/* ==========================================================================
   visiontherapy.cool — site layer
   Everything here sits on top of m3.css + m3-components.css and uses only
   M3 tokens. No hard-coded colours.
   ========================================================================== */

body {
  background: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
}

.vt-main { display: block; min-block-size: 60vh; }

.vt-section { padding-block: clamp(40px, 6vw, 72px); }
.vt-section--tight { padding-block: clamp(24px, 3.5vw, 40px); }
.vt-section--tonal { background: var(--md-sys-color-surface-container-low); }

.vt-muted { color: var(--md-sys-color-on-surface-variant); }
.vt-center { text-align: center; }
.vt-stack > * + * { margin-block-start: 16px; }
.vt-hidden { display: none !important; }

.vt-lede {
  font: var(--md-type-body-large, 400 16px/24px Roboto, sans-serif);
  font-size: clamp(1rem, .95rem + .35vw, 1.18rem);
  line-height: 1.6;
  color: var(--md-sys-color-on-surface-variant);
  max-width: 62ch;
}

.vt-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--md-sys-color-primary);
  margin-block-end: 10px;
}

.vt-skip {
  position: absolute;
  left: 12px; top: -80px;
  z-index: 200;
  padding: 12px 20px;
  border-radius: var(--md-sys-shape-corner-full);
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  text-decoration: none;
  transition: top 150ms var(--md-sys-motion-easing-standard, ease);
}
.vt-skip:focus { top: 12px; }

/* ============================================================== app bar */
.vt-appbar {
  position: sticky;
  top: 0;
  z-index: 100;
  block-size: auto;
  padding: 0;
  background: var(--md-sys-color-surface);
  transition: background-color 200ms var(--md-sys-motion-easing-standard, ease),
              box-shadow 200ms var(--md-sys-motion-easing-standard, ease);
}
.vt-appbar.is-scrolled {
  background: var(--md-sys-color-surface-container);
  box-shadow: 0 1px 2px 0 rgb(0 0 0 / .2), 0 1px 3px 1px rgb(0 0 0 / .1);
}
.vt-appbar__inner {
  flex: 1 1 auto;          /* .md-top-app-bar is display:flex — the inner must grow */
  display: flex;
  align-items: center;
  gap: 12px;
  min-inline-size: 0;
  min-block-size: 64px;
  max-inline-size: 1440px;
  margin-inline: auto;
  padding-inline: clamp(16px, 3vw, 48px);
}
.vt-appbar__actions { display: flex; align-items: center; gap: 4px; margin-inline-start: auto; }

.vt-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--md-sys-color-on-surface);
  font: var(--md-type-title-medium, 500 16px/24px Roboto, sans-serif);
  letter-spacing: -.01em;
  flex: none;
}
.vt-brand:hover { color: var(--md-sys-color-on-surface); }
.vt-brand__mark {
  inline-size: 34px; block-size: 34px;
  flex: none;
  display: grid; place-items: center;
  border-radius: var(--md-sys-shape-corner-full);
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}
.vt-brand__tld { color: var(--md-sys-color-on-surface-variant); font-weight: 400; }

/* ---- nav ---- */
.vt-nav { display: flex; align-items: center; gap: 2px; margin-inline-start: 12px; }
.vt-nav__item {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  block-size: 40px;
  padding-inline: 14px;
  border-radius: var(--md-sys-shape-corner-full);
  text-decoration: none;
  color: var(--md-sys-color-on-surface-variant);
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  white-space: nowrap;
  transition: background-color 150ms var(--md-sys-motion-easing-standard, ease),
              color 150ms var(--md-sys-motion-easing-standard, ease);
}
.vt-nav__item:hover {
  background: color-mix(in srgb, var(--md-sys-color-on-surface) 8%, transparent);
  color: var(--md-sys-color-on-surface);
}
.vt-nav__item.is-active {
  background: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}
.vt-nav__glyph { display: inline-flex; }
.vt-nav-toggle { display: none; }

@media (max-width: 1023px) {
  .vt-nav__label { display: none; }
  .vt-nav__item { padding-inline: 10px; }
}
@media (max-width: 839px) {
  .vt-nav-toggle { display: inline-flex; }
  .vt-nav {
    display: none;
    position: absolute;
    inset-inline: 0;
    top: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    margin: 0;
    padding: 8px 12px 16px;
    background: var(--md-sys-color-surface-container);
    border-block-end: 1px solid var(--md-sys-color-outline-variant);
    box-shadow: 0 4px 8px 3px rgb(0 0 0 / .15);
  }
  .vt-nav.is-open { display: flex; }
  .vt-nav__item { block-size: 52px; padding-inline: 16px; border-radius: var(--md-sys-shape-corner-large); }
  .vt-nav__label { display: inline; }
}

/* ================================================================= hero */
.vt-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(40px, 7vw, 88px) clamp(36px, 5vw, 64px);
  background:
    radial-gradient(120% 100% at 8% -20%, var(--md-sys-color-primary-container), transparent 58%),
    radial-gradient(100% 90% at 96% 0%, var(--md-sys-color-tertiary-container), transparent 55%),
    var(--md-sys-color-surface);
}
html[data-theme="dark"] .vt-hero {
  background:
    radial-gradient(120% 100% at 8% -20%, color-mix(in srgb, var(--md-sys-color-primary-container) 55%, transparent), transparent 58%),
    radial-gradient(100% 90% at 96% 0%, color-mix(in srgb, var(--md-sys-color-tertiary-container) 40%, transparent), transparent 55%),
    var(--md-sys-color-surface);
}
.vt-hero__grid {
  display: grid;
  gap: 40px;
  grid-template-columns: minmax(0, 1fr);
  align-items: center;
}
@media (min-width: 960px) {
  .vt-hero__grid { grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: 56px; }
}
.vt-hero h1 { max-width: 22ch; margin-block-end: 20px; text-wrap: balance; }
.vt-hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin-block-start: 28px; }

.vt-stats { display: flex; flex-wrap: wrap; gap: 28px 36px; margin-block-start: 36px; }
.vt-stat__n {
  font: var(--md-type-headline-medium, 400 28px/36px Roboto, sans-serif);
  font-weight: 500;
  line-height: 1;
  color: var(--md-sys-color-on-surface);
}
.vt-stat__l {
  margin-block-start: 6px;
  font: var(--md-type-label-medium, 500 12px/16px Roboto, sans-serif);
  color: var(--md-sys-color-on-surface-variant);
}

.vt-hero__fig { margin: 0; }
.vt-hero__fig svg { width: 100%; height: auto; overflow: visible; }
@media (max-width: 959px) { .vt-hero__fig { display: none; } }

/* ------------------------------------------------------------ trust row */
.vt-trust {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  padding-block: 18px;
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
  color: var(--md-sys-color-on-surface-variant);
}
.vt-trust span { display: inline-flex; align-items: center; gap: 8px; }
.vt-trust .md-icon { color: var(--md-sys-color-primary); }

/* ================================================================ grids */
.vt-grid { display: grid; gap: 16px; }
.vt-grid--2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr)); }
.vt-grid--3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); }
.vt-grid--4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr)); }
/* A lone card in an auto-fit track would stretch the full width; cap it. */
.vt-grid--3 > :only-child, .vt-grid--2 > :only-child { max-inline-size: 520px; }

.vt-section-head {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 24px;
  align-items: flex-end;
  justify-content: space-between;
  margin-block-end: 24px;
}
.vt-section-head p { margin: 8px 0 0; }

/* ================================================================= tags */
.vt-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  block-size: 24px;
  padding-inline: 10px;
  border-radius: var(--md-sys-shape-corner-small);
  font: var(--md-type-label-medium, 500 12px/16px Roboto, sans-serif);
  white-space: nowrap;
  background: var(--md-sys-color-surface-container-highest);
  color: var(--md-sys-color-on-surface-variant);
}
.vt-tag .md-icon, .vt-tag svg { flex: none; }
.vt-tag--cat[data-tone="primary"]   { background: var(--md-sys-color-primary-container);   color: var(--md-sys-color-on-primary-container); }
.vt-tag--cat[data-tone="secondary"] { background: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.vt-tag--cat[data-tone="tertiary"]  { background: var(--md-sys-color-tertiary-container);  color: var(--md-sys-color-on-tertiary-container); }
.vt-tag--screen  { background: var(--md-sys-color-tertiary-container); color: var(--md-sys-color-on-tertiary-container); }
.vt-tag--partial { background: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.vt-tag--gear    { background: var(--md-sys-color-surface-container-highest); color: var(--md-sys-color-on-surface-variant); }
.vt-tags { display: flex; flex-wrap: wrap; gap: 6px; }

/* ======================================================= exercise cards */
.vt-ex-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
  block-size: 100%;
}
.vt-ex-card__tags { display: flex; flex-wrap: wrap; gap: 6px; }
.vt-ex-card__name { margin: 2px 0 0; }
.vt-ex-card__sum { margin: 0; flex: 1 1 auto; }
.vt-ex-card__foot {
  display: flex;
  gap: 16px;
  align-items: center;
  padding-block-start: 12px;
  border-block-start: 1px solid var(--md-sys-color-outline-variant);
}
.vt-ex-card__foot span { display: inline-flex; align-items: center; gap: 5px; }

/* ================================================================ video */
.vt-video { margin: 0; display: grid; gap: 10px; }
.vt-video__frame {
  position: relative;
  aspect-ratio: 16 / 9;
  border-radius: var(--md-sys-shape-corner-medium);
  overflow: hidden;
  background: #0a0a0a;
  border: 1px solid var(--md-sys-color-outline-variant);
}
.vt-video__frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.vt-video__facade {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  border: 0; padding: 0; margin: 0;
  cursor: pointer;
  background-color: #0a0a0a;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.vt-video__facade::after {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgb(0 0 0 / .05), rgb(0 0 0 / .45));
}
.vt-video__play {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
  inline-size: 64px; block-size: 44px;
  display: grid; place-items: center;
  border-radius: var(--md-sys-shape-corner-medium);
  background: rgb(20 20 20 / .82);
  color: #fff;
  transition: background-color 150ms var(--md-sys-motion-easing-standard, ease),
              transform 150ms var(--md-sys-motion-easing-emphasized, ease);
}
.vt-video__facade:hover .vt-video__play { background: #ea3323; transform: translate(-50%, -50%) scale(1.06); }
.vt-video__facade:focus-visible { outline: 3px solid var(--md-sys-color-primary); outline-offset: -3px; }
.vt-video__meta { display: grid; gap: 2px; }
.vt-video__title { color: var(--md-sys-color-on-surface); }
.vt-video__chan { color: var(--md-sys-color-on-surface-variant); }
.vt-videos { display: grid; gap: 24px; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }

/* =============================================================== notice */
.vt-notice {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 16px 18px;
  border-radius: var(--md-sys-shape-corner-medium);
  background: var(--md-sys-color-surface-container-high);
  color: var(--md-sys-color-on-surface);
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
}
.vt-notice > .md-icon { flex: none; margin-block-start: 1px; }
.vt-notice__body > :last-child { margin-block-end: 0; }
.vt-notice__title { font-weight: 500; margin: 0 0 4px; }
.vt-notice--info  { background: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.vt-notice--tip   { background: var(--md-sys-color-tertiary-container);  color: var(--md-sys-color-on-tertiary-container); }
.vt-notice--warn  { background: color-mix(in srgb, var(--md-sys-color-error-container) 70%, var(--md-sys-color-surface)); color: var(--md-sys-color-on-error-container); }
.vt-notice--stop  { background: var(--md-sys-color-error-container); color: var(--md-sys-color-on-error-container); }
.vt-notice a { color: inherit; }

/* =========================================================== breadcrumb */
.vt-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-block-end: 16px;
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
  color: var(--md-sys-color-on-surface-variant);
}
.vt-crumbs a { color: var(--md-sys-color-on-surface-variant); text-decoration: none; }
.vt-crumbs a:hover { color: var(--md-sys-color-primary); text-decoration: underline; }

/* ========================================================= filter strip */
.vt-filters {
  position: sticky;
  top: 64px;
  z-index: 40;
  padding-block: 16px;
  background: var(--md-sys-color-surface);
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
}
.md-chip-set--scrolling { max-inline-size: 100%; }
.vt-filters__row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-block-end: 12px;
}
.vt-search { position: relative; flex: 1 1 260px; max-inline-size: 400px; }
.vt-search input {
  inline-size: 100%;
  block-size: 48px;
  padding-inline: 48px 16px;
  border: 0;
  border-radius: var(--md-sys-shape-corner-full);
  background: var(--md-sys-color-surface-container-high);
  color: var(--md-sys-color-on-surface);
  font: var(--md-type-body-large, 400 16px/24px Roboto, sans-serif);
}
.vt-search input::placeholder { color: var(--md-sys-color-on-surface-variant); }
.vt-search input:focus-visible { outline: 3px solid var(--md-sys-color-primary); outline-offset: 1px; }
.vt-search__icon {
  position: absolute;
  inset-inline-start: 16px; top: 50%;
  transform: translateY(-50%);
  color: var(--md-sys-color-on-surface-variant);
  pointer-events: none;
  display: inline-flex;
}
.vt-count { margin-inline-start: auto; color: var(--md-sys-color-on-surface-variant); }

/* ================================================== exercise detail page */
.vt-detail { display: grid; gap: 28px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 1000px) {
  .vt-detail { grid-template-columns: minmax(0, 1fr) 320px; gap: 48px; align-items: start; }
  .vt-detail__side { position: sticky; top: 84px; }
}
.vt-detail__main { min-inline-size: 0; }
.vt-detail__side { display: grid; gap: 16px; align-content: start; }
@media (max-width: 999px) { .vt-detail__side { order: -1; } }

.vt-block { margin-block-start: 40px; }
.vt-block > h2 { margin-block-end: 16px; }

.vt-specs { display: grid; gap: 0; }
.vt-specs > div {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 14px;
  padding-block: 12px;
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
}
.vt-specs > div:last-child { border-block-end: 0; }
.vt-specs dt, .vt-specs .k {
  font: var(--md-type-label-medium, 500 12px/16px Roboto, sans-serif);
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--md-sys-color-on-surface-variant);
  padding-block-start: 2px;
}
.vt-specs .v { font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif); }

/* ------------------------------------------------- screen/gear switcher */
.vt-modes { margin-block-start: 28px; }
.vt-modes__switch { margin-block-end: 20px; max-inline-size: 460px; }
.vt-modepanel[hidden] { display: none; }
.vt-mode-head {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  padding: 14px 18px;
  margin-block-end: 20px;
  border-radius: var(--md-sys-shape-corner-medium);
  background: var(--md-sys-color-surface-container);
}
.vt-mode-head__icon {
  inline-size: 40px; block-size: 40px;
  flex: none;
  display: grid; place-items: center;
  border-radius: var(--md-sys-shape-corner-full);
  background: var(--md-sys-color-tertiary-container);
  color: var(--md-sys-color-on-tertiary-container);
}
.vt-mode-head--gear .vt-mode-head__icon {
  background: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}
.vt-mode-head__text { flex: 1 1 240px; min-inline-size: 0; }
.vt-mode-head__text strong { display: block; }

/* numbered steps */
.vt-steps { counter-reset: st; list-style: none; padding: 0; margin: 0; }
.vt-steps > li {
  counter-increment: st;
  position: relative;
  padding-inline-start: 46px;
  margin-block-end: 18px;
}
.vt-steps > li::before {
  content: counter(st);
  position: absolute;
  inset-inline-start: 0; top: -2px;
  inline-size: 30px; block-size: 30px;
  display: grid; place-items: center;
  border-radius: var(--md-sys-shape-corner-full);
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
}

.vt-list { list-style: none; padding: 0; margin: 0; }
.vt-list li { position: relative; padding-inline-start: 22px; margin-block: 8px; }
.vt-list li::before {
  content: "";
  position: absolute;
  inset-inline-start: 2px; top: .62em;
  inline-size: 10px; block-size: 2px;
  border-radius: 1px;
  background: var(--md-sys-color-outline);
}
.vt-list--check li::before {
  inline-size: 6px; block-size: 11px; top: .32em;
  background: none;
  border: solid var(--md-sys-color-primary);
  border-width: 0 2.2px 2.2px 0;
  transform: rotate(42deg);
  border-radius: 0;
}

/* ============================================================== programs */
.vt-phase {
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-large);
  overflow: hidden;
  margin-block-end: 16px;
  background: var(--md-sys-color-surface);
}
.vt-phase__head {
  padding: 20px 22px;
  background: var(--md-sys-color-surface-container-low);
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
}
.vt-phase__weeks {
  font: var(--md-type-label-medium, 500 12px/16px Roboto, sans-serif);
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--md-sys-color-primary);
}
.vt-phase__head h3 { margin: 6px 0 6px; }
.vt-phase__body { padding: 20px 22px; }

.vt-session {
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-medium);
  padding: 16px 18px;
  margin-block-end: 14px;
  background: var(--md-sys-color-surface-container-lowest);
}
.vt-session__head {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  margin-block-end: 12px;
}
.vt-blocks { list-style: none; padding: 0; margin: 0; }
.vt-blocks li {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 14px;
  padding-block: 10px;
  border-block-start: 1px dashed var(--md-sys-color-outline-variant);
  align-items: start;
}
.vt-blocks li:first-child { border-block-start: 0; }
.vt-blocks__t {
  font-family: 'Roboto Mono', ui-monospace, monospace;
  font-size: 13px;
  color: var(--md-sys-color-on-surface-variant);
  padding-block-start: 2px;
}
.vt-blocks__n { font-weight: 500; text-decoration: none; color: var(--md-sys-color-on-surface); }
.vt-blocks__n:hover { color: var(--md-sys-color-primary); text-decoration: underline; }
.vt-blocks__d { margin: 3px 0 0; color: var(--md-sys-color-on-surface-variant); }

/* ========================================================= session player */
.vt-player {
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-extra-large);
  overflow: hidden;
  background: var(--md-sys-color-surface);
}
.vt-player__stage {
  padding: clamp(28px, 5vw, 52px) 24px;
  text-align: center;
  background: var(--md-sys-color-surface-container-low);
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
}
.vt-player__kicker {
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--md-sys-color-primary);
}
.vt-player__title { margin: 10px 0 0; }
.vt-player__clock {
  font-family: 'Roboto Mono', ui-monospace, monospace;
  font-variant-numeric: tabular-nums;
  font-size: clamp(3rem, 2rem + 7vw, 5.5rem);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -.04em;
  margin-block: 20px 12px;
  color: var(--md-sys-color-on-surface);
}
.vt-player__bar { max-inline-size: 440px; margin-inline: auto; }
.vt-player__note { max-inline-size: 56ch; margin: 14px auto 0; color: var(--md-sys-color-on-surface-variant); }
.vt-player__controls {
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: center;
  padding: 18px 24px;
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
}
.vt-player__body { padding: 12px 12px 16px; }
.vt-queue { list-style: none; padding: 0; margin: 0; }
.vt-queue li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
  padding: 12px 14px;
  border-radius: var(--md-sys-shape-corner-medium);
  cursor: pointer;
}
.vt-queue li:hover { background: var(--md-sys-color-surface-container); }
.vt-queue li.is-now { background: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); font-weight: 500; }
.vt-queue li.is-done { color: var(--md-sys-color-on-surface-variant); }
.vt-queue__n, .vt-queue__d {
  font-family: 'Roboto Mono', ui-monospace, monospace;
  font-size: 13px;
  color: inherit;
  opacity: .8;
}

/* ================================================================ quiz */
.vt-quiz-opts { display: grid; gap: 10px; }
.vt-quiz-opt {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 14px 16px;
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-medium);
  background: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  font: var(--md-type-body-large, 400 16px/24px Roboto, sans-serif);
  text-align: start;
  cursor: pointer;
  transition: background-color 150ms var(--md-sys-motion-easing-standard, ease),
              border-color 150ms var(--md-sys-motion-easing-standard, ease);
}
.vt-quiz-opt:hover { background: var(--md-sys-color-surface-container); }
.vt-quiz-opt[aria-pressed="true"] {
  background: var(--md-sys-color-secondary-container);
  border-color: var(--md-sys-color-secondary);
  color: var(--md-sys-color-on-secondary-container);
}
.vt-quiz-opt__box {
  inline-size: 20px; block-size: 20px;
  flex: none;
  margin-block-start: 2px;
  border: 2px solid var(--md-sys-color-outline);
  border-radius: var(--md-sys-shape-corner-extra-small);
  display: grid; place-items: center;
}
.vt-quiz-opt[aria-pressed="true"] .vt-quiz-opt__box {
  background: var(--md-sys-color-primary);
  border-color: var(--md-sys-color-primary);
}
.vt-quiz-opt[aria-pressed="true"] .vt-quiz-opt__box::after {
  content: "";
  inline-size: 5px; block-size: 10px;
  border: solid var(--md-sys-color-on-primary);
  border-width: 0 2px 2px 0;
  transform: rotate(42deg) translateY(-1px);
}

/* ============================================================== guides */
.vt-prose { max-inline-size: 74ch; }
.vt-prose h2 { margin-block: 2.2em .6em; }
.vt-prose h3 { margin-block: 1.6em .4em; }
.vt-prose p, .vt-prose ul, .vt-prose ol { margin-block: 0 1.1em; }
.vt-prose > p:first-child { font-size: 1.08rem; color: var(--md-sys-color-on-surface-variant); }
.vt-prose li { margin-block: .35em; }
.vt-prose .vt-notice, .vt-prose .vt-video { margin-block: 1.8em; }
.vt-prose a { color: var(--md-sys-color-primary); }

.vt-toc {
  padding: 18px 22px;
  border-radius: var(--md-sys-shape-corner-medium);
  background: var(--md-sys-color-surface-container-low);
  margin-block: 28px;
}
.vt-toc h2 {
  margin: 0 0 8px;
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--md-sys-color-on-surface-variant);
}
.vt-toc ol { margin: 0; padding-inline-start: 1.3em; }
.vt-toc a { text-decoration: none; }
.vt-toc a:hover { text-decoration: underline; }

/* =============================================================== tables */
.vt-table-wrap { overflow-x: auto; margin-block-end: 1.2em; }
.vt-table { border-collapse: collapse; inline-size: 100%; min-inline-size: 520px; }
.vt-table th, .vt-table td {
  text-align: start;
  padding: 12px 16px;
  border-block-end: 1px solid var(--md-sys-color-outline-variant);
  vertical-align: top;
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
}
.vt-table th {
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  color: var(--md-sys-color-on-surface-variant);
  background: var(--md-sys-color-surface-container-low);
}
.vt-table tbody tr:last-child td { border-block-end: 0; }

/* ============================================================ divider */
.vt-rule {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-block: 40px 20px;
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--md-sys-color-on-surface-variant);
}
.vt-rule::after { content: ""; flex: 1; block-size: 1px; background: var(--md-sys-color-outline-variant); }

/* ================================================================ empty */
.vt-empty {
  text-align: center;
  padding: 64px 20px;
  color: var(--md-sys-color-on-surface-variant);
}
.vt-empty .md-icon { opacity: .5; }

/* =============================================================== footer */
.vt-footer {
  margin-block-start: 72px;
  padding-block: 48px 32px;
  background: var(--md-sys-color-surface-container-low);
  border-block-start: 1px solid var(--md-sys-color-outline-variant);
}
.vt-footer__grid {
  display: grid;
  gap: 32px;
  grid-template-columns: 1fr;
}
@media (min-width: 600px) {
  .vt-footer__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .vt-footer__brand { grid-column: 1 / -1; }
}
@media (min-width: 900px) {
  .vt-footer__grid { grid-template-columns: minmax(0, 1.6fr) repeat(3, minmax(0, 1fr)); }
  .vt-footer__brand { grid-column: auto; }
}
.vt-footer__brand p { margin: 14px 0 0; max-inline-size: 44ch; }
.vt-footer__h {
  margin: 0 0 12px;
  font: var(--md-type-label-large, 500 14px/20px Roboto, sans-serif);
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--md-sys-color-on-surface-variant);
}
.vt-footer__list { list-style: none; padding: 0; margin: 0; }
.vt-footer__list li { margin-block: 8px; }
.vt-footer__list a {
  color: var(--md-sys-color-on-surface-variant);
  text-decoration: none;
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
}
.vt-footer__list a:hover { color: var(--md-sys-color-primary); text-decoration: underline; }
.vt-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  justify-content: space-between;
  margin-block-start: 36px;
  padding-block-start: 24px;
  border-block-start: 1px solid var(--md-sys-color-outline-variant);
  font: var(--md-type-body-medium, 400 14px/20px Roboto, sans-serif);
  color: var(--md-sys-color-on-surface-variant);
}

/* ================================================================ print */
@media print {
  .vt-appbar, .vt-footer, .vt-filters, .vt-skip, .no-print { display: none !important; }
  body { background: #fff; color: #000; }
  a { color: #000; text-decoration: none; }
}