:root {
  --theme: #21c0ea;
  --theme-light: #7ce0f6;
  --theme-deep: #0e8fb8;
  --banner-ink: #ffffff;
  --banner-muted: rgba(255, 255, 255, 0.92);
  --download-ink: #0b8fb8;
  --text-primary: #12202b;
  --text-secondary: #4d5d6a;
  --text-muted: #7b8791;
  --surface: #ffffff;
  --line: rgba(33, 192, 234, 0.18);
  --shadow: 0 0.12rem 0.36rem rgba(12, 84, 110, 0.1);
  --shadow-card: 0 0.1rem 0.28rem rgba(12, 84, 110, 0.08);
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --radius-btn: 0.08rem;
  --radius-card: 0.12rem;
}

* {
  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 60% 40% at 90% 10%, rgba(33, 192, 234, 0.1), transparent 55%),
    radial-gradient(ellipse 50% 35% at 5% 70%, rgba(18, 168, 214, 0.07), transparent 50%),
    linear-gradient(180deg, #f5fcff 0%, #eef8fb 45%, #f8fafb 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 20% 30%, rgba(33, 192, 234, 0.06), transparent 40%),
    radial-gradient(circle at 80% 60%, rgba(14, 143, 184, 0.05), transparent 42%);
}

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

/* —— Header: underline nav + circle mark —— */
.header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: rgba(247, 252, 255, 0.82);
  border-bottom: 1px solid rgba(33, 192, 234, 0.12);
  animation: fade-down 0.55s ease-out both;
}

.header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.16rem 0.28rem;
}

.company {
  display: flex;
  align-items: center;
  color: var(--theme-deep);
}

.company__name {
  font-size: 0.22rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.28rem;
  font-size: 0.2rem;
  color: var(--text-secondary);
}

.nav span,
.nav a {
  position: relative;
  padding: 0.06rem 0.02rem;
  transition: color 0.25s ease;
}

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

.nav span.active::after,
.nav a:hover::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  border-radius: 1px;
  background: var(--theme);
}

.nav a:hover {
  color: var(--theme-deep);
}

/* —— Hero: text left, phone right —— */
.banner {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #1ab4e0 0%, #21c0ea 38%, #5ad4f0 72%, #8ee4f7 100%);
  animation: fade-in 0.6s ease-out both;
}

.banner__blob {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(0.04rem);
}

.banner__blob--a {
  width: 3.2rem;
  height: 3.2rem;
  top: -1rem;
  right: 18%;
  background: rgba(255, 255, 255, 0.18);
  animation: blob-drift 12s ease-in-out infinite;
}

.banner__blob--b {
  width: 2.4rem;
  height: 2.4rem;
  bottom: -0.6rem;
  left: 8%;
  background: rgba(14, 143, 184, 0.28);
  animation: blob-drift 14s ease-in-out infinite reverse;
}

.banner__blob--c {
  width: 1.6rem;
  height: 1.6rem;
  top: 40%;
  left: 42%;
  background: rgba(255, 255, 255, 0.12);
  animation: blob-drift 10s ease-in-out infinite 1s;
}

.appContent {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.4rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.72rem 0.28rem 0.56rem;
}

.banner-desc {
  flex: 1 1 48%;
  min-width: 0;
  color: var(--banner-ink);
  animation: slide-right 0.7s ease-out 0.12s both;
}

.banner-tag {
  display: inline-block;
  margin-bottom: 0.16rem;
  padding: 0.04rem 0.14rem;
  font-size: 0.18rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--theme-deep);
  background: rgba(255, 255, 255, 0.9);
  border-radius: var(--radius-btn);
}

.appName {
  margin-bottom: 0.18rem;
  font-size: 0.56rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.04em;
  text-shadow: 0 0.04rem 0.16rem rgba(10, 90, 120, 0.18);
}

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

.appDesc + .appDesc {
  margin-bottom: 0.32rem;
}

.download-link {
  display: inline-block;
  margin-top: 0.08rem;
}

.download {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.2rem;
  padding: 0.16rem 0.36rem;
  font-size: 0.22rem;
  font-weight: 600;
  color: var(--download-ink);
  background: #fff;
  border-radius: var(--radius-btn);
  box-shadow: 0 0.08rem 0.24rem rgba(10, 90, 120, 0.18);
  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, 0.7), transparent);
  transform: skewX(-20deg);
  pointer-events: none;
}

.download-link:hover .download {
  transform: translateY(-0.04rem) scale(1.03);
  box-shadow: 0 0.14rem 0.36rem rgba(10, 90, 120, 0.28);
  animation: none;
}

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

.phonePic-wrap {
  position: relative;
  flex: 0 0 42%;
  max-width: 3.6rem;
  display: flex;
  justify-content: center;
  animation: slide-up 0.75s ease-out 0.2s both;
}

.phonePic-ring {
  position: absolute;
  width: 85%;
  height: 85%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.28) 0%, transparent 68%);
  pointer-events: none;
}

.phonePic {
  position: relative;
  z-index: 1;
  width: 100%;
  height: auto;
  border-radius: 0.16rem;
  filter: drop-shadow(0 0.16rem 0.36rem rgba(10, 70, 100, 0.28));
}

/* —— Features: 2-column card grid —— */
.appInfo {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.64rem 0.28rem 0.8rem;
}

.section-head {
  margin-bottom: 0.4rem;
  text-align: left;
}

.section-title {
  position: relative;
  display: inline-block;
  font-size: 0.36rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.04em;
  padding-left: 0.16rem;
}

.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.08rem;
  bottom: 0.08rem;
  width: 0.06rem;
  border-radius: 0.03rem;
  background: linear-gradient(180deg, var(--theme), var(--theme-deep));
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.28rem;
}

.item {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  opacity: 0;
  transform: translateY(0.24rem);
  transition:
    opacity 0.55s ease,
    transform 0.55s ease,
    box-shadow 0.3s ease,
    border-color 0.3s ease;
}

.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;
}

.item:hover {
  border-color: rgba(33, 192, 234, 0.35);
  box-shadow: var(--shadow);
}

.item__media {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.32rem 0.24rem 0.12rem;
  border-radius: 0.14rem;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(33, 192, 234, 0.08) 0%, transparent 100%);
}

.item__media img {
  width: 55%;
  max-width: 2.2rem;
  height: auto;
  border-radius: 0.14rem;
}

.function-desc {
  padding: 0.12rem 0.28rem 0.32rem;
  text-align: center;
}

.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 kept for commented markup / reveal class */
.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;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-card);
}

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

.contact-row {
  display: flex;
  gap: 0.16rem;
  font-size: 0.2rem;
  color: var(--text-secondary);
  margin-top: 0.1rem;
}

.contact-row span {
  flex-shrink: 0;
  color: var(--text-muted);
}

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

/* —— Footer —— */
.copyright {
  border-top: 1px solid rgba(33, 192, 234, 0.12);
  background: rgba(255, 255, 255, 0.65);
}

.copyright-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.16rem 0.28rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.28rem 0.24rem 0.36rem;
  font-size: 0.16rem;
  color: var(--text-muted);
}

.beian-link {
  display: inline-flex;
  align-items: center;
  gap: 0.06rem;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.beian-link:hover {
  color: var(--theme-deep);
}

.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 0.08rem 0.24rem rgba(10, 90, 120, 0.18);
  }
  50% {
    transform: translateY(-0.02rem) scale(1.02);
    box-shadow: 0 0.12rem 0.32rem rgba(10, 90, 120, 0.28);
  }
}

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

@keyframes fade-down {
  from {
    opacity: 0;
    transform: translateY(-0.16rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

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

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

@keyframes blob-drift {
  0%,
  100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(0.2rem, -0.15rem) scale(1.06);
  }
}

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

  .company__name {
    font-size: 0.18rem;
    max-width: 3.2rem;
    white-space: normal;
    line-height: 1.3;
  }

  .nav {
    gap: 0.18rem;
    font-size: 0.18rem;
  }

  .appContent {
    flex-direction: column;
    align-items: stretch;
    padding: 0.48rem 0.2rem 0.4rem;
    gap: 0.32rem;
  }

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

  .appName {
    font-size: 0.44rem;
  }

  .appDesc {
    font-size: 0.22rem;
  }

  .phonePic-wrap {
    flex: none;
    max-width: 3rem;
    margin: 0 auto;
  }

  .appInfo {
    padding: 0.48rem 0.2rem 0.64rem;
  }

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

  .feature-grid {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }

  .item__media img {
    width: 48%;
  }

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

  .copyright-inner {
    flex-direction: column;
    gap: 0.08rem;
    text-align: center;
  }
}