/* 关关通·小学英语 营销首页样式（landing 专用，自包含，不 link app/css/site.css）。
    唯一视觉规格：docs/ISTUDY-FAMILY-VISUAL-CONSTITUTION.md（v1.3）。
    色值、字号、圆角、轨宽一律来自 app/css/tokens.css，本文件零裸取值。
    UI 重设计（ENG-UI-FACADE）：落地页与学习区共用一套组件词汇，引 site.css 复用。 */
@import url("app/css/tokens.css");
@import url("app/css/site.css");

.skip-link {
  position: absolute; inset-inline-start: 16px; top: -48px;
  background: var(--surface); color: var(--brand-strong);
  padding: 10px 22px; border-radius: var(--radius-pill); z-index: 90; text-decoration: none;
}
.skip-link:focus { top: 16px; }

* { box-sizing: border-box; }
html { font-size: 16px; }

body {
  margin: 0;
  background: var(--lavender);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--type-body);
  line-height: 1.65;
  overflow-wrap: break-word;
}

/* 暖白主站体，纸感方格底与 app 门面页同构 */
.site-shell {
  background-color: rgba(255, 253, 247, 0.96);
  background-image:
    linear-gradient(rgba(104, 70, 232, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(104, 70, 232, 0.025) 1px, transparent 1px);
  background-size: 22px 22px;
  width: min(100% - 24px, 1540px);
  margin-inline: auto;
  margin-block: 12px;
  border-radius: var(--radius-shell);
  overflow: clip;
}

h1, h2, h3 { color: var(--ink); margin: 0 0 10px; }
p { margin: 10px 0; }
img { max-width: 100%; }
.title-line { display: block; }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden; clip-path: inset(50%);
  white-space: nowrap;
}

:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }

/* ── 楷体关键词与日光黄短底线（每区块至多一个） ───────────────── */
.accent-script {
  position: relative; isolation: isolate; z-index: 0;
  display: inline-block;
  color: var(--brand);
  font-family: var(--font-accent);
  font-size: 1.02em;
  letter-spacing: -0.06em;
  line-height: 0.92;
}
.accent-word { position: relative; z-index: 1; }
.accent-brush {
  position: absolute; z-index: 0; inset-inline: -0.06em; inset-block-end: -0.04em;
  height: 0.28em; background: var(--sun); transform: rotate(-1deg);
}

/* ── 行动件 ──────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  border: 0; border-radius: var(--radius-pill); padding: 12px 22px;
  background: var(--brand); color: #FFFFFF; font-weight: 650;
  text-decoration: none; min-height: 44px; text-align: center;
}
.btn-lg { min-height: 52px; padding: 14px 28px; font-size: 1.03rem; }

@media (hover: hover) and (pointer: fine) {
  .btn { transition: var(--motion-feedback); }
  .btn:hover { background: var(--brand-strong); transform: translateY(-2px); box-shadow: var(--shadow-soft); }
  .step-card { transition: var(--motion-feedback); }
  .step-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-raised); }
  .letter-toggle { transition: var(--motion-feedback); }
  .letter-toggle:hover { background: var(--lavender); box-shadow: var(--shadow-soft); }
  .voice-play { transition: var(--motion-feedback); }
  .voice-play:hover { transform: scale(1.06); box-shadow: var(--shadow-soft); }
}

/* ── 1. 头部 ─────────────────────────────────────────────────── */
/* 左右内衬与正文轨同源推导（总纲 §4.1）：main 是 min(100% - 48px, var(--content)) 居中，
   等价于左右各留 max(24px, (100% - 内容轨)/2)。页头以前自写一套 clamp，宽档差 80px。 */
.site-header {
  display: flex; flex-wrap: wrap; gap: 10px 16px;
  align-items: center; justify-content: space-between;
  min-height: 74px;
  padding-block: 12px;
  padding-inline: max(24px, (100% - var(--content)) / 2);
  border-bottom: 1px solid var(--border);
}
.brand {
  display: inline-flex; align-items: center; gap: 9px; min-width: 0;
  font-weight: 800; color: var(--brand-strong);
  font-size: 1.28rem; letter-spacing: -0.02em;
}
.brand-mark {
  display: inline-grid; place-items: center; flex: 0 0 48px; width: 48px; height: 38px;
  border-radius: var(--radius-pill); background: var(--brand); color: #FFFFFF;
  font-family: var(--font-accent); font-size: 1.38rem; line-height: 1; font-weight: 700;
}
.brand-copy { display: inline-flex; flex-direction: column; min-width: 0; }
.brand-name { line-height: 1.15; }
.brand-tag {
  color: var(--ink-muted); font-size: var(--type-label);
  line-height: 1.2; font-weight: 650; letter-spacing: 0.02em;
}

/* ── 版心 ────────────────────────────────────────────────────── */
main {
  width: min(100% - 48px, var(--content));
  margin-inline: auto;
  padding-block: clamp(22px, 4vw, 52px) 0;
}

/* ── 2. Hero ─────────────────────────────────────────────────── */
.hero {
  display: grid; gap: clamp(26px, 4vw, 52px); align-items: center;
  background: linear-gradient(118deg, var(--hero-soft) 0%, var(--surface) 52%, var(--surface) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-hero);
  box-shadow: var(--shadow-raised);
  padding: clamp(26px, 4vw, 56px);
  overflow: hidden;
}
.hero-copy { min-width: 0; }
.eyebrow {
  display: flex; align-items: center; gap: 10px; margin: 0 0 16px;
  color: var(--brand-strong); font-size: var(--type-label); line-height: 1.3;
  font-weight: 780; letter-spacing: 0.06em;
}
.eyebrow-rule {
  flex: 0 0 28px; width: 28px; height: 4px;
  border-radius: var(--radius-pill); background: var(--coral);
}
/* 语义断行：两行各自可独立理解，字号按列宽收，任一档都不许把一行折断 */
.hero-title {
  margin: 0 0 20px;
  font-size: clamp(2.15rem, 4.6vw, 4.5rem);
  line-height: 1.06; letter-spacing: -0.075em; font-weight: 800;
}
.hero-lead {
  margin: 0 0 26px; max-inline-size: 36rem;
  font-size: var(--type-lead); line-height: 1.8; font-weight: 520; color: var(--ink-muted);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: center; }
.hero-note { font-size: var(--type-supporting); color: var(--ink-muted); }
.hero-art {
  position: relative; min-width: 0; min-height: 300px;
  display: flex; align-items: flex-end; justify-content: center;
}
/* 剪纸拱形舞台：人物立在胶囊上，与 app 门面页 Hero 同一手法 */
.hero-art::before {
  content: ""; position: absolute; z-index: 0;
  bottom: -46px; left: 50%; transform: translateX(-50%) rotate(-1deg);
  width: min(78%, 400px); height: 92%;
  background: var(--lavender); border-radius: var(--radius-pill);
}
.hero-art img {
  position: relative; z-index: 1;
  display: block; width: auto; max-width: 100%; height: auto; max-height: 460px;
}

/* ── 3. 四大支撑点条 ─────────────────────────────────────────── */
.supports { margin-top: var(--rhythm); }
.support-list {
  list-style: none; margin: 0; padding: 0;
  display: grid; gap: clamp(16px, 2vw, 22px);
}
.support {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-panel); padding: clamp(20px, 2.4vw, 28px);
  box-shadow: var(--shadow-soft);
}
.support-num {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  border-radius: var(--radius-pill); background: var(--lavender);
  color: var(--brand-strong); font-weight: 800; font-size: 0.9rem;
}
.support h3 {
  margin: 14px 0 8px;
  font-size: 1.22rem; line-height: 1.25; letter-spacing: -0.03em; font-weight: 780;
}
.support p { margin: 0; font-size: var(--type-supporting); line-height: 1.7; color: var(--ink-muted); }

/* ── 4. 深紫叙事面板 ─────────────────────────────────────────── */
.story-panel {
  margin-top: var(--rhythm);
  background: var(--dark-panel);
  border-radius: var(--radius-hero);
  padding: clamp(30px, 5vw, 72px);
  display: grid; gap: clamp(26px, 4vw, 56px); align-items: center;
  color: #FFFFFF;
}
.story-copy { min-width: 0; }
.story-eyebrow {
  margin: 0 0 16px; color: var(--sun);
  font-size: var(--type-label); font-weight: 800; letter-spacing: 0.08em;
}
/* 面板标题下限按窄屏列宽收（token 的 2.55rem 下限是为宽列定的，窄屏会折断语义行） */
.story-title {
  margin: 0 0 20px; color: #FFFFFF;
  font-size: clamp(1.7rem, 3.6vw, 4.1rem);
  line-height: 1.12; letter-spacing: -0.055em; font-weight: 800;
}
.story-body {
  margin: 0 0 14px; max-inline-size: 36em;
  font-size: var(--type-body); line-height: 1.8; color: rgba(255, 255, 255, 0.86);
}
.story-body:last-child { margin-bottom: 0; }

.card-label {
  margin: 0 0 12px;
  font-size: var(--type-label); font-weight: 780; letter-spacing: 0.06em;
}
.voice-card {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius-panel);
  padding: clamp(20px, 2.6vw, 28px);
  min-width: 0;
}
.voice-card .card-label { color: rgba(255, 255, 255, 0.72); }
/* 无脚本时露出的原生控件；landing.js 接管后由 .is-enhanced 换成自定义皮肤。 */
.voice-audio { display: block; width: 100%; max-width: 100%; margin-bottom: 14px; }
.voice-shell { display: none; }
.voice-card.is-enhanced .voice-audio { display: none; }
.voice-card.is-enhanced .voice-shell { display: block; }
.voice-head { display: flex; align-items: center; gap: 14px; }
.voice-play {
  flex: 0 0 52px; width: 52px; height: 52px; border-radius: var(--radius-pill);
  background: var(--sun); display: inline-grid; place-items: center;
  border: 0; padding: 0; cursor: pointer; appearance: none;
}
.voice-icon { grid-area: 1 / 1; fill: var(--dark-panel); }
.voice-icon-pause,
.voice-card.is-playing .voice-icon-play { display: none; }
.voice-card.is-playing .voice-icon-pause { display: block; }
.voice-meta { display: flex; flex-direction: column; min-width: 0; }
.voice-name { font-size: 0.95rem; font-weight: 750; }
.voice-time { margin-top: 4px; font-size: 0.82rem; color: rgba(255, 255, 255, 0.66); }
.voice-track {
  margin: 18px 0 14px; height: 6px;
  border-radius: var(--radius-pill); background: rgba(255, 255, 255, 0.22);
}
.voice-progress {
  width: var(--voice-progress, 0%); height: 100%;
  border-radius: var(--radius-pill); background: var(--sun);
}
.voice-caption { margin: 0; font-size: 0.95rem; line-height: 1.75; color: rgba(255, 255, 255, 0.82); }
.voice-highlight { color: #FFFFFF; background: rgba(255, 201, 74, 0.28); border-radius: 6px; padding: 1px 4px; }

/* ── 5. 学习闭环四卡 ─────────────────────────────────────────── */
.steps { margin-top: var(--rhythm); }
.section-head {
  display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: 18px 32px; margin-bottom: clamp(26px, 3.5vw, 44px);
}
.section-title {
  margin: 0; min-width: 0;
  font-size: clamp(2.1rem, 5vw, 4.8rem);
  line-height: 1.14; letter-spacing: -0.065em; font-weight: 800;
}
.section-note {
  margin: 0; max-inline-size: 31rem; min-width: 0;
  font-size: var(--type-supporting); line-height: 1.7; color: var(--ink-muted);
}
.step-grid { display: grid; gap: clamp(16px, 2vw, 22px); }
.step-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-card); padding: clamp(22px, 2.6vw, 30px);
  box-shadow: var(--shadow-soft);
}
.step-art {
  display: block; width: 100%; height: auto; aspect-ratio: 1 / 1;
  margin: -8px 0 16px; border-radius: var(--radius-panel);
  background: var(--lavender); object-fit: cover;
}
.step-card h3 {
  margin: 14px 0 10px;
  font-size: clamp(1.2rem, 1.55vw, 1.55rem);
  line-height: 1.22; letter-spacing: -0.04em; font-weight: 780;
}
.step-card p { margin: 0; font-size: var(--type-supporting); line-height: 1.7; color: var(--ink-muted); }
.tag {
  display: inline-block; border-radius: var(--radius-pill); padding: 4px 13px;
  font-size: 0.82rem; font-weight: 720; background: var(--lavender); color: var(--ink);
  transform: rotate(-1.2deg);
}
.tag-lavender { background: var(--lavender); color: var(--brand-strong); }
.tag-sun { background: var(--sun); }
.tag-mint { background: var(--mint); }
.tag-coral { background: var(--coral); }

/* ── 6. 黄色重点面板 ─────────────────────────────────────────── */
.feature-panel {
  margin-top: var(--rhythm);
  background: var(--sun);
  border: 1px solid rgba(23, 19, 31, 0.18);
  border-radius: var(--radius-hero);
  padding: clamp(30px, 5vw, 68px);
  display: grid; gap: clamp(26px, 4vw, 52px); align-items: center;
}
.feature-copy { min-width: 0; }
.feature-eyebrow {
  margin: 0 0 16px; color: var(--ink);
  font-size: var(--type-label); font-weight: 800; letter-spacing: 0.08em;
}
.feature-title {
  margin: 0 0 18px;
  font-size: clamp(1.7rem, 3.6vw, 4.1rem);
  line-height: 1.12; letter-spacing: -0.055em; font-weight: 800;
}
.feature-body { margin: 0; max-inline-size: 32em; font-size: var(--type-body); line-height: 1.8; color: var(--ink); }
.mastery-card {
  background: var(--canvas); border-radius: var(--radius-panel);
  padding: clamp(20px, 2.6vw, 28px); box-shadow: var(--shadow-soft); min-width: 0;
}
.mastery-card .card-label { color: var(--ink-muted); }
.mastery-rows { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.mastery-row { display: flex; flex-wrap: wrap; gap: 6px 12px; align-items: center; }
.row-name { flex: 0 0 3.2em; font-size: 0.9rem; font-weight: 750; }
.row-dots { display: inline-flex; gap: 5px; }
.dot { display: inline-block; width: 12px; height: 12px; border-radius: var(--radius-pill); }
.dot-ok { background: var(--ok); }
.dot-mid { background: var(--sun); }
.dot-none { background: var(--lavender-deep); }
.row-val { margin-inline-start: auto; font-size: 0.88rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.mastery-legend { margin: 14px 0 0; font-size: var(--type-label); line-height: 1.6; color: var(--ink-muted); }

/* ── 7. 致同行家长 ───────────────────────────────────────────── */
/* 信纸化：淡紫底座托一张居中暖白纸，装饰层（blob、圆点、胶带）只做错落，
   不参与阅读顺序也不接收指针；纸面本身不旋转，正文保持稳定对齐。 */
.letter {
  position: relative; overflow: hidden;
  margin-top: var(--rhythm);
  background: var(--lavender); border: 1px solid var(--lavender-deep);
  border-radius: var(--radius-hero);
  padding: clamp(30px, 5vw, 76px) clamp(20px, 4vw, 64px);
}
.letter-blob, .letter-dot { position: absolute; z-index: 0; display: block; pointer-events: none; }
.letter-blob-sun {
  inset-inline-start: -34px; inset-block-start: 8%;
  width: 128px; height: 128px; background: var(--sun);
  border-radius: 54% 46% 42% 58%;
}
.letter-blob-coral {
  inset-inline-end: -26px; inset-block-end: 12%;
  width: 96px; height: 96px; background: var(--coral);
  border-radius: 44% 56% 60% 40%; opacity: 0.85;
}
.letter-dot { width: 16px; height: 16px; border-radius: var(--radius-pill); }
.letter-dot-a { inset-inline-end: 12%; inset-block-start: 42px; background: var(--coral); }
.letter-dot-b { inset-inline-start: 16%; inset-block-end: 40px; background: var(--brand); opacity: 0.5; }

.letter-paper {
  position: relative; z-index: 1;
  max-inline-size: 680px; margin-inline: auto;
  background: var(--canvas);
  border-radius: var(--radius-panel);
  box-shadow: var(--shadow-raised);
  padding: clamp(30px, 4.4vw, 64px);
}
/* 胶带贴条：纯 CSS，压在纸面边缘，只旋转装饰本身 */
.letter-tape { position: absolute; z-index: 2; display: block; pointer-events: none; }
.letter-tape-top {
  inset-block-start: -13px; inset-inline-start: 50%;
  width: 132px; height: 27px; margin-inline-start: -66px;
  background: var(--sun); transform: rotate(-2deg);
}
.letter-tape-foot {
  inset-block-end: -11px; inset-inline-start: 34px;
  width: 92px; height: 23px;
  background: var(--coral); transform: rotate(1.5deg);
}
.letter-paper > .eyebrow { margin: 0 0 12px; }
.letter-title {
  position: relative;
  margin: 0 0 30px; padding-bottom: 14px;
  font-family: var(--font-accent);
  font-size: clamp(2rem, 3.2vw, 3rem);
  line-height: 1.15; letter-spacing: -0.04em; font-weight: 700; color: var(--brand-strong);
}
.letter-title::after {
  content: ""; position: absolute; inset-block-end: 0; inset-inline-start: 0;
  width: 76px; height: 5px; border-radius: var(--radius-pill); background: var(--sun);
}
.letter-body p { margin: 0 0 18px; font-size: var(--type-lead); line-height: 1.9; color: var(--ink); }
.letter-body p:last-child { margin-bottom: 0; }
.letter-body strong { font-weight: 800; }

/* 折叠：原生 details，零 JS。收起态只露信首段与「读全信」，其余段落仍在 DOM。 */
.letter-more { margin-block-start: 22px; }
.letter-toggle {
  display: inline-flex; align-items: center; gap: 9px;
  min-height: 44px; padding: 10px 22px;
  border: 1px solid var(--lavender-deep); border-radius: var(--radius-pill);
  background: var(--hero-soft); color: var(--brand-strong);
  font-size: var(--type-supporting); font-weight: 780; letter-spacing: 0.02em;
  cursor: pointer; list-style: none;
}
.letter-toggle::-webkit-details-marker { display: none; }
.letter-toggle::marker { content: ""; }
.letter-toggle-arrow {
  flex: 0 0 auto; width: 8px; height: 8px; margin-block-start: -4px;
  border-inline-end: 2px solid currentColor; border-block-end: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 200ms cubic-bezier(0.2, 0, 0, 1);
}
.letter-more[open] .letter-toggle-arrow { transform: rotate(225deg); }
.letter-toggle-less { display: none; }
.letter-more[open] .letter-toggle-more { display: none; }
.letter-more[open] .letter-toggle-less { display: inline; }
.letter-more[open] .letter-body { margin-block-start: 24px; }
.letter-more[open] > .letter-body,
.letter-more[open] > .letter-sign { animation: letter-reveal 220ms cubic-bezier(0.2, 0, 0, 1); }
@keyframes letter-reveal {
  from { opacity: 0; transform: translateY(-6px); }
}
.letter-sign {
  position: relative; display: block;
  margin: 32px 0 0; padding-bottom: 12px;
  text-align: end;
  font-family: var(--font-accent);
  font-size: 1.34rem; letter-spacing: -0.02em;
  color: var(--brand-strong); font-weight: 700;
}
.letter-sign::after {
  content: ""; position: absolute; inset-block-end: 0; inset-inline-end: 0;
  width: 108px; height: 5px; border-radius: var(--radius-pill); background: var(--sun);
}

/* ── 8. 三原则卡 ─────────────────────────────────────────────── */
.principles {
  margin-top: var(--rhythm);
  display: grid; gap: clamp(16px, 2vw, 22px);
}
.principle { border-radius: var(--radius-panel); padding: clamp(22px, 2.6vw, 30px); }
.principle-lavender { background: var(--lavender); }
.principle-brand { background: var(--brand); }
.principle-brand h3 { color: #FFFFFF; }
.principle-brand p { color: rgba(255, 255, 255, 0.9); }
.principle-sun { background: var(--sun); }
.principle h3 {
  margin: 14px 0 10px;
  font-size: 1.25rem; line-height: 1.25; letter-spacing: -0.03em; font-weight: 800;
}
.principle p { margin: 0; font-size: var(--type-supporting); line-height: 1.7; color: var(--ink); }
.principle-num {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  border-radius: var(--radius-pill); font-weight: 800; font-size: 0.9rem;
}
.num-brand { background: var(--brand); color: #FFFFFF; }
.num-sun { background: var(--sun); color: var(--ink); }
.num-ink { background: var(--ink); color: #FFFFFF; }

/* ── 9. Closing ──────────────────────────────────────────────── */
.closing {
  position: relative; overflow: hidden;
  margin-block: var(--rhythm);
  background: var(--lavender); border: 1px solid var(--lavender-deep);
  border-radius: var(--radius-hero);
  padding: clamp(34px, 6vw, 80px);
  text-align: center;
}
.closing-blob { position: absolute; z-index: 0; display: block; pointer-events: none; }
.closing-blob-coral {
  inset-inline-start: -24px; inset-block-start: 38px;
  width: 90px; height: 90px; background: var(--coral);
  border-radius: 46% 54% 58% 42%; opacity: 0.8;
}
.closing-blob-sun {
  inset-inline-end: -18px; inset-block-end: -26px;
  width: 120px; height: 120px; background: var(--sun);
  border-radius: 52% 48% 44% 56%;
}
.closing h2, .closing p, .closing .btn { position: relative; z-index: 1; }
.closing h2 {
  margin: 0 0 14px; color: var(--brand-strong);
  font-size: clamp(1.9rem, 3.4vw, 3.1rem);
  line-height: 1.14; letter-spacing: -0.055em; font-weight: 800;
}
.closing p {
  margin: 0 auto 26px; max-inline-size: 30em;
  font-size: var(--type-body); line-height: 1.8; color: var(--ink-muted);
}

/* ── 10. 页脚 ────────────────────────────────────────────────── */
.site-footer {
  display: flex; flex-wrap: wrap; gap: 6px 22px; align-items: center;
  border-top: 1px solid var(--border);
  padding-block: 16px 22px;
  padding-inline: max(24px, (100% - var(--content)) / 2);
  color: var(--ink-muted); font-size: var(--type-supporting);
}
.footer-brand {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--brand-strong); font-weight: 700; min-height: 44px;
}
.footer-mark {
  display: inline-grid; place-items: center; width: 28px; height: 24px;
  border-radius: var(--radius-pill); background: var(--brand); color: #FFFFFF;
  font-family: var(--font-accent); font-size: 0.9rem; line-height: 1;
}
.footer-line { margin: 0; line-height: 1.6; }

/* ── 响应式 ──────────────────────────────────────────────────── */
/* 窄屏四卡改为左插画右文案（与站内入口卡同构），长页不被四张方图撑爆 */
@media (max-width: 760px) {
  .step-card {
    display: grid; grid-template-columns: minmax(0, 92px) minmax(0, 1fr);
    gap: 16px; align-items: start;
  }
  .step-art { grid-row: span 3; margin: 0; border-radius: var(--radius-inline); }
  .step-card .tag { justify-self: start; }
}

@media (min-width: 761px) {
  .support-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .step-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .principles { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .site-header { min-height: 88px; }
}

@media (min-width: 1024px) {
  .hero { grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr); }
  .story-panel { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
  .feature-panel { grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); }
  .support-list { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .step-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* 430px 及以下：主要行动纵向排列，大圆角降档 */
@media (max-width: 430px) {
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn { width: 100%; }
  .hero-note { text-align: center; }
  .closing .btn { width: 100%; }
  .hero, .story-panel, .feature-panel, .letter, .closing { border-radius: 34px; }
  /* 窄屏把信纸的两层内距收薄，正文行长优先，紫底仍留一条可见的边 */
  .letter { padding-inline: 14px; }
  .letter-paper { padding: 26px 20px 24px; border-radius: var(--radius-inline); }
  .letter-tape-top { width: 104px; height: 22px; margin-inline-start: -52px; inset-block-start: -10px; }
  .letter-tape-foot { width: 74px; height: 19px; inset-inline-start: 22px; inset-block-end: -9px; }
  .site-shell { border-radius: 28px; }
  main { width: min(100% - 28px, var(--content)); }
  /* 窄档正文轨改留 14px，页眉页脚跟着同一个数走 */
  .site-header, .site-footer { padding-inline: 14px; }
  /* 掌握度行收紧，保证「名称 + 圆点 + 文字」在一行读完 */
  .dot { width: 10px; height: 10px; }
  .row-dots { gap: 4px; }
  .row-name { flex-basis: 2.8em; }
  .row-val { font-size: 0.82rem; }
}

@media (max-width: 360px) {
  .hero-title { font-size: 1.75rem; }
  .section-title { font-size: 1.8rem; }
  .story-title, .feature-title { font-size: 1.6rem; }
  .row-val { margin-inline-start: 0; }
  .step-card { grid-template-columns: minmax(0, 76px) minmax(0, 1fr); gap: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

/* ---- 门面三页之落地页（ENG-UI-FACADE） ----
   landing.js 给 body 挂 landing-ng 后生效；选择器全部收在 body.landing-ng 下，
   旧样式继续服务零脚本兜底页。组件一律复用 site.css 词汇（paper-card、
   section-head、btn、bar-track、facade-hero 等），本段只做落地页自己的布局。 */

.landing-ng main { padding-block-end: 32px; }

/* 页头按钮跟上新按钮圆角档（DEV-005） */
.landing-ng .site-header .btn { border-radius: var(--radius-btn); }

/* 页头：与学习台同形（拱形舞台、装饰层、文案列），加一个真实进度块。
   高度预算 1.6 屏（capture-matrix 登记值）：标题一行、页头压到 360。 */
.landing-ng .lg-hero { margin-block: 0 24px; }
.landing-ng .facade-hero.has-art.lg-hero { min-height: 360px; }
.landing-ng .lg-hero .hero-copy { padding: clamp(24px, 3vw, 36px); }
.landing-ng .lg-hero-actions { align-items: center; }
.landing-ng .lg-hero-note { font-size: var(--type-supporting); color: var(--ink-muted); }
.landing-ng .lg-progress { margin: 0; max-inline-size: 26rem; }
.landing-ng .lg-progress-note { margin: 0; font-size: var(--type-supporting); color: var(--ink-muted); }
.landing-ng .lg-link {
  display: inline-flex; align-items: center; min-height: 44px; padding-inline: 4px;
  color: var(--brand-strong); font-weight: 600; text-decoration: none;
}
@media (hover: hover) and (pointer: fine) {
  .landing-ng .lg-link:hover { text-decoration: underline; text-underline-offset: 3px; }
}

/* 学什么：五个能力域行式列表，真值数量成列右对齐 */
.landing-ng .lg-domains { margin-block: 0 24px; }
.landing-ng .lg-domains .section-head { margin-block-end: 12px; }
.landing-ng .lg-total { margin: 0 0 0 auto; font-size: var(--type-supporting); white-space: nowrap; }
.landing-ng .lg-domain-list { list-style: none; margin: 0; padding: 0; }
.landing-ng .lg-domain-row {
  display: flex; align-items: center; gap: 12px; min-height: 56px; padding-block: 6px;
  border-top: 1px solid var(--border); min-inline-size: 0;
}
.landing-ng .lg-domain-row:last-child { border-bottom: 1px solid var(--border); }
.landing-ng .lg-domain-row > .obj { flex: 0 0 var(--obj-sm); }
.landing-ng .lg-domain-copy {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 12px;
  flex: 1 1 auto; min-inline-size: 0;
}
.landing-ng .lg-domain-title { font-size: var(--type-body); font-weight: 700; }
.landing-ng .lg-domain-desc { font-size: var(--type-supporting); color: var(--ink-muted); }
.landing-ng .lg-domain-meta {
  flex: 0 0 auto; min-inline-size: 8em; text-align: end;
  font-size: var(--type-supporting); color: var(--ink-muted);
  font-variant-numeric: tabular-nums; white-space: nowrap;
}
@media (width < 560px) {
  .landing-ng .lg-domain-row { flex-wrap: wrap; }
  .landing-ng .lg-domain-copy { flex: 1 1 calc(100% - var(--obj-sm) - 12px); }
  .landing-ng .lg-domain-meta {
    min-inline-size: 0; text-align: start;
    margin-inline-start: calc(var(--obj-sm) + 12px);
  }
  .landing-ng .lg-total { white-space: normal; text-align: end; }
}

/* 收尾：浅紫面板，三条给家长的保证加登录行动 */
.landing-ng .lg-closing {
  margin-block: 0; padding-block: clamp(20px, 3vw, 24px);
}
.landing-ng .lg-closing .section-head { margin-block-end: 12px; }
.landing-ng .lg-points { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.landing-ng .lg-points li { display: flex; align-items: center; gap: 8px; }
.landing-ng .lg-points svg { flex: 0 0 auto; color: var(--brand); }
.landing-ng .lg-closing-actions {
  display: flex; flex-wrap: wrap; gap: 10px 14px; align-items: center; margin-block-start: 16px;
}

/* 空状态与出错态：全站统一面板（组件规格 §5.14 与 §5.15），样式词汇在 site.css */
.landing-ng .facade-state { max-inline-size: 34rem; margin-inline: auto; }