:root {
      --brand: #f26500;
      --brand-dark: #d95800;
      --brand-soft: #fff6ed;
      --brand-blue: #1a6bff;
      --text: #16181d;
      --muted: #5c6370;
      --line: #e6e9f0;
      --surface: #f5f7fb;
      --radius: 14px;
      --radius-lg: 20px;
      --shadow: 0 16px 48px rgba(22, 32, 52, 0.09);
      --shadow-sm: 0 4px 20px rgba(22, 32, 52, 0.06);
      --max: 1180px;
      --banner-inner: 1320px;
      --section-pad-y: 88px;
      --section-pad-x: 28px;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html {
      scroll-behavior: smooth;
      scroll-padding-top: clamp(56px, 14vw, 80px);
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      color: var(--text);
      line-height: 1.6;
      background: var(--surface);
      -webkit-text-size-adjust: 100%;
      text-size-adjust: 100%;
    }
    a { color: inherit; text-decoration: none; }
    img { max-width: 100%; height: auto; display: block; }

    .sg-visually-hidden {
      position: absolute;
      width: 1px;
      height: 1px;
      padding: 0;
      margin: -1px;
      overflow: hidden;
      clip: rect(0, 0, 0, 0);
      white-space: nowrap;
      border: 0;
    }
    .sg-skip-link {
      position: fixed;
      left: 0;
      top: 0;
      z-index: 10050;
      padding: 12px 18px;
      margin: 8px;
      font-size: 0.92rem;
      font-weight: 600;
      color: #fff;
      background: var(--brand);
      border-radius: 10px;
      box-shadow: 0 4px 18px rgba(255, 106, 0, 0.35);
      transform: translateY(-160%);
      transition: transform 0.2s ease;
    }
    .sg-skip-link:focus {
      transform: translateY(0);
      outline: 2px solid #fff;
      outline-offset: 2px;
    }

    .sg-header {
      position: sticky;
      top: 0;
      left: 0;
      right: 0;
      z-index: 200;
      width: 100%;
      max-width: none;
      padding-top: env(safe-area-inset-top, 0);
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(20px) saturate(1.12);
      -webkit-backdrop-filter: blur(20px) saturate(1.12);
      border-bottom: none;
      box-shadow: none;
      overflow: visible;
    }
    .sg-header__inner {
      width: auto;
      max-width: none;
      margin: 0;
      padding: 10px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      min-height: 64px;
      box-sizing: border-box;
      flex: 0 0 auto;
    }
    .sg-brand { display: flex; align-items: center; flex-shrink: 0; line-height: 0; }
    .sg-brand__logo { display: block; height: 36px; width: auto; }
    .sg-nav {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: flex-end;
      gap: 10px 22px;
    }
    .sg-nav a {
      font-size: 0.94rem;
      color: #333;
      padding: 6px 0;
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }
    .sg-nav a:hover { color: var(--brand); }
    .sg-nav a[aria-current="page"] {
      color: var(--brand);
      font-weight: 600;
      border-bottom: 2px solid var(--brand);
    }
    .sg-nav a.sg-nav__cta {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 10px 22px;
      border-radius: 999px;
      font-size: 0.92rem;
      font-weight: 600;
      color: #fff;
      background: linear-gradient(180deg, #4f9dff, #2b7efc);
      box-shadow: 0 6px 22px rgba(43, 126, 252, 0.38);
      border-bottom: none;
    }
    .sg-nav a.sg-nav__cta:hover {
      color: #fff;
      filter: brightness(1.05);
      transform: translateY(-1px);
    }

    .sg-nav__toggle {
      display: none;
      align-items: center;
      justify-content: center;
      width: 44px;
      height: 44px;
      margin: 0 0 0 auto;
      padding: 0;
      border: none;
      border-radius: 10px;
      background: rgba(0, 0, 0, 0.04);
      color: #333;
      cursor: pointer;
      flex-shrink: 0;
    }
    .sg-nav__toggle:hover {
      background: rgba(255, 106, 0, 0.1);
    }
    .sg-nav__toggle:focus-visible {
      outline: 2px solid var(--brand);
      outline-offset: 2px;
    }
    .sg-nav__toggle-bars {
      display: flex;
      flex-direction: column;
      justify-content: center;
      gap: 5px;
      width: 22px;
      height: 18px;
    }
    .sg-nav__toggle-bars span {
      display: block;
      height: 2px;
      border-radius: 1px;
      background: currentColor;
      transition: transform 0.25s ease, opacity 0.2s ease;
    }
    body.is-nav-open .sg-nav__toggle-bars span:nth-child(1) {
      transform: translateY(7px) rotate(45deg);
    }
    body.is-nav-open .sg-nav__toggle-bars span:nth-child(2) {
      opacity: 0;
    }
    body.is-nav-open .sg-nav__toggle-bars span:nth-child(3) {
      transform: translateY(-7px) rotate(-45deg);
    }
    .sg-nav-backdrop {
      display: none;
    }
    body.is-nav-open {
      overflow: hidden;
      touch-action: none;
    }

    .sg-hero {
      position: relative;
      display: flex;
      flex-direction: column;
      min-height: min(92vh, 960px);
      overflow: hidden;
    }
    .sg-hero__bg {
      position: absolute;
      inset: 0;
      z-index: 0;
      background: url("images/top-bg_bb6c7cb.png") center top / cover no-repeat;
    }
    .sg-hero__bg::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      background: linear-gradient(
        180deg,
        rgba(245, 248, 252, 0.75) 0%,
        rgba(245, 248, 252, 0.35) 38%,
        transparent 65%
      );
    }
    .sg-hero__main {
      position: relative;
      z-index: 1;
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 40px 20px 8px;
      text-align: center;
    }
    .sg-hero__inner {
      width: 100%;
      max-width: var(--banner-inner);
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      align-items: center;
    }
    .sg-hero__title {
      color: #0c2340;
      font-weight: 800;
      line-height: 1.2;
      text-shadow: 0 1px 0 rgba(255, 255, 255, 0.85);
      margin: 0 0 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 0.35em;
    }
    .sg-hero__title-brand {
      font-size: clamp(1rem, 2.4vw, 1.35rem);
      font-weight: 700;
      letter-spacing: 0.24em;
      color: #1a4a7a;
      opacity: 1;
    }
    .sg-hero__title-slogan {
      font-size: clamp(1.65rem, 4.5vw, 2.85rem);
      letter-spacing: 0.06em;
      color: #071a2e;
    }
    .sg-hero__sub {
      margin: 0 0 22px;
      color: #3d4f66;
      font-size: clamp(0.88rem, 1.8vw, 1.05rem);
      font-weight: 400;
      letter-spacing: 0.12em;
      max-width: 36em;
      line-height: 1.6;
    }
    .sg-hero__sub strong {
      color: #0f2744;
      font-weight: 700;
    }
    .sg-hero__downloads {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 12px 14px;
      margin-bottom: 28px;
      max-width: 900px;
      padding: 0 12px;
    }
    .sg-hero__dl-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 12px 22px;
      border-radius: 999px;
      font-size: 0.92rem;
      font-weight: 600;
      color: #fff;
      background: linear-gradient(135deg, var(--brand), var(--brand-dark));
      box-shadow: 0 8px 28px rgba(255, 106, 0, 0.4);
      transition: transform 0.15s, box-shadow 0.15s, filter 0.15s;
      white-space: nowrap;
    }
    .sg-hero__dl-btn:hover {
      filter: brightness(1.06);
      transform: translateY(-2px);
      box-shadow: 0 12px 32px rgba(255, 106, 0, 0.45);
    }
    .sg-hero__dl-btn--secondary {
      color: #163c66;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(22, 50, 90, 0.2);
      box-shadow: 0 4px 16px rgba(22, 40, 70, 0.08);
    }
    .sg-hero__dl-btn--secondary:hover {
      color: #0f2d52;
      background: #fff;
      border-color: rgba(22, 50, 90, 0.3);
      box-shadow: 0 6px 20px rgba(22, 40, 70, 0.12);
    }
    .sg-hero__laptop {
      flex: 1;
      display: flex;
      align-items: flex-end;
      justify-content: center;
      width: 100%;
      margin-top: 72px;
      min-height: 0;
    }
    .sg-hero__laptop-frame {
      position: relative;
      width: 100%;
      line-height: 0;
    }
    .sg-hero__laptop-frame .sg-hero__mac {
      width: 100%;
      max-width: none;
      height: auto;
      display: block;
      filter: drop-shadow(0 32px 56px rgba(25, 90, 150, 0.3));
      margin-bottom: -12px;
    }
    .sg-hero__overlay-gif {
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      width: 45%;
      max-width: min(92%, 900px);
      object-fit: contain;
      pointer-events: none;
      z-index: 2;
    }

    section { padding: var(--section-pad-y) var(--section-pad-x); }
    .sg-section-head {
      max-width: var(--max);
      margin: 0 auto 40px;
      text-align: center;
    }
    .sg-section-head h2 {
      font-size: clamp(1.35rem, 3vw, 1.65rem);
      font-weight: 800;
      margin-bottom: 12px;
    }
    .sg-section-head p {
      color: var(--muted);
      font-size: 1.02rem;
      line-height: 1.7;
      max-width: 48em;
      margin: 0 auto;
    }

    .sg-dl-grid {
      max-width: var(--max);
      margin: 0 auto;
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .sg-dl-card {
      border: 1px solid var(--line);
      border-radius: var(--radius);
      padding: 28px 26px;
      background: #fafafa;
      box-shadow: 0 4px 20px rgba(28, 28, 28, 0.04);
    }
    .sg-dl-card h3 {
      font-size: 1.12rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text);
    }
    .sg-dl-card p {
      font-size: 0.94rem;
      color: var(--muted);
      line-height: 1.75;
      margin-bottom: 16px;
    }
    .sg-dl-card__btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 24px;
      border-radius: 999px;
      font-size: 0.9rem;
      font-weight: 600;
      color: #fff;
      background: linear-gradient(135deg, var(--brand), var(--brand-dark));
      box-shadow: 0 6px 18px rgba(255, 106, 0, 0.3);
    }
    .sg-dl-card__btn:hover { filter: brightness(1.05); transform: translateY(-1px); }
    .sg-dl-card__meta {
      display: block;
      margin-top: 10px;
      font-size: 0.8rem;
      color: #888;
    }

    .sg-dl-steps {
      background: var(--brand-soft);
    }
    .sg-dl-steps__inner {
      max-width: var(--max);
      margin: 0 auto;
    }
    .sg-dl-steps__list {
      list-style: none;
      counter-reset: step;
      max-width: 42em;
      margin: 0 auto;
    }
    .sg-dl-steps__list li {
      position: relative;
      padding-left: 3rem;
      margin-bottom: 22px;
      font-size: 0.96rem;
      color: var(--muted);
      line-height: 1.75;
    }
    .sg-dl-steps__list li::before {
      counter-increment: step;
      content: counter(step);
      position: absolute;
      left: 0;
      top: 0;
      width: 2rem;
      height: 2rem;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--brand), var(--brand-dark));
      color: #fff;
      font-weight: 800;
      font-size: 0.95rem;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .sg-dl-steps__list strong { color: var(--text); }

    .sg-dl-note {
      background: #f8f9fb;
    }
    .sg-dl-note__inner {
      max-width: var(--max);
      margin: 0 auto;
    }
    .sg-dl-note__inner h2 { text-align: center; margin-bottom: 20px; font-size: 1.35rem; font-weight: 800; }
    .sg-dl-note__inner > p {
      font-size: 0.94rem;
      color: var(--muted);
      line-height: 1.85;
      margin-bottom: 14px;
    }

    .sg-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      border-radius: 999px;
      font-size: 0.95rem;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
    }
    .sg-btn--primary {
      background: linear-gradient(135deg, var(--brand), var(--brand-dark));
      color: #fff;
      box-shadow: 0 8px 24px rgba(255, 106, 0, 0.35);
    }
    .sg-btn--primary:hover { transform: translateY(-1px); }

    footer.sg-footer {
      background: linear-gradient(180deg, #141414 0%, #0f0f0f 100%);
      color: #9a9a9a;
      padding: 56px var(--section-pad-x) calc(40px + env(safe-area-inset-bottom, 0px));
      font-size: 0.875rem;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
    }
    .sg-footer__inner {
      max-width: var(--banner-inner);
      margin: 0 auto;
      text-align: center;
    }
    .sg-footer__top {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: center;
      gap: 14px 28px;
      margin-bottom: 28px;
      padding-bottom: 28px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .sg-footer__brand {
      display: inline-flex;
      align-items: center;
      line-height: 0;
    }
    .sg-footer__brand-link {
      display: inline-flex;
      align-items: center;
      opacity: 0.92;
    }
    .sg-footer__brand-link:hover {
      opacity: 1;
    }
    .sg-footer__brand-link img {
      display: block;
      height: 32px;
      width: auto;
    }
    .sg-footer__tagline {
      margin: 0;
      font-size: 0.82rem;
      color: #7a7a7a;
      line-height: 1.5;
      max-width: 28em;
    }
    .sg-footer__nav {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      align-items: center;
      gap: 10px 8px;
      margin-bottom: 24px;
    }
    .sg-footer__nav a {
      color: #c8c8c8;
      font-size: 0.9rem;
      padding: 4px 10px;
      border-radius: 6px;
    }
    .sg-footer__nav a:hover {
      color: #fff;
      background: rgba(255, 255, 255, 0.06);
    }
    .sg-footer__nav a[aria-current="page"] {
      color: var(--brand);
      font-weight: 600;
    }
    .sg-footer__nav span[aria-hidden="true"] {
      color: #444;
      user-select: none;
      font-size: 0.65rem;
    }
    .sg-footer__cta {
      margin-bottom: 22px;
    }
    .sg-footer__cta .sg-btn--primary {
      padding: 11px 28px;
      font-size: 0.92rem;
    }
    .sg-footer__copy {
      margin: 0;
      font-size: 0.76rem;
      color: #555;
    }
    .sg-footer__live {
      margin: 14px 0 0;
      font-size: 0.76rem;
      color: #666;
      font-variant-numeric: tabular-nums;
    }
    .sg-footer__biz {
      max-width: 46em;
      margin: 0 auto 24px;
      padding-top: 8px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      text-align: left;
    }
    .sg-footer__biz p {
      font-size: 0.78rem;
      color: #6e6e6e;
      line-height: 1.65;
      margin: 0 0 12px;
    }
    .sg-footer__biz p:last-child {
      margin-bottom: 0;
    }
    .sg-footer__biz strong {
      color: #9a9a9a;
    }

    .sg-dl-card__header {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 10px 12px;
      margin-bottom: 12px;
    }
    .sg-dl-card__header h3 {
      margin-bottom: 0;
      flex: 1 1 auto;
      min-width: 0;
    }
    .sg-dl-card__tag {
      display: inline-flex;
      align-items: center;
      flex-shrink: 0;
      padding: 4px 12px;
      border-radius: 999px;
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.02em;
      line-height: 1.3;
    }
    .sg-dl-card__tag--new {
      color: #fff;
      background: linear-gradient(135deg, var(--brand), var(--brand-dark));
    }
    .sg-dl-card__tag--chip {
      color: var(--brand);
      background: rgba(255, 106, 0, 0.12);
      border: 1px solid rgba(255, 106, 0, 0.25);
    }
    .sg-dl-card__tag--sync {
      color: #1b6ec4;
      background: rgba(43, 126, 252, 0.1);
      border: 1px solid rgba(43, 126, 252, 0.22);
    }
    .sg-dl-card__tag--privacy {
      color: #2d7a3e;
      background: rgba(45, 122, 62, 0.1);
      border: 1px solid rgba(45, 122, 62, 0.22);
    }
    .sg-hero__dl-btn--accent {
      background: #ff6a00 !important;
      box-shadow: 0 8px 28px rgba(255, 106, 0, 0.42);
    }

    @media (prefers-reduced-motion: reduce) {
      html {
        scroll-behavior: auto;
      }
      .sg-nav__toggle-bars span,
      .sg-nav,
      .sg-nav-backdrop,
      .sg-hero__dl-btn,
      .sg-dl-card__btn,
      .sg-btn,
      .sg-skip-link {
        transition-duration: 0.01ms !important;
      }
    }

    @media (min-width: 901px) {
      .sg-header {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        gap: 16px;
        width: 100%;
        max-width: none;
        margin: 0;
        padding-left: 24px;
        padding-right: 24px;
        box-sizing: border-box;
      }
      .sg-header__inner {
        flex: 0 0 auto;
        width: auto;
        max-width: none;
        margin: 0;
        padding-left: 0;
        padding-right: 0;
      }
      .sg-header .sg-nav {
        position: static;
        display: flex !important;
        flex-direction: row;
        flex-wrap: nowrap;
        align-items: center;
        justify-content: flex-end;
        flex: 1 1 auto;
        min-width: 0;
        gap: 10px 22px;
        width: auto;
        max-width: none;
        overflow-x: auto;
        overflow-y: visible;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: thin;
        height: auto;
        min-height: 0;
        margin: 0;
        padding: 0;
        transform: none !important;
        visibility: visible !important;
        pointer-events: auto !important;
        background: transparent;
        border: none;
        box-shadow: none;
      }
      .sg-nav__toggle {
        display: none !important;
      }
      .sg-nav-backdrop {
        display: none !important;
      }
      .sg-header .sg-nav a {
        white-space: nowrap;
        flex-shrink: 0;
      }
    }

    @media (max-width: 900px) {
      :root { --section-pad-y: 56px; --section-pad-x: 18px; }
      .sg-hero { min-height: auto; }
      .sg-hero__main {
        padding-left: clamp(14px, 4vw, 22px);
        padding-right: clamp(14px, 4vw, 22px);
      }
      .sg-hero__laptop { margin-top: 36px; }
      .sg-hero__title-brand { letter-spacing: 0.1em; }
      .sg-hero__sub { letter-spacing: 0.06em; }
      .sg-hero__downloads { flex-direction: column; align-items: stretch; }
      .sg-hero__dl-btn { justify-content: center; min-height: 46px; }
      .sg-section-head { margin-bottom: 28px; }
      .sg-section-head h2 { font-size: clamp(1.3rem, 4.2vw, 1.6rem); }
      .sg-dl-grid { grid-template-columns: 1fr; gap: 18px; }
      .sg-dl-card { padding: 22px 18px; }
      .sg-dl-card__btn {
        width: 100%;
        min-height: 46px;
        box-sizing: border-box;
      }
      .sg-header__inner {
        position: relative;
        z-index: 310;
        width: 100%;
        flex-wrap: nowrap;
        justify-content: space-between;
        align-items: center;
      }
      .sg-nav__toggle {
        display: inline-flex;
      }
      .sg-nav-backdrop {
        display: block;
        position: fixed;
        inset: 0;
        z-index: 9980;
        background: rgba(20, 20, 20, 0.45);
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        transition: opacity 0.25s ease, visibility 0.25s;
      }
      body.is-nav-open .sg-nav-backdrop {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
      }
      .sg-nav {
        position: fixed;
        top: calc(env(safe-area-inset-top, 0px) + 56px);
        right: 0;
        bottom: 0;
        left: auto;
        width: min(300px, 88vw);
        max-width: 100%;
        height: calc(100dvh - env(safe-area-inset-top, 0px) - 56px);
        height: calc(100vh - env(safe-area-inset-top, 0px) - 56px);
        max-height: none;
        margin: 0;
        padding: 12px 16px calc(24px + env(safe-area-inset-bottom, 0px));
        flex-direction: column;
        align-items: stretch;
        flex-wrap: nowrap;
        gap: 2px;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(14px);
        -webkit-backdrop-filter: blur(14px);
        border-left: 1px solid var(--line);
        box-shadow: -12px 0 40px rgba(0, 0, 0, 0.12);
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        z-index: 10000;
        transform: translateX(100%);
        visibility: hidden;
        pointer-events: none;
        transition: transform 0.3s ease, visibility 0.3s;
      }
      body.is-nav-open .sg-nav {
        transform: translateX(0);
        visibility: visible;
        pointer-events: auto;
      }
      .sg-nav a {
        padding: 14px 14px;
        border-radius: 10px;
        display: flex;
        align-items: center;
        width: 100%;
        box-sizing: border-box;
      }
      .sg-nav a.sg-nav__cta {
        margin-top: 10px;
        justify-content: center;
        border-bottom: none;
      }
      .sg-nav a[aria-current="page"] {
        border-bottom: none;
        font-weight: 600;
        color: var(--brand);
        background: rgba(255, 106, 0, 0.1);
      }
      .sg-dl-steps__list li { padding-left: 2.75rem; margin-bottom: 18px; }
      .sg-footer__nav a {
        min-height: 44px;
        padding: 10px 12px;
        display: inline-flex;
        align-items: center;
      }
    }

    @media (max-width: 480px) {
      :root { --section-pad-y: 44px; --section-pad-x: 14px; }
      .sg-header__inner { padding: 8px 12px; gap: 10px; }
      .sg-brand__logo { height: 28px; max-width: min(160px, 52vw); object-fit: contain; }
      .sg-hero__main { padding-top: 28px; }
      .sg-hero__title-slogan { font-size: clamp(1.4rem, 6.5vw, 1.9rem); }
      .sg-hero__title-brand {
        font-size: clamp(0.8rem, 3vw, 1rem);
        letter-spacing: 0.06em;
      }
      .sg-hero__sub { font-size: 0.88rem; letter-spacing: 0.04em; padding: 0 4px; }
      .sg-section-head p { font-size: 0.94rem; }
      .sg-dl-card h3 { font-size: 1.05rem; }
      .sg-dl-steps__list { padding: 0 4px; }
      .sg-dl-steps__list li { font-size: 0.92rem; }
      .sg-footer__biz { padding-left: 4px; padding-right: 4px; }
    }