:root {
  --theme: #0087de;
  --theme-light: #59b1ea;
  --theme-deep: #0069ad;
  --text-primary: #12202b;
  --text-secondary: #4d5d6a;
  --text-muted: #7b8791;
  --surface: #ffffff;
  --line: rgba(0, 135, 222, 0.16);
  --shadow: 0 0.12rem 0.36rem rgba(0, 95, 182, 0.1);
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --radius: 0.14rem;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

ul {
  list-style: none;
}

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

html {
  height: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  position: relative;
  min-height: 100%;
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: 0.01em;
  color: var(--text-primary);
  overflow-x: hidden;
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, rgba(0, 135, 222, 0.1), transparent 60%),
    linear-gradient(180deg, #f3f8fc 0%, #eaf3fa 40%, #f7fafc 100%);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

.page-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(circle at 50% 20%, rgba(0, 135, 222, 0.05), transparent 45%),
    radial-gradient(circle at 15% 80%, rgba(0, 105, 173, 0.04), transparent 40%);
}

.header,
.layout,
.copyright {
  position: relative;
  z-index: 1;
}

/* —— Header: centered brand bar (non-sticky) —— */
.header {
  position: relative;
  z-index: 10;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid rgba(0, 135, 222, 0.1);
  animation: fade-in 0.5s ease-out both;
}

.header__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.1rem;
  max-width: 900px;
  margin: 0 auto;
  padding: 0.22rem 0.28rem 0.18rem;
  text-align: center;
}

.company {
  display: flex;
  align-items: center;
  justify-content: center;
}

.company__name {
  font-size: 0.24rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--theme-deep);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.32rem;
  font-size: 0.18rem;
  color: var(--text-muted);
}

.nav span.active {
  color: var(--theme);
  font-weight: 600;
}

.nav a {
  padding: 0.04rem 0.16rem;
  color: var(--theme-deep);
  border: 1px solid rgba(0, 135, 222, 0.35);
  border-radius: 0.06rem;
  transition: background 0.25s ease, color 0.25s ease;
}

.nav a:hover {
  color: #fff;
  background: var(--theme);
  border-color: var(--theme);
}

/* —— Hero: centered stack —— */
.banner {
  position: relative;
  overflow: hidden;
  animation: fade-in 0.65s ease-out both;
}

.banner__wash {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 80% at 50% 0%, rgba(0, 135, 222, 0.14), transparent 70%),
    radial-gradient(ellipse 50% 40% at 20% 90%, rgba(89, 177, 234, 0.12), transparent 55%),
    radial-gradient(ellipse 45% 35% at 85% 70%, rgba(0, 105, 173, 0.08), transparent 50%);
}

.appContent {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 900px;
  margin: 0 auto;
  padding: 0.56rem 0.28rem 0.4rem;
  text-align: center;
}

.banner-desc {
  width: 100%;
  animation: slide-down 0.65s ease-out 0.1s both;
}

.banner-tag {
  display: inline-block;
  margin-bottom: 0.14rem;
  font-size: 0.18rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--theme);
}

.appName {
  margin-bottom: 0.14rem;
  font-size: 0.54rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.06em;
  color: var(--text-primary);
}

.appDesc {
  font-size: 0.24rem;
  line-height: 1.55;
  color: var(--text-secondary);
}

.appDesc + .appDesc {
  margin-bottom: 0.28rem;
}

.download-link {
  display: inline-block;
}

.download {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.4rem;
  padding: 0.15rem 0.4rem;
  font-size: 0.22rem;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(135deg, var(--theme-light), var(--theme) 55%, var(--theme-deep));
  border-radius: 0.1rem;
  box-shadow: 0 0.1rem 0.28rem rgba(0, 105, 173, 0.28);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  animation: download-pulse 2.4s ease-in-out infinite;
}

.download::after {
  content: "";
  position: absolute;
  top: 0;
  left: -120%;
  width: 55%;
  height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, 0.55), transparent);
  transform: skewX(-20deg);
  pointer-events: none;
}

.download-link:hover .download {
  transform: translateY(-0.04rem) scale(1.03);
  box-shadow: 0 0.16rem 0.4rem rgba(0, 105, 173, 0.4);
  animation: none;
}

.download-link:hover .download::after {
  animation: download-shine 0.75s ease;
}

.phonePic-wrap {
  position: relative;
  width: 55%;
  max-width: 3.4rem;
  margin-top: 0.4rem;
  animation: slide-up 0.75s ease-out 0.22s both;
}

.phonePic-glow {
  position: absolute;
  width: 90%;
  height: 50%;
  left: 5%;
  bottom: 0;
  border-radius: 50%;
  background: radial-gradient(ellipse, rgba(0, 135, 222, 0.22) 0%, transparent 70%);
  pointer-events: none;
}

.phonePic {
  position: relative;
  z-index: 1;
  width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 0.16rem;
  filter: drop-shadow(0 0.14rem 0.32rem rgba(0, 80, 150, 0.2));
}

/* —— Features: vertical timeline —— */
.appInfo {
  max-width: 900px;
  margin: 0 auto;
  padding: 0.48rem 0.28rem 0.8rem;
}

.section-head {
  margin-bottom: 0.44rem;
  text-align: center;
}

.section-title {
  display: inline-block;
  font-size: 0.36rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text-primary);
}

.section-title::after {
  content: "";
  display: block;
  width: 0.48rem;
  height: 0.05rem;
  margin: 0.12rem auto 0;
  border-radius: 0.03rem;
  background: var(--theme);
}

.feature-timeline {
  position: relative;
  padding-left: 0.56rem;
}

.feature-timeline::before {
  content: "";
  position: absolute;
  left: 0.18rem;
  top: 0.12rem;
  bottom: 0.12rem;
  width: 2px;
  background: linear-gradient(180deg, var(--theme-light), var(--theme) 40%, rgba(0, 135, 222, 0.15));
  border-radius: 1px;
}

.item {
  position: relative;
  margin-bottom: 0.32rem;
  opacity: 0;
  transform: translateY(0.24rem);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.item:last-child {
  margin-bottom: 0;
}

.item.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.item:nth-child(2).is-visible {
  transition-delay: 0.08s;
}

.item:nth-child(3).is-visible {
  transition-delay: 0.16s;
}

.item:nth-child(4).is-visible {
  transition-delay: 0.24s;
}

.timeline-node {
  position: absolute;
  left: -0.56rem;
  top: 0.36rem;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 0.38rem;
  height: 0.38rem;
  font-size: 0.16rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(145deg, var(--theme-light), var(--theme-deep));
  border: 2px solid #fff;
  border-radius: 50%;
  box-shadow: 0 0.04rem 0.12rem rgba(0, 105, 173, 0.25);
}

.item__body {
  display: flex;
  align-items: center;
  gap: 0.24rem;
  padding: 0.24rem 0.28rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.item__media {
  flex: 0 0 28%;
  max-width: 1.8rem;
  border-radius: 0.14rem;
  overflow: hidden;
}

.item__media img {
  width: 100%;
  height: auto;
  border-radius: 0.14rem;
}

.function-desc {
  flex: 1;
  min-width: 0;
  text-align: left;
}

.function-desc h2 {
  margin-bottom: 0.06rem;
  font-size: 0.26rem;
  font-weight: 700;
  color: var(--text-primary);
}

.function-desc p {
  font-size: 0.2rem;
  color: var(--text-secondary);
}

/* —— Contact —— */
.contact {
  margin-top: 0.56rem;
  opacity: 0;
  transform: translateY(0.2rem);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.contact.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.contact-panel {
  padding: 0.36rem 0.4rem;
  text-align: center;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.contact-title {
  margin-bottom: 0.2rem;
  font-size: 0.28rem;
  font-weight: 700;
  color: var(--theme-deep);
}

.contact-row {
  font-size: 0.2rem;
  color: var(--text-secondary);
  margin-top: 0.12rem;
}

.contact-row--stack {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.04rem;
}

.contact-row span {
  color: var(--text-muted);
}

.contact-row em {
  font-style: normal;
  color: var(--text-primary);
  word-break: break-all;
}

/* —— Footer: stacked —— */
.copyright {
  border-top: 1px solid rgba(0, 135, 222, 0.1);
  background: rgba(255, 255, 255, 0.7);
}

.copyright-inner--stack {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.1rem;
  max-width: 900px;
  margin: 0 auto;
  padding: 0.28rem 0.24rem 0.36rem;
  font-size: 0.16rem;
  color: var(--text-muted);
  text-align: center;
}

.copyright-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.1rem 0.2rem;
}

.copyright-line a {
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.copyright-line a:hover {
  color: var(--theme);
}

.beian-link {
  display: inline-flex;
  align-items: center;
  gap: 0.06rem;
}

.copyright-img {
  width: 0.18rem;
  height: 0.18rem;
  border-radius: 0.04rem;
}

@keyframes download-pulse {
  0%,
  100% {
    transform: translateY(0) scale(1);
    box-shadow: 0 0.1rem 0.28rem rgba(0, 105, 173, 0.28);
  }
  50% {
    transform: translateY(-0.02rem) scale(1.02);
    box-shadow: 0 0.14rem 0.36rem rgba(0, 105, 173, 0.4);
  }
}

@keyframes download-shine {
  from {
    left: -120%;
  }
  to {
    left: 140%;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slide-down {
  from {
    opacity: 0;
    transform: translateY(-0.2rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slide-up {
  from {
    opacity: 0;
    transform: translateY(0.28rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 768px) {
  .header__inner {
    padding: 0.18rem 0.2rem 0.14rem;
  }

  .company__name {
    font-size: 0.2rem;
    letter-spacing: 0.03em;
  }

  .nav {
    gap: 0.2rem;
    font-size: 0.16rem;
  }

  .appContent {
    padding: 0.4rem 0.2rem 0.32rem;
  }

  .appName {
    font-size: 0.42rem;
  }

  .appDesc {
    font-size: 0.22rem;
  }

  .phonePic-wrap {
    width: 70%;
    max-width: 2.8rem;
    margin-top: 0.32rem;
  }

  .appInfo {
    padding: 0.4rem 0.2rem 0.64rem;
  }

  .section-title {
    font-size: 0.32rem;
  }

  .feature-timeline {
    padding-left: 0.48rem;
  }

  .feature-timeline::before {
    left: 0.15rem;
  }

  .timeline-node {
    left: -0.48rem;
    width: 0.34rem;
    height: 0.34rem;
    top: 0.28rem;
    font-size: 0.14rem;
  }

  .item__body {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.12rem;
    padding: 0.22rem 0.2rem;
  }

  .item__media {
    flex: none;
    max-width: 1.6rem;
  }

  .function-desc {
    text-align: center;
  }

  .function-desc h2 {
    font-size: 0.24rem;
  }

  .contact-panel {
    padding: 0.28rem 0.2rem;
  }

  .copyright-line {
    flex-direction: column;
    gap: 0.06rem;
  }
}