:root {
  color-scheme: light;
  --ink: #112019;
  --muted: #66736d;
  --green: #00a184;
  --green-bright: #00deb5;
  --green-deep: #006d59;
  --mint: #d9fff3;
  --mint-soft: #effcf8;
  --yellow: #ffdc58;
  --yellow-deep: #b47a10;
  --blue-soft: #e7f5fb;
  --blue: #315f77;
  --paper: #ffffff;
  --line: #dbe3de;
  --dark: #13221b;
  --page: 1160px;
  --section-space: 112px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", sans-serif;
  letter-spacing: 0;
}

/* 嵌入博客后使用普通文档布局，避免博客全局 body 的 flex 规则改变产品页面高度。 */
body.notodo-page {
  display: block;
  min-height: 100vh;
}

/* 博客头部沿用全站结构；这里仅补足产品页需要的层级和白色背景。 */
.notodo-blog-header {
  position: relative;
  z-index: 70;
  background: var(--paper);
}

body.menu-open {
  overflow: hidden;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

/* 键盘导航时提供清晰焦点，鼠标点击不额外显示外框。 */
:focus-visible {
  outline: 3px solid var(--yellow);
  outline-offset: 4px;
}

.site-header {
  position: fixed;
  z-index: 50;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  padding: 0 max(24px, calc((100vw - var(--page)) / 2));
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: border-color 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(255, 255, 255, 0.97);
  box-shadow: 0 8px 28px rgba(17, 32, 25, 0.05);
}

/* 首屏导航与真实照片融合；滚动后恢复白底深色文字。 */
.site-header:not(.is-scrolled) .brand,
.site-header:not(.is-scrolled) .site-nav {
  color: white;
}

.site-header:not(.is-scrolled) .menu-button span {
  background: white;
}

.site-header:not(.is-scrolled) .nav-cta {
  background: white;
  color: var(--ink);
}

body.menu-open .site-header {
  background: white;
}

body.menu-open .site-header .brand,
body.menu-open .site-header .site-nav {
  color: var(--ink);
}

body.menu-open .site-header .menu-button span {
  background: var(--ink);
}

.brand,
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
}

.brand img,
.footer-brand img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  color: #37433d;
  font-size: 14px;
  font-weight: 650;
}

.site-nav a:not(.nav-cta):hover {
  color: var(--green-deep);
}

.nav-cta,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 750;
}

.nav-cta {
  min-height: 40px;
  background: var(--dark);
  color: white;
}

.button-dark {
  background: var(--dark);
  color: white;
}

.button-disabled {
  cursor: default;
  user-select: none;
}

.button:not(.button-disabled):hover,
.nav-cta:hover {
  background: #25372e;
}

.menu-button {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 0;
  background: transparent;
}

.menu-button span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 4px auto;
  background: var(--ink);
}

.hero {
  position: relative;
  /* 首屏保留约 96px 的下一屏提示，让场景沉浸但不把后续内容完全藏住。 */
  min-height: min(860px, calc(100svh - 96px));
  overflow: hidden;
  background: #273129;
  color: white;
}

.hero-photo,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-photo {
  z-index: 1;
  opacity: 0;
  object-fit: cover;
  object-position: center;
  transition: opacity 900ms ease;
}

.hero-photo.is-active {
  opacity: 1;
}

/* 单层暗色遮罩保证文字可读，同时保留右侧卧室与门外手机的真实细节。 */
.hero-shade {
  z-index: 2;
  background: rgba(13, 22, 17, 0.36);
}

.hero-inner {
  position: relative;
  z-index: 6;
  width: min(var(--page), calc(100% - 48px));
  min-height: min(860px, calc(100svh - 96px));
  margin: 0 auto;
}

.hero-copy {
  position: relative;
  z-index: 8;
  width: min(600px, 56%);
  padding: clamp(132px, 18vh, 190px) 0 76px;
}

.eyebrow,
.stage-label {
  margin: 0 0 14px;
  color: var(--green-deep);
  font-size: 14px;
  font-weight: 800;
}

.hero h1 {
  margin: 0;
  font-size: 108px;
  line-height: 0.9;
  font-weight: 850;
}

.hero-slogan {
  margin: 28px 0 0;
  font-size: 42px;
  line-height: 1.15;
  font-weight: 800;
}

.hero-detail {
  max-width: 500px;
  margin: 18px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: 18px;
  line-height: 1.7;
}

.hero .text-link {
  color: white;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 34px;
}

.notodo-store-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-width: 205px;
  min-height: 62px;
  padding: 10px 20px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 12px;
  background: linear-gradient(135deg, #00b894 0%, #008f75 100%);
  color: white;
  box-shadow: none;
  transition: transform 180ms ease, background 180ms ease;
}

.notodo-store-button:hover {
  transform: translateY(-2px);
  background: linear-gradient(135deg, #00d6ad 0%, #00a184 100%);
  box-shadow: none;
}

.notodo-store-button img {
  width: 25px;
  height: 30px;
  object-fit: contain;
}

.notodo-store-button span {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
}

.notodo-store-button strong {
  font-size: 17px;
  line-height: 1.15;
  font-weight: 720;
}

.notodo-store-button small {
  color: rgba(255, 255, 255, 0.7);
  font-size: 11px;
  line-height: 1.2;
}

/* 场景切换控件使用细线与文字，不遮挡真实照片。 */
.hero-scenes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  width: min(540px, 100%);
  margin: 38px 0 0;
}

.hero-scene-button {
  display: grid;
  gap: 5px;
  padding-top: 14px;
  border: 0;
  border-top: 5px solid rgba(255, 255, 255, 0.34);
  border-radius: 0;
  background: transparent;
  color: white;
  text-align: left;
  cursor: pointer;
  transition: border-color 240ms ease;
}

.hero-scene-button strong {
  font-size: 16px;
}

.hero-scene-button span {
  color: rgba(255, 255, 255, 0.72);
  font-size: 12px;
  font-weight: 700;
}

.hero-scene-button.is-active {
  border-top-color: var(--green-bright);
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: #174739;
  font-size: 15px;
  font-weight: 750;
}

.hero-note {
  position: absolute;
  z-index: 9;
  right: max(24px, calc((100vw - var(--page)) / 2));
  bottom: 20px;
  margin: 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}

.section {
  padding: var(--section-space) 24px;
}

main#top {
  position: relative;
}

.page-language-switch {
  position: absolute;
  z-index: 12;
  top: 40px;
  right: 40px;
  font-size: 13px;
  font-weight: 800;
}

.page-language-switch summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-width: 94px;
  height: 38px;
  padding: 0 14px;
  border: 1px solid rgba(255, 255, 255, 0.62);
  border-radius: 19px;
  background: rgba(20, 31, 27, 0.24);
  color: white;
  cursor: pointer;
  list-style: none;
  backdrop-filter: blur(10px);
}

.page-language-switch summary::-webkit-details-marker {
  display: none;
}

.page-language-switch summary:hover,
.page-language-switch[open] summary {
  background: rgba(20, 31, 27, 0.42);
}

.page-language-switch[open] summary span {
  transform: rotate(180deg);
}

.language-menu {
  position: absolute;
  top: 46px;
  right: 0;
  width: 132px;
  overflow: hidden;
  border: 1px solid rgba(18, 53, 45, 0.12);
  border-radius: 10px;
  background: white;
}

.language-menu a {
  display: block;
  padding: 11px 14px;
  color: var(--ink);
  text-decoration: none;
}

.language-menu a:hover {
  background: var(--mint-soft);
}

.language-menu a.is-current {
  color: var(--green-deep);
  font-weight: 850;
}

.section-inner {
  width: min(var(--page), 100%);
  margin: 0 auto;
}

.section-heading {
  max-width: 610px;
}

.section-heading h2,
.reward-copy h2,
.trust-block h2,
.download-section h2 {
  margin: 0;
  font-size: 48px;
  line-height: 1.15;
}

.section-heading > p:not(.eyebrow),
.reward-copy > p,
.trust-block > p,
.download-section > div > p:not(.eyebrow) {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.section-intro {
  /* 第一段减少顶部留白，与首屏共同形成可见的下一屏提示。 */
  padding-top: 58px;
  background: white;
}

.intro-layout {
  display: grid;
  /* 左侧承担产品解释，右侧示例主动收窄，避免标题过早换行。 */
  grid-template-columns: 1.18fr 0.82fr;
  gap: 72px;
  align-items: center;
}

.notodo-examples {
  border-top: 1px solid var(--line);
}

.example-row {
  display: grid;
  grid-template-columns: 42px 1fr auto;
  gap: 16px;
  align-items: center;
  min-height: 92px;
  border-bottom: 1px solid var(--line);
}

.example-row span {
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
}

.example-row strong {
  font-size: 24px;
}

.example-row em {
  color: var(--muted);
  font-size: 14px;
  font-style: normal;
}

.science-citation {
  display: grid;
  grid-template-columns: 106px minmax(260px, 0.95fr) minmax(360px, 1.25fr) 28px;
  gap: 28px;
  align-items: start;
  width: min(var(--page), 100%);
  margin: 64px auto 0;
  padding: 34px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.citation-index {
  color: var(--green-deep);
  font-size: 14px;
  font-weight: 850;
  line-height: 1.6;
}

.citation-finding {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

.citation-paper {
  display: grid;
  gap: 6px;
}

.citation-paper strong {
  color: var(--green-deep);
  font-size: 14px;
}

.citation-paper em {
  font-size: 15px;
  font-style: normal;
  font-weight: 750;
  line-height: 1.45;
}

.citation-paper small {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.citation-evidence {
  display: grid;
  gap: 8px;
}

.citation-evidence > strong {
  font-size: 16px;
}

.citation-evidence q {
  margin-top: 6px;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 16px;
  line-height: 1.55;
}

.citation-evidence small {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.citation-arrow {
  color: var(--green);
  font-size: 22px;
}

.section-journey {
  background: var(--mint-soft);
  padding-top: 64px;
  padding-bottom: 64px;
}

.journey-heading {
  max-width: none;
  margin: 0;
}

@media (min-width: 901px) {
  .journey-heading h2 {
    font-size: clamp(30px, 2.35vw, 38px);
  }

  .graduate-layout .section-heading {
    max-width: none;
  }

  .graduate-layout .section-heading h2 {
    font-size: clamp(36px, 3vw, 44px);
    white-space: nowrap;
  }
}

.journey-layout {
  display: grid;
  gap: 20px;
}

.milestone-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.milestone-tab {
  display: grid;
  gap: 10px;
  min-height: 104px;
  padding: 16px;
  border: 1px solid #cce6dd;
  border-radius: 8px;
  background: white;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}

.milestone-tab span {
  color: var(--muted);
  font-size: 13px;
}

.milestone-tab strong {
  font-size: 21px;
}

.milestone-tab.is-active {
  border-color: var(--green);
  background: white;
  color: var(--ink);
}

.milestone-tab.is-active span {
  color: var(--green-deep);
}

.milestone-progress {
  display: block;
  height: 9px;
  overflow: hidden;
  border-radius: 5px;
  background: #dce8e3;
}

.milestone-progress b {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--green);
  transition: width 380ms ease;
}

/* 当前阶段展示真实的局部进度，之前阶段完成，之后阶段保持为空。 */
.journey-layout[data-current-stage="7"] .milestone-tab[data-stage="7"] .milestone-progress b {
  width: 71%;
}

.journey-layout[data-current-stage="21"] .milestone-tab[data-stage="7"] .milestone-progress b,
.journey-layout[data-current-stage="66"] .milestone-tab[data-stage="7"] .milestone-progress b,
.journey-layout[data-current-stage="66"] .milestone-tab[data-stage="21"] .milestone-progress b {
  width: 100%;
}

.journey-layout[data-current-stage="21"] .milestone-tab[data-stage="21"] .milestone-progress b {
  width: 71%;
}

.journey-layout[data-current-stage="66"] .milestone-tab[data-stage="66"] .milestone-progress b {
  width: 85%;
}

.stage-panel {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  min-height: 520px;
  background: transparent;
}

.stage-content {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 26px;
  padding: 18px 0 18px 42px;
}

.stage-copy {
  padding: 0 8px;
}

.stage-copy h3 {
  margin: 0;
  font-size: 36px;
}

.stage-copy > p:not(.stage-label) {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.7;
}

.stage-copy .stage-message {
  color: var(--green-deep);
  font-weight: 750;
}

.progress-visual {
  position: relative;
  display: grid;
  place-items: center;
  background: transparent;
}

.progress-ring {
  display: flex;
  align-items: baseline;
  justify-content: center;
  width: 220px;
  height: 220px;
  padding-top: 62px;
  border: 22px solid var(--green);
  border-radius: 50%;
}

.progress-ring strong {
  font-size: 72px;
  line-height: 1;
}

.progress-ring span {
  margin-left: 6px;
  font-size: 18px;
  font-weight: 700;
}

.progress-visual > p {
  position: absolute;
  bottom: 28px;
  margin: 0;
  color: var(--green-deep);
  font-size: 13px;
  font-weight: 750;
}

.section-reward {
  background: var(--yellow);
}

.section-reward,
.section-graduate {
  padding-top: 40px;
  padding-bottom: 0px;
}

.section-widgets {
  background: white;
}

.reward-layout,
.graduate-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 100px;
  align-items: center;
}

.reward-copy blockquote {
  margin: 34px 0 0;
  padding-left: 20px;
  border-left: 4px solid var(--yellow-deep);
  color: #6f4d0d;
  font-size: 21px;
  font-weight: 800;
}

.device-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 790px;
  padding: 30px 20px 74px;
  overflow: hidden;
  border-radius: 8px;
}

.reward-device-stage {
  background: var(--yellow);
}

.graduate-device-stage {
  background: white;
}

/*
  手机成品图统一图片位：后续把真实整机 PNG 放入 assets，并将本容器替换为 img。
  max-width 控制桌面端大小，aspect-ratio 保证三处比例完全一致。
*/
.device-image-slot {
  position: relative;
  z-index: 2;
  width: min(100%, 390px);
  max-height: 680px;
  object-fit: contain;
}

.device-image-slot-compact {
  width: min(74%, 320px);
}

.device-caption {
  position: absolute;
  z-index: 3;
  right: auto;
  bottom: 18px;
  left: 50%;
  width: calc(100% - 40px);
  margin: 0;
  color: rgba(62, 46, 8, 0.78);
  font-size: 13px;
  font-weight: 750;
  line-height: 1.6;
  text-align: center;
  transform: translateX(-50%);
}

.reward-card {
  width: 100%;
  min-height: 100%;
  padding: 62px 24px 24px;
  border: 10px solid #ffdc58;
  border-radius: 42px;
  background: white;
  text-align: center;
  box-shadow: none;
}

.reward-card-top {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

.reward-card > p {
  margin: 66px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.reward-card h3,
.reward-card h4 {
  margin: 18px 0 0;
  font-size: 26px;
  line-height: 1.25;
}

.reward-card h4 {
  color: var(--yellow-deep);
}

.reward-card hr {
  width: 70%;
  margin: 46px auto 0;
  border: 0;
  border-top: 2px solid #e4bd41;
}

.reward-card small {
  display: block;
  margin-top: 70px;
  color: var(--muted);
}

.section-graduate {
  background: white;
}

.graduate-layout {
  grid-template-columns: 1.05fr 0.95fr;
}

.certificate-preview {
  position: relative;
  min-height: 100%;
  padding: 58px 14px 14px;
  background: var(--green-bright);
}

.certificate-paper {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 594px;
  padding: 32px 22px;
  background: white;
  text-align: center;
}

.certificate-paper h3 {
  margin: 34px 0 0;
  font-size: 34px;
}

.certificate-paper p {
  margin: 38px 0 0;
  color: var(--muted);
}

.certificate-paper h4,
.certificate-paper h5 {
  margin: 12px 0 0;
  font-size: 25px;
}

.certificate-paper h5 {
  color: var(--green);
}

.certificate-paper small {
  margin-top: auto;
  color: var(--muted);
}

.graduate-device-stage .device-caption {
  color: var(--green-deep);
}

.graduate-quote {
  color: var(--green-deep) !important;
  font-size: 22px !important;
  font-weight: 800;
}

.section-trust {
  background: var(--blue-soft);
}

.trust-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: #bfd8e4;
  border: 1px solid #bfd8e4;
}

.trust-block {
  min-height: 510px;
  padding: 48px;
  background: white;
}

.trust-number {
  display: block;
  margin: 42px 0 12px;
  color: var(--blue);
  font-size: 112px;
  line-height: 0.9;
  font-weight: 850;
}

.trust-block .fine-print {
  font-size: 14px;
}

.privacy-block {
  background: var(--dark);
  color: white;
}

.privacy-block .eyebrow {
  color: var(--green-bright);
}

.privacy-list {
  margin: 34px 0;
  padding: 0;
  list-style: none;
}

.privacy-list li {
  display: grid;
  grid-template-columns: 78px 1fr;
  gap: 18px;
  padding: 17px 0;
  border-bottom: 1px solid #30443a;
}

.privacy-list span {
  color: var(--green-bright);
  font-weight: 800;
}

.privacy-list strong {
  font-size: 15px;
}

.dark-link {
  color: white;
}

.widget-strip {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 70px;
  align-items: center;
  margin-top: 0;
}

.widget-strip h2 {
  margin: 0;
  font-size: 38px;
}

.widget-strip p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.7;
}

.widget-images {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 22px;
}

.widget-images img:first-child {
  width: 180px;
}

.widget-images img:last-child {
  width: 388px;
}

.section-faq {
  background: white;
}

.faq-layout {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 90px;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-list details {
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  position: relative;
  padding: 26px 48px 26px 0;
  font-size: 18px;
  font-weight: 750;
  list-style: none;
  cursor: pointer;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  position: absolute;
  top: 20px;
  right: 4px;
  font-size: 28px;
  font-weight: 400;
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list details p {
  margin: 0;
  padding: 0 48px 24px 0;
  color: var(--muted);
  line-height: 1.7;
}

.download-section {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 520px;
  padding: 72px max(24px, calc((100vw - var(--page)) / 2));
  overflow: hidden;
  background: var(--dark);
  color: white;
}

.download-section::after {
  position: absolute;
  z-index: 1;
  inset: 0;
  background: rgba(10, 20, 15, 0.48);
  content: "";
}

.download-section > img {
  position: absolute;
  z-index: 0;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 66%;
}

.download-section > div {
  position: relative;
  z-index: 2;
  max-width: 620px;
}

.download-section .eyebrow { color: #9df6d8; }

.download-section > div > p:not(.eyebrow) {
  color: rgba(255, 255, 255, 0.8);
}

.download-section .notodo-store-button {
  margin-top: 30px;
}

.site-footer {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 20px 36px;
  align-items: center;
  padding: 42px max(24px, calc((100vw - var(--page)) / 2));
  background: var(--dark);
  color: white;
}

.site-footer > p,
.site-footer > small {
  margin: 0;
  color: #b9c7c0;
}

.footer-links {
  display: flex;
  gap: 24px;
  font-size: 14px;
}

.site-footer small {
  grid-column: 1 / -1;
  padding-top: 16px;
  border-top: 1px solid #30443a;
}

.reveal {
  opacity: 1;
  transform: none;
}

.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 520ms ease, transform 520ms ease;
}

.js .reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* 隐私政策使用与主站相同的品牌语言，同时保持长文阅读的舒适宽度。 */
.legal-page {
  background: #f7faf8;
}

.legal-header {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  padding: 0 max(24px, calc((100vw - 900px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.legal-back {
  color: var(--green-deep);
  font-size: 14px;
  font-weight: 750;
}

.legal-content {
  width: min(900px, calc(100% - 40px));
  margin: 0 auto;
  padding: 84px 64px;
  background: white;
  font-size: 17px;
  line-height: 1.9;
}

.legal-content h1 {
  margin: 0 0 34px;
  font-size: 48px;
  line-height: 1.1;
}

.legal-content h3 {
  margin: 44px 0 12px;
  font-size: 24px;
}

.legal-content p,
.legal-content li {
  color: #48564f;
}

.legal-content strong {
  color: var(--ink);
}

.legal-content hr {
  margin: 42px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

.legal-content li + li {
  margin-top: 8px;
}

.legal-footer {
  padding: 36px 20px;
  background: var(--dark);
  color: white;
  text-align: center;
}

.legal-footer p {
  margin: 0;
}

/* 桌面短屏同步收紧首屏，避免路径信息与场景底部相撞。 */
@media (max-height: 700px) and (min-width: 641px) {
  .hero-copy { padding-top: 116px; }
  .hero h1 { font-size: 88px; }
  .hero-slogan { margin-top: 20px; font-size: 34px; }
  .hero-detail { margin-top: 12px; line-height: 1.5; }
  .hero-actions { margin-top: 22px; }
  .hero-scenes { margin-top: 30px; }
}

@media (max-width: 900px) {
  :root { --section-space: 84px; }

  .site-header { padding: 0 22px; }
  .menu-button { display: block; }

  .site-nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 22px;
    background: white;
  }

  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 18px 4px; border-bottom: 1px solid var(--line); font-size: 18px; }
  .site-nav .nav-cta { margin-top: 18px; border-bottom: 0; }

  .hero-inner {
    width: min(100% - 44px, 760px);
  }

  .hero-copy { width: 54%; }
  .hero h1 { font-size: 78px; }
  .hero-slogan { font-size: 31px; }

  .intro-layout,
  .reward-layout,
  .graduate-layout,
  .faq-layout,
  .widget-strip {
    grid-template-columns: 1fr;
    gap: 54px;
  }

  .journey-layout { grid-template-columns: 1fr; }
  .milestone-tabs { grid-template-columns: repeat(3, 1fr); }
  .milestone-tab { display: grid; min-height: 84px; }

  /* 平板宽度把研究结论移到第二行，避免论文标题和摘要互相挤压。 */
  .science-citation { grid-template-columns: 96px 1fr 28px; }
  .citation-evidence { grid-column: 2 / -1; }
  .citation-arrow { grid-column: 3; grid-row: 1; }

  .stage-panel { grid-template-columns: 0.95fr 1.05fr; }
  .stage-content { gap: 26px; padding: 18px 0 18px 30px; }
  .stage-copy { padding: 0; }
  .stage-copy h3 { font-size: 30px; }

  .reward-layout { grid-template-columns: 1fr 0.9fr; gap: 48px; }
  .graduate-layout { grid-template-columns: 0.9fr 1fr; gap: 48px; }
  .section-reward,
  .section-graduate,
  .section-journey { padding-top: 54px; padding-bottom: 54px; }
  .trust-grid { grid-template-columns: 1fr; }
  .widget-images { justify-content: flex-start; }

}

@media (max-width: 640px) {
  :root { --section-space: 70px; }

  .reward-layout {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .section-reward,
  .section-graduate,
  .section-journey { padding-top: 44px; padding-bottom: 44px; }

  .hero {
    min-height: calc(100svh - 72px);
  }

  .hero-inner {
    display: block;
    min-height: calc(100svh - 72px);
    width: calc(100% - 40px);
  }

  .hero-copy {
    position: relative;
    z-index: 8;
    width: 100%;
    padding: 112px 0 0;
  }

  .hero h1 { font-size: 68px; }
  .hero-slogan { margin-top: 18px; font-size: 29px; }
  .hero-detail { max-width: 330px; margin-top: 12px; font-size: 16px; line-height: 1.55; }

  .hero-actions {
    align-items: flex-start;
    flex-direction: column;
    gap: 14px;
    margin-top: 22px;
  }

  .hero-actions .notodo-store-button {
    min-width: 190px;
    min-height: 56px;
    padding: 8px 16px;
  }
  .hero-actions .text-link { font-size: 13px; }

  .hero-scenes {
    width: 330px;
    margin-top: 32px;
  }

  .hero-scene-button strong { font-size: 14px; }
  .hero-scene-button span { font-size: 11px; }

  .hero-photo { object-position: 52% center; }
  .hero-shade { background: rgba(10, 18, 14, 0.5); }
  .hero-note { right: 20px; bottom: 12px; font-size: 11px; }

  .section { padding-right: 20px; padding-left: 20px; }

  .section-heading h2,
  .reward-copy h2,
  .trust-block h2,
  .download-section h2 {
    font-size: 34px;
  }

  .section-heading > p:not(.eyebrow),
  .reward-copy > p,
  .trust-block > p,
  .download-section > div > p:not(.eyebrow) {
    font-size: 16px;
  }

  .example-row {
    grid-template-columns: 34px 1fr;
    min-height: 82px;
  }

  .example-row strong { font-size: 20px; }
  .example-row em { grid-column: 2; margin-top: -12px; }

  .science-citation {
    grid-template-columns: 70px 1fr 24px;
    gap: 14px;
    margin-top: 48px;
  }
  .citation-evidence { grid-column: 2 / -1; }
  .citation-arrow { grid-column: 3; grid-row: 1; }

  .milestone-tabs { gap: 6px; }
  .milestone-tab { min-height: 98px; padding: 12px 10px; }
  .milestone-tab span { font-size: 11px; }
  .milestone-tab strong { font-size: 16px; }

  .stage-panel {
    grid-template-columns: 1fr;
    grid-template-areas: "heading" "tabs" "visual" "copy";
  }
  .stage-content { display: contents; }
  .milestone-tabs { grid-area: tabs; padding: 24px 18px 0; }
  .progress-visual { grid-area: visual; min-height: 500px;padding-top:20px;padding-bottom:20px; }
  .journey-heading { grid-area: heading; padding: 0 18px; }
  .stage-copy { grid-area: copy; padding: 8px 18px 24px; }

  .device-stage { min-height: 730px; }
  .device-image-slot { width: min(100%, 340px); }
  .device-image-slot-compact { width: min(76%, 300px); }
  .reward-card { min-height: 100%; padding: 54px 18px 18px; border-width: 9px; }
  .reward-card > p { margin-top: 48px; }
  .reward-card h3, .reward-card h4 { font-size: 23px; }
  .reward-card hr { margin-top: 32px; }
  .reward-card small { margin-top: 46px; }
  .device-caption { right: auto; bottom: 12px; font-size: 11px; }

  .graduate-layout { display: flex; flex-direction: column-reverse; }
  .certificate-preview { width: 100%; min-height: 100%; padding-top: 54px; }
  .certificate-paper { min-height: 518px; }
  .certificate-paper h3 { font-size: 31px; }
  .certificate-paper h4, .certificate-paper h5 { font-size: 22px; }

  .trust-block { min-height: auto; padding: 34px 24px; }
  .trust-number { font-size: 88px; }

  .widget-images { align-items: flex-end; gap: 10px; }
  .widget-images img:first-child { width: 29%; }
  .widget-images img:last-child { width: 68%; }

  .download-section {
    min-height: 560px;
    padding: 64px 20px;
  }

  .download-section > img { object-position: 56% center; }

  .site-footer { grid-template-columns: 1fr; }
  .footer-links { margin-top: 10px; }

  .legal-header { padding: 0 20px; }
  .legal-content {
    width: 100%;
    padding: 58px 20px;
  }
  .legal-content h1 { font-size: 36px; }
  .legal-content h3 { font-size: 21px; }
}