/* Shared product shell. Lesson pages keep their own skin variables and imagery. */
:root {
  --lesson-shell-sans: "Noto Sans SC Local", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --lesson-shell-serif: "Noto Serif SC Local", "Noto Serif SC", Georgia, serif;
  --lesson-shell-accent: #b85c3d;
  --lesson-shell-accent-strong: #214d3e;
  --lesson-shell-paper: #fff9e9;
  --lesson-shell-line: #c8d5cf;
  --lesson-shell-ink: #183b34;
  --lesson-shell-muted: #60746d;
  --lesson-shell-max: 1280px;
}

body[data-lesson-shell="v1"] {
  font-family: var(--lesson-shell-sans);
  font-size: 16px;
  line-height: 1.75;
}

body[data-lesson-shell="v1"] h1,
body[data-lesson-shell="v1"] h2,
body[data-lesson-shell="v1"] h3 {
  font-family: var(--lesson-shell-serif);
}

body[data-lesson-shell="v1"] main h1 {
  font-size: 64px;
  line-height: 1.08;
}

body[data-lesson-shell="v1"] main h2 {
  font-size: 40px;
  line-height: 1.2;
}

body[data-lesson-shell="v1"] main h3 {
  font-size: 22px;
}

body[data-lesson-shell="v1"] [data-shell-header] {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  min-width: 0;
  box-sizing: border-box;
  margin-inline: 0;
  padding: 9px clamp(16px, 4vw, 56px);
  color: #fff;
  background: var(--lesson-shell-accent-strong);
  border-bottom: 1px solid rgba(255, 255, 255, .18);
}

body[data-lesson-shell="v1"] [data-shell-header] > * {
  min-width: 0;
}

body[data-lesson-shell="v1"] [data-shell-header] > :last-child {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

body[data-lesson-shell="v1"] [data-shell-header] .brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  color: inherit;
  font-size: 14px;
  font-weight: 850;
  text-decoration: none;
}

body[data-lesson-shell="v1"] [data-shell-header] .brand-mark {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, .58);
  border-radius: 50%;
  font-family: var(--lesson-shell-serif);
}

body[data-lesson-shell="v1"] [data-shell-nav] {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  max-width: var(--lesson-shell-max);
  margin: 0 auto;
  padding: 10px clamp(16px, 4vw, 56px) 14px;
}

body[data-lesson-shell="v1"] [data-shell-nav] a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 14px;
  border: 1px solid var(--lesson-shell-line);
  border-radius: 4px;
  color: var(--lesson-shell-accent-strong);
  background: var(--lesson-shell-paper);
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
}

body[data-lesson-shell="v1"] [data-shell-nav] a:hover,
body[data-lesson-shell="v1"] [data-shell-nav] a:focus-visible,
body[data-lesson-shell="v1"] [data-shell-nav] a[aria-current="true"] {
  color: #fff;
  border-color: var(--lesson-shell-accent);
  background: var(--lesson-shell-accent);
}

body[data-lesson-shell="v1"] [data-action="full-audio"],
body[data-lesson-shell="v1"] [data-action="segment-audio"],
body[data-lesson-shell="v1"] [data-action="recite"] {
  min-height: 44px;
  font-family: var(--lesson-shell-sans);
  font-size: 14px;
  font-weight: 850;
  border-radius: 4px;
}

body[data-lesson-shell="v1"] #text,
body[data-lesson-shell="v1"] #recite,
body[data-lesson-shell="v1"] .paragraph {
  scroll-margin-top: var(--lesson-shell-stack-offset, 120px);
}

body[data-lesson-shell="v1"] #listen {
  scroll-margin-top: var(--lesson-shell-header-height, 58px);
}

body[data-lesson-shell="v1"] #listen {
  position: sticky;
  top: var(--lesson-shell-header-height, 58px);
  z-index: 15;
}

body[data-lesson-shell="v1"] .mode-switch {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border-radius: 999px;
  background: var(--lesson-shell-paper);
  border: 1px solid var(--lesson-shell-line);
}

body[data-lesson-shell="v1"] .mode-switch button {
  min-height: 44px;
  padding: 0 14px;
  color: var(--lesson-shell-muted);
  background: transparent;
  border: 0;
  border-radius: 999px;
  font-family: var(--lesson-shell-sans);
  font-size: 14px;
  font-weight: 850;
  white-space: nowrap;
}

body[data-lesson-shell="v1"] .mode-switch button[aria-pressed="true"] {
  color: #fff;
  background: var(--lesson-shell-accent-strong);
}

body[data-lesson-shell="v1"] .mode-switch button:focus-visible {
  outline: 3px solid #f2b84b;
  outline-offset: 2px;
}

body[data-lesson-shell="v1"] [data-action="full-audio"]:focus-visible,
body[data-lesson-shell="v1"] [data-action="segment-audio"]:focus-visible,
body[data-lesson-shell="v1"] [data-action="recite"]:focus-visible,
body[data-lesson-shell="v1"] [data-shell-nav] a:focus-visible {
  outline: 3px solid #f2b84b;
  outline-offset: 2px;
}

body[data-lesson-shell="v1"] .paragraph-text {
  font-size: 20px;
  line-height: 2.05;
}

body[data-lesson-shell="v1"] .paragraph > div > p {
  font-size: 20px;
  line-height: 2.05;
}

body[data-lesson-shell="v1"] .paragraph-title h3 {
  font-size: 22px;
}

body[data-lesson-shell="v1"] .section-kicker {
  font-family: var(--lesson-shell-sans);
}

@media (max-width: 600px) {
  body[data-lesson-shell="v1"] main h1 {
    font-size: 44px;
  }

  body[data-lesson-shell="v1"] main h2 {
    font-size: 30px;
  }

  body[data-lesson-shell="v1"] .paragraph-text,
  body[data-lesson-shell="v1"] .paragraph > div > p {
    font-size: 18px;
  }

  body[data-lesson-shell="v1"] [data-shell-header] {
    align-items: flex-start;
  }

  body[data-lesson-shell="v1"] #listen {
    top: var(--lesson-shell-header-height, 52px);
    padding-block: 0;
  }

  body[data-lesson-shell="v1"] #text,
  body[data-lesson-shell="v1"] #recite,
  body[data-lesson-shell="v1"] .paragraph {
    scroll-margin-top: var(--lesson-shell-stack-offset, 112px);
  }

  body[data-lesson-shell="v1"] [data-shell-header] .topbar-meta,
  body[data-lesson-shell="v1"] [data-shell-header] .top-meta {
    max-width: 10em;
    text-align: right;
    line-height: 1.35;
  }

  body[data-lesson-shell="v1"] [data-shell-nav] a {
    flex: 1 1 0;
    justify-content: center;
    padding-inline: 8px;
  }

  body[data-lesson-shell="v1"] .mode-switch {
    order: 2;
    flex: 1 1 100%;
  }

  body[data-lesson-shell="v1"] .mode-switch button {
    flex: 1 1 0;
  }

  body[data-lesson-shell="v1"] #listen .listen-inner,
  body[data-lesson-shell="v1"] #listen .reader-bar-inner {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px 10px;
    padding-block: 10px;
  }

  body[data-lesson-shell="v1"] #listen .progress-wrap,
  body[data-lesson-shell="v1"] #listen > div > .progress,
  body[data-lesson-shell="v1"] #listen > div > .time,
  body[data-lesson-shell="v1"] #listen .listen-status {
    display: none;
  }
}