:root { --yellow: #f9df73; --yellow-strong: #ffd806; --ink: #252525; --paper: #f7f7f5; --white: #fff; --copy: #666; --line: #e5e4df; --page: 71rem; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; line-height: 1.5; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, p, figure, ol { margin: 0; }
:focus-visible { outline: 3px solid #1b67b0; outline-offset: 3px; }
.page-shell { width: min(calc(100% - 2rem), var(--page)); margin-inline: auto; }
.site-header { position: sticky; z-index: 20; top: 0; background: var(--ink); }
.header-shell { min-height: 3.5rem; display: flex; align-items: center; justify-content: space-between; gap: 1.25rem; color: var(--white); }
.brand { display: inline-flex; align-items: center; gap: 0.55rem; color: var(--yellow-strong); font-size: 1.03rem; font-weight: 800; }
.brand-logo { width: 1.85rem; height: 1.85rem; flex: none; }
.site-nav { display: flex; gap: 1.05rem; font-size: 0.9375rem; }
.site-nav a { color: #f3f3f3; transition: color 160ms ease; }
.site-nav a:hover { color: var(--yellow-strong); }
.header-download { color: #f3f3f3; font-size: 0.9375rem; font-weight: 700; border: 1px solid #fff; padding: 0.45rem 1.25rem; border-radius: 4px; }
.header-download:hover { border-color: var(--yellow-strong); color: var(--yellow-strong); }
.hero { background-color: var(--yellow); background-image: url("../images/yellow-paper-texture.svg"); background-size: 12rem 12rem; }
.hero-layout { position: relative; min-height: 46.2rem; display: grid; grid-template-columns: minmax(24rem, 0.9fr) minmax(28rem, 1.1fr); align-items: center; gap: clamp(3rem, 8vw, 8.5rem); padding-block: 4.3rem; }
.hero-device-slot { position: relative; z-index: 1; width: min(100%, 30rem); height: 31rem; justify-self: center; margin: 0; }
.hero-visual { position: relative; z-index: 1; display: block; width: 100%; height: 100%; object-fit: contain; }
.hero-art-decor { position: absolute; z-index: 0; right: 2.55rem; bottom: 5.15rem; width: 32rem; height: 13.2rem; pointer-events: none; }
.hero-art-decor i { position: absolute; display: block; overflow: hidden; border: 1px solid rgb(37 37 37 / 16%); border-radius: 2px; background-color: rgb(249 223 115 / 68%); background-position: center; background-size: cover; box-shadow: 0 0.6rem 1.1rem rgb(94 69 0 / 9%); filter: grayscale(1) sepia(0.38) contrast(0.88); mix-blend-mode: multiply; opacity: 0.42; }
.hero-art-decor i::before { content: ""; position: absolute; inset: 0; background: linear-gradient(145deg, rgb(255 245 192 / 36%), rgb(249 223 115 / 18%)); }
.hero-art-decor i:first-child { bottom: 0.4rem; left: 0rem; width: 6.65rem; height: 9.5rem; background-image: url("../images/cover-01.webp"); transform: rotate(-13deg); }
.hero-art-decor i:nth-child(2) { bottom: 1.1rem; left: 5.7rem; z-index: 1; width: 6.95rem; height: 9.9rem; background-image: url("../images/cover-02.webp"); transform: rotate(-6deg); }
.hero-art-decor i:nth-child(3) { bottom: 2rem; left: 11.35rem; z-index: 2; width: 7.3rem; height: 10.4rem; background-image: url("../images/cover-03.webp"); transform: rotate(1deg); }
.hero-art-decor i:nth-child(4) { right: 7.15rem; bottom: 1rem; z-index: 3; width: 6.9rem; height: 9.85rem; background-image: url("../images/cover-04.webp"); transform: rotate(8deg); }
.hero-art-decor i:last-child { right: 0.45rem; bottom: 0.2rem; z-index: 4; width: 6.55rem; height: 9.3rem; background-image: url("../images/cover-05.webp"); transform: rotate(14deg); }
@media (max-width: 1100px) {
  .hero-art-decor { display: none; }
  .hero-layout { min-height: 38rem; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); gap: 2.5rem; }
}
.hero-content { position: relative; z-index: 1; max-width: 31rem; margin-bottom: 10rem; }
@media (max-width: 1100px) {
  .hero-content { margin-bottom: 0; }
}
h1, h2 { font-weight: 800; letter-spacing: 0; line-height: 1.22; }
h1 { font-size: clamp(2.45rem, 4.7vw, 3.85rem); }
.hero-summary { margin-top: 0.75rem; font-size: 1.05rem; }
.hero-ctas { display: flex; flex-wrap: wrap; gap: 0.7rem; margin-top: 1.9rem; }
.hero-cta { min-height: 3.5rem; display: inline-flex; align-items: center; justify-content: center; gap: 0.8rem; padding-inline: 1.25rem; border: 1px solid var(--ink); border-radius: 5px; font-size: 1rem; font-weight: 800; transition: background 160ms ease, color 160ms ease, transform 160ms ease; }
.hero-cta-icon { width: 1.12rem; height: 1.12rem; flex: none; }
.hero-cta:hover { transform: translateY(-2px); }
.hero-cta-primary { color: var(--white); background: var(--ink); box-shadow: 0 8px 0 rgb(37 37 37 / 12%); }
.hero-cta-primary:hover { background: #3d3d3a; }
.hero-cta-secondary { background: rgb(255 255 255 / 62%); }
.hero-cta-secondary:hover { background: var(--white); }
.download-actions { display: grid; gap: 0.65rem; min-width: 12rem; }
.platform-button { min-height: 5.5rem; display: grid; grid-template-columns: 2.25rem minmax(0, 1fr) 2rem; align-items: center; gap: 0.7rem; padding: 0.6rem 0.75rem; border: 1px solid rgb(37 37 37 / 18%); border-radius: 6px; color: var(--ink); box-shadow: 0 7px 0 rgb(37 37 37 / 12%); transition: background 160ms ease, color 160ms ease, box-shadow 160ms ease, transform 160ms ease; }
.platform-button:hover { transform: translateY(-2px); box-shadow: 0 9px 0 rgb(37 37 37 / 14%); }
.platform-button img { width: 2.25rem; height: 2.25rem; }
.platform-button-copy { display: grid; gap: 0.05rem; }
.platform-button-main { color: var(--white); border-color: var(--ink); background: var(--ink); }
.platform-button-main:hover { background: #3d3d3a; }
.platform-button-ios { background: rgb(255 255 255 / 90%); }
.platform-button-ios:hover { background: var(--white); }
.platform-label { display: block; font-size: 1rem; font-weight: 700; }
.platform-button strong { display: block; font-size: 0.9375rem; }
.platform-button-arrow { width: 2rem; height: 2rem; display: inline-flex; align-items: center; justify-content: center; border: 1px solid currentColor; border-radius: 50%; font-size: 1rem; line-height: 1; }
.content-section { padding-block: 6.5rem; }
.section-heading { max-width: 40rem; }
.center-heading { margin-inline: auto; text-align: center; }
h2 { font-size: clamp(2rem, 3.8vw, 3.25rem); }
.section-heading > p, .section-copy > p, .download-summary { margin-top: 1.2rem; color: var(--copy); font-size: 1rem; line-height: 1.8; }
.cover-slots { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0.8rem; margin-top: 3rem; }
.cover-slot { overflow: hidden; aspect-ratio: 0.69; border-radius: 2px; background: #ecece8; }
.cover-slot img { display: block; width: 100%; height: 100%; object-fit: cover; }
.reading { background: var(--white); }
.split-layout { display: grid; grid-template-columns: minmax(0, 1fr) minmax(22rem, 0.85fr); align-items: center; gap: clamp(3rem, 10vw, 10rem); }
.section-copy { max-width: 32rem; }
.reading-list { display: grid; gap: 0.9rem; margin-top: 2rem; padding: 0; list-style: none; }
.reading-list li { display: grid; grid-template-columns: 2.5rem 1fr; gap: 0.5rem; padding-top: 0.9rem; border-top: 1px solid var(--line); font-size: 1rem; }
.reading-list b { color: #9b830d; }
.reading-list span { color: var(--copy); }
.reader-device-stack { position: relative; width: min(100%, 31rem); height: 27.5rem; justify-self: center; }
.reader-device-stack figcaption { position: absolute; right: 0; bottom: -2rem; left: 0; color: var(--copy); text-align: center; font-size: 0.875rem; }
.reader-tablet { position: absolute; top: 0.8rem; left: 0; width: min(100%, 29rem); aspect-ratio: 1.48; padding: 1.25rem; border: 1px solid #deded8; border-radius: 0.8rem; background: #fff; box-shadow: 0 16px 34px rgb(37 37 37 / 9%); }
.tablet-camera { position: absolute; top: 0.47rem; left: 50%; width: 0.26rem; height: 0.26rem; border-radius: 50%; background: #c9c8c1; transform: translateX(-50%); }
.tablet-screen { height: 100%; overflow: hidden; border: 1px solid #efeee9; background: #fff; }
.tablet-header { display: grid; grid-template-columns: 1.4rem 1fr 1.4rem; align-items: center; min-height: 2rem; padding: 0 0.55rem; border-bottom: 1px solid #efeee9; color: #5e5d58; text-align: center; }
.tablet-header > span:first-child { font-size: 1.25rem; line-height: 1; }
.tablet-header > span:last-child { font-size: 0.72rem; letter-spacing: 0.09rem; }
.tablet-header b { font-size: 0.65rem; }
.tablet-canvas { position: relative; height: calc(100% - 4rem); overflow: hidden; background: #eef0ed; }
.tablet-canvas img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: center 40%; }
.tablet-canvas span, .reader-canvas span { position: absolute; right: 0.65rem; bottom: 0.65rem; padding: 0.2rem 0.45rem; color: #fff; background: rgb(37 37 37 / 72%); font-size: 0.58rem; }
.tablet-footer { display: grid; grid-template-columns: 1.4rem 1fr 2.4rem; align-items: center; height: 2rem; padding: 0 0.55rem; color: #77756f; font-size: 0.55rem; }
.tablet-footer i { position: relative; height: 2px; margin-inline: 0.55rem; background: #e9e8e2; }
.tablet-footer i::after { content: ""; position: absolute; inset: 0 auto 0 0; width: 26%; background: var(--yellow-strong); }
.reader-mockup { position: absolute; right: 0; bottom: 0; width: min(100%, 15rem); overflow: hidden; border: 1px solid #deded8; border-radius: 0.55rem; background: #fff; box-shadow: 0 16px 34px rgb(37 37 37 / 17%); }
.reader-status { display: flex; justify-content: space-between; padding: 0.42rem 0.7rem 0.18rem; color: #77756f; font-size: 0.52rem; }
.reader-header { display: grid; grid-template-columns: 1.7rem 1fr 1.7rem; align-items: center; min-height: 2.8rem; padding: 0 0.55rem; border-bottom: 1px solid #efeee9; text-align: center; }
.reader-header > span { color: #5e5d58; font-size: 1.25rem; line-height: 1; }
.reader-header > span:last-child { font-size: 0.75rem; letter-spacing: 0.1rem; }
.reader-header b, .reader-header small { display: block; }
.reader-header b { font-size: 0.69rem; }
.reader-header small { margin-top: 0.08rem; color: #96948d; font-size: 0.52rem; }
.reader-canvas { position: relative; height: 15.8rem; overflow: hidden; background: #eef0ed; }
.reader-canvas img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.reader-meta { display: flex; justify-content: space-between; padding: 0.48rem 0.65rem 0.3rem; color: #8c8981; font-size: 0.52rem; }
.reader-meta b { color: #5f5d56; font-weight: 600; }
.reader-progress { height: 3px; margin: 0 0.65rem; background: #e9e8e2; }
.reader-progress span { display: block; width: 26%; height: 100%; background: var(--yellow-strong); }
.reader-toolbar { display: flex; justify-content: space-around; padding: 0.72rem 0.4rem; color: #64625c; font-size: 0.58rem; }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 3.5rem; border-top: 1px solid #d8d7d1; }
.feature-grid article { min-height: 10rem; padding: 1.5rem 1.2rem 1.5rem 0; border-bottom: 1px solid #d8d7d1; }
.feature-grid article + article { padding-left: 1.2rem; border-left: 1px solid #d8d7d1; }
.feature-grid h3 { margin-top: 0; font-size: 1.12rem; }
.feature-grid p { margin-top: 0.65rem; color: var(--copy); font-size: 1rem; line-height: 1.75; }
.download-section { background-color: #f5d957; background-image: url("../images/yellow-paper-texture.svg"); background-position: 2.5rem 1.5rem; background-size: 12rem 12rem; }
.download-layout { min-height: 29rem; display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 5rem; padding-block: 4.5rem; }
.download-panel { width: 18rem; }
.faq { background: var(--white); }
.faq-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); align-items: stretch; gap: 1rem; margin-top: 3.5rem; }
.faq-card { min-height: 0; position: relative; overflow: hidden; padding: 1.4rem; border: 1px solid #deded8; border-radius: 6px; background: #fff; }
.faq-card h3 { font-size: 1.125rem; line-height: 1.5; }
.faq-card p { margin-top: 0.75rem; color: var(--copy); font-size: 1rem; line-height: 1.8; }
.site-footer { padding: 1.65rem 1rem; color: #898780; background: var(--paper); text-align: center; font-size: 0.875rem; }
@media (max-width: 760px) {
  .faq-grid { grid-template-columns: 1fr; gap: 0.8rem; margin-top: 2.7rem; }
  .faq-card { min-height: 0; padding: 1.25rem; }
}
.mobile-download { position: fixed; z-index: 30; right: 0; bottom: 0; left: 0; display: none; align-items: center; gap: 0.65rem; min-height: 4.4rem; padding: 0.55rem 0.8rem; border-top: 1px solid #e1e0da; background: rgb(255 255 255 / 97%); box-shadow: 0 -4px 20px rgb(37 37 37 / 7%); }
.mobile-logo { width: 2.35rem; height: 2.35rem; flex: none; }
.mobile-copy { min-width: 0; flex: 1; }
.mobile-copy b, .mobile-copy small { display: block; }
.mobile-copy b { font-size: 0.9375rem; }
.mobile-copy small { color: #77756e; font-size: 0.8125rem; }
.mobile-action { display: inline-flex; min-height: 2.65rem; align-items: center; justify-content: center; padding-inline: 1.1rem; border-radius: 4px; background: var(--yellow-strong); font-size: 0.9375rem; font-weight: 800; }
@media (max-width: 760px) {
  .site-header { position: static; }
  .site-nav { display: none; }
  .header-shell { min-height: 3.5rem; }
  .header-download { min-height: 2.5rem; display: inline-flex; align-items: center; padding-inline: 0.75rem; }
  .hero-layout { min-height: auto; grid-template-columns: 1fr; gap: 2.4rem; padding-block: 3.4rem 2rem; text-align: center; }
  .hero-device-slot { order: 2; width: min(100%, 19rem); height: 22rem; }
  .hero-content { width: 100%; max-width: 30rem; margin-inline: auto; margin-bottom: 0; }
  .hero-summary { max-width: 22rem; margin-inline: auto; font-size: 0.94rem; }
  .hero-ctas { width: min(100%, 19rem); margin: 1.65rem auto 0; flex-direction: column; }
  .hero-cta { min-height: 3.25rem; }
  .download-actions { width: min(100%, 19rem); }
  .platform-button { min-height: 5rem; text-align: left; }
  .content-section { padding-block: 4.75rem; }
  .cover-slots { grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 0.6rem; }
  .cover-slot { grid-column: span 2; }
  .cover-slot:nth-child(4) { grid-column: 2 / span 2; }
  .cover-slot:nth-child(5) { grid-column: 4 / span 2; }
  .split-layout { grid-template-columns: 1fr; gap: 2.8rem; }
  .reading .section-copy { margin-inline: auto; text-align: center; }
  .reading .reading-list { width: min(100%, 19rem); margin-inline: auto; text-align: left; }
  .reader-device-stack { width: min(100%, 24rem); height: 22rem; }
  .reader-tablet { top: 0; width: min(100%, 23rem); padding: 0.85rem; border-radius: 0.6rem; }
  .tablet-camera { top: 0.3rem; width: 0.2rem; height: 0.2rem; }
  .tablet-header { min-height: 1.5rem; }
  .tablet-canvas { height: calc(100% - 3rem); }
  .tablet-footer { height: 1.5rem; }
  .reader-mockup { width: min(100%, 11.2rem); }
  .reader-status { padding: 0.32rem 0.5rem 0.14rem; font-size: 0.42rem; }
  .reader-header { min-height: 2.15rem; padding: 0 0.42rem; }
  .reader-header b { font-size: 0.56rem; }
  .reader-header small { font-size: 0.42rem; }
  .reader-canvas { height: 11.5rem; }
  .reader-meta { padding: 0.36rem 0.48rem 0.24rem; font-size: 0.42rem; }
  .reader-progress { margin: 0 0.48rem; }
  .reader-toolbar { padding: 0.56rem 0.35rem; font-size: 0.47rem; }
  .feature-grid { grid-template-columns: 1fr 1fr; margin-top: 2.7rem; }
  .feature-grid article { min-height: 10rem; padding: 1rem; }
  .feature-grid article + article { border-left: 0; }
  .feature-grid article:nth-child(even) { border-left: 1px solid #d8d7d1; }
  .feature-grid h3 { margin-top: 0; }
  .download-layout { min-height: auto; grid-template-columns: 1fr; gap: 2.5rem; padding-block: 4.5rem 5.2rem; text-align: center; }
  .download-panel { width: min(100%, 19rem); margin-inline: auto; }
  .mobile-download { display: flex; }
  .site-footer { padding-bottom: 5.8rem; }
}
@media (max-width: 390px) {
  .page-shell { width: min(calc(100% - 1.5rem), var(--page)); }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-grid article:nth-child(even) { border-left: 0; }
  .feature-grid article { min-height: auto; }
}
@media (max-width: 340px) {
  h1 { font-size: 2.25rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; }
}
.reader-tablet { top: auto; bottom: 12px; }
.reader-mockup { border: 3px solid #deded8; border-radius: 1.45rem; box-shadow: 0 18px 36px rgb(37 37 37 / 22%); }
.reader-mockup::before { content: ""; position: absolute; z-index: 2; top: 0.6rem; left: 50%; width: 2.2rem; height: 0.7rem; border-radius: 0.72rem; background: #272727; transform: translateX(-50%); }
.reader-mockup::after { content: ""; position: absolute; z-index: 2; bottom: 0.2rem; left: 50%; width: 3.25rem; height: 0.16rem; border-radius: 1rem; background: #c5c5c3; transform: translateX(-50%); }
.reader-status, .reader-header, .reader-meta, .reader-toolbar { background: #fff; }
.reader-status { padding-top: 0.48rem; }
@media (max-width: 760px) {
  .reader-tablet { top: auto; bottom: 0.75rem; }
  .reader-mockup { padding: 0; border: 2px solid #deded8; border-radius: 1.12rem; }
  .reader-mockup::before { top: 0.46rem; width: 1.7rem; height: 0.55rem; border-radius: 0.55rem; }
  .reader-mockup::after { bottom: 0.15rem; width: 2.5rem; height: 0.12rem; }
  .reader-status { padding-top: 0.37rem; }
}
.reader-mockup { width: min(100%, 12rem); }
.reader-canvas { height: calc(100% - 9rem); }
.reader-status { border-radius: 1.14rem 1.14rem 0 0; overflow: hidden; }
.reader-toolbar { border-radius: 0 0 1.14rem 1.14rem; overflow: hidden; }
@media (max-width: 760px) {
  .reader-device-stack { width: min(calc(100% - 1rem), 22rem); }
  .reader-tablet { width: 100%; }
  .reader-mockup { right: 2rem; width: min(100%, 9.3rem); height: 20.15rem; }
  .reader-canvas { height: calc(100% - 7rem); }
  .reader-status { border-radius: 0.94rem 0.94rem 0 0; }
  .reader-toolbar { border-radius: 0 0 0.94rem 0.94rem; }
}