: var(--fs-base); font-weight: 600; text-decoration: none; line-height: 1.3; text-align: center;
  transition: transform var(--dur-2) var(--spring), background-color var(--dur-2) var(--ease-std), color var(--dur-2) var(--ease-std),
    box-shadow var(--dur-2) var(--ease-std), filter var(--dur-2) var(--ease-std);
}
.btn:active:not([disabled]) { transform: scale(0.97); transition-duration: var(--dur-1); }
.btn .ic { inline-size: 18px; block-size: 18px; }
/* small controls keep a 44px touch target with an invisible hit area */
.btn-sm::before, .icon-btn::before { content: ""; position: absolute; inset: min(0px, calc((var(--ctl-sm) - 44px) / 2)); border-radius: inherit; }
.btn-sm::before { inset-inline: 0; }
.btn-primary { background: var(--indigo); color: var(--on-indigo); }
@media (hover: hover) { .btn-primary:hover { filter: brightness(1.08); } }
/* secondary = tinted (Apple "gray/tinted" button): no outline, a soft accent fill */
.btn-ghost { background: var(--tint); color: var(--indigo); }
@media (hover: hover) { .btn-ghost:hover { background: color-mix(in srgb, var(--indigo) 17%, transparent); } }
.btn-sm { min-block-size: var(--ctl-sm); padding-inline: 14px; font-size: var(--fs-sm); gap: 6px; }
.btn-sm .ic { inline-size: 16px; block-size: 16px; }
.btn-lg { min-block-size: var(--ctl-lg); padding-inline: 28px; font-size: var(--fs-md); }
.icon-btn {
  position: relative; inline-size: var(--ctl-sm); block-size: var(--ctl-sm); border-radius: 50%; border: 0; background: transparent; color: var(--ink-2);
  display: inline-grid; place-items: center; padding: 0;
  transition: transform var(--dur-2) var(--spring), background-color var(--dur-2) var(--ease-std), color var(--dur-2) var(--ease-std);
}
@media (hover: hover) { .icon-btn:hover { background: color-mix(in srgb, var(--ink) 7%, transparent); color: var(--ink); } }
.icon-btn:active { transform: scale(0.9); transition-duration: var(--dur-1); }
.icon-btn svg { inline-size: 21px; block-size: 21px; }
.icon-btn[aria-pressed="true"] { background: var(--tint); color: var(--indigo); }

/* ---- header: translucent material, transparent at rest, scroll-edge hairline once content slides under ------- */
.site-header { position: sticky; inset-block-start: 0; z-index: 50; padding-block-start: var(--safe-t);
  transition: background-color var(--dur-3) var(--ease-std), box-shadow var(--dur-3) var(--ease-std), -webkit-backdrop-filter var(--dur-3), backdrop-filter var(--dur-3); }
.site-header.scrolled { background: var(--mat); -webkit-backdrop-filter: var(--mat-blur); backdrop-filter: var(--mat-blur); box-shadow: 0 0.5px 0 var(--sep); }
.nav { position: relative; display: flex; align-items: center; gap: 4px; min-block-size: var(--header-h); }
.brand { display: inline-flex; align-items: center; gap: 8px; min-block-size: 44px; font-weight: 800; font-size: 1.0625rem; text-decoration: none; margin-inline-end: auto;
  transition: opacity var(--dur-2) var(--ease-std), visibility var(--dur-2); }
/* brand lockup (design/logo, mark A): mark at the start, Persian name, then the Latin name after a hairline (>= 600px) */
.brand-mark { inline-size: 28px; block-size: 28px; flex: none; }
.brand-mark .bm-l { fill: var(--brand-a); }
.brand-mark .bm-r { fill: var(--brand-b); }
.brand { color: var(--ink); }
.brand-fa { font-family: "Estedad", var(--f-body); font-weight: 800; font-size: 1.125rem; line-height: 1; }
.brand-en { display: none; font-family: "Atkinson Next", sans-serif; font-weight: 700; font-size: 1rem; line-height: 1;
  letter-spacing: -0.02em; padding-inline-start: 10px; border-inline-start: 1px solid var(--sep); color: var(--ink-2); }
@media (min-width: 600px) { .brand-en { display: inline; } }
.brand-foot { margin-block-end: 8px; }
.brand-foot .brand-mark { inline-size: 32px; block-size: 32px; }
.nav-links { display: none; gap: 2px; margin-inline-end: 12px; }
.nav-links a { position: relative; display: inline-flex; align-items: center; min-block-size: 36px; padding-inline: 12px; border-radius: 999px; text-decoration: none;
  font-size: var(--fs-sm); font-weight: 500; color: var(--ink-2); transition: color var(--dur-2) var(--ease-std), background-color var(--dur-2) var(--ease-std); }
@media (hover: hover) { .nav-links a:hover { color: var(--ink); } }
.nav-links a[aria-current="page"] { color: var(--ink); font-weight: 650; }
.nav-links a[aria-current="page"]::after { content: ""; position: absolute; inset-inline: 12px; inset-block-end: 2px; block-size: 2px; border-radius: 2px; background: var(--indigo); }
@media (min-width: 900px) { .nav-links { display: flex; } }
.nav-actions { display: flex; align-items: center; gap: 2px; }
.nav-actions .btn { margin-inline-start: 6px; }
/* compact title: the page's large title moves here once it scrolls under the header (ui.js), phones only */
.nav-title { position: absolute; inset-inline: 96px; inset-block: 0; display: grid; place-items: center; pointer-events: none; opacity: 0;
  font-weight: 650; font-size: var(--fs-md); line-height: 1.3; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  transform: translateY(6px); transition: opacity var(--dur-2) var(--ease-std), transform var(--dur-3) var(--spring); }
.nav-title > span { overflow: hidden; text-overflow: ellipsis; max-inline-size: 100%; }
@media (max-width: 899px) {
  .site-header.titled .nav-title { opacity: 1; transform: none; }
  .site-header.titled .brand { opacity: 0; visibility: hidden; }
}

/* ---- reveal system ------------------------------------------------------- */
html.js:not([data-motion="0"]) .reveal:not(.is-in) { opacity: 0; transform: translateY(18px); }
.reveal { transition: opacity 600ms var(--ease-out), transform 600ms var(--ease-out); transition-delay: var(--d, 0ms); }
html.ready-all .reveal { opacity: 1 !important; transform: none !important; }
html[data-motion="0"] .reveal { transition-duration: 120ms; }

/* split words (Persian is split by WORD only, never by letter: keeps joining intact) */
.w { display: inline-block; overflow: hidden; vertical-align: bottom; padding-block: 0.22em 0.12em; margin-block: -0.22em -0.12em; }
.wi { display: inline-block; }
html.js:not([data-motion="0"]) [data-split]:not(.is-in) .wi { transform: translateY(115%); }
[data-split] .wi { transition: transform 800ms var(--ease-out); transition-delay: calc(var(--i, 0) * 55ms + 120ms); }
html.ready-all [data-split] .wi { transform: none !important; }

/* ---- hero ---------------------------------------------------------------- */
.hero { position: relative; isolation: isolate; padding-block: clamp(24px, 5vw, 72px) clamp(48px, 7vw, 112px); overflow: clip;
  margin-block-start: calc(-1 * (var(--header-h) + var(--safe-t))); padding-block-start: calc(var(--header-h) + var(--safe-t) + clamp(20px, 5vw, 72px)); }
.hero-bg { position: absolute; inset: 0; z-index: -1; pointer-events: none; }
/* the aurora: complete on its own (no JS, tier 0, no WebGL). Three soft glows of the brand family on the page ground. */
.aurora { position: absolute; inset: 0; overflow: hidden; }
.au { position: absolute; border-radius: 50%; filter: blur(clamp(36px, 6vw, 80px)); opacity: 1; will-change: transform; }
.au-a { inline-size: 66vmax; aspect-ratio: 1; inset-block-start: -22vmax; inset-inline-end: -12vmax; background: radial-gradient(closest-side, var(--hero-a), transparent); }
.au-b { inline-size: 56vmax; aspect-ratio: 1; inset-block-end: -16vmax; inset-inline-start: -12vmax; background: radial-gradient(closest-side, var(--hero-b), transparent); }
.au-c { inline-size: 34vmax; aspect-ratio: 1; inset-block-start: 8%; inset-inline-start: 30%; background: radial-gradient(closest-side, var(--hero-c), transparent); opacity: 0.55; }
/* tier >= 1 without the WebGL layer: the glows drift very slowly (60s+, well below vestibular-trigger frequencies) */
html[data-motion="1"] .au, html[data-motion="2"] .au, html[data-motion="3"] .au { animation: au-drift 64s var(--ease-std) infinite alternate; }
html[data-motion] .au-b { animation-duration: 78s; animation-delay: -20s; }
html[data-motion] .au-c { animation-duration: 90s; animation-delay: -40s; }
@keyframes au-drift { 0% { transform: translate3d(0, 0, 0) scale(1); } 50% { transform: translate3d(-4vw, 3vh, 0) scale(1.08); } 100% { transform: translate3d(3vw, -2vh, 0) scale(0.96); } }
/* the WebGL layer fades in over the CSS aurora only after its first real frame (hero-shader.js adds .live) */
.hero-bg canvas { position: absolute; inset: 0; inline-size: 100%; block-size: 100%; opacity: 0; transition: opacity 1200ms var(--ease-std); }
.hero-bg canvas.live { opacity: 1; }
.hero-bg:has(canvas.live) .au { animation-play-state: paused; } /* one moving layer at a time */
.hero-bg::after { content: ""; position: absolute; inset: auto 0 0; block-size: 40%; background: linear-gradient(to bottom, transparent, var(--paper)); }
@media (prefers-reduced-transparency: reduce), (prefers-contrast: more), (forced-colors: active) { .aurora, .hero-bg canvas { display: none; } }
.hero-grid { display: grid; gap: 40px; align-items: center; }
@media (min-width: 960px) { .hero-grid { grid-template-columns: 1.15fr 0.85fr; gap: 64px; } }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; padding: 4px 14px; border-radius: 999px;
  background: var(--mat-card); -webkit-backdrop-filter: var(--mat-blur); backdrop-filter: var(--mat-blur); box-shadow: var(--e1);
  font-weight: 600; font-size: var(--fs-xs); color: var(--ink-2);
}
.eyebrow .en { color: var(--ink); letter-spacing: var(--ls-small); }
.hero h1 { font-size: var(--fs-hero); margin-block: 20px 16px; line-height: var(--lh-display); font-weight: 800; }
.hero h1 .accent { color: var(--indigo); }
.lead { font-size: clamp(var(--fs-md), 0.4vw + 0.95rem, 1.25rem); color: var(--ink-2); max-inline-size: 34em; line-height: 1.75; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-block-start: 28px; }
.hero-note { margin-block-start: 14px; font-size: var(--fs-sm); color: var(--ink-2); }

/* sentence card: the hero's one focal object, a floating material card */
.scard {
  position: relative; background: var(--mat-card); -webkit-backdrop-filter: var(--mat-blur); backdrop-filter: var(--mat-blur);
  border-radius: var(--r-xl); padding: clamp(18px, 2.4vw, 26px); box-shadow: var(--e2); max-inline-size: 460px; margin-inline: auto; inline-size: 100%;
}
.bar { flex: 1; block-size: 6px; border-radius: 999px; background: color-mix(in srgb, var(--ink) 9%, transparent); overflow: hidden; }
.bar > i { display: block; block-size: 100%; inline-size: 100%; background: var(--teal-deco); border-radius: inherit; transform-origin: right center; transform: scaleX(var(--p, 0)); transition: transform var(--dur-3) var(--spring); }
[dir="ltr"] .bar > i, .bar.ltr > i { transform-origin: left center; }
.streak { display: inline-flex; align-items: center; gap: 4px; font-weight: 800; color: var(--ink); }
.streak svg { inline-size: 18px; block-size: 18px; color: #ff9f0a; }
.streak.tick svg { animation: flame-pop 700ms var(--ease-pop); }
.xp-pop {
  position: absolute; z-index: 5; pointer-events: none; font-weight: 800; color: #1d1d1f; background: var(--saffron); padding: 2px 12px; border-radius: 999px; font-family: var(--f-display);
  animation: xp-rise 900ms var(--ease-out) forwards;
}

/* ---- sections ------------------------------------------------------------ */
.section { padding-block: clamp(64px, 9vw, 128px); }
.section-head { max-inline-size: 42rem; margin-block-end: clamp(28px, 4vw, 48px); }
.section-head h2 { font-size: var(--fs-h2-mkt); margin-block: 8px 12px; line-height: 1.3; font-weight: 750; }
.section-head p { color: var(--ink-2); font-size: clamp(var(--fs-md), 0.3vw + 0.95rem, 1.1875rem); line-height: 1.8; }
.kicker { color: var(--indigo); font-weight: 650; font-size: var(--fs-sm); }

/* evidence strip */
.strip { border-block: 0.5px solid var(--sep); background: var(--card); padding-block: 16px; }
.strip-in { display: flex; flex-wrap: wrap; gap: 10px 24px; align-items: center; justify-content: center; font-weight: 600; font-size: var(--fs-sm); color: var(--ink-2); }
.strip-in span { display: inline-flex; align-items: center; gap: 6px; }
.strip-in svg { inline-size: 16px; block-size: 16px; color: var(--teal); }

/* bento */
.bento { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 760px) { .bento { grid-template-columns: repeat(6, 1fr); } .b1 { grid-column: span 3; } .b2 { grid-column: span 3; } .b3 { grid-column: span 2; } .b4 { grid-column: span 4; } }
.bcard { position: relative; background: var(--card); border-radius: var(--r-xl); padding: clamp(22px, 2.6vw, 32px); overflow: hidden; box-shadow: var(--e1); }
.bcard h3 { font-size: var(--fs-xl); margin-block: 10px 8px; line-height: 1.4; }
.bcard p { color: var(--ink-2); font-size: var(--fs-base); }
.bnum { font-family: var(--f-display); font-weight: 700; font-size: var(--fs-xs); color: var(--indigo); letter-spacing: var(--ls-caps); }
.bviz { margin-block-start: 18px; block-size: 72px; }
.bviz svg { inline-size: 100%; block-size: 100%; overflow: visible; }
.draw { stroke-dasharray: 1; stroke-dashoffset: 1; }
.is-in .draw, .draw.is-in { stroke-dashoffset: 0; transition: stroke-dashoffset 1400ms var(--ease-out) 200ms; }
html:not(.js) .draw, html[data-motion="0"] .draw, html.ready-all .draw { stroke-dashoffset: 0; }

/* roadmap */
.road { position: relative; list-style: none; margin: 0; padding: 0; display: grid; gap: 20px; }
.road::before { content: ""; position: absolute; inset-block: 12px; inset-inline-start: 27px; inline-size: 3px; border-radius: 3px; background: var(--hair); }
.road-fill { position: absolute; inset-block: 12px; inset-inline-start: 27px; inline-size: 3px; border-radius: 3px; background: linear-gradient(to bottom, var(--indigo), var(--teal-deco)); transform-origin: top; transform: scaleY(var(--fill, 0)); }
html:not(.js) .road-fill, html[data-motion="0"] .road-fill, html.ready-all .road-fill { transform: scaleY(1); }
.step { position: relative; display: grid; grid-template-columns: 58px 1fr; gap: 16px; align-items: start; }
.node {
  position: relative; z-index: 1; inline-size: 58px; block-size: 58px; border-radius: 50%; display: grid; place-items: center; font-family: var(--f-display); font-weight: 800; font-size: 1.1rem;
  background: var(--paper); border: 3px solid var(--hair); color: var(--ink-2); transition: transform 400ms var(--ease-pop), background-color 300ms, border-color 300ms, color 300ms;
}
.step.lit .node { background: var(--indigo); border-color: var(--indigo); color: var(--on-indigo); transform: scale(1.08); }
.step.soon.lit .node { background: var(--paper); color: var(--ink-2); border-style: dashed; border-color: var(--line); }
.scard-step { background: var(--card); border-radius: var(--r-lg); padding: 20px 22px; box-shadow: var(--e1); }
.scard-step h3 { font-size: var(--fs-md); display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.badge { font-size: 0.8rem; font-weight: 700; padding: 2px 12px; border-radius: 999px; background: color-mix(in srgb, var(--teal-deco) 16%, transparent); color: var(--teal); font-family: var(--f-body); }
.badge.soon { background: var(--paper-2); color: var(--ink-2); }
.scard-step p { color: var(--ink-2); margin-block: 4px 8px; font-size: var(--fs-sm); }
.scard-step ul { margin: 0; padding-inline-start: 20px; color: var(--ink); font-size: var(--fs-sm); }
.scard-step li { margin-block: 2px; }
@media (min-width: 900px) {
  .road { gap: 0; }
  .road::before, .road-fill { inset-inline-start: calc(50% - 1.5px); }
  .step { grid-template-columns: 1fr 58px 1fr; gap: 24px; padding-block: 12px; }
  .step .node { grid-column: 2; grid-row: 1; justify-self: center; }
  .step .scard-step { grid-column: 3; grid-row: 1; }
  .step:nth-child(even) .scard-step { grid-column: 1; }
}
html.js:not([data-motion="0"]) .step:not(.is-in) .scard-step { opacity: 0; transform: translateY(24px); }
.step .scard-step { transition: opacity 600ms var(--ease-out), transform 700ms var(--spring); }
html.ready-all .step .scard-step { opacity: 1 !important; transform: none !important; }

/* exam band (always dark) */
.on-dark {
  --paper: #000000; --paper-2: #2c2c2e; --card: #1c1c1e; --ink: #f5f5f7; --ink-2: #a1a1a6; --indigo: #9a9cff; --on-indigo: #0b0b10;
  --teal: #3fd3c6; --teal-deco: #3fd3c6; --saffron: #ffc84d; --line: #76767e; --hair: #2c2c30; --sep: rgb(84 84 88 / 0.55);
  --tint: rgb(154 156 255 / 0.18); --mat-card: rgb(28 28 30 / 0.8); --e1: 0 0 0 0.5px rgb(255 255 255 / 0.06);
  background: var(--paper); color: var(--ink); border-radius: var(--r-xl); margin-inline: 8px;
}
.exam-grid { display: grid; gap: 40px; align-items: center; }
@media (min-width: 960px) { .exam-grid { grid-template-columns: 1.1fr 0.9fr; } }
.exam-grid h2 { font-size: var(--fs-h2-mkt); margin-block: 8px 12px; line-height: 1.3; }
/* segmented control (iOS): a fill track, the selected segment is a raised card */
.tabs { display: inline-flex; padding: 2px; border-radius: 999px; background: var(--paper-2); margin-block: 12px 20px; }
.tab { border: 0; background: transparent; padding: 6px 20px; min-block-size: var(--ctl-sm); border-radius: 999px; font-weight: 600; font-size: var(--fs-sm); font-family: var(--f-display);
  color: var(--ink); transition: background-color var(--dur-2) var(--ease-std), box-shadow var(--dur-2) var(--ease-std); }
.tab[aria-selected="true"] { background: var(--card); box-shadow: 0 1px 3px rgb(0 0 0 / 0.12), 0 0 0 0.5px rgb(0 0 0 / 0.04); }
.on-dark .tab[aria-selected="true"] { background: #636366; }
.task-list { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; list-style: none; direction: ltr; }
.task-list li { padding: 6px 14px; border-radius: 999px; background: var(--card); font-family: var(--f-display); font-weight: 600; font-size: var(--fs-sm); line-height: 1.5; }
.tabpanel[hidden] { display: none; }
.tabpanel.swap li { animation: chip-in 420ms var(--ease-out) backwards; animation-delay: calc(var(--i, 0) * 35ms); }
.disclaimer { margin-block-start: 18px; padding: 12px 16px; border-radius: var(--r-md); background: color-mix(in srgb, var(--ink) 6%, transparent); color: var(--ink-2); font-size: var(--fs-sm); }
.dials { display: flex; gap: 24px; flex-wrap: wrap; justify-content: center; }
.dial { position: relative; inline-size: min(176px, 42vw); aspect-ratio: 1; }
.dial svg { inline-size: 100%; block-size: 100%; transform: rotate(-90deg); }
.dial .track { stroke: var(--paper-2); }
.dial .val { stroke: var(--saffron); stroke-linecap: round; transition: stroke-dashoffset 1800ms var(--ease-out); }
.dial.timer .val { stroke: var(--teal-deco); }
.dial-num { position: absolute; inset: 0; display: grid; place-content: center; text-align: center; font-family: var(--f-display); direction: ltr; }
.dial-num b { font-size: clamp(1.625rem, 4vw, 2.25rem); font-variant-numeric: tabular-nums; line-height: 1.1; letter-spacing: -0.02em; }
.dial-num small { color: var(--ink-2); font-size: var(--fs-2xs); line-height: 1.3; font-family: var(--f-body); }
.dial.timer .val { animation: timer-run 40s linear infinite paused; }
html[data-motion="2"] .dial.timer.in-view .val, html[data-motion="3"] .dial.timer.in-view .val { animation-play-state: running; }

/* skills */
.tiles { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .tiles { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .tiles { grid-template-columns: repeat(3, 1fr); } }
.tile { background: var(--card); border-radius: var(--r-xl); padding: 16px 16px 22px; box-shadow: var(--e1); display: grid; grid-template-rows: 112px auto; gap: 16px; }
.tile h3 { font-size: var(--fs-lg); display: flex; align-items: baseline; gap: 8px; padding-inline: 6px; }
.tile h3 .en { font-size: var(--fs-2xs); color: var(--ink-2); font-weight: 600; letter-spacing: var(--ls-caps); text-transform: uppercase; }
.tile p { color: var(--ink-2); font-size: var(--fs-sm); margin-block-start: 4px; padding-inline: 6px; }
.demo { border-radius: var(--r-md); background: var(--paper); display: grid; place-items: center; overflow: hidden; position: relative; direction: ltr; }
/* listening: waveform */
.wave { display: flex; align-items: center; gap: 5px; block-size: 70px; }
.wave i { inline-size: 6px; border-radius: 6px; background: var(--indigo); block-size: 30%; transform-origin: center; }
.wave i:nth-child(1) { block-size: 28%; } .wave i:nth-child(2) { block-size: 55%; } .wave i:nth-child(3) { block-size: 80%; } .wave i:nth-child(4) { block-size: 45%; }
.wave i:nth-child(5) { block-size: 95%; } .wave i:nth-child(6) { block-size: 60%; } .wave i:nth-child(7) { block-size: 35%; } .wave i:nth-child(8) { block-size: 75%; }
.wave i:nth-child(9) { block-size: 50%; } .wave i:nth-child(10) { block-size: 88%; } .wave i:nth-child(11) { block-size: 40%; } .wave i:nth-child(12) { block-size: 25%; }
html[data-motion="2"] .in-view .wave i, html[data-motion="3"] .in-view .wave i { animation: wave 1.1s var(--ease-std) infinite alternate; }
.wave i:nth-child(3n) { animation-delay: -0.2s !important; } .wave i:nth-child(3n+1) { animation-delay: -0.55s !important; } .wave i:nth-child(4n) { animation-duration: 0.8s !important; }
/* speaking: mic rings */
.mic { position: relative; inline-size: 44px; block-size: 44px; border-radius: 50%; background: var(--teal-deco); display: grid; place-items: center; color: #0f0e22; }
.mic svg { inline-size: 22px; block-size: 22px; }
.mic::before, .mic::after { content: ""; position: absolute; inset: 0; border-radius: 50%; border: 2px solid var(--teal-deco); opacity: 0; }
html[data-motion="2"] .in-view .mic::before, html[data-motion="3"] .in-view .mic::before { animation: ring 1.8s var(--ease-out) infinite; }
html[data-motion="2"] .in-view .mic::after, html[data-motion="3"] .in-view .mic::after { animation: ring 1.8s var(--ease-out) 0.9s infinite; }
/* reading: highlight sweep */
.lines { display: grid; gap: 10px; inline-size: 72%; }
.lines i { display: block; block-size: 10px; border-radius: 6px; background: linear-gradient(to right, var(--saffron) 0 0) no-repeat, var(--hair); background-size: 0% 100%, 100% 100%; }
.lines i:nth-child(2) { inline-size: 88%; } .lines i:nth-child(3) { inline-size: 64%; }
.lines i:nth-child(1) { background-size: 100% 100%, 100% 100%; }
html[data-motion="2"] .in-view .lines i, html[data-motion="3"] .in-view .lines i { animation: sweep 3.6s var(--ease-std) infinite; }
html[data-motion="2"] .in-view .lines i:nth-child(2), html[data-motion="3"] .in-view .lines i:nth-child(2) { animation-delay: 0.5s; }
html[data-motion="2"] .in-view .lines i:nth-child(3), html[data-motion="3"] .in-view .lines i:nth-child(3) { animation-delay: 1s; }
/* writing: correction */
.write { font-family: var(--f-display); font-weight: 600; font-size: var(--fs-md); display: flex; gap: 8px; align-items: baseline; }
.write .fix { position: relative; display: inline-grid; }
.write .fix span { grid-area: 1 / 1; }
.write .wrong { color: var(--bad); text-decoration: line-through; }
.write .right { color: var(--ok); opacity: 0; }
html[data-motion="2"] .in-view .write .wrong, html[data-motion="3"] .in-view .write .wrong { animation: wrong-out 4.5s infinite; }
html[data-motion="2"] .in-view .write .right, html[data-motion="3"] .in-view .write .right { animation: right-in 4.5s infinite; }
html[data-motion="0"] .write .wrong, html[data-motion="1"] .write .wrong { opacity: 0.5; } html[data-motion="0"] .write .right, html[data-motion="1"] .write .right { opacity: 1; position: static; }
/* vocab: flip card */
.flip { inline-size: 130px; block-size: 76px; perspective: 600px; }
.flip > div { position: relative; inline-size: 100%; block-size: 100%; transform-style: preserve-3d; }
.flip b { position: absolute; inset: 0; display: grid; place-items: center; backface-visibility: hidden; border-radius: var(--r-md); background: var(--card); border: 1.5px solid var(--hair); font-family: var(--f-display); font-size: var(--fs-md); }
.flip b + b { transform: rotateY(180deg); background: var(--indigo); color: var(--on-indigo); border-color: var(--indigo); font-family: "Vazirmatn NL", sans-serif; direction: rtl; }
html[data-motion="2"] .in-view .flip > div, html[data-motion="3"] .in-view .flip > div { animation: flip 5s var(--ease-std) infinite; }
/* grammar: a/an */
.gram { font-family: var(--f-display); font-weight: 600; font-size: var(--fs-md); display: flex; gap: 8px; align-items: center; }
.gram .gap { display: inline-grid; min-inline-size: 48px; border-bottom: 3px solid var(--indigo); text-align: center; }
.gram .gap span { grid-area: 1 / 1; }
.gram .a { color: var(--bad); }
.gram .an { color: var(--ok); opacity: 0; }
html[data-motion="2"] .in-view .gram .a, html[data-motion="3"] .in-view .gram .a { animation: wrong-out 4s infinite; }
html[data-motion="2"] .in-view .gram .an, html[data-motion="3"] .in-view .gram .an { animation: right-in 4s infinite; }
html[data-motion="0"] .gram .an, html[data-motion="1"] .gram .an { opacity: 1; } html[data-motion="0"] .gram .a, html[data-motion="1"] .gram .a { opacity: 0; }

/* persian speakers */
.notes { display: grid; gap: 12px; grid-template-columns: 1fr; }
@media (min-width: 700px) { .notes { grid-template-columns: repeat(2, 1fr); } }
.note { display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: center; background: var(--card); border-radius: var(--r-lg); padding: 14px 18px; font-size: var(--fs-sm); box-shadow: var(--e1); }
.note .en { font-weight: 700; font-size: var(--fs-md); color: var(--indigo); background: var(--tint); padding: 4px 12px; border-radius: var(--r-sm); }
.note small { display: block; color: var(--teal); font-weight: 700; font-size: var(--fs-xs); line-height: 1.4; }

/* plans */
.plans { display: grid; gap: 16px; grid-template-columns: 1fr; max-inline-size: 820px; }
@media (min-width: 760px) { .plans { grid-template-columns: repeat(2, 1fr); } }
.plan { background: var(--card); border-radius: var(--r-xl); padding: 24px; display: grid; gap: 12px; align-content: start; font-size: var(--fs-sm); box-shadow: var(--e1); }
.plan.featured { box-shadow: var(--e1), inset 0 0 0 2px var(--indigo); position: relative; }
.plan.featured::after { content: "پیشنهادی"; position: absolute; inset-block-start: -11px; inset-inline-start: 18px; background: var(--indigo); color: var(--on-indigo); font-size: var(--fs-xs); font-weight: 700; padding: 1px 12px; border-radius: 999px; }
.plan h3 { font-size: var(--fs-lg); }
.plan .price { color: var(--ink-2); font-weight: 600; }
.plan ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 6px; }
.plan li { display: flex; gap: 10px; align-items: baseline; }
.plan li::before { content: "✓"; color: var(--ok); font-weight: 800; }
.draft-note { margin-block-start: 12px; color: var(--ink-2); font-size: var(--fs-sm); }

/* faq: one grouped list, inset separators, a chevron that turns */
.faq { display: grid; gap: 0; max-inline-size: 780px; background: var(--card); border-radius: var(--r-lg); box-shadow: var(--e1); overflow: hidden; }
.faq details { position: relative; padding-inline: 20px; }
.faq details + details::before { content: ""; position: absolute; inset-block-start: 0; inset-inline: 20px 0; block-size: 0.5px; background: var(--sep); }
.faq summary { cursor: pointer; font-weight: 600; padding-block: 14px; list-style: none; display: flex; justify-content: space-between; gap: 16px; align-items: center; min-block-size: 52px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: ""; inline-size: 8px; block-size: 8px; flex: none; border: solid var(--ink-2); border-width: 0 1.75px 1.75px 0; transform: translateY(-2px) rotate(45deg);
  transition: transform var(--dur-3) var(--spring); }
.faq details[open] summary::after { transform: translateY(2px) rotate(-135deg); }
.faq details > p { padding-block: 0 16px; color: var(--ink-2); font-size: var(--fs-base); }

/* footer */
.closing { text-align: center; display: grid; gap: 14px; justify-items: center; padding-block-end: 44px; }
.closing h2 { font-size: var(--fs-h2-mkt); max-inline-size: 18em; }
.fine { border-block-start: 0.5px solid var(--sep); padding-block-start: 18px; color: var(--ink-2); font-size: var(--fs-sm); display: grid; gap: 6px; }

/* ---- lesson page --------------------------------------------------------- */
.lesson-wrap { min-block-size: 100dvh; display: grid; grid-template-rows: auto 1fr; }
.lesson-top { display: flex; align-items: center; gap: 12px; padding-block: 12px; }
.lesson-top .bar { block-size: 10px; }
.lesson-main { display: grid; align-content: start; padding-block: 8px 40px; }
.lcard { max-inline-size: 640px; margin-inline: auto; inline-size: 100%; display: grid; gap: 16px; }
.lcard .qn { font-weight: 700; color: var(--teal); font-size: var(--fs-sm); }
.qtext { font-family: var(--f-display); font-size: clamp(1.25rem, 1.4vw + 0.95rem, 1.625rem); font-weight: 700; direction: ltr; text-align: start; unicode-bidi: isolate; line-height: 1.4; }
.qhint { color: var(--ink-2); }
.opts { display: grid; gap: 10px; }
.opt {
  text-align: start; direction: ltr; border: 1.5px solid var(--hair); border-radius: var(--r-lg); background: var(--card); padding: 10px 16px; font-family: var(--f-display); font-weight: 500; font-size: 1.0625rem; min-block-size: 52px;
  display: flex; align-items: center; gap: 12px; transition: transform 160ms var(--ease-std), border-color 160ms, background-color 160ms;
}
.opt kbd { font-family: var(--f-display); font-size: var(--fs-2xs); border: 1px solid var(--hair); border-radius: var(--r-xs); padding: 0 6px; color: var(--ink-2); line-height: 1.6; }
button.opt:hover:not([disabled]) { transform: translateY(-2px); border-color: var(--indigo); }
.opt[disabled] { cursor: default; }
.opt.right { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, var(--card)); }
.opt.wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, var(--card)); }
html[data-motion="2"] .opt.wrong.fresh, html[data-motion="3"] .opt.wrong.fresh { animation: shake 280ms var(--ease-std); }
html[data-motion="2"] .opt.right.fresh, html[data-motion="3"] .opt.right.fresh { animation: opt-pop 420ms var(--ease-pop); }
.opt .mark { margin-inline-start: auto; font-weight: 800; }
.opt.right .mark { color: var(--ok); } .opt.wrong .mark { color: var(--bad); }
.sheet { border-radius: var(--r-lg); padding: 14px 18px; display: grid; gap: 8px; border: 1.5px solid var(--hair); background: var(--paper-2); }
.sheet.ok { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 10%, var(--paper)); }
.sheet.no { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 8%, var(--paper)); }
html[data-motion="2"] .sheet, html[data-motion="3"] .sheet { animation: sheet-up 280ms var(--ease-out); }
.sheet strong { font-size: var(--fs-md); }
.sheet.ok strong { color: var(--ok); } .sheet.no strong { color: var(--bad); }
.sheet .ans { font-family: var(--f-display); font-weight: 700; }
.done { text-align: center; display: grid; gap: 14px; justify-items: center; padding-block: 20px; }
.done h2 { font-size: clamp(var(--fs-xl), 1.5vw + 1rem, 2rem); }
.done .stats { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.stat { background: var(--card); border: 1px solid var(--hair); border-radius: var(--r-lg); padding: 10px 18px; min-inline-size: 112px; }
.stat b { display: block; font-family: var(--f-display); font-size: var(--fs-xl); font-variant-numeric: tabular-nums; direction: ltr; line-height: 1.3; }
.stat span { color: var(--ink-2); font-size: var(--fs-sm); }
.htmx-request .opt { opacity: 0.7; }
#fx { position: fixed; inset: 0; z-index: 90; pointer-events: none; inline-size: 100%; block-size: 100%; }

/* ---- keyframes ----------------------------------------------------------- */
@keyframes wave { from { transform: scaleY(0.35); } to { transform: scaleY(1.15); } }
@keyframes ring { 0% { transform: scale(1); opacity: 0.7; } 100% { transform: scale(2.3); opacity: 0; } }
@keyframes sweep { 0% { background-size: 0% 100%, 100% 100%; } 45%, 80% { background-size: 100% 100%, 100% 100%; } 100% { background-size: 0% 100%, 100% 100%; } }
@keyframes wrong-out { 0%, 40% { opacity: 1; } 55%, 100% { opacity: 0; } }
@keyframes right-in { 0%, 45% { opacity: 0; transform: translateY(6px); } 60%, 90% { opacity: 1; transform: none; } 100% { opacity: 0; } }
@keyframes flip { 0%, 35% { transform: rotateY(0); } 50%, 85% { transform: rotateY(180deg); } 100% { transform: rotateY(360deg); } }
@keyframes timer-run { from { stroke-dashoffset: 0; } to { stroke-dashoffset: var(--len, 339.3); } }
@keyframes slot-pop { 0% { transform: scale(0.6) translateY(10px); opacity: 0; } 100% { transform: none; opacity: 1; } }
@keyframes xp-rise { 0% { transform: translateY(0) scale(0.7); opacity: 0; } 20% { opacity: 1; transform: translateY(-10px) scale(1.05); } 100% { transform: translateY(-64px) scale(1); opacity: 0; } }
@keyframes flame-pop { 0% { transform: scale(1); } 40% { transform: scale(1.35) rotate(-8deg); } 100% { transform: scale(1); } }
@keyframes chip-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-6px); } 75% { transform: translateX(6px); } }
@keyframes opt-pop { 0% { transform: scale(0.97); } 60% { transform: scale(1.02); } 100% { transform: scale(1); } }
@keyframes sheet-up { from { transform: translateY(14px); opacity: 0; } to { transform: none; opacity: 1; } }

/* ---- view transitions (progressive enhancement; Chromium/Safari) ---------- */
@view-transition { navigation: auto; }
::view-transition-old(root), ::view-transition-new(root) { animation-duration: 260ms; animation-timing-function: var(--ease-std); }

/* ---- reduced motion / tier 0 --------------------------------------------- */
html[data-motion="0"] *, html[data-motion="0"] *::before, html[data-motion="0"] *::after {
  animation: none !important; scroll-behavior: auto !important;
}
html[data-motion="0"] .btn, html[data-motion="0"] .chip, html[data-motion="0"] .bcard, html[data-motion="0"] .note, html[data-motion="0"] .opt { transition-duration: 0.01ms; }
html[data-motion="0"] .bcard:hover, html[data-motion="0"] .btn:hover, html[data-motion="0"] .chip:hover { transform: none; }
@media (prefers-reduced-motion: reduce) { @view-transition { navigation: none; } }

/* ---- lesson catalogue ---- */
.lessons-page { padding-block: 28px 64px; display: grid; gap: 28px; }
.lessons-head { display: grid; gap: 8px; max-inline-size: 60ch; }
.lessons-head h1 { font-size: var(--fs-h1); margin: 0; }
.lgroup { display: grid; gap: 12px; }
.lgroup h2 { font-size: var(--fs-lg); margin: 0; display: flex; gap: 8px; align-items: baseline; }
.lgroup h2 .en { font-family: var(--f-display); color: var(--teal); }
.llist { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); }
.lrow { display: grid; gap: 4px; padding: 14px 16px; border-radius: var(--r-lg); background: var(--card); border: 1px solid var(--hair); color: inherit; text-decoration: none; min-block-size: 100%; transition: transform 0.25s var(--ease-out), border-color 0.25s var(--ease-out); }
.lrow:hover { transform: translateY(-2px); border-color: var(--indigo); }
.lrow:focus-visible { outline: 2px solid var(--indigo); outline-offset: 2px; }
.lkind { font-size: var(--fs-xs); font-weight: 700; color: var(--teal); }
.ltitle { font-weight: 700; font-size: var(--fs-md); }
.lblurb { color: var(--ink-2); font-size: var(--fs-sm); }
.lmeta { margin-block-start: 4px; font-size: var(--fs-sm); color: var(--ink-2); }
.lbest { display: inline-block; padding: 2px 10px; border-radius: 999px; border: 1.5px solid var(--ok); color: var(--ok); font-weight: 800; font-variant-numeric: tabular-nums; }
html[data-motion="0"] .lrow { transition-duration: 0.01ms; }
html[data-motion="0"] .lrow:hover { transform: none; }

/* ---- practice tools ---- */
.tool-page { padding-block: 28px 64px; display: grid; gap: 18px; }
.taskpick { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.taskpick label { font-weight: 700; }
select, textarea { font: inherit; color: var(--ink); background: var(--card); border: 1px solid var(--hair); border-radius: var(--r-md); padding: 8px 12px; }
select:focus-visible, textarea:focus-visible, .stile:focus-visible, .rate:focus-visible { outline: 2px solid var(--indigo); outline-offset: 2px; }
.prompt-card { background: var(--card); border: 1px solid var(--hair); border-radius: var(--r-lg); padding: 16px 18px; display: grid; gap: 8px; }
.prompt-ctx { white-space: pre-line; color: var(--ink-2); margin: 0; }
.prompt-main { font-weight: 700; font-size: var(--fs-md); margin: 0; }
.prompt-meta { margin: 0; color: var(--ink-2); font-size: var(--fs-sm); }
.wform { display: grid; gap: 10px; }
.wform label[for="text"] { font-weight: 700; }
.wform textarea { inline-size: 100%; resize: vertical; line-height: 1.7; font-size: var(--fs-md); min-block-size: 16em; }
.wbar { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.wc.short { color: var(--bad); }
.wc { font-variant-numeric: tabular-nums; }
.timer { font-family: var(--f-display); font-weight: 700; font-size: var(--fs-md); font-variant-numeric: tabular-nums; }
.timer.over { color: var(--bad); }
.levelpick { margin-inline-start: auto; }
.fbcard { display: grid; gap: 12px; background: var(--card); border: 1px solid var(--hair); border-radius: var(--r-lg); padding: 18px; }
.fbcard h2, .fbcard h3 { margin: 0; }
.fbcard h2 { font-size: var(--fs-lg); }
.fbcard h3 { font-size: var(--fs-md); color: var(--teal); }
.fbmeta { margin: 0; color: var(--ink-2); font-size: var(--fs-sm); }
.annot { white-space: pre-wrap; line-height: 1.9; padding: 12px 14px; border-radius: var(--r-md); background: var(--paper-2); }
mark.m { background: color-mix(in srgb, var(--saffron) 38%, var(--card)); color: var(--ink); border-radius: 6px; padding: 1px 4px; }
mark.m sup { font-weight: 800; margin-inline-end: 3px; font-size: 0.7em; }
.issues { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.issue { border: 1px solid var(--hair); border-radius: var(--r-md); padding: 12px 14px; display: grid; gap: 6px; background: var(--paper); }
.issue p { margin: 0; }
.issue-head { display: flex; gap: 10px; align-items: center; }
.badge { display: inline-grid; place-items: center; inline-size: 22px; block-size: 22px; border-radius: 50%; background: var(--indigo); color: var(--on-indigo); font-weight: 700; font-size: var(--fs-2xs); }
.fix del { color: var(--bad); }
.fix ins { color: var(--ok); text-decoration: none; font-weight: 700; }
.ex { color: var(--ink-2); font-size: var(--fs-sm); }
.checks, .selfcheck { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.check { padding: 6px 12px; border-radius: var(--r-sm); border: 1px solid var(--hair); font-size: var(--fs-sm); }
.check.ok { border-color: var(--ok); }
.check.warn { border-color: var(--bad); }
.selfcheck label { display: flex; gap: 10px; align-items: baseline; }
.tileline { min-block-size: 56px; display: flex; flex-wrap: wrap; gap: 6px; padding: 10px; border: 1.5px dashed var(--line); border-radius: var(--r-md); align-content: flex-start; }
.tilepool { display: flex; flex-wrap: wrap; gap: 8px; }
.stile { font: inherit; font-weight: 600; color: var(--ink); background: var(--card); border: 1.5px solid var(--hair); border-radius: var(--r-sm); padding: 8px 12px; min-block-size: 44px; cursor: pointer; transition: transform 0.2s var(--ease-out), border-color 0.2s var(--ease-out); }
.stile:hover { transform: translateY(-2px); border-color: var(--indigo); }
.tileactions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn[disabled] { opacity: 0.5; cursor: not-allowed; }
.rvstats { display: flex; flex-wrap: wrap; gap: 8px 22px; margin: 0; color: var(--ink-2); }
.rvstats b { color: var(--ink); font-variant-numeric: tabular-nums; }
.rvcard .qtext .pos { font-size: 0.9rem; font-weight: 600; color: var(--ink-2); }
.rvex { margin: 0; font-size: var(--fs-md); color: var(--ink-2); }
.rvfa { margin: 0; font-size: var(--fs-xl); font-weight: 700; color: var(--teal); }
.rvexfa { margin: 0; color: var(--ink-2); }
.rates { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); }
.rate { font: inherit; display: grid; gap: 2px; justify-items: center; padding: 10px 8px; background: var(--card); color: var(--ink); border: 1.5px solid var(--hair); border-radius: var(--r-lg); cursor: pointer; transition: transform 0.2s var(--ease-out), border-color 0.2s var(--ease-out); }
.rate:hover { transform: translateY(-2px); border-color: var(--indigo); }
.rate .rl { font-weight: 700; }
.rate .rw { font-size: var(--fs-xs); color: var(--ink-2); }
.rate kbd { font-size: var(--fs-2xs); border: 1px solid var(--hair); border-radius: var(--r-xs); padding: 0 5px; color: var(--ink-2); }
.rate.r1 { border-color: color-mix(in srgb, var(--bad) 60%, var(--hair)); }
.rate.r4 { border-color: color-mix(in srgb, var(--ok) 60%, var(--hair)); }
html[data-motion="0"] .stile, html[data-motion="0"] .rate { transition-duration: 0.01ms; }
html[data-motion="0"] .stile:hover, html[data-motion="0"] .rate:hover { transform: none; }
.sheet + .tileactions { margin-block-start: 14px; }
#sres { margin-block-start: 16px; }

/* a notice paragraph is inline text: as a grid its leading icon took a row of its own and every link split the text
   into separate rows */
p.sheet:not(.hint) { display: block; }
p.sheet:not(.hint) > .ic:first-child { vertical-align: -0.2em; margin-inline-end: 4px; }