:root {
  --ink: #141414;
  --ink-soft: #2e2e2c;
  --paper: #fafaf9;
  --surface: #ffffff;
  --text-secondary: #52524e;
  --border: #dededb;
  --ink-muted-text: #a8a8a3;
  --shadow-card: none;
  --shadow-elevated: none;
  --radius-sm: 0;
  --radius-md: 0;
  --radius-lg: 0;
  --radius-pill: 0;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: 0;
}

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

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

button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
  padding: 14px 32px;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background 300ms ease, border-color 300ms ease, backdrop-filter 300ms ease;
}

.site-header.scrolled,
.site-header.nav-open {
  background: rgba(250, 250, 249, 0.94);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(14px);
}

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

.site-header.scrolled .nav-toggle span,
.site-header.nav-open .nav-toggle span {
  background: var(--ink);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  color: #ffffff;
  font-size: 18px;
  font-weight: 500;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.brand-mark svg {
  display: block;
  width: 100%;
  height: 100%;
  animation: ic-logo-spin 5s linear infinite;
  transform-origin: 50% 50%;
  will-change: transform;
}

.brand-mark rect {
  fill: transparent;
}

.brand-mark g {
  fill: currentColor;
}

@keyframes ic-logo-spin {
  0% {
    transform: rotate(0deg);
    animation-timing-function: cubic-bezier(0.33, 0, 0.67, 0.33);
  }

  40% {
    transform: rotate(240deg);
    animation-timing-function: linear;
  }

  60% {
    transform: rotate(480deg);
    animation-timing-function: cubic-bezier(0.33, 0.67, 0.67, 1);
  }

  100% {
    transform: rotate(720deg);
  }
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
  color: #ffffff;
  font-size: 14px;
  font-weight: 400;
}

.nav-links a {
  position: relative;
  padding-bottom: 3px;
  transition: opacity 200ms ease;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 220ms cubic-bezier(0.8, 0.05, 0.2, 0.95);
}

.nav-links a:hover::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin: 0 auto;
  border-radius: 2px;
  background: #ffffff;
  transition: background 200ms ease;
}

.nav-actions,
.button-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.button-row.center {
  justify-content: center;
}

.store-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  padding: 9px 18px;
  font-weight: 500;
  line-height: 1.1;
  white-space: nowrap;
  transition: background 350ms cubic-bezier(0.8, 0.05, 0.2, 0.95), color 350ms cubic-bezier(0.8, 0.05, 0.2, 0.95), border-color 350ms cubic-bezier(0.8, 0.05, 0.2, 0.95), transform 200ms ease, box-shadow 200ms ease;
}

.store-button.large {
  min-height: 54px;
  padding: 14px 24px;
}

.store-button.primary {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}

.store-button.ghost {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--border);
}

.store-button.primary:hover {
  background: var(--ink-soft);
  border-color: var(--ink-soft);
}

.store-button.ghost:hover {
  border-color: var(--ink);
}

.store-button:hover {
  transform: translateY(-2px);
}

.store-button:active {
  transform: translateY(1px);
  box-shadow: none;
}

.hero-section {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(460px, 1.15fr);
  gap: 46px;
  align-items: center;
  min-height: 100vh;
  padding: 128px max(24px, calc((100vw - 1180px) / 2)) 88px;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
}

/* Flat magazine-ink backdrop. */
.hero-section::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: none;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--ink);
  font-size: 15px;
  font-weight: 400;
}

.hero-content .eyebrow,
.section-heading.dark .eyebrow {
  color: var(--paper);
}

.hero-content h1 {
  max-width: 620px;
  margin: 0;
  font-size: 76px;
  line-height: 1.04;
  font-weight: 700;
  letter-spacing: 0;
}

.hero-en {
  margin: 16px 0 0;
  color: var(--paper);
  font-size: 27px;
  line-height: 1.2;
  font-weight: 400;
  letter-spacing: 0.2px;
}

.hero-copy {
  max-width: 540px;
  margin: 22px 0 34px;
  color: var(--ink-muted-text);
  font-size: 21px;
  line-height: 1.65;
}

.hero-product {
  position: relative;
  z-index: 2;
  min-height: 560px;
}

.hero-image {
  position: absolute;
  border-radius: var(--radius-lg);
  object-fit: cover;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-elevated);
}

.hero-image.main {
  right: 0;
  bottom: 0;
  width: 320px;
  height: 590px;
}

.hero-image.panel {
  left: 0;
  top: 40px;
  width: 320px;
  height: 590px;
}

.section-heading {
  width: min(860px, 100%);
  margin: 0 auto 96px;
  text-align: center;
}

.section-heading h2,
.features-intro h2,
.faq-copy h2,
.download-section h2 {
  margin: 0;
  color: var(--ink);
  font-size: 44px;
  line-height: 1.14;
  font-weight: 700;
  letter-spacing: 0;
}

.section-heading p:not(.eyebrow),
.features-intro p {
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.7;
}

.stats-section {
  padding: 180px 24px;
  background: var(--ink);
  color: var(--paper);
}

.stats-section .section-heading {
  margin-bottom: 96px;
}

.section-heading.dark h2,
.section-heading.dark p:not(.eyebrow) {
  color: var(--paper);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.stats-grid article {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 210px;
  padding: 40px 28px;
  border-radius: var(--radius-lg);
  background: var(--ink);
  border: 1px solid rgba(250, 250, 249, 0.22);
}

.stats-grid strong {
  display: block;
  color: var(--paper);
  font-size: 54px;
  line-height: 1;
  font-weight: 700;
}

.stats-grid span {
  display: block;
  margin-top: 16px;
  color: var(--ink-muted-text);
  font-weight: 700;
}

.features-section,
.source-section,
.faq-section {
  padding: 180px max(24px, calc((100vw - 1180px) / 2));
}

.features-section {
  background: var(--surface);
}

.features-intro {
  max-width: 860px;
  margin: 0 auto 96px;
  text-align: center;
}

.features-intro .button-row {
  justify-content: center;
}

.features-intro p {
  margin: 18px 0 28px;
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-item,
.faq-item {
  padding: 36px 28px;
  border-radius: var(--radius-md);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
}

.feature-item span {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  border-radius: var(--radius-pill);
  padding: 4px 12px;
  background: #f5f5f4;
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
}

.feature-item h3,
.faq-item h3 {
  margin: 18px 0 9px;
  color: var(--ink);
  font-size: 23px;
  line-height: 1.2;
}

.feature-item p,
.faq-item p {
  margin: 0;
  color: var(--text-secondary);
}

.faq-section {
  background: var(--surface);
}

.source-section {
  background: var(--surface);
  padding-top: 180px;
  padding-bottom: 180px;
}

.source-section .section-heading {
  margin-bottom: 96px;
}

/* 研报机构跑马灯：Collections 式分类滚动 */
.marquee-container {
  display: flex;
  flex-direction: column;
  gap: 18px;
  width: 100%;
  overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 7%, #000 93%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 7%, #000 93%, transparent);
}

.marquee-row {
  overflow: hidden;
  white-space: nowrap;
}

.marquee-content {
  display: inline-flex;
  align-items: center;
  gap: 28px;
  animation: marquee-left 40s linear infinite;
  will-change: transform;
}

.marquee-row:nth-child(1) .marquee-content {
  animation-duration: 38s;
}

.marquee-row:nth-child(2) .marquee-content {
  animation-duration: 46s;
}

.marquee-row:nth-child(3) .marquee-content {
  animation-duration: 42s;
}

.marquee-row.marquee-reverse .marquee-content {
  animation-name: marquee-right;
}

.marquee-container:hover .marquee-content {
  animation-play-state: paused;
}

@keyframes marquee-left {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-50%);
  }
}

@keyframes marquee-right {
  from {
    transform: translateX(-50%);
  }
  to {
    transform: translateX(0);
  }
}
.marquee-item {
  color: var(--ink);
  font-size: clamp(20px, 2.9vw, 34px);
  line-height: 1.1;
  font-weight: 400;
  white-space: nowrap;
}

.marquee-sep {
  color: var(--ink);
  font-size: 0.55em;
  user-select: none;
}

.source-cta {
  margin: 40px 0 0;
  text-align: center;
}

.source-more {
  margin-top: auto;
  padding-top: 22px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  transition: opacity 200ms ease;
}

.faq-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.faq-copy {
  margin-bottom: 34px;
}

.download-section {
  padding: 180px 24px;
  text-align: center;
  background: var(--ink);
  color: var(--paper);
}

.download-section h2 {
  margin-bottom: 24px;
  color: var(--paper);
}

.download-intro {
  max-width: 720px;
  margin: 0 auto 36px;
  color: var(--ink-muted-text);
  font-size: 17px;
  line-height: 1.75;
  text-align: center;
}

/* 痛点共鸣（#value 上半，新增） */
.value-section {
  padding: 180px max(24px, calc((100vw - 1180px) / 2));
  background: var(--paper);
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.pain-item {
  padding-top: 32px;
  padding-bottom: 8px;
  border-top: 3px solid var(--ink);
}

.pain-item h3 {
  margin: 0 0 10px;
  color: var(--ink);
  font-size: 22px;
  line-height: 1.2;
  font-weight: 700;
}

.pain-item p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 17px;
  line-height: 1.6;
}

/* 用户反馈（新增，占位模拟反馈） */
.testimonial-section {
  padding: 180px max(24px, calc((100vw - 1180px) / 2));
  background: var(--paper);
}

.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.testimonial-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 38px 30px;
  border-radius: var(--radius-md);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
}

.testimonial-card .tag {
  align-self: flex-start;
  border-radius: var(--radius-pill);
  padding: 4px 12px;
  background: #f5f5f4;
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
}

.testimonial-card h3 {
  margin: 0;
  color: var(--ink);
  font-size: 21px;
  line-height: 1.25;
  font-weight: 700;
}

.testimonial-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.6;
}

/* 产品功能：图文交替展示（feature-visual 内为占位 mockup） */
.features-showcase {
  padding: 180px max(24px, calc((100vw - 1180px) / 2));
  background: var(--paper);
}

.features-showcase .section-heading {
  margin-bottom: 16px;
}

.feature-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 64px;
  align-items: center;
  margin-top: 72px;
}

.feature-row.reverse .feature-visual {
  order: 2;
}

.feature-visual {
  display: flex;
  justify-content: center;
}

.feature-image {
  display: block;
  width: 100%;
  max-width: 440px;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

.feature-text h3 {
  margin: 0 0 18px;
  color: var(--ink);
  font-size: 38px;
  line-height: 1.14;
  font-weight: 500;
}

.feature-text p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 19px;
  line-height: 1.7;
}

/* 锚点跳转避开固定 header */
#value,
#features,
#sources,
#faq,
#about {
  scroll-margin-top: 92px;
}

/* FAQ 手风琴：一行一行点击展开 */
.faq-list {
  grid-template-columns: 1fr;
  gap: 14px;
}

.faq-item summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  list-style: none;
  cursor: pointer;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.3;
  font-weight: 700;
  transition: color 200ms ease;
}

.faq-item summary:hover {
  color: var(--ink);
}

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

.faq-item summary::after {
  content: "+";
  flex: 0 0 auto;
  color: var(--ink);
  font-size: 28px;
  line-height: 1;
  font-weight: 400;
}

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

.faq-item p {
  margin: 16px 0 0;
}

@media (max-width: 900px) {
.feature-row {
    grid-template-columns: 1fr;
    gap: 28px;
    margin-top: 56px;
  }

.feature-row.reverse .feature-visual {
    order: 0;
  }

.feature-image {
    max-width: 320px;
  }

.feature-text h3 {
    font-size: 28px;
  }
}

@media (max-width: 760px) {
.features-showcase {
    padding-top: 72px;
    padding-bottom: 72px;
  }
}

.site-footer {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  padding: 42px max(24px, calc((100vw - 1180px) / 2));
  background: var(--ink);
  color: var(--paper);
}

.site-footer strong {
  color: var(--paper);
  font-size: 20px;
}

.site-footer p {
  margin: 8px 0 0;
  color: var(--ink-muted-text);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  color: var(--ink-muted-text);
  font-weight: 400;
}

.footer-links a {
  transition: color 200ms ease;
}

.footer-links a:hover {
  color: var(--paper);
}

/* Scroll-reveal only applies once main.js tags <html class="js">; without JS all content stays visible. */
html.js .reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms cubic-bezier(0.8, 0.05, 0.2, 0.95), transform 600ms cubic-bezier(0.8, 0.05, 0.2, 0.95);
}

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

@media (prefers-reduced-motion: reduce) {
html {
    scroll-behavior: auto;
  }

*,
*::before,
*::after {
    transition: none !important;
    animation: none !important;
  }

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

@media (max-width: 1100px) {
.nav-toggle {
    display: flex;
  }

.nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 8px 24px 18px;
    background: var(--paper);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-card);
    color: var(--ink);
    font-size: 16px;
    display: none;
  }

.site-header.nav-open .nav-links {
    display: flex;
  }

.nav-links a {
    padding: 12px 0;
  }

.nav-links a::after {
    display: none;
  }

.hero-section {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 100px;
  }

.hero-content h1 {
    font-size: 58px;
  }

.hero-product {
    min-height: 620px;
  }

.stats-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

.features-section {
    grid-template-columns: 1fr;
  }

.features-intro {
    position: static;
  }
}

@media (max-width: 760px) {
.site-header {
    padding: 14px 18px;
  }

.brand {
    font-size: 16px;
  }

.brand-mark {
    width: 30px;
    height: 30px;
  }

.nav-actions {
    margin-left: auto;
  }

.nav-actions .store-button {
    display: none;
  }

.hero-section {
    padding: 180px 18px 0;
    gap: 28px;
  }

.hero-content h1 {
    font-size: 43px;
  }

.hero-en {
    margin: 12px 0 0;
    font-size: 20px;
  }

.hero-copy {
    margin: 18px 0 26px;
    font-size: 15px;
  }

.hero-product {
    min-height: 430px;
  }

.hero-image.panel {
    display: none;
  }

.hero-image.main {
    left: 50%;
    right: auto;
    bottom: 0;
    transform: translateX(-50%);
    width: min(280px, calc(100% - 40px));
    height: 420px;
  }

.stats-section,
.value-section,
.features-section,
.source-section,
.testimonial-section,
.faq-section,
.download-section {
    padding-top: 72px;
    padding-bottom: 72px;
  }

.section-heading,
.faq-copy {
    text-align: left;
  }

.section-heading h2,
.features-intro h2,
.faq-copy h2,
.download-section h2 {
    font-size: 34px;
  }

/* 移动端：kicker 标签与大标题、卡片标题与正文留白偏紧，统一放宽 */
.eyebrow {
    margin-bottom: 20px;
  }

.pain-item h3,
.feature-item h3 {
    margin-bottom: 14px;
  }

.stats-grid,
.pain-grid,
.feature-list,
.testimonial-grid,
.faq-list {
    grid-template-columns: 1fr;
  }

.faq-list {
    gap: 14px;
  }

.site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 430px) {
.nav-links {
    gap: 18px;
    font-size: 13px;
  }

.nav-actions .store-button.primary {
    min-height: 36px;
    padding: 8px 12px;
    font-size: 12px;
  }

.button-row {
    align-items: stretch;
  }

.button-row .store-button {
    width: 100%;
  }

.hero-content h1 {
    font-size: 37px;
  }

.stats-grid article {
    min-height: 150px;
  }

.stats-grid strong {
    font-size: 46px;
  }
}

.hero-section .store-button.primary,
.download-section .store-button.primary,
.site-header:not(.scrolled):not(.nav-open) .store-button.primary {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--paper);
}

.hero-section .store-button.ghost,
.download-section .store-button.ghost,
.site-header:not(.scrolled):not(.nav-open) .store-button.ghost {
  background: transparent;
  color: var(--paper);
  border-color: rgba(250, 250, 249, 0.4);
}

/* Hover states for the on-ink store buttons. */
.hero-section .store-button.primary:hover,
.download-section .store-button.primary:hover,
.site-header:not(.scrolled):not(.nav-open) .store-button.primary:hover {
  background: #ececea;
  border-color: #ececea;
}

.hero-section .store-button.ghost:hover,
.download-section .store-button.ghost:hover,
.site-header:not(.scrolled):not(.nav-open) .store-button.ghost:hover {
  background: rgba(250, 250, 249, 0.08);
  border-color: var(--paper);
}