:root {
      color-scheme: light;
      --font-sans: "PingFang SC", "SF Pro SC", "SF Pro Text", "Helvetica Neue", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
      --ink: #1a1a1a;
      --ink-soft: #4a4a4a;
      --ink-faint: #767676;
      --wash: #f7f7f5;
      --wash-2: #efefec;
      --surface: #ffffff;
      --accent: #2f5d52;
      --accent-deep: #244840;
      --line: rgba(26, 26, 26, 0.08);
      --line-strong: rgba(26, 26, 26, 0.12);
      --shadow-soft: 0 1px 2px rgba(26, 26, 26, 0.04), 0 8px 24px rgba(26, 26, 26, 0.06);
      --shadow-phone: 0 16px 48px rgba(26, 26, 26, 0.12);
      --header-h: 64px;
      --content-w: min(1080px, calc(100vw - clamp(32px, 6vw, 64px)));
      --section-gap: clamp(80px, 10vh, 112px);
      --radius-lg: 16px;
      --radius-md: 12px;
    }

    html[lang="en"] {
      --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    }

    *, *::before, *::after { box-sizing: border-box; }

    html {
      scroll-behavior: smooth;
    }

    body {
      margin: 0;
      font-family: var(--font-sans);
      color: var(--ink);
      line-height: 1.65;
      background: var(--wash);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: clip;
    }

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

    a { color: inherit; }

    .ambient {
      position: fixed;
      inset: 0;
      z-index: 0;
      pointer-events: none;
      overflow: hidden;
    }

    .ambient span {
      position: absolute;
      border-radius: 50%;
      filter: blur(64px);
      opacity: 0.35;
    }

    .ambient .b1 {
      width: min(60vw, 480px);
      height: min(60vw, 480px);
      top: -10%;
      right: -12%;
      background: radial-gradient(circle, rgba(255, 255, 255, 0.9) 0%, transparent 70%);
    }

    .ambient .b2 {
      width: min(50vw, 360px);
      height: min(50vw, 360px);
      bottom: 20%;
      left: -12%;
      background: radial-gradient(circle, rgba(47, 93, 82, 0.06) 0%, transparent 70%);
    }

    .ambient .b3 {
      width: 240px;
      height: 240px;
      bottom: -4%;
      right: 8%;
      background: radial-gradient(circle, rgba(255, 255, 255, 0.8) 0%, transparent 72%);
    }

    .ambient .b4 {
      display: none;
    }

    /* 顶栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      z-index: 100;
      height: var(--header-h);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 0 clamp(16px, 4vw, 32px);
      padding-top: env(safe-area-inset-top, 0);
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(12px) saturate(1.2);
      border-bottom: 1px solid var(--line);
    }

    .site-header__inner {
      width: var(--content-w);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 20px;
    }

    .site-header__brand-group {
      display: flex;
      align-items: center;
      gap: clamp(12px, 2vw, 18px);
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      font-weight: 600;
      letter-spacing: -0.01em;
      color: var(--ink);
      flex-shrink: 0;
    }

    .brand__app-icon {
      width: 32px;
      height: 32px;
      flex-shrink: 0;
    }

    .brand span {
      font-size: 1rem;
    }

    .brand-divider {
      width: 1px;
      height: 24px;
      background: var(--line-strong);
      flex-shrink: 0;
    }

    .brand__company-logo {
      display: block;
      height: 28px;
      width: auto;
      flex-shrink: 0;
    }

    .site-nav {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: clamp(10px, 1.6vw, 20px);
      min-width: 0;
      flex: 1;
    }

    .site-nav a:not(.btn) {
      text-decoration: none;
      font-size: clamp(0.75rem, 1.4vw, 0.8125rem);
      font-weight: 500;
      color: var(--ink-soft);
      white-space: nowrap;
      flex-shrink: 0;
      transition: color 0.2s;
    }

    .site-nav a:not(.btn):hover {
      color: var(--ink);
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 0.65em 1.25em;
      border-radius: 10px;
      font-size: 0.875rem;
      font-weight: 600;
      letter-spacing: -0.01em;
      text-decoration: none;
      border: none;
      cursor: pointer;
      transition: background 0.2s, transform 0.15s, box-shadow 0.2s;
      white-space: nowrap;
    }

    .btn:active {
      transform: scale(0.98);
    }

    .btn--primary {
      background: var(--accent);
      color: #fff;
      box-shadow: 0 1px 2px rgba(26, 26, 26, 0.06);
    }

    .btn--primary:hover {
      background: var(--accent-deep);
      box-shadow: 0 4px 12px rgba(47, 93, 82, 0.2);
    }

    .btn--ghost {
      background: var(--surface);
      color: var(--ink-soft);
      border: 1px solid var(--line-strong);
    }

    .btn--ghost:hover {
      background: var(--wash-2);
      color: var(--ink);
    }

    .btn svg {
      width: 18px;
      height: 18px;
      flex-shrink: 0;
    }

    /* 页面主体 */
    .page {
      position: relative;
      z-index: 1;
    }

    section {
      scroll-margin-top: calc(var(--header-h) + 16px);
    }

    .container {
      width: var(--content-w);
      margin: 0 auto;
    }

    /* Hero */
    .hero {
      padding:
        calc(var(--header-h) + clamp(56px, 10vh, 96px))
        0
        clamp(48px, 7vh, 72px);
    }

    .hero__inner {
      margin: 0 auto;
    }

    [data-auto-align] {
      text-align: center;
    }

    [data-auto-align].is-align-start {
      text-align: start;
    }

    [data-auto-align].is-align-start .hero__icon {
      margin-left: 0;
      margin-right: auto;
    }

    [data-auto-align].is-align-start .hero__actions,
    [data-auto-align].is-align-start .cta__actions {
      justify-content: flex-start;
    }

    .hero__icon {
      width: clamp(80px, 14vw, 96px);
      height: auto;
      margin: 0 auto;
      transform: rotate(-5deg);
      filter: drop-shadow(0 8px 20px rgba(26, 26, 26, 0.08));
    }

    .hero__title {
      margin: clamp(20px, 3vh, 28px) 0 0;
      font-size: clamp(1.875rem, 4.5vw, 2.75rem);
      font-weight: 700;
      line-height: 1.25;
      letter-spacing: -0.03em;
    }

    .hero__lead {
      margin: clamp(16px, 2.5vh, 20px) 0 0;
      font-size: clamp(0.9375rem, 2vw, 1.0625rem);
      color: var(--ink-soft);
      line-height: 1.7;
      font-weight: 400;
    }

    .hero__lead + .hero__lead {
      margin-top: 0.85em;
    }

    .hero__actions {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 14px;
      margin-top: clamp(28px, 4vh, 40px);
    }

    /* 功能区块 */
    .features {
      border-top: 1px solid var(--line);
      padding-top: clamp(40px, 6vh, 64px);
      padding-bottom: var(--section-gap);
    }

    .features__header {
      margin-bottom: clamp(48px, 7vh, 72px);
    }

    .features__header h2 {
      margin: 0;
      font-size: clamp(1.375rem, 3vw, 1.75rem);
      font-weight: 700;
      letter-spacing: -0.02em;
    }

    .features__header p {
      margin: 0.5em 0 0;
      color: var(--ink-faint);
      font-size: 0.9375rem;
    }

    [data-auto-align]:not(.is-align-start) .features__header p {
      margin-left: auto;
      margin-right: auto;
    }

    .feature {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: clamp(32px, 5vw, 72px);
      align-items: center;
      padding: clamp(40px, 6vh, 64px) 0;
    }

    .feature + .feature {
      border-top: 1px solid var(--line);
    }

    .feature--reverse .feature__copy {
      order: 2;
    }

    .feature--reverse .feature__media {
      order: 1;
    }

    .feature__tag {
      display: inline-block;
      margin-bottom: 0.75em;
      padding: 0.3em 0.7em;
      border-radius: 6px;
      background: rgba(47, 93, 82, 0.08);
      color: var(--accent);
      font-size: 0.75rem;
      font-weight: 600;
      letter-spacing: 0.04em;
    }

    .feature__title {
      margin: 0;
      font-size: clamp(1.25rem, 2.8vw, 1.625rem);
      font-weight: 700;
      line-height: 1.35;
      letter-spacing: -0.02em;
    }

    .feature__body {
      margin: 0.875em 0 0;
      color: var(--ink-soft);
      font-size: clamp(0.9375rem, 1.8vw, 1rem);
      line-height: 1.75;
    }

    .feature__body p {
      margin: 0;
    }

    .feature__body p + p {
      margin-top: 0.75em;
    }

    .feature__media {
      position: relative;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 360px;
    }

    .feature__media--single img {
      width: min(100%, 300px);
      filter: drop-shadow(var(--shadow-phone));
    }

    .feature__media--duo {
      min-height: 400px;
    }

    .feature__media--duo img:first-child {
      position: relative;
      z-index: 2;
      width: min(58%, 220px);
      filter: drop-shadow(var(--shadow-phone));
      transform: translateX(12%);
    }

    .feature__media--duo img:last-child {
      position: absolute;
      z-index: 1;
      width: min(58%, 220px);
      filter: drop-shadow(0 20px 48px rgba(42, 38, 34, 0.1));
      transform: translateX(-18%) translateY(8%) scale(0.94);
      opacity: 0.92;
    }

    .feature--reverse .feature__media--duo img:first-child {
      transform: translateX(-12%);
    }

    .feature--reverse .feature__media--duo img:last-child {
      transform: translateX(18%) translateY(8%) scale(0.94);
    }

    /* 为什么选择 */
    .why {
      padding: var(--section-gap) 0;
    }

    .why__header {
      text-align: center;
      margin-bottom: clamp(40px, 6vh, 56px);
    }

    .why__header h2 {
      margin: 0;
      font-size: clamp(1.375rem, 3vw, 1.75rem);
      font-weight: 700;
      letter-spacing: -0.02em;
    }

    .why__grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: clamp(18px, 3vw, 24px);
    }

    .why-card {
      padding: clamp(20px, 3.5vw, 28px);
      border-radius: var(--radius-md);
      background: var(--surface);
      border: 1px solid var(--line);
      box-shadow: var(--shadow-soft);
    }

    .why-card h3 {
      margin: 0;
      font-size: clamp(1rem, 2.2vw, 1.125rem);
      font-weight: 700;
      line-height: 1.45;
      letter-spacing: -0.015em;
    }

    .why-card p {
      margin: 0.75em 0 0;
      color: var(--ink-soft);
      font-size: 0.9375rem;
      line-height: 1.7;
    }

    /* 结尾 CTA */
    .cta {
      padding-bottom: clamp(64px, 10vh, 96px);
    }

    .cta__card {
      padding: clamp(36px, 6vw, 56px);
      border-radius: var(--radius-lg);
      background: var(--surface);
      border: 1px solid var(--line);
      box-shadow: var(--shadow-soft);
    }

    .cta__title {
      margin: 0;
      font-size: clamp(1.5rem, 3.5vw, 2rem);
      font-weight: 700;
      line-height: 1.3;
      letter-spacing: -0.025em;
    }

    .cta__body {
      margin: 0.875em 0 0;
      color: var(--ink-soft);
      font-size: clamp(0.9375rem, 2vw, 1rem);
      line-height: 1.75;
    }

    [data-auto-align]:not(.is-align-start) .cta__body {
      margin-left: auto;
      margin-right: auto;
    }

    .cta__body + .cta__body {
      margin-top: 0.5em;
    }

    .cta__actions {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 14px;
      margin-top: clamp(28px, 4vh, 36px);
    }

    /* 页脚 */
    .site-footer {
      padding: clamp(24px, 3vh, 32px) clamp(16px, 4vw, 32px);
      padding-bottom: calc(clamp(24px, 3vh, 32px) + env(safe-area-inset-bottom, 0));
      text-align: center;
      font-size: 0.8125rem;
      color: var(--ink-faint);
      border-top: 1px solid var(--line);
      background: var(--surface);
    }

    .site-footer a {
      color: var(--ink-faint);
      text-decoration: none;
    }

    .site-footer a:hover {
      color: var(--ink);
      text-decoration: underline;
    }

    .site-footer__beian {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      vertical-align: middle;
    }

    .site-footer__beian img {
      height: 13px;
      width: auto;
    }

    .site-footer > div + div {
      margin-top: 6px;
    }

    /* 入场动画 */
    .reveal {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.7s ease, transform 0.7s ease;
    }

    .reveal.is-visible {
      opacity: 1;
      transform: none;
    }

    /* 响应式 */
    @media (max-width: 900px) {
      .feature {
        grid-template-columns: 1fr;
      }

      .feature--reverse .feature__copy,
      .feature--reverse .feature__media {
        order: unset;
      }

      .feature__media {
        min-height: 280px;
      }

      .feature__media--duo {
        min-height: 340px;
      }

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

      .site-nav {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        mask-image: linear-gradient(to right, transparent, #000 12px, #000 calc(100% - 12px), transparent);
      }

      .site-nav::-webkit-scrollbar {
        display: none;
      }
    }

    @media (max-width: 720px) {
      .brand span {
        display: none;
      }

      .brand-divider,
      .brand__company-logo {
        display: none;
      }
    }

    @media (max-width: 480px) {
      .feature__media--duo img:first-child,
      .feature__media--duo img:last-child {
        width: min(52%, 180px);
      }
    }

    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      .reveal {
        opacity: 1;
        transform: none;
        transition: none;
      }
    }

    /* 语言切换 */
    .lang-switch {
      font-size: clamp(0.75rem, 1.4vw, 0.8125rem);
      font-weight: 600;
      color: var(--accent);
      text-decoration: none;
      white-space: nowrap;
      flex-shrink: 0;
    }

    .lang-switch:hover {
      color: var(--accent-deep);
    }

    .site-nav .lang-switch {
      margin-left: 4px;
      padding-left: clamp(10px, 1.6vw, 16px);
      border-left: 1px solid var(--line);
    }