:root {
  color-scheme: light;
  --ink: #17233a;
  --muted: #637089;
  --line: #dfe5ef;
  --surface: #ffffff;
  --soft: #f3f6fb;
  --blue: #3467eb;
  --blue-dark: #2854c7;
  --gold: #e6b95e;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: #f7f8fb;
  line-height: 1.6;
}

.error-page {
  display: grid;
  min-height: 100vh;
  place-items: center;
}

.error-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 60px 20px;
  text-align: center;
}

.error-content img {
  margin-bottom: 28px;
  border-radius: 18px;
  box-shadow: 0 18px 40px rgba(36, 54, 91, 0.18);
}

.error-content h1 {
  font-size: clamp(42px, 7vw, 72px);
}

.error-code {
  margin: 0 0 10px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 700;
}

.error-content > p:not(.error-code) {
  margin: 18px 0 30px;
  color: var(--muted);
}

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

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

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  align-items: center;
  width: min(1180px, calc(100% - 40px));
  height: 76px;
  margin: 0 auto;
  border-bottom: 1px solid rgba(223, 229, 239, 0.85);
  background: #f7f8fb;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 750;
  letter-spacing: -0.02em;
}

.brand img {
  border-radius: 11px;
  box-shadow: 0 6px 18px rgba(31, 44, 74, 0.12);
}

nav {
  display: flex;
  gap: 34px;
  margin-left: auto;
  color: var(--muted);
  font-size: 14px;
}

nav a,
footer a {
  transition: color 160ms ease;
}

nav a:hover,
footer a:hover {
  color: var(--blue);
}

.header-download {
  margin-left: 34px;
  padding: 8px 18px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--surface);
  font-size: 14px;
  font-weight: 650;
  transition: border-color 160ms ease, transform 160ms ease;
}

.header-download:hover {
  border-color: #b9c6dc;
  transform: translateY(-1px);
}

main,
footer {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  align-items: center;
  min-height: 560px;
  padding: 64px 7% 72px;
}

h1,
h2,
h3,
p {
  overflow-wrap: break-word;
}

h1 {
  max-width: 700px;
  margin: 0;
  font-size: clamp(44px, 5.4vw, 68px);
  line-height: 1.12;
  letter-spacing: -0.045em;
}

.lead {
  max-width: 650px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 20px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 24px;
  border: 1px solid transparent;
  border-radius: 7px;
  font-size: 15px;
  font-weight: 700;
  transition: background 160ms ease, border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

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

.button-primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 6px 14px rgba(52, 103, 235, 0.18);
}

.button-primary:hover {
  background: var(--blue-dark);
  box-shadow: 0 8px 18px rgba(52, 103, 235, 0.22);
}

.button-secondary {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.72);
}

.button-secondary:hover {
  border-color: #b9c6dc;
  background: #fff;
}

.platforms {
  margin: 18px 0 0;
  color: #8490a4;
  font-size: 13px;
}

.hero-art {
  display: grid;
  place-items: center;
  min-height: 300px;
}

.app-icon {
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 22%;
  box-shadow: 0 18px 35px rgba(36, 54, 91, 0.18);
}

.product-shot {
  overflow: hidden;
  border: 1px solid #d6dce8;
  border-radius: 10px;
  background: var(--surface);
  box-shadow: 0 18px 45px rgba(42, 53, 78, 0.1);
}

.section {
  padding: 120px 0;
}

.section-heading {
  max-width: 720px;
  margin: 0 0 46px;
}

h2 {
  margin: 0;
  font-size: clamp(32px, 3.8vw, 46px);
  line-height: 1.18;
  letter-spacing: -0.045em;
}

.section-heading > p:last-child,
.preview-copy > p {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.feature-grid article {
  min-height: 220px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  transition: border-color 180ms ease;
}

.feature-grid article:hover {
  border-color: #c5d0e3;
}

h3 {
  margin: 0;
  font-size: 21px;
  letter-spacing: -0.025em;
}

.feature-grid p {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.preview {
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(0, 1.28fr);
  align-items: center;
  gap: 7%;
}

.preview-copy ul {
  display: grid;
  gap: 12px;
  margin: 30px 0 0;
  padding: 0;
  color: var(--ink);
  list-style: none;
}

.preview-copy li {
  position: relative;
  padding-left: 25px;
}

.preview-copy li::before {
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
  content: "";
  transform: translateY(-50%);
}

.preview-image {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 16px 40px rgba(42, 53, 78, 0.1);
}

.note-gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.note-gallery figure {
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 12px 32px rgba(42, 53, 78, 0.08);
}

.note-gallery img {
  width: 100%;
  aspect-ratio: 1.51;
  object-fit: cover;
}

.note-gallery figcaption {
  padding: 15px 18px;
  color: var(--muted);
  font-size: 13px;
}

.note-types {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}

.note-types article {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.note-types span {
  display: block;
  margin-bottom: 18px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.1em;
}

.note-types p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.format-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
}

caption {
  position: absolute;
  overflow: hidden;
  width: 1px;
  height: 1px;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

th,
td {
  padding: 20px 22px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: middle;
}

thead th {
  color: var(--muted);
  background: var(--soft);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.05em;
}

tbody th {
  font-size: 14px;
  white-space: nowrap;
}

tbody td {
  color: var(--muted);
  font-size: 14px;
}

tbody tr:last-child th,
tbody tr:last-child td {
  border-bottom: 0;
}

.support-yes,
.support-no {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}

.support-yes {
  color: #28724a;
  background: #e7f5ec;
}

.support-no {
  color: #6e7789;
  background: #edf0f5;
}

.format-hint {
  margin: 18px 4px 0;
  color: var(--muted);
  font-size: 13px;
}

.privacy {
  display: grid;
  grid-template-columns: 1fr 0.75fr;
  align-items: end;
  gap: 9%;
  padding: 76px;
  border-radius: 8px;
  color: #f8faff;
  background: #18233a;
}

.privacy > p {
  margin: 0;
  color: #b9c3d5;
  font-size: 17px;
}

.cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 150px 20px;
  text-align: center;
}

.cta img {
  margin-bottom: 28px;
  border-radius: 18px;
  box-shadow: 0 12px 28px rgba(36, 54, 91, 0.14);
}

.cta p {
  margin: 16px 0 30px;
  color: var(--muted);
}

footer {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 28px 0 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.footer-brand {
  font-size: 15px;
}

footer p {
  margin: 0;
}

footer p:last-child {
  justify-self: end;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: 90px 4% 70px;
    text-align: center;
  }

  .hero-copy {
    z-index: 2;
  }

  .lead {
    margin-right: auto;
    margin-left: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-art {
    min-height: 300px;
  }

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

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

  .note-gallery {
    grid-template-columns: 1fr;
  }

  .preview-copy {
    max-width: 650px;
  }

  .privacy {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 30px;
  }
}

@media (max-width: 640px) {
  .site-header,
  main,
  footer {
    width: min(100% - 28px, 1180px);
  }

  .site-header {
    height: 66px;
  }

  nav {
    display: none;
  }

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

  .hero {
    padding: 72px 0 55px;
  }

  h1 {
    font-size: clamp(43px, 14vw, 62px);
  }

  .hero-art {
    min-height: 250px;
  }

  .app-icon {
    width: 140px;
    height: 140px;
  }

  .product-shot {
    border-radius: 12px;
  }

  .section {
    padding: 100px 0;
  }

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

  .note-types {
    grid-template-columns: 1fr;
  }

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

  .privacy {
    padding: 42px 28px;
  }

  .cta {
    padding: 110px 10px;
  }

  footer {
    grid-template-columns: 1fr auto;
    gap: 10px;
  }

  footer > p:nth-child(2) {
    display: none;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}