/* ========== Reset & Base ========== */
html, body {
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
}
body {
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  -khtml-user-select: none;
  user-select: none;
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: #333;
  background: #fff;
}
a {
  text-decoration: none;
  color: inherit;
}
img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}
h1, h2, h3, h4, h5, h6, p {
  margin: 0;
}

/* ========== Layout ========== */
#box {
  margin: 0;
  overflow-x: hidden;
}
.mid {
  text-align: center;
}

/* ========== Header ========== */
#header {
  padding: 13px 0;
  border-bottom: #F1F1F1 1px solid;
  background: #fff;
  position: sticky;
  top: 0;
  z-index: 100;
}
#header #top {
  width: 980px;
  max-width: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  box-sizing: border-box;
}
#header #logo {
  display: flex;
  align-items: center;
  gap: 0;
}
#header #logo img {
  height: 28px;
  width: auto;
}
.divider {
  margin: 0 10px;
  width: 1px;
  height: 10px;
  font-size: 11px;
  color: #ddd;
}
.logo-ai-text {
  font-size: 12px;
  font-weight: bold;
  margin-left: 4px;
}
.logo-ai-sub {
  font-size: 12px;
}
#header #topdown {
  display: flex;
  align-items: center;
  gap: 0;
}
.nav-home {
  font-size: 13px;
  margin-right: 15px;
  color: #333;
}
.btn-download-header img {
  height: 30px;
  width: auto;
}

/* ========== Hero ========== */
.hero {
  margin-top: 90px;
  padding: 0 16px 0;
}
.hero-title {
  margin: 20px auto 0;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.4;
  max-width: 980px;
  color: #1a1a1a;
}
.hero-desc {
  margin: 12px auto 0;
  font-size: 14px;
  color: #666;
  line-height: 1.8;
  max-width: 980px;
}
.hero-download {
  margin-top: 20px;
}
.adown {
  background: linear-gradient(to right, #FF6027, #FF06A0);
  border-radius: 20px;
  color: #fff;
  padding: 10px;
  font-size: 14px;
  display: inline-block;
  width: 174px;
  text-align: center;
  transition: opacity 0.2s;
}
.adown:hover {
  opacity: 0.9;
}
.hero-imag {
  margin-top: 100px;
  background: linear-gradient(#FFF, #EDEFFF);
  position: relative;
  z-index: 1;
}
.hero-imag img {
  max-width: 1020px;
  box-shadow: 0 0 40px #DDD9F3;
  border: 10px solid #fff;
  border-bottom: 0;
  z-index: 1;
  border-radius: 16px;
}

/* ========== AI Section ========== */
.ai-section {
  background: #494766 url('/styles/img/ai-logo-cc.png') no-repeat center;
  background-size: cover;
  position: relative;
  z-index: 999;
  margin-top: -20px;
  color: #fff;
  padding-bottom: 0;
}
.section-title-light {
  font-size: 42px;
  padding-top: 160px;
  margin: 0;
  font-weight: 700;
  line-height: 1.3;
}
.section-desc-light {
  font-size: 18px;
  line-height: 32px;
  padding-top: 20px;
  max-width: 700px;
  margin: 0 auto;
  color: rgba(255,255,255,0.9);
}
.ai-btn-wrap {
  padding: 50px 0;
}
.ai-btn {
  border-radius: 20px;
  border: 1px solid rgba(255,255,255,0.6);
  padding: 10px 50px;
  font-size: 14px;
  cursor: pointer;
  display: inline-block;
  transition: background 0.2s;
}
.ai-btn:hover {
  background: rgba(255,255,255,0.1);
}
.ai-img-wrap {
  padding-bottom: 150px;
}
.ai-img-wrap img {
  max-width: 960px;
  border-radius: 16px;
}

/* ========== Cloud Section ========== */
.cloud-section {
  background: #fff;
  padding-bottom: 0;
}
.section-title {
  font-size: 42px;
  padding-top: 50px;
  margin: 0;
  font-weight: 700;
  line-height: 1.3;
  color: #1a1a1a;
}
.section-desc {
  font-size: 18px;
  line-height: 32px;
  padding-top: 10px;
  max-width: 700px;
  margin: 0 auto;
  color: #666;
}
.gradient-text {
  background-image: linear-gradient(to right, #EB3838, #EB3685);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.cloud-img-wrap {
  max-width: 960px;
  margin: 0 auto;
  padding-top: 50px;
  padding-bottom: 80px;
}
.cloud-img-wrap img {
  width: 100%;
  border-radius: 12px;
}

/* ========== UI Upgrade Section ========== */
.ui-section {
  background: linear-gradient(to bottom right, #CB5DE2, #F57E2F);
  color: #fff;
  padding-bottom: 0;
}
.ui-img-wrap {
  padding: 50px 0 150px 0;
}
.ui-img-wrap img {
  border-radius: 20px;
  max-width: 960px;
}

/* ========== Enterprise Section ========== */
.enterprise-section {
  background: #fff;
  padding-bottom: 0;
}
.enterprise-img-wrap {
  max-width: 960px;
  margin: 0 auto;
  padding-top: 50px;
  padding-bottom: 80px;
}
.enterprise-img-wrap img {
  border-radius: 20px;
  width: 100%;
}

/* ========== Features Section ========== */
.features-section {
  background: #f8f9fa;
  padding: 80px 16px;
}
.features-heading {
  font-size: 32px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 12px;
}
.features-sub {
  font-size: 16px;
  color: #888;
  max-width: 600px;
  margin: 0 auto 48px;
  line-height: 1.6;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 960px;
  margin: 0 auto;
}
.feature-card {
  background: #fff;
  border-radius: 12px;
  padding: 28px 24px;
  text-align: left;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
  transition: box-shadow 0.2s;
}
.feature-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: #1a1a1a;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 14px;
  color: #888;
  line-height: 1.7;
}
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}
.icon-doc { background: #EEF2FF; color: #2B5AED; }
.icon-doc::before { content: "W"; font-weight: bold; }
.icon-sheet { background: #F0FDF4; color: #16A34A; }
.icon-sheet::before { content: "S"; font-weight: bold; }
.icon-ppt { background: #FFF7ED; color: #EA580C; }
.icon-ppt::before { content: "P"; font-weight: bold; }
.icon-pdf { background: #FDF2F8; color: #DB2777; }
.icon-pdf::before { content: "D"; font-weight: bold; }
.icon-cloud { background: #F5F3FF; color: #7C3AED; }
.icon-cloud::before { content: "☁"; font-weight: bold; }
.icon-collab { background: #EFF6FF; color: #2563EB; }
.icon-collab::before { content: "⊕"; font-weight: bold; }

/* ========== Download Section ========== */
.download-section {
  background: #fff;
  padding: 80px 16px;
}
.download-heading {
  font-size: 32px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 16px;
}
.download-desc {
  font-size: 16px;
  color: #888;
  max-width: 600px;
  margin: 0 auto 32px;
  line-height: 1.8;
}
.download-btns {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}
.btn-download-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(to right, #FF6027, #FF06A0);
  border-radius: 24px;
  color: #fff;
  padding: 12px 36px;
  font-size: 16px;
  font-weight: 500;
  transition: opacity 0.2s;
}
.btn-download-primary:hover {
  opacity: 0.9;
}
.btn-icon {
  font-size: 18px;
}
.btn-download-secondary {
  display: inline-flex;
  align-items: center;
  background: #fff;
  border: 1px solid #e5e5e5;
  border-radius: 24px;
  color: #555;
  padding: 12px 36px;
  font-size: 16px;
  font-weight: 500;
  transition: background 0.2s;
}
.btn-download-secondary:hover {
  background: #f9f9f9;
}
.download-note {
  font-size: 12px;
  color: #bbb;
  margin-top: 16px;
}

/* ========== Footer ========== */
#footer {
  margin-top: 0;
  border-top: #F1F1F1 1px solid;
  padding: 20px 16px 16px;
  color: #999;
  text-align: center;
  font-size: 12px;
  background: #fff;
}
.footer-nav {
  margin-bottom: 12px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
}
.footer-nav a {
  color: #999;
  font-size: 13px;
  transition: color 0.2s;
}
.footer-nav a:hover {
  color: #555;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  #header #top {
    width: 100%;
    padding: 0 12px;
  }
  .nav-home {
    display: none;
  }
  .hero {
    margin-top: 40px;
  }
  .hero-title {
    font-size: 24px;
  }
  .section-title, .section-title-light {
    font-size: 28px;
    padding-left: 16px;
    padding-right: 16px;
  }
  .section-desc, .section-desc-light {
    font-size: 15px;
    padding-left: 16px;
    padding-right: 16px;
  }
  .features-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
  }
  .ai-section {
    background-size: cover;
  }
  .section-title-light {
    padding-top: 80px;
  }
}