:root {
  color-scheme: light;
  --by-bg: #faf8ff;
  --by-surface: #ffffff;
  --by-surface-soft: #f2f3ff;
  --by-surface-raised: #eaedff;
  --by-surface-strong: #dae2fd;
  --by-text: #131b2e;
  --by-muted: #464555;
  --by-muted-soft: rgba(70, 69, 85, 0.72);
  --by-primary: #3525cd;
  --by-primary-strong: #4f46e5;
  --by-primary-soft: #e2dfff;
  --by-secondary-soft: #8fa7fe;
  --by-line: rgba(119, 117, 135, 0.18);
  --by-line-strong: rgba(119, 117, 135, 0.3);
  --by-shadow-soft: 0 18px 42px rgba(40, 48, 68, 0.06);
  --by-shadow-strong: 0 24px 60px rgba(40, 48, 68, 0.12);
  --by-radius-card: 2rem;
  --by-radius-panel: 3rem;
  --by-container: 80rem;
  --by-page-padding: clamp(1.25rem, 3vw, 3rem);
  --by-font-display: "Manrope", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --by-font-body: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

html[data-lang="zh"] .lang-en,
html[data-lang="en"] .lang-zh {
  display: none !important;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--by-font-body);
  color: var(--by-text);
  background:
    radial-gradient(circle at 85% 8%, rgba(79, 70, 229, 0.16), transparent 24%),
    radial-gradient(circle at 12% 16%, rgba(143, 167, 254, 0.16), transparent 22%),
    var(--by-bg);
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--by-font-display);
  color: var(--by-text);
}

p,
ul,
ol {
  margin: 0;
}

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

button,
input,
textarea,
select {
  font: inherit;
}

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(53, 37, 205, 0.18);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: -3rem;
  z-index: 60;
  padding: 0.65rem 1rem;
  border-radius: 999px;
  background: var(--by-primary);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
}

.by-shell {
  width: min(100% - 2 * var(--by-page-padding), var(--by-container));
  margin: 0 auto;
}

.by-nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  border-bottom: 1px solid rgba(218, 226, 253, 0.8);
  background: rgba(250, 248, 255, 0.84);
  backdrop-filter: blur(20px);
}

.by-nav-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
}

.by-brand {
  font-family: var(--by-font-display);
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.04em;
}

.by-nav-group {
  display: flex;
  align-items: center;
  gap: 0.8rem 1.75rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.by-nav-links {
  display: flex;
  align-items: center;
  gap: 0.85rem 1.5rem;
  flex-wrap: wrap;
  font-size: clamp(0.95rem, 1.15vw, 1rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.by-nav-link {
  opacity: 0.72;
  padding-bottom: 0.15rem;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, opacity 0.2s ease, border-color 0.2s ease;
}

.by-nav-link:hover {
  color: var(--by-primary);
  opacity: 1;
}

.by-nav-link.is-current {
  color: var(--by-primary);
  opacity: 1;
  border-color: var(--by-primary);
}

.by-lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  padding: 0.25rem;
  border-radius: 999px;
  border: 1px solid var(--by-line);
  background: rgba(255, 255, 255, 0.74);
}

.by-lang-button {
  min-width: 3.25rem;
  height: 2rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--by-muted);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 700;
}

.by-lang-button.is-active {
  background: var(--by-primary);
  color: #fff;
}

.by-main {
  padding-top: 6.4rem;
}

.by-hero {
  position: relative;
  overflow: hidden;
  padding: 3rem 0 5rem;
}

.by-hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(21rem, 28rem);
  gap: 3rem;
  align-items: start;
}

.by-hero-glow {
  position: absolute;
  inset: auto -8rem -6rem auto;
  width: 24rem;
  height: 24rem;
  border-radius: 50%;
  background: rgba(79, 70, 229, 0.22);
  filter: blur(80px);
  pointer-events: none;
}

.by-hero-glow-secondary {
  position: absolute;
  inset: 0 auto auto -7rem;
  width: 18rem;
  height: 18rem;
  border-radius: 50%;
  background: rgba(143, 167, 254, 0.2);
  filter: blur(70px);
  pointer-events: none;
}

.by-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 0.95rem;
  border-radius: 999px;
  background: rgba(53, 37, 205, 0.08);
  color: var(--by-primary);
  font-size: 0.9rem;
  font-weight: 700;
}

.by-display {
  margin-top: 1rem;
  font-size: clamp(2.8rem, 8vw, 4.75rem);
  line-height: 1.05;
  letter-spacing: -0.05em;
  font-weight: 800;
}

html[data-lang="zh"] .by-display {
  line-height: 1.06;
  letter-spacing: -0.03em;
}

.by-display-line {
  display: block;
}

.by-lead {
  max-width: 42rem;
  margin-top: 1.25rem;
  color: var(--by-muted);
  font-size: clamp(1.08rem, 1.5vw, 1.25rem);
  line-height: 1.75;
}

.by-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.75rem;
}

.by-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3.5rem;
  padding: 0 1.75rem;
  border-radius: 1rem;
  border: 1px solid transparent;
  font-size: 1rem;
  font-weight: 700;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.by-btn:hover {
  transform: translateY(-1px);
}

.by-btn-primary {
  background: var(--by-primary);
  color: #fff;
}

.by-btn-secondary {
  border-color: var(--by-line-strong);
  background: rgba(255, 255, 255, 0.82);
}

.by-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-top: 1rem;
  color: var(--by-primary);
  font-size: 0.98rem;
  font-weight: 700;
}

.by-proof {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.9rem;
  padding: 0;
  list-style: none;
}

.by-proof li {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  border: 1px solid rgba(199, 196, 216, 0.5);
  background: rgba(234, 237, 255, 0.52);
  color: var(--by-muted);
  font-size: 0.92rem;
  font-weight: 600;
}

.by-proof li::before {
  content: "";
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--by-primary);
  flex: 0 0 auto;
}

.by-panel,
.by-card,
.by-faq details,
.by-contact-card,
.by-install-card,
.by-app-panel {
  border: 1px solid var(--by-line);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: var(--by-shadow-soft);
}

.by-panel {
  padding: 2rem;
  border-radius: var(--by-radius-card);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(234, 237, 255, 0.82));
}

.by-panel-dark {
  border-color: rgba(255, 255, 255, 0.08);
  background: linear-gradient(180deg, #1d2340 0%, #28345d 100%);
  box-shadow: var(--by-shadow-strong);
}

.by-panel-dark h2,
.by-panel-dark h3,
.by-panel-dark h4,
.by-panel-dark p,
.by-panel-dark li,
.by-panel-dark span,
.by-panel-dark strong {
  color: #fff;
}

.by-panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.2rem;
}

.by-panel-label {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--by-primary);
}

.by-panel-dark .by-panel-label,
.by-panel-dark .by-panel-note {
  color: rgba(255, 255, 255, 0.7);
}

.by-panel-title {
  font-size: 1.35rem;
  line-height: 1.15;
  font-weight: 800;
}

.by-panel-note {
  color: var(--by-muted);
  font-size: 0.92rem;
  font-weight: 600;
}

.by-screenshot {
  width: 100%;
  overflow: hidden;
  border-radius: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.by-stage-list,
.by-step-list,
.by-note-list {
  display: grid;
  gap: 0.85rem;
  padding: 0;
  list-style: none;
}

.by-stage-item,
.by-step,
.by-note-item {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 0.9rem;
  align-items: start;
}

.by-stage-card {
  padding: 1rem;
  border-radius: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.08);
}

.by-index {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  border-radius: 1rem;
  background: var(--by-primary-soft);
  color: var(--by-primary);
  font-size: 0.88rem;
  font-weight: 800;
}

.by-panel-dark .by-index {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.by-stage-item h3,
.by-step h3,
.by-note-item h3 {
  font-size: 1.15rem;
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.by-stage-item p,
.by-step p,
.by-note-item p {
  margin-top: 0.35rem;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.96rem;
  line-height: 1.65;
}

.by-section {
  padding: 5rem 0;
}

.by-section-soft {
  background: rgba(234, 237, 255, 0.44);
}

.by-section-head {
  max-width: 44rem;
  margin-bottom: 2.25rem;
}

.by-section-title {
  margin-top: 1rem;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.08;
  letter-spacing: -0.04em;
  font-weight: 800;
}

html[data-lang="zh"] .by-section-title {
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.by-section-copy {
  margin-top: 1rem;
  color: var(--by-muted);
  font-size: 1.05rem;
  line-height: 1.75;
}

.by-card-grid {
  display: grid;
  gap: 1.5rem;
}

.by-card-grid-three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

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

.by-card-grid-five {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.by-card {
  padding: 2rem;
  border-radius: var(--by-radius-card);
}

.by-card-accent {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(226, 223, 255, 0.9));
}

.by-card-label {
  color: var(--by-primary);
  font-size: 0.84rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.by-card-title {
  margin-top: 0.85rem;
  font-size: 1.55rem;
  line-height: 1.12;
  letter-spacing: -0.03em;
  font-weight: 800;
}

.by-card-copy {
  margin-top: 0.85rem;
  color: var(--by-muted);
  font-size: 1rem;
  line-height: 1.72;
}

.by-list {
  display: grid;
  gap: 0.8rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.by-list li {
  padding: 0.9rem 1rem;
  border-radius: 1.25rem;
  border: 1px solid rgba(199, 196, 216, 0.38);
  background: var(--by-surface-soft);
  color: var(--by-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

.by-pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.1rem;
}

.by-pill {
  display: inline-flex;
  align-items: center;
  min-height: 2rem;
  padding: 0 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--by-line);
  background: rgba(255, 255, 255, 0.82);
  color: var(--by-muted);
  font-size: 0.88rem;
  font-weight: 600;
}

.by-dual-grid,
.by-contact-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.by-install-card,
.by-app-panel {
  padding: 2rem;
  border-radius: var(--by-radius-card);
}

.by-release-version {
  margin-top: 1rem;
  font-size: clamp(3.2rem, 6vw, 4.8rem);
  line-height: 0.95;
  letter-spacing: -0.08em;
  font-weight: 800;
}

.by-step-list {
  margin-top: 1.2rem;
}

.by-step .by-index,
.by-note-item .by-index {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 999px;
}

.by-step p,
.by-note-item p {
  margin-top: 0;
  color: var(--by-muted);
}

.by-faq {
  display: grid;
  gap: 1rem;
}

.by-faq details {
  padding: 1.2rem 1.4rem;
  border-radius: 1.5rem;
}

.by-faq summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--by-font-display);
  font-size: 1.18rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

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

.by-faq p {
  margin-top: 0.85rem;
  color: var(--by-muted);
  line-height: 1.72;
}

.by-contact-band {
  padding: 6rem 0;
  background: var(--by-primary);
}

.by-contact-panel {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(21rem, 28rem);
  gap: 3rem;
  padding: 3rem;
  overflow: hidden;
  border-radius: var(--by-radius-panel);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--by-shadow-strong);
}

.by-contact-panel::before,
.by-contact-panel::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  pointer-events: none;
}

.by-contact-panel::before {
  width: 18rem;
  height: 18rem;
  left: -6rem;
  top: -7rem;
  background: rgba(143, 167, 254, 0.22);
}

.by-contact-panel::after {
  width: 20rem;
  height: 20rem;
  right: -8rem;
  bottom: -8rem;
  background: rgba(79, 70, 229, 0.18);
}

.by-contact-copy,
.by-contact-side {
  position: relative;
  z-index: 1;
}

.by-contact-side {
  padding: 2rem;
  border-radius: var(--by-radius-card);
  border: 1px solid var(--by-line);
  background: #fff;
  box-shadow: var(--by-shadow-soft);
}

.by-contact-qr {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid rgba(199, 196, 216, 0.5);
}

.by-contact-qr img {
  width: 6rem;
  height: 6rem;
  padding: 0.35rem;
  border-radius: 1.25rem;
  border: 1px solid var(--by-line);
  background: #fff;
  object-fit: contain;
}

.by-contact-qr h3 {
  font-size: 1.45rem;
  font-weight: 800;
}

.by-contact-tag {
  margin-top: 0.35rem;
  color: var(--by-primary);
  font-size: 0.95rem;
  font-weight: 700;
}

.by-contact-grid {
  margin-top: 1.5rem;
}

.by-contact-card {
  padding: 1.35rem 1.4rem;
  border-radius: 1.5rem;
}

.by-contact-label {
  color: var(--by-muted);
  font-size: 0.88rem;
  font-weight: 600;
}

.by-contact-value {
  display: block;
  margin-top: 0.5rem;
  font-family: var(--by-font-display);
  font-size: 1.45rem;
  line-height: 1.1;
  letter-spacing: -0.03em;
  font-weight: 800;
}

.by-contact-note {
  margin-top: 0.65rem;
  color: var(--by-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

.by-contact-tip {
  margin-top: 1.2rem;
  color: var(--by-muted-soft);
  font-size: 0.88rem;
  line-height: 1.6;
}

.by-footer {
  border-top: 1px solid rgba(218, 226, 253, 0.9);
  background: rgba(234, 237, 255, 0.44);
}

.by-footer-shell {
  display: grid;
  gap: 1.5rem;
  padding: 2.4rem 0 2rem;
}

.by-footer-top {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.6fr);
  gap: 2rem 3rem;
  align-items: start;
}

.by-footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1.25rem 1.5rem;
}

.by-footer-block {
  display: grid;
  gap: 0.75rem;
  align-content: start;
}

.by-footer-title {
  color: var(--by-muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.by-footer-links {
  display: grid;
  gap: 0.55rem;
}

.by-social-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.65rem;
}

.by-social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  min-height: 3rem;
  padding: 0.65rem 0.8rem;
  border: 1px solid rgba(119, 117, 135, 0.14);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.74);
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.by-social-link:hover {
  transform: translateY(-1px);
  border-color: rgba(53, 37, 205, 0.22);
  background: rgba(255, 255, 255, 0.92);
  color: var(--by-primary);
}

.by-social-icon {
  display: inline-grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--by-primary-strong) 0%, var(--by-primary) 100%);
  color: #fff;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  flex: 0 0 auto;
}

.by-social-label {
  font-size: 0.94rem;
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.by-footer-links a,
.by-footer-links span,
.by-footer-inline-link {
  color: var(--by-text);
  font-size: 0.98rem;
  line-height: 1.55;
  font-weight: 600;
}

.by-footer-links a:hover,
.by-footer-inline-link:hover {
  color: var(--by-primary);
}

.by-footer-note {
  color: var(--by-muted);
  font-size: 0.94rem;
  line-height: 1.72;
}

.by-footer-bottom {
  padding-top: 1rem;
  border-top: 1px solid rgba(218, 226, 253, 0.9);
}

.by-footer-copy {
  color: var(--by-muted-soft);
  font-size: 0.95rem;
  line-height: 1.6;
}

@media (max-width: 1100px) {
  .by-hero-grid,
  .by-dual-grid,
  .by-contact-panel,
  .by-contact-grid {
    grid-template-columns: 1fr;
  }

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

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

  .by-footer-top,
  .by-footer-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .by-nav-shell {
    align-items: flex-start;
    padding: 0.85rem 0;
  }

  .by-nav-group {
    justify-content: flex-start;
    gap: 0.6rem 1rem;
  }

  .by-nav-links {
    gap: 0.55rem 1rem;
    font-size: 0.82rem;
  }

  .by-brand {
    font-size: 1.35rem;
  }

  .by-lang-button {
    min-width: 2.75rem;
  }

  .by-footer-shell {
    padding: 2rem 0 1.7rem;
  }

  .by-footer-grid {
    gap: 1rem;
  }

  .by-social-links {
    grid-template-columns: 1fr;
  }

  .by-main {
    padding-top: 7.25rem;
  }

  .by-hero {
    padding: 2rem 0 4rem;
  }

  .by-section,
  .by-contact-band {
    padding: 4rem 0;
  }

  .by-display {
    font-size: clamp(2.45rem, 12vw, 3.65rem);
  }

  .by-section-title {
    font-size: clamp(1.9rem, 9vw, 2.5rem);
  }

  .by-card-grid-two,
  .by-card-grid-three,
  .by-card-grid-five,
  .by-contact-grid {
    grid-template-columns: 1fr;
  }

  .by-contact-panel,
  .by-panel,
  .by-card,
  .by-install-card,
  .by-app-panel,
  .by-contact-side {
    padding: 1.5rem;
  }

  .by-contact-qr {
    flex-direction: column;
    align-items: flex-start;
  }
}