:root {
  --paper: #fffdf8;
  --paper-warm: #fff8ec;
  --ink: #3d281e;
  --muted: #806b5d;
  --orange: #f28d10;
  --orange-deep: #b95d08;
  --yellow: #ffcd27;
  --line: #eddfcc;
  --white: #ffffff;
  --radius: 5px;
  --page: min(1200px, calc(100% - 48px));
  --header-height: 72px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 18px);
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

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

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

button {
  font: inherit;
}

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

h1,
h2,
h3,
p,
ul,
figure {
  margin: 0;
}

ul {
  padding: 0;
  list-style: none;
}

.page-width {
  width: var(--page);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: var(--header-height);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.98);
}

.nav-shell {
  display: flex;
  align-items: center;
  min-height: var(--header-height);
  gap: 26px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 19px;
  font-weight: 800;
}

.brand img,
.footer-brand img {
  width: 36px;
  height: 36px;
  object-fit: contain;
}

.site-nav {
  margin: 0 auto;
}

.site-nav ul {
  display: flex;
  gap: 30px;
}

.site-nav a {
  display: block;
  padding: 23px 0 19px;
  border-bottom: 3px solid transparent;
  font-size: 14px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav .is-active {
  border-color: var(--orange);
  color: var(--orange-deep);
}

.nav-download,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 9px 17px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--yellow);
  font-size: 14px;
  font-weight: 800;
  transition: transform 160ms ease, background-color 160ms ease;
}

.nav-download:hover,
.nav-download:focus-visible,
.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  background: var(--orange);
}

.nav-download .icon {
  filter: brightness(0);
}

.menu-toggle {
  display: none;
}

.hero {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 480px;
  align-items: center;
  min-height: 580px;
  gap: 40px;
}

.hero-copy {
  padding: 80px 0;
}

.section-label {
  color: var(--orange-deep);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.1em;
}

.section-label::before {
  display: inline-block;
  width: 24px;
  height: 2px;
  margin: 0 9px 4px 0;
  background: var(--yellow);
  content: "";
}

.hero h1 {
  margin-top: 16px;
  font-size: 20px;
  line-height: 1.4;
  letter-spacing: 0;
}

.hero-summary {
  max-width: 470px;
  margin-top: 14px;
  overflow: hidden;
  color: var(--muted);
  font-size: 16px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.hero-actions {
  margin-top: 30px;
}

.hero .button {
  min-width: 160px;
}

.update-label {
  display: inline-block;
  margin-top: 10px;
  padding: 6px 9px;
  border-radius: var(--radius);
  color: var(--muted);
  background: var(--white);
  font-size: 12px;
  font-weight: 700;
}

.hero-visual {
  position: relative;
  justify-self: end;
  width: 480px;
  height: 515px;
}

.phone-frame {
  position: absolute;
  top: 10px;
  right: 0;
  width: 260px;
  padding: 11px;
  border: 12px solid #252527;
  border-radius: var(--radius);
  background: #252527;
  box-shadow: 16px 20px 32px rgba(78, 46, 20, 0.18);
}

.phone-frame img,
.reading-shot img,
.screen-grid img {
  width: 100%;
  height: auto;
  aspect-ratio: 9 / 16;
  object-fit: contain;
  background: var(--white);
}

.progress-card {
  position: absolute;
  bottom: 94px;
  left: 44px;
  z-index: 1;
  width: 280px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 10px 15px 28px rgba(78, 46, 20, 0.11);
}

.progress-card p,
.progress-card strong,
.progress-card b,
.progress-card span,
.progress-card small {
  display: block;
}

.progress-card p {
  font-size: 14px;
  font-weight: 800;
}

.progress-card strong {
  margin-top: 7px;
  font-size: 24px;
}

.progress {
  height: 6px;
  margin: 10px 0 13px;
  border-radius: var(--radius);
  background: #f1ede6;
}

.progress i {
  display: block;
  width: 36%;
  height: 100%;
  border-radius: var(--radius);
  background: var(--yellow);
}

.progress-card b {
  font-size: 12px;
}

.progress-card span,
.progress-card small {
  color: var(--muted);
  font-size: 12px;
}

.features,
.screenshots,
.reading,
.help,
.reviews {
  padding: 88px 0;
}

.section-head [id$="-title"],
.download-inner [id$="-title"] {
  margin-top: 8px;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.04em;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-top: 42px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature-grid article {
  display: grid;
  grid-template-columns: 46px 1fr;
  column-gap: 15px;
  padding: 30px 26px;
  border-right: 1px solid var(--line);
}

.feature-grid article:last-child {
  border-right: 0;
}

.feature-grid h3 {
  font-size: 17px;
}

.feature-grid p {
  grid-column: 2;
  margin-top: 7px;
  color: var(--muted);
  font-size: 13px;
}

.icon {
  display: inline-block;
  width: 20px;
  height: 20px;
  flex: 0 0 auto;
}

.icon::before {
  display: block;
  width: 100%;
  height: 100%;
  background-position: center;
  background-repeat: no-repeat;
  background-size: contain;
  content: "";
}

.icon-download::before {
  background-image: url("../icons/download.svg");
}

.icon-menu::before {
  background-image: url("../icons/menu.svg");
}

.icon-search::before {
  background-image: url("../icons/search.svg");
}

.icon-grid::before {
  background-image: url("../icons/grid.svg");
}

.icon-shelf::before {
  background-image: url("../icons/shelf.svg");
}

.icon-clock::before {
  background-image: url("../icons/clock.svg");
}

.icon-history::before {
  background-image: url("../icons/history.svg");
}

.icon-chevron::before {
  background-image: url("../icons/chevron.svg");
}

.icon-question::before {
  background-image: url("../icons/question.svg");
}

.feature-grid .icon {
  width: 40px;
  height: 40px;
  padding: 8px;
  border: 1px solid #f9cf8b;
  border-radius: var(--radius);
  background: #fff6e7;
}

.screenshots {
  background: var(--paper-warm);
}

.split-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
}

.split-head > p {
  max-width: 400px;
  color: var(--muted);
  font-size: 13px;
}

.screen-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 15px;
  margin-top: 38px;
}

.screen-grid figure {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.screen-grid figure > div {
  padding: 9px 9px 0;
}

.screen-grid figcaption {
  display: flex;
  gap: 8px;
  padding: 12px 11px 14px;
  border-top: 1px solid var(--line);
}

.screen-grid figcaption b {
  color: var(--orange-deep);
  font-size: 12px;
}

.screen-grid figcaption strong {
  font-size: 14px;
}

.reading-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 290px;
  align-items: center;
  gap: 80px;
}

.reading-info ul {
  margin-top: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.reading-info li {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 15px 18px;
  border-bottom: 1px solid var(--line);
}

.reading-info li:last-child {
  border-bottom: 0;
}

.reading-info li .icon {
  width: 24px;
  height: 24px;
}

.reading-info li b,
.reading-info li small {
  display: block;
}

.reading-info li b {
  font-size: 14px;
}

.reading-info li small {
  color: var(--muted);
  font-size: 12px;
}

.reading-shot {
  width: 260px;
  justify-self: center;
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper-warm);
}

.help {
  padding-top: 74px;
  background: #fffaf1;
}

.help-grid {
  max-width: none;
}

.help .section-head h2:not(.section-label) {
  font-size: 30px;
}

.faq-column,
.official-column {
  display: block;
}

.official-column {
  margin-top: 72px;
  padding-top: 0;
  border-top: 0;
}

.faq-list {
  display: grid;
  gap: 9px;
  max-width: 760px;
  margin: 26px auto 0;
}

.faq-list article,
.official-row {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.faq-list button,
.official-row button {
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 48px;
  padding: 11px 14px;
  border: 0;
  border-radius: var(--radius);
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  text-align: left;
}

.faq-list button .icon,
.official-row button .icon:last-child {
  margin-left: auto;
  transition: transform 160ms ease;
}

.faq-list button[aria-expanded="true"] .icon,
.official-row button[aria-expanded="true"] .icon:last-child {
  transform: rotate(180deg);
}

.faq-list article > div,
.official-row > div {
  padding: 0 14px 14px;
  color: var(--muted);
  font-size: 12px;
}

.official-column {
  align-self: auto;
}

.official-row {
  max-width: none;
  margin: 0;
}

.official-row button {
  gap: 10px;
}

.official-row a {
  color: var(--orange-deep);
  font-size: 13px;
  font-weight: 700;
}

.reviews {
  background: var(--paper);
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 38px;
}

.review-grid article {
  display: flex;
  flex-direction: column;
  min-height: 226px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.review-grid header {
  display: flex;
  align-items: center;
  gap: 9px;
}

.review-grid header span {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: var(--radius);
  color: var(--orange-deep);
  background: #fff0cf;
  font-size: 13px;
  font-weight: 800;
}

.review-grid header b {
  font-size: 13px;
}

.review-grid article > p {
  margin-top: 13px;
  color: var(--muted);
  font-size: 13px;
}

.review-grid time {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: #a58b78;
  font-size: 12px;
}

.download {
  padding: 46px 0 84px;
}

.download-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
  padding: 34px 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff7e7;
}

.download h2:not(.section-label) {
  margin-top: 7px;
  font-size: clamp(23px, 3vw, 35px);
  line-height: 1.2;
}

.button-dark {
  min-width: 160px;
  color: var(--white);
  background: var(--orange);
}

.button-dark .icon {
  filter: brightness(0) invert(1);
}

.site-footer {
  padding: 44px 0 20px;
  color: #ebd8ca;
  background: #4a291a;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.8fr 0.8fr 0.8fr;
  gap: 46px;
}

.footer-brand strong {
  display: block;
  margin-top: 8px;
  color: var(--white);
  font-size: 19px;
}

.footer-brand p,
.site-footer li {
  margin-top: 7px;
  color: #d8b8a5;
  font-size: 12px;
}

.site-footer h2 {
  color: var(--white);
  font-size: 14px;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--white);
}

.copyright {
  width: var(--page);
  margin: 34px auto 0;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  color: #caa894;
  font-size: 12px;
  text-align: center;
}

@media (max-width: 900px) {
  .site-nav {
    display: none;
  }

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

  .menu-toggle {
    display: grid;
    width: 42px;
    height: 42px;
    place-items: center;
    border: 1px solid var(--orange);
    border-radius: var(--radius);
    background: transparent;
  }

  .site-nav.is-open {
    display: block;
    position: absolute;
    top: calc(100% + 1px);
    right: 0;
    left: 0;
    padding: 9px 24px 16px;
    border-bottom: 1px solid var(--line);
    background: var(--paper);
    box-shadow: 0 14px 24px rgba(78, 46, 20, 0.12);
  }

  .site-nav.is-open ul {
    display: grid;
    gap: 4px;
  }

  .site-nav.is-open a {
    display: block;
    padding: 10px 11px;
    border-left: 3px solid transparent;
    border-bottom: 0;
    color: inherit;
    font-size: 14px;
    font-weight: 700;
  }

  .site-nav.is-open a:hover,
  .site-nav.is-open a:focus-visible {
    border-color: var(--orange);
    background: #fff4df;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .hero-copy {
    padding: 65px 0 25px;
    text-align: center;
  }

  .hero-summary {
    max-width: 100%;
    margin-right: auto;
    margin-left: auto;
  }

  .hero-visual {
    justify-self: center;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid article {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .feature-grid article:last-child {
    border-bottom: 0;
  }

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

  .reading-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .reading-shot {
    order: -1;
  }

  .help-grid {
    grid-template-columns: 1fr;
  }

  .faq-column,
  .official-column {
    display: block;
  }

  .official-column {
    margin-top: 52px;
  }
}

@media (max-width: 620px) {
  :root {
    --page: min(100% - 30px, 1200px);
    --header-height: 62px;
  }

  body {
    padding-top: var(--header-height);
  }

  .site-header {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    isolation: isolate;
    transform: translate3d(0, 0, 0);
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
  }

  .nav-shell {
    gap: 10px;
  }

  .brand {
    gap: 7px;
    font-size: 16px;
  }

  .brand img {
    width: 32px;
    height: 32px;
  }

  .nav-download {
    min-height: 36px;
    padding: 7px 10px;
    font-size: 12px;
  }

  .nav-download .icon {
    display: none;
  }

  .menu-toggle {
    width: 36px;
    height: 36px;
  }

  .site-nav.is-open {
    padding: 8px 15px 14px;
  }

  .hero-copy {
    padding-top: 46px;
  }

  .hero h1 {
    font-size: 51px;
  }

  .hero-summary {
    margin-top: 14px;
    font-size: 14px;
  }

  .hero-actions {
    margin-top: 23px;
  }

  .hero-visual {
    width: 100%;
    height: 460px;
  }

  .phone-frame {
    right: 0;
    width: 238px;
    border-width: 10px;
  }

  .progress-card {
    bottom: 68px;
    left: 16px;
    width: min(82%, 270px);
  }

  .features,
  .screenshots,
  .reading,
  .help,
  .reviews {
    padding: 60px 0;
  }

  .split-head {
    display: block;
  }

  .split-head > p {
    margin-top: 12px;
  }

  .screen-grid {
    gap: 10px;
    margin-top: 30px;
  }

  .screen-grid figure > div {
    padding: 6px 6px 0;
  }

  .screen-grid figcaption {
    display: block;
    padding: 9px;
  }

  .screen-grid figcaption strong {
    margin-left: 7px;
  }

  .reading-info li {
    padding: 13px;
  }

  .review-grid {
    grid-template-columns: 1fr;
    margin-top: 30px;
  }

  .review-grid article {
    min-height: auto;
  }

  .download {
    padding: 42px 0 60px;
  }

  .download-inner {
    display: grid;
    gap: 22px;
    padding: 28px 22px;
  }

  .button-dark {
    width: 100%;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 30px 18px;
    text-align: center;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .footer-brand img {
    margin-right: auto;
    margin-left: auto;
  }
}