/* ============ 基础重置 ============ */
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #E8F1FF;
  background: #000814;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }

/* ============ 全局深空背景层（覆盖所有页面） ============ */
.space-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 70% 30%, rgba(20, 60, 110, 0.35) 0%, transparent 55%),
    radial-gradient(ellipse at 20% 80%, rgba(10, 30, 70, 0.45) 0%, transparent 60%),
    linear-gradient(180deg, #000409 0%, #000814 50%, #020a1a 100%);
}

/* 星星层 */
.stars {
  position: absolute;
  inset: 0;
  background-repeat: repeat;
}
.stars.layer-1 {
  background-image:
    radial-gradient(1px 1px at 20px 30px, #ffffff, transparent),
    radial-gradient(1px 1px at 60px 120px, #cfe3ff, transparent),
    radial-gradient(1px 1px at 110px 70px, #ffffff, transparent),
    radial-gradient(1px 1px at 180px 150px, #b6cdff, transparent),
    radial-gradient(1px 1px at 220px 40px, #ffffff, transparent);
  background-size: 250px 200px;
  animation: twinkle 5s ease-in-out infinite alternate;
  opacity: 0.85;
}
.stars.layer-2 {
  background-image:
    radial-gradient(1.5px 1.5px at 40px 80px, #ffffff, transparent),
    radial-gradient(1.5px 1.5px at 130px 200px, #d8e8ff, transparent),
    radial-gradient(1.5px 1.5px at 200px 100px, #ffffff, transparent),
    radial-gradient(1.5px 1.5px at 280px 30px, #a8c6ff, transparent);
  background-size: 320px 260px;
  animation: twinkle 7s ease-in-out infinite alternate;
  opacity: 0.7;
}
.stars.layer-3 {
  background-image:
    radial-gradient(2px 2px at 80px 160px, #ffffff, transparent),
    radial-gradient(2px 2px at 240px 60px, #e3eeff, transparent),
    radial-gradient(2px 2px at 360px 220px, #ffffff, transparent);
  background-size: 400px 300px;
  animation: twinkle 9s ease-in-out infinite alternate;
  opacity: 0.55;
}
@keyframes twinkle {
  0% { opacity: 0.35; }
  100% { opacity: 0.9; }
}

/* 星云 */
.nebula {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.4;
  mix-blend-mode: screen;
}
.nebula-1 {
  width: 600px; height: 600px;
  top: -10%; left: -8%;
  background: radial-gradient(circle, #3b9eff 0%, transparent 70%);
  animation: drift 40s ease-in-out infinite alternate;
}
.nebula-2 {
  width: 500px; height: 500px;
  bottom: 5%; right: -10%;
  background: radial-gradient(circle, #6a4bff 0%, transparent 70%);
  animation: drift 50s ease-in-out infinite alternate-reverse;
}
@keyframes drift {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(40px, 30px) scale(1.1); }
}

/* ============ 地球（缓慢旋转） ============ */
.earth-wrap {
  position: absolute;
  top: 8%;
  right: 6%;
  width: 360px;
  height: 360px;
}
.earth-glow {
  position: absolute;
  inset: -40px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(59, 158, 255, 0.35) 0%, rgba(59, 158, 255, 0.08) 50%, transparent 70%);
  filter: blur(8px);
  animation: glowPulse 6s ease-in-out infinite alternate;
}
@keyframes glowPulse {
  0% { opacity: 0.6; transform: scale(1); }
  100% { opacity: 1; transform: scale(1.06); }
}
.earth {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  overflow: hidden;
  box-shadow:
    inset -30px -20px 60px 10px rgba(0, 0, 0, 0.7),
    inset 20px 15px 50px rgba(120, 180, 255, 0.15),
    0 0 60px rgba(59, 158, 255, 0.4);
}
/* 地球表面：长条纹理水平滚动模拟自转 */
.earth-surface {
  position: absolute;
  top: 0;
  left: 0;
  width: 200%;
  height: 100%;
  background:
    radial-gradient(ellipse 60px 40px at 40px 80px, #2e7d32, transparent 70%),
    radial-gradient(ellipse 80px 50px at 140px 120px, #1b5e20, transparent 70%),
    radial-gradient(ellipse 50px 35px at 220px 90px, #388e3c, transparent 70%),
    radial-gradient(ellipse 70px 45px at 330px 140px, #2e7d32, transparent 70%),
    radial-gradient(ellipse 55px 38px at 420px 100px, #1b5e20, transparent 70%),
    radial-gradient(ellipse 65px 42px at 510px 130px, #388e3c, transparent 70%),
    radial-gradient(ellipse 50px 35px at 600px 95px, #2e7d32, transparent 70%),
    radial-gradient(ellipse 75px 50px at 690px 135px, #1b5e20, transparent 70%),
    linear-gradient(180deg, #1565c0 0%, #1976d2 30%, #0d47a1 70%, #082d6b 100%);
  animation: earthRotate 60s linear infinite;
}
.earth-clouds {
  position: absolute;
  top: 0;
  left: 0;
  width: 200%;
  height: 100%;
  background:
    radial-gradient(ellipse 90px 25px at 100px 60px, rgba(255,255,255,0.5), transparent 70%),
    radial-gradient(ellipse 70px 20px at 250px 160px, rgba(255,255,255,0.4), transparent 70%),
    radial-gradient(ellipse 100px 28px at 400px 100px, rgba(255,255,255,0.45), transparent 70%),
    radial-gradient(ellipse 80px 22px at 550px 180px, rgba(255,255,255,0.4), transparent 70%),
    radial-gradient(ellipse 90px 25px at 680px 70px, rgba(255,255,255,0.45), transparent 70%);
  animation: earthRotate 75s linear infinite;
  opacity: 0.85;
}
.earth-shade {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, transparent 30%, rgba(0,0,0,0.55) 90%);
  pointer-events: none;
}
@keyframes earthRotate {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ============ 月球地表（底部弧形） ============ */
.moon-surface {
  position: absolute;
  bottom: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 200%;
  height: 360px;
  border-radius: 50% 50% 0 0 / 100% 100% 0 0;
  background: linear-gradient(180deg, #4a4f5c 0%, #2d313c 50%, #1a1d26 100%);
  box-shadow: 0 -20px 60px rgba(120, 140, 180, 0.15);
}
.moon-surface::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 40px;
  background: linear-gradient(180deg, rgba(200,210,230,0.4), transparent);
  border-radius: 50% 50% 0 0;
}
.crater {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 40%, #5a6070, #1a1d26);
  box-shadow: inset 2px 2px 4px rgba(255,255,255,0.15), inset -2px -2px 4px rgba(0,0,0,0.5);
}
.c1 { width: 60px; height: 60px; top: 80px; left: 18%; }
.c2 { width: 40px; height: 40px; top: 130px; left: 35%; }
.c3 { width: 80px; height: 80px; top: 60px; left: 52%; }
.c4 { width: 35px; height: 35px; top: 150px; left: 68%; }
.c5 { width: 50px; height: 50px; top: 90px; left: 82%; }

/* ============ 宇航员 ============ */
.astronaut {
  position: absolute;
  bottom: 140px;
  left: 4%;
  width: 200px;
  height: 320px;
  animation: floatAstro 6s ease-in-out infinite alternate;
  filter: drop-shadow(0 10px 30px rgba(0,0,0,0.6));
}
.astronaut svg { width: 100%; height: 100%; display: block; }
@keyframes floatAstro {
  0% { transform: translateY(0) rotate(-1deg); }
  100% { transform: translateY(-18px) rotate(1deg); }
}

/* ============ 顶部导航 ============ */
.topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 40px;
  background: linear-gradient(180deg, rgba(0,8,20,0.7) 0%, transparent 100%);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.5px;
}
.brand-mark {
  width: 28px; height: 28px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, #4db8ff, #0a4a8a 70%, #062040);
  box-shadow: 0 0 16px rgba(59,158,255,0.7), inset -3px -3px 6px rgba(0,0,0,0.4);
}
.brand-name em {
  font-style: normal;
  font-weight: 400;
  color: #4db8ff;
  font-size: 15px;
  margin-left: 4px;
}
.menu {
  display: flex;
  gap: 8px;
}
.menu-item {
  padding: 8px 18px;
  font-size: 15px;
  color: #c7d6ee;
  border-radius: 8px;
  position: relative;
  transition: color 0.25s, background 0.25s;
}
.menu-item:hover { color: #fff; background: rgba(59,158,255,0.12); }
.menu-item.active {
  color: #fff;
  background: rgba(59,158,255,0.18);
  box-shadow: 0 0 0 1px rgba(59,158,255,0.4) inset;
}
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.menu-toggle span {
  width: 26px; height: 2px;
  background: #c7d6ee;
  border-radius: 2px;
  transition: 0.3s;
}

/* ============ 内容区 ============ */
.content {
  position: relative;
  z-index: 10;
  padding: 120px 40px 60px;
  max-width: 1200px;
  margin: 0 auto;
  min-height: 100vh;
}
.page { display: none; animation: fadeIn 0.6s ease; }
.page.active { display: block; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ 首页 Hero ============ */
.hero { text-align: center; padding: 40px 0 50px; }
.eyebrow {
  font-size: 13px;
  letter-spacing: 4px;
  color: #4db8ff;
  margin-bottom: 14px;
  font-weight: 600;
}
.hero .title {
  font-size: clamp(40px, 7vw, 76px);
  font-weight: 800;
  letter-spacing: 2px;
  line-height: 1.1;
  background: linear-gradient(180deg, #ffffff 0%, #9fc6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero .title span {
  font-size: 0.55em;
  font-weight: 400;
  color: #4db8ff;
  -webkit-text-fill-color: #4db8ff;
  margin-left: 12px;
  letter-spacing: 4px;
}
.subtitle {
  font-size: clamp(18px, 2.2vw, 24px);
  color: #d6e4ff;
  margin: 16px 0 14px;
  letter-spacing: 6px;
}
.desc {
  max-width: 680px;
  margin: 0 auto 28px;
  color: #a8bbd8;
  font-size: 15px;
  line-height: 1.8;
}
.cta-row { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 32px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn.primary {
  background: linear-gradient(135deg, #3b9eff 0%, #1e6dd6 100%);
  color: #fff;
  box-shadow: 0 8px 24px rgba(59,158,255,0.45);
}
.btn.primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(59,158,255,0.6); }
.btn.ghost {
  background: rgba(255,255,255,0.06);
  color: #d6e4ff;
  border: 1px solid rgba(255,255,255,0.25);
  backdrop-filter: blur(6px);
}
.btn.ghost:hover { background: rgba(255,255,255,0.14); transform: translateY(-2px); }

/* 特性卡片 */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 50px;
}
.feature-card {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 16px;
  padding: 28px 24px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}
.feature-card:hover {
  transform: translateY(-6px);
  border-color: rgba(59,158,255,0.5);
  box-shadow: 0 12px 40px rgba(59,158,255,0.25);
}
.feature-ico {
  width: 48px; height: 48px;
  border-radius: 12px;
  margin-bottom: 18px;
  background: linear-gradient(135deg, rgba(59,158,255,0.3), rgba(59,158,255,0.08));
  border: 1px solid rgba(59,158,255,0.4);
  position: relative;
}
.feature-ico::after {
  content: "";
  position: absolute;
  inset: 12px;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}
.ico-rocket::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><path d='M4.5 16.5c-1.5 1.26-2 5-2 5s3.74-.5 5-2c.71-.84.7-2.13-.09-2.91a2.18 2.18 0 0 0-2.91-.09z'/><path d='M12 15l-3-3a22 22 0 0 1 2-3.95A12.88 12.88 0 0 1 22 2c0 2.72-.78 7.5-6 11a22.35 22.35 0 0 1-4 2z'/><path d='M9 12H4s.55-3.26 2-4c1.62-.83 5 0 5 0M12 15v5s3.26-.55 4-2c.83-1.62 0-5 0-5'/></svg>"); }
.ico-shield::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><path d='M12 22s8-4 8-10V5l-8-3-8 3v7c0 6 8 10 8 10z'/><path d='M9 12l2 2 4-4'/></svg>"); }
.ico-bolt::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><path d='M13 2L3 14h9l-1 8 10-12h-9l1-8z'/></svg>"); }
.ico-coin::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23ffd700' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><circle cx='12' cy='12' r='9'/><path d='M14.5 9.5a2.5 2.5 0 0 0-2.5-1.5c-1.5 0-2.5 1-2.5 2s1 2 2.5 2 2.5 1 2.5 2-1 2-2.5 2a2.5 2.5 0 0 1-2.5-1.5M12 6v1.5M12 16.5V18'/></svg>"); }
.ico-brand::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><path d='M12 2l3 6 6 .9-4.5 4.4 1 6.2L12 16.5 6.5 19.5l1-6.2L3 8.9 9 8z'/></svg>"); }
.ico-tech::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><rect x='3' y='3' width='18' height='18' rx='2'/><path d='M9 9h6v6H9zM3 9h2M3 15h2M19 9h2M19 15h2M9 3v2M15 3v2M9 19v2M15 19v2'/></svg>"); }
.ico-flow::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234db8ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'><path d='M3 12h4l3-9 4 18 3-9h4'/></svg>"); }
.feature-card h3 { font-size: 18px; margin-bottom: 8px; color: #fff; }
.feature-card p { font-size: 13px; line-height: 1.7; color: #a8bbd8; }

/* 数据条 */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 50px;
  padding: 24px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 16px;
  backdrop-filter: blur(10px);
}
.stat { text-align: center; }
.stat b {
  display: block;
  font-size: 26px;
  font-weight: 800;
  color: #4db8ff;
  text-shadow: 0 0 16px rgba(59,158,255,0.5);
}
.stat span { font-size: 12px; color: #a8bbd8; margin-top: 4px; display: block; }

/* ============ 通用页头 ============ */
.page-head { text-align: center; padding: 20px 0 10px; }
.page-head h2 {
  font-size: clamp(30px, 4.5vw, 46px);
  font-weight: 800;
  background: linear-gradient(180deg, #fff 0%, #9fc6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.page-sub {
  color: #a8bbd8;
  font-size: 15px;
  margin-top: 10px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ============ 合作流程 ============ */
.process { margin-top: 50px; }
.block-title {
  text-align: center;
  font-size: 20px;
  margin-bottom: 28px;
  color: #d6e4ff;
  position: relative;
}
.block-title::after {
  content: "";
  display: block;
  width: 40px; height: 2px;
  background: #3b9eff;
  margin: 10px auto 0;
  box-shadow: 0 0 10px rgba(59,158,255,0.7);
}
.process-steps {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}
.step {
  text-align: center;
  padding: 20px 28px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 14px;
  backdrop-filter: blur(8px);
  min-width: 140px;
}
.step-no {
  display: block;
  font-size: 22px;
  font-weight: 800;
  color: #4db8ff;
  text-shadow: 0 0 12px rgba(59,158,255,0.6);
}
.step span:last-child { font-size: 14px; color: #d6e4ff; margin-top: 6px; display: block; }
.step-line {
  width: 40px; height: 2px;
  background: linear-gradient(90deg, rgba(59,158,255,0.6), rgba(59,158,255,0.2));
}

/* 联系卡 */
.contact-card {
  margin-top: 50px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px 36px;
  background: linear-gradient(135deg, rgba(59,158,255,0.15), rgba(255,255,255,0.04));
  border: 1px solid rgba(59,158,255,0.3);
  border-radius: 18px;
  backdrop-filter: blur(12px);
  flex-wrap: wrap;
}
.contact-info h3 { font-size: 20px; margin-bottom: 12px; color: #fff; }
.contact-info p { font-size: 14px; color: #c7d6ee; line-height: 1.9; }

/* ============ 下载区 ============ */
.dl-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 40px;
}
.dl-card {
  text-align: center;
  padding: 32px 24px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 18px;
  backdrop-filter: blur(12px);
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}
.dl-card:hover {
  transform: translateY(-6px);
  border-color: rgba(59,158,255,0.5);
  box-shadow: 0 12px 40px rgba(59,158,255,0.25);
}
.dl-ico {
  width: 64px; height: 64px;
  margin: 0 auto 16px;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(59,158,255,0.25), rgba(59,158,255,0.05));
  border: 1px solid rgba(59,158,255,0.4);
  position: relative;
}
.dl-ico::after {
  content: "";
  position: absolute;
  inset: 16px;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}
.dl-ico.win::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%234db8ff'><path d='M3 5.5l8-1.1v7.3H3V5.5zm0 13l8 1.1v-7.2H3v6.1zM12 4.3L21 3v8.7h-9V4.3zm0 15.3l9 1.2V12h-9v7.6z'/></svg>"); }
.dl-ico.mac::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%234db8ff'><path d='M18.5 17.4c-.4 1-1 2-1.7 2.8-.7.8-1.5 1.2-2.4 1.2-.8 0-1.2-.5-2.2-.5s-1.5.5-2.3.5c-.9 0-1.7-.6-2.4-1.5C6 18 5 14.5 5.7 11.8c.4-1.4 1.6-2.4 2.8-2.4.9 0 1.7.6 2.3.6.6 0 1.5-.7 2.6-.6.5 0 1.8.2 2.7 1.4-2.3 1.4-1.9 4.6.4 6.6-.3.4-.5 1-.8 1.4zM13.5 6.5c.5-.6.8-1.4.7-2.2-.7 0-1.5.4-2 1-.5.6-.8 1.4-.7 2.2.7 0 1.5-.4 2-1z'/></svg>"); }
.dl-ico.android::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%234db8ff'><path d='M6 9v7c0 .6.4 1 1 1h1v3c0 .6.4 1 1 1s1-.4 1-1v-3h4v3c0 .6.4 1 1 1s1-.4 1-1v-3h1c.6 0 1-.4 1-1V9H6zM4 9c-.6 0-1 .4-1 1v5c0 .6.4 1 1 1s1-.4 1-1v-5c0-.6-.4-1-1-1zm16 0c-.6 0-1 .4-1 1v5c0 .6.4 1 1 1s1-.4 1-1v-5c0-.6-.4-1-1-1zM15 5.2l1.3-1.9c.1-.1 0-.3-.1-.3-.1 0-.2 0-.3.1L14.5 5c-.7-.3-1.6-.5-2.5-.5s-1.8.2-2.5.5L8 3.1c0-.1-.1-.1-.2-.1s-.2.1-.1.3l1.3 1.9C7.4 6 6 7.5 6 9.5h12c0-2-1.4-3.5-3-4.3z'/></svg>"); }
.dl-ico.ios::after { background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%234db8ff'><path d='M17 2h-3v6h4V5c0-1.7-1.3-3-1-3zM9.5 2H7C5.3 2 4 3.3 4 5v14c0 1.7 1.3 3 3 3h10c1.7 0 3-1.3 3-3V5c0-1.7-1.3-3-3-3h-3l1.5 1.5L13 6l-1.5-2.5L9.5 2z'/></svg>"); }
.dl-card h3 { font-size: 20px; margin-bottom: 6px; color: #fff; }
.dl-card .ver { font-size: 13px; color: #4db8ff; }
.dl-card .req { font-size: 12px; color: #8a9bbb; margin: 4px 0 18px; }

.scan-row {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin-top: 40px;
  flex-wrap: wrap;
}
.scan-card {
  text-align: center;
  padding: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 14px;
  backdrop-filter: blur(8px);
}
.qr {
  width: 120px; height: 120px;
  background:
    linear-gradient(45deg, transparent 46%, #d6e4ff 46% 54%, transparent 54%) 0 0/16px 16px,
    linear-gradient(-45deg, transparent 46%, #d6e4ff 46% 54%, transparent 54%) 0 0/16px 16px,
    #0a1428;
  border: 8px solid #d6e4ff;
  border-radius: 8px;
  margin-bottom: 10px;
}
.scan-card p { font-size: 13px; color: #c7d6ee; }

/* ============ 关于我们 ============ */
.about-block {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 36px;
  margin-top: 40px;
  align-items: start;
}
.about-text h3 {
  font-size: 20px;
  color: #4db8ff;
  margin: 24px 0 12px;
}
.about-text h3:first-child { margin-top: 0; }
.about-text p {
  font-size: 14px;
  line-height: 1.9;
  color: #c7d6ee;
}
.about-list {
  list-style: none;
  display: grid;
  gap: 10px;
}
.about-list li {
  font-size: 14px;
  color: #c7d6ee;
  padding-left: 22px;
  position: relative;
}
.about-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 7px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #4db8ff;
  box-shadow: 0 0 10px rgba(59,158,255,0.8);
}
.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.stat-big {
  text-align: center;
  padding: 28px 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 14px;
  backdrop-filter: blur(8px);
}
.stat-big b {
  display: block;
  font-size: 30px;
  font-weight: 800;
  color: #4db8ff;
  text-shadow: 0 0 18px rgba(59,158,255,0.5);
}
.stat-big span { font-size: 13px; color: #a8bbd8; margin-top: 4px; display: block; }

/* ============ 底部 ============ */
.footer {
  margin-top: 60px;
  padding-top: 28px;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
}
.footer p { font-size: 13px; color: #8a9bbb; }
.footer-note { margin-top: 6px; font-size: 12px; color: #5a6b8a; }

/* ============ 响应式 ============ */
@media (max-width: 900px) {
  .about-block { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .earth-wrap { width: 260px; height: 260px; top: 4%; right: 2%; opacity: 0.85; }
  .astronaut { width: 150px; height: 240px; bottom: 160px; left: 2%; }
}
@media (max-width: 720px) {
  .menu { display: none; position: absolute; top: 100%; right: 0; left: 0; flex-direction: column; background: rgba(0,8,20,0.95); padding: 16px; gap: 4px; border-top: 1px solid rgba(255,255,255,0.1); }
  .menu.open { display: flex; }
  .menu-item { text-align: center; }
  .menu-toggle { display: flex; }
  .topbar { padding: 14px 20px; }
  .content { padding: 100px 20px 50px; }
  .earth-wrap { width: 200px; height: 200px; top: 6%; }
  .astronaut { width: 120px; height: 200px; bottom: 180px; }
  .process-steps { flex-direction: column; }
  .step-line { width: 2px; height: 24px; background: linear-gradient(180deg, rgba(59,158,255,0.6), rgba(59,158,255,0.2)); }
  .contact-card { flex-direction: column; align-items: stretch; text-align: center; }
  .contact-card .btn { align-self: center; }
}