:root {
  --bg: #fff;
  --surface: #f2f2f7;
  --raised: #fff;
  --text: #000;
  --secondary: rgba(60, 60, 67, 0.78);
  --border: rgba(60, 60, 67, 0.29);
  --accent: #007aff;
  --on-accent: #fff;
  --pressed: #0062cc;
  --reading-bg: #fff;
  --reading-text: #000;
  --shadow: rgba(0, 0, 0, 0.13);
  color-scheme: light dark;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.65;
  letter-spacing: -0.018em;
}
a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
button,
input {
  font: inherit;
}
button,
a,
input {
  touch-action: manipulation;
}
button {
  cursor: pointer;
}
a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 5px;
}
h1,
h2,
h3,
p {
  margin-top: 0;
}
h1,
h2,
h3 {
  line-height: 1.06;
  letter-spacing: -0.055em;
}
h1 {
  font-size: clamp(48px, 6.5vw, 88px);
  font-weight: 720;
  margin-bottom: 26px;
}
h2 {
  font-size: clamp(34px, 4.1vw, 54px);
  font-weight: 690;
  margin-bottom: 24px;
}
h3 {
  font-size: 23px;
  font-weight: 650;
  letter-spacing: -0.035em;
  line-height: 1.22;
}
p {
  color: var(--secondary);
}
.wrap {
  width: min(1120px, calc(100% - 64px));
  margin-inline: auto;
}
header {
  background: var(--bg);
  border-bottom: 1px solid var(--surface);
  position: sticky;
  top: 0;
  z-index: 20;
}
.nav {
  height: 82px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  font-size: 18px;
  font-weight: 650;
  letter-spacing: -0.04em;
  color: var(--text);
  white-space: nowrap;
}
.brand img {
  border-radius: 23%;
}
.brand-reader {
  margin-left: -5px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 25px;
  font-size: 14px;
  font-weight: 550;
}
.nav-links > a {
  color: var(--secondary);
}
.nav-links .nav-download {
  background: var(--accent);
  color: var(--on-accent);
  border-radius: 24px;
  padding: 8px 17px;
}
.menu {
  display: none;
}
.hero {
  text-align: center;
  padding-top: 78px;
}
.intro {
  font-size: 16px;
  font-weight: 550;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.hero-copy {
  font-size: 21px;
  line-height: 1.55;
  max-width: 610px;
  margin: 0 auto 30px;
}
.actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 11px;
  border-radius: 12px;
  padding: 11px 22px;
  border: 0;
  font-weight: 600;
  text-decoration: none;
  line-height: 1.15;
}
.button:hover {
  text-decoration: none;
  background: var(--pressed);
}
.primary {
  color: var(--on-accent);
  background: var(--accent);
}
.button small {
  display: block;
  font-size: 10px;
  font-weight: 450;
  letter-spacing: 0;
  margin-bottom: 3px;
}
.button span {
  text-align: left;
  font-size: 21px;
}
.text-link {
  font-weight: 550;
  font-size: 15px;
}
.text-link span {
  margin-left: 8px;
}
.fine {
  font-size: 13px;
  margin: 16px 0 0;
}
.hero-preview {
  max-width: 870px;
  height: 495px;
  margin: 70px auto 0;
  position: relative;
  border-radius: 36px 36px 0 0;
  background: var(--surface);
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding-top: 48px;
}
.page-preview {
  width: 370px;
  padding: 35px 36px 30px;
  background: var(--raised);
  border: 1px solid var(--border);
  border-radius: 12px;
  transform: rotate(-5deg);
  box-shadow: 0 18px 45px var(--shadow);
  text-align: left;
  margin-top: 40px;
  margin-right: -30px;
}
.preview-title {
  font-size: 14px;
  font-weight: 550;
  margin-bottom: 20px;
}
.book-text {
  font-family: Georgia, serif;
  font-size: 18px;
  line-height: 1.75;
  color: var(--text);
  margin-bottom: 16px;
}
.highlight-line {
  background: var(--accent);
  color: var(--on-accent);
  padding: 5px 8px;
  margin: 0 -8px 15px;
  font-family: Georgia, serif;
  font-size: 18px;
}
.page-foot {
  border-top: 1px solid var(--border);
  font-size: 11px;
  padding-top: 14px;
  text-align: center;
  color: var(--secondary);
}
.phone-preview {
  width: 255px;
  height: 500px;
  flex-shrink: 0;
  background: var(--raised);
  border: 7px solid var(--text);
  border-radius: 42px;
  position: relative;
  box-shadow: 12px 15px 40px var(--shadow);
  transform: rotate(6deg);
  padding: 50px 17px 20px;
}
.phone-island {
  height: 19px;
  width: 78px;
  border-radius: 25px;
  background: var(--text);
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
}
.phone-bar {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--accent);
}
.phone-book {
  font-size: 12px;
  margin-top: 35px;
  color: var(--secondary);
}
.focus-preview {
  font-size: 32px;
  line-height: 1.3;
  margin: 65px 0 60px;
  letter-spacing: -0.04em;
}
.focus-preview strong {
  font-weight: 550;
  color: var(--accent);
}
.phone-progress {
  height: 3px;
  background: var(--surface);
  border-radius: 2px;
}
.phone-progress span {
  display: block;
  width: 38%;
  height: 100%;
  background: var(--accent);
}
.phone-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 10px;
  margin-top: 22px;
}
.phone-controls > span:nth-child(2) {
  color: var(--accent);
  font-size: 22px;
}
.phone-caption {
  font-size: 9px;
  color: var(--secondary);
  margin-top: 25px;
}
.preview-note {
  font-size: 11px;
  margin-top: 10px;
}
.section {
  padding-block: 105px;
}
.section-heading {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 80px;
  align-items: center;
  margin-bottom: 50px;
}
.section-heading p {
  font-size: 19px;
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 36px;
}
.feature-symbol {
  color: var(--accent);
  font-size: 36px;
  font-weight: 350;
  margin-bottom: 24px;
  height: 48px;
}
.feature-grid p {
  font-size: 16px;
  line-height: 1.65;
}
.feature-grid h3 {
  font-size: 21px;
}
.demo-section {
  background: var(--surface);
  padding-block: 95px;
}
.demo-layout {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 85px;
  align-items: center;
}
.muted {
  font-size: 14px;
}
.demo {
  background: var(--raised);
  padding: 28px 30px;
  border-radius: 22px;
}
.demo-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  font-size: 12px;
  color: var(--secondary);
}
.reset {
  border: 0;
  background: transparent;
  color: var(--accent);
  font-size: 12px;
  padding: 8px 0;
}
.demo-word {
  height: 170px;
  display: grid;
  place-items: center;
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 550;
  letter-spacing: -0.05em;
  overflow-wrap: anywhere;
}
progress {
  display: block;
  width: 100%;
  height: 3px;
  border: 0;
  background: var(--surface);
  accent-color: var(--accent);
  border-radius: 3px;
}
progress::-webkit-progress-bar {
  background: var(--surface);
}
progress::-webkit-progress-value {
  background: var(--accent);
}
progress::-moz-progress-bar {
  background: var(--accent);
}
.demo-bottom {
  display: flex;
  justify-content: space-between;
  gap: 25px;
  align-items: center;
  margin-top: 25px;
}
.demo-bottom .button {
  font-size: 14px;
  min-width: 110px;
  padding: 14px;
}
.demo-bottom label {
  font-size: 13px;
  max-width: 160px;
  display: block;
  text-align: right;
}
.demo-bottom input {
  display: block;
  width: 100%;
  margin-top: 7px;
  accent-color: var(--accent);
}
.library-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 110px;
  align-items: center;
}
.app-image {
  max-width: 330px;
  margin: auto;
  border-radius: 24px;
  overflow: hidden;
  background: var(--surface);
}
.app-image img {
  display: block;
  width: 100%;
  height: auto;
}
.steps {
  list-style: none;
  counter-reset: step;
  padding: 0;
  margin-block: 35px;
}
.steps li {
  position: relative;
  padding-left: 46px;
  counter-increment: step;
}
.steps li:before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 28px;
  height: 28px;
  text-align: center;
  font-size: 14px;
  line-height: 26px;
  color: var(--accent);
}
.steps h3 {
  font-size: 19px;
  margin-bottom: 8px;
}
.steps p {
  font-size: 15px;
  margin-bottom: 25px;
}
.guides-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.guide-card {
  color: var(--text);
  display: block;
}
.guide-card:hover {
  text-decoration: none;
}
.guide-card:hover h3,
.guide-card:hover h2 {
  text-decoration: underline;
}
.guide-card p {
  font-size: 16px;
}
.guide-art {
  height: 230px;
  background: var(--surface);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 25px;
}
.words-art {
  font-family: Georgia, serif;
  font-size: 37px;
  line-height: 1.25;
  text-align: center;
  color: var(--text);
}
.files-art {
  gap: 14px;
}
.files-art > span {
  font-size: 16px;
  font-weight: 600;
  border: 1px solid var(--border);
  background: var(--raised);
  border-radius: 8px;
  padding: 27px 16px;
}
.files-art > span:nth-child(2) {
  transform: translateY(-13px);
  color: var(--accent);
}
.guide-type {
  font-size: 12px;
  color: var(--secondary);
  display: block;
  margin-bottom: 12px;
}
.guide-card h3 {
  font-size: 26px;
}
.read-link {
  font-size: 14px;
  color: var(--accent);
  font-weight: 550;
}
.faq {
  display: grid;
  grid-template-columns: 1fr 1.25fr;
  gap: 90px;
  border-top: 1px solid var(--border);
}
details {
  border-bottom: 1px solid var(--border);
  padding: 21px 0;
}
details:first-child {
  padding-top: 0;
}
summary {
  cursor: pointer;
  font-size: 17px;
  font-weight: 550;
  list-style: none;
  position: relative;
  padding-right: 30px;
}
summary:after {
  content: "+";
  position: absolute;
  right: 3px;
  color: var(--accent);
  font-size: 23px;
  font-weight: 350;
  top: -4px;
}
details[open] summary:after {
  content: "−";
}
details p {
  font-size: 15px;
  margin: 15px 30px 0 0;
}
.closing {
  text-align: center;
  background: var(--surface);
  padding-block: 85px;
}
.closing img {
  border-radius: 17px;
  margin-bottom: 25px;
}
.closing h2 {
  font-size: clamp(37px, 5vw, 60px);
}
.closing p {
  margin-bottom: 25px;
}
.closing .fine {
  margin-bottom: 0;
}
footer {
  padding-block: 45px 25px;
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 35px;
}
.footer-top p {
  margin: 0;
  font-size: 14px;
}
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 22px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 12px;
}
.footer-bottom p {
  margin: 0;
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 32px 64px;
}
.footer-group {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}
.footer-group h2 {
  margin: 0 0 4px;
  font-size: 14px;
  font-weight: 650;
  line-height: 1.4;
  letter-spacing: normal;
  color: var(--text);
}
.footer-bottom a {
  color: var(--secondary);
}
.article {
  padding-block: 70px 100px;
}
.article h1 {
  max-width: 900px;
  font-size: clamp(38px, 5.5vw, 68px);
  margin-bottom: 40px;
}
.back {
  font-size: 14px;
  display: block;
  margin-bottom: 50px;
}
.article-body {
  max-width: 680px;
}
.article-body h2 {
  font-size: 29px;
  margin-top: 45px;
  letter-spacing: -0.035em;
}
.article-body p,
.article-body li {
  font-size: 18px;
}
.article-body li {
  margin-bottom: 15px;
  color: var(--secondary);
}
.lead {
  font-size: 23px;
  line-height: 1.5;
}
.article aside {
  background: var(--surface);
  padding: 30px;
  border-radius: 15px;
  margin-top: 50px;
}
.article aside h2 {
  margin-top: 0;
}
.guides-index {
  min-height: 65vh;
}
.guides-index .guides-grid {
  margin-top: 65px;
}
.guides-index h2 {
  font-size: 30px;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip {
  position: fixed;
  left: 15px;
  top: -100px;
  background: var(--bg);
  padding: 10px;
  z-index: 40;
}
.skip:focus {
  top: 10px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000;
    --surface: #1c1c1e;
    --raised: #2c2c2e;
    --text: #fff;
    --secondary: rgba(235, 235, 245, 0.78);
    --border: rgba(84, 84, 88, 0.6);
    --accent: #0a84ff;
    --pressed: #3395ff;
    --shadow: rgba(255, 255, 255, 0.04);
  }
}
@media (max-width: 950px) {
  .brand-reader {
    display: none;
  }
  .nav-links {
    gap: 18px;
  }
  .feature-grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
  .demo-layout {
    gap: 40px;
  }
  .library-section {
    gap: 55px;
  }
  .section-heading {
    gap: 40px;
  }
  .faq {
    gap: 40px;
  }
  .hero-preview {
    height: 460px;
  }
  .phone-preview {
    width: 240px;
  }
}
@media (max-width: 650px) {
  .wrap {
    width: calc(100% - 40px);
  }
  .nav {
    height: 68px;
  }
  .brand {
    font-size: 17px;
  }
  .menu {
    display: block;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg);
    color: var(--text);
    font-size: 13px;
    padding: 7px 12px;
  }
  .nav-links {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 68px;
    background: var(--bg);
    padding: 20px;
    box-shadow: 0 12px 20px var(--shadow);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open {
    display: flex;
  }
  .nav-links a {
    padding: 12px;
  }
  .nav-links .nav-download {
    margin-top: 10px;
    text-align: center;
  }
  .hero {
    padding-top: 55px;
  }
  .hero h1 {
    font-size: 49px;
  }
  .hero-copy {
    font-size: 18px;
    line-height: 1.55;
  }
  .intro {
    font-size: 14px;
  }
  .actions {
    flex-direction: column;
    gap: 18px;
  }
  .hero-preview {
    margin-top: 45px;
    height: 390px;
    border-radius: 24px 24px 0 0;
    padding-top: 30px;
  }
  .page-preview {
    width: 240px;
    padding: 25px 22px;
    margin-right: -75px;
    margin-top: 35px;
    flex-shrink: 0;
  }
  .book-text,
  .highlight-line {
    font-size: 15px;
  }
  .phone-preview {
    width: 200px;
    height: 420px;
    padding: 47px 13px 15px;
    transform: rotate(5deg);
    border-width: 5px;
    border-radius: 34px;
  }
  .focus-preview {
    font-size: 26px;
    margin: 45px 0;
  }
  .phone-book {
    margin-top: 25px;
  }
  .phone-caption {
    font-size: 8px;
  }
  .phone-controls {
    font-size: 9px;
  }
  .section {
    padding-block: 65px;
  }
  .section-heading {
    display: block;
    margin-bottom: 30px;
  }
  .section-heading p {
    font-size: 17px;
  }
  .feature-grid {
    gap: 24px;
  }
  .feature-grid h3 {
    font-size: 19px;
  }
  .feature-grid p {
    font-size: 14px;
  }
  .feature-symbol {
    margin-bottom: 15px;
  }
  .demo-section {
    padding-block: 60px;
  }
  .demo-layout,
  .library-section,
  .faq {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .demo {
    padding: 22px;
  }
  .demo-word {
    height: 145px;
  }
  .library-section {
    gap: 40px;
  }
  .app-image {
    max-width: 260px;
  }
  .guides-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .guide-art {
    height: 200px;
  }
  .faq h2 {
    margin-bottom: 0;
  }
  .closing {
    padding-block: 60px;
  }
  .footer-top,
  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
    gap: 20px;
  }
  .article {
    padding-top: 45px;
  }
  .article h1 {
    font-size: 42px;
  }
  .article .lead {
    font-size: 21px;
  }
  .article-body p,
  .article-body li {
    font-size: 17px;
  }
  .back {
    margin-bottom: 35px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *:before,
  *:after {
    animation: none !important;
    transition: none !important;
  }
}