/* ============================================================
   星通云官网 · 样式
   主色：薄荷青绿（品牌 logo）
   ============================================================ */

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

:root {
  --bg:        #080D16;
  --bg-soft:   #0C1320;
  --card:      #101927;
  --card-hi:   #142032;
  --line:      rgba(255,255,255,.085);
  --line-hi:   rgba(23,184,144,.42);
  --text:      #E9F0F8;
  --text-2:    #A7B6C8;
  --text-3:    #6D7F94;
  --brand:     #17B890;
  --brand-lt:  #4FD9AE;
  --brand-dim: rgba(23,184,144,.14);
  --accent-r:  #E8503A;
  --accent-o:  #F5A623;
  --accent-b:  #4A90D9;
  --radius:    16px;
  --wrap:      1160px;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a { color: inherit; text-decoration: none; }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------------- 导航 ---------------- */

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background .3s, border-color .3s, backdrop-filter .3s;
  border-bottom: 1px solid transparent;
}

.nav.scrolled {
  background: rgba(8,13,22,.82);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}

.nav-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 17px;
  letter-spacing: .3px;
  flex-shrink: 0;
}

.brand img { border-radius: 9px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 30px;
  font-size: 14.5px;
  color: var(--text-2);
}

.nav-links a { transition: color .2s; white-space: nowrap; }
.nav-links a:hover { color: var(--text); }

.nav-links .nav-ext { color: var(--text-2); }

.nav-links .nav-cta {
  color: var(--brand-lt);
  border: 1px solid var(--line-hi);
  background: var(--brand-dim);
  padding: 7px 15px;
  border-radius: 999px;
  font-weight: 500;
  transition: background .2s, color .2s;
}

.nav-links .nav-cta:hover {
  background: var(--brand);
  color: #04120E;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  padding: 8px;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform .25s, opacity .25s;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------------- Hero ---------------- */

.hero {
  position: relative;
  padding: 168px 0 110px;
  overflow: hidden;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.032) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.032) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 78% 62% at 50% 0%, #000 35%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 78% 62% at 50% 0%, #000 35%, transparent 78%);
  pointer-events: none;
}

.hero-glow {
  position: absolute;
  top: -300px;
  left: 50%;
  width: 900px;
  height: 700px;
  transform: translateX(-50%);
  background: radial-gradient(circle, rgba(23,184,144,.20) 0%, rgba(23,184,144,.06) 42%, transparent 68%);
  filter: blur(20px);
  pointer-events: none;
}

.hero-inner { position: relative; text-align: center; }

.eyebrow {
  font-size: 12px;
  letter-spacing: .28em;
  color: var(--brand-lt);
  margin: 0 0 22px;
  font-weight: 500;
}

.hero h1 {
  font-size: clamp(38px, 6.2vw, 66px);
  line-height: 1.14;
  font-weight: 600;
  letter-spacing: -.02em;
  margin: 0 0 26px;
}

.hero h1 em {
  font-style: normal;
  background: linear-gradient(100deg, var(--brand-lt), #7FE7C4 55%, var(--brand));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lead {
  max-width: 660px;
  margin: 0 auto 38px;
  font-size: 17px;
  line-height: 1.85;
  color: var(--text-2);
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 58px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .18s, background .22s, border-color .22s, color .22s;
}

.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--brand);
  color: #04140F;
}

.btn-primary:hover {
  background: var(--brand-lt);
  box-shadow: 0 8px 26px rgba(23,184,144,.28);
}

.btn-ghost {
  border-color: var(--line);
  color: var(--text);
  background: rgba(255,255,255,.02);
}

.btn-ghost:hover {
  border-color: var(--line-hi);
  background: var(--brand-dim);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.hero-stats li {
  padding: 0 44px;
  border-left: 1px solid var(--line);
  text-align: center;
}

.hero-stats li:first-child { border-left: 0; }

.hero-stats strong {
  display: block;
  font-size: 32px;
  font-weight: 600;
  color: var(--brand-lt);
  line-height: 1.2;
}

.hero-stats span { font-size: 13px; color: var(--text-3); }

/* ---------------- 通用区块 ---------------- */

.section { padding: 104px 0; }

.section-alt {
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.sec-head { text-align: center; margin-bottom: 56px; }

.sec-head-left { text-align: left; margin-bottom: 30px; }

.sec-tag {
  font-size: 11.5px;
  letter-spacing: .26em;
  color: var(--brand);
  font-weight: 600;
  margin: 0 0 14px;
}

.sec-head h2 {
  font-size: clamp(27px, 3.6vw, 38px);
  font-weight: 600;
  letter-spacing: -.015em;
  margin: 0 0 14px;
}

.sec-sub { color: var(--text-2); margin: 0; font-size: 15.5px; }

/* ---------------- 卡片网格 ---------------- */

.grid-4, .grid-3 {
  display: grid;
  gap: 18px;
}

.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform .22s ease, border-color .22s, background .22s;
  position: relative;
  overflow: hidden;
}

.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  background: radial-gradient(circle at 50% 0%, rgba(23,184,144,.10), transparent 62%);
  opacity: 0;
  transition: opacity .25s;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--line-hi);
  background: var(--card-hi);
}

.card:hover::after { opacity: 1; }

.card-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--brand-dim);
  border: 1px solid rgba(23,184,144,.22);
  margin-bottom: 20px;
  color: var(--brand-lt);
}

.card-icon svg { width: 22px; height: 22px; }

.card h3 {
  font-size: 16.5px;
  font-weight: 600;
  margin: 0 0 9px;
  letter-spacing: .01em;
}

.card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-2);
}

/* 硬件卡片 */
.hw-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform .22s, border-color .22s, background .22s;
}

.hw-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-hi);
  background: var(--card-hi);
}

/* 产品图区域：统一浅色底，深色产品/浅色产品都能放 */
.hw-media {
  aspect-ratio: 1 / 1;
  background: linear-gradient(165deg, #F5F8FB 0%, #E2E9F2 100%);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.hw-media img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: transform .4s cubic-bezier(.2,.7,.3,1);
}

.hw-card:hover .hw-media img { transform: scale(1.04); }

.hw-body { padding: 24px 24px 28px; text-align: center; }

.hw-card h3 { margin: 0 0 8px; font-size: 17px; font-weight: 600; }
.hw-card p { margin: 0; font-size: 13.5px; line-height: 1.7; color: var(--text-2); }

/* ---------------- 下载中心 ---------------- */

.dl-list { display: grid; gap: 14px; }

.dl-item {
  display: grid;
  grid-template-columns: 62px 1fr auto;
  align-items: center;
  gap: 24px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 28px;
  transition: border-color .22s, background .22s, transform .22s;
}

.dl-item:hover {
  border-color: var(--line-hi);
  background: var(--card-hi);
  transform: translateX(3px);
}

.dl-no {
  font-size: 22px;
  font-weight: 600;
  color: var(--brand);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}

.dl-main h3 {
  margin: 0 0 7px;
  font-size: 16.5px;
  font-weight: 600;
}

.dl-meta {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-3);
}

.dl-meta b {
  color: var(--brand-lt);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.dl-actions { display: flex; gap: 10px; flex-wrap: wrap; }

.btn-sm {
  padding: 9px 20px;
  font-size: 13.5px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--text-2);
  transition: border-color .2s, color .2s, background .2s;
  white-space: nowrap;
}

.btn-sm:hover { border-color: var(--line-hi); color: var(--text); }

.btn-sm-primary {
  background: var(--brand-dim);
  border-color: var(--line-hi);
  color: var(--brand-lt);
}

.btn-sm-primary:hover { background: var(--brand); color: #04140F; }

.dl-note {
  margin: 26px 0 0;
  font-size: 13px;
  color: var(--text-3);
  text-align: center;
}

/* ---------------- 关于我们 ---------------- */

.about-grid {
  display: grid;
  grid-template-columns: 1.08fr .92fr;
  gap: 56px;
  align-items: center;
}

.about-body {
  font-size: 15.5px;
  line-height: 1.95;
  color: var(--text-2);
  max-width: 560px;
}

.about-body p { margin: 0 0 16px; }
.about-body p:last-child { margin-bottom: 0; }

.about-qr {
  display: flex;
  gap: 26px;
  margin-top: 34px;
  flex-wrap: wrap;
}

.about-qr figure {
  margin: 0;
  text-align: center;
}

.about-qr img {
  width: 104px;
  height: 104px;
  border-radius: 12px;
  background: #fff;
  padding: 6px;
  border: 1px solid var(--line);
  object-fit: contain;
}

.about-qr figcaption {
  margin-top: 9px;
  font-size: 12.5px;
  color: var(--text-3);
  letter-spacing: .04em;
}

.about-art { position: relative; }

.about-art img {
  width: 100%;
  height: auto;
  border-radius: 22px;
  /* 让深色配图边缘融进页面背景 */
  -webkit-mask-image: radial-gradient(ellipse 86% 84% at 50% 50%, #000 58%, transparent 100%);
  mask-image: radial-gradient(ellipse 86% 84% at 50% 50%, #000 58%, transparent 100%);
}

.about-art::before {
  content: "";
  position: absolute;
  /* 只上下外扩，左右不越界，避免在窄屏产生横向滚动 */
  inset: -16% 0;
  background: radial-gradient(circle at 55% 45%, rgba(74,144,217,.16), transparent 62%);
  filter: blur(28px);
  pointer-events: none;
  z-index: -1;
}

/* ---------------- CTA 条 ---------------- */

.cta-band {
  padding: 74px 0;
  background:
    radial-gradient(ellipse 60% 130% at 50% 50%, rgba(23,184,144,.13), transparent 70%),
    var(--bg);
  border-top: 1px solid var(--line);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}

.cta-inner h2 { margin: 0 0 8px; font-size: 26px; font-weight: 600; }
.cta-inner p { margin: 0; color: var(--text-2); font-size: 15px; }

/* ---------------- 页脚 ---------------- */

.footer {
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  padding-top: 58px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.1fr 1.4fr .9fr;
  gap: 40px;
  padding-bottom: 44px;
}

.footer-brand { display: flex; gap: 14px; align-items: flex-start; }
.footer-brand img { border-radius: 11px; flex-shrink: 0; }
.footer-brand strong { display: block; font-size: 16px; margin-bottom: 4px; }
.footer-brand p { margin: 0; font-size: 13px; color: var(--text-3); }

.footer-contact p {
  margin: 0 0 10px;
  font-size: 13.5px;
  color: var(--text-2);
  display: flex;
  gap: 14px;
}

.footer-contact span { color: var(--text-3); flex: 0 0 76px; }
.footer-contact b { font-weight: 500; color: var(--text); }
.footer-contact a { transition: color .2s; }
.footer-contact a:hover { color: var(--brand-lt); }

.footer-links { display: flex; flex-direction: column; gap: 10px; font-size: 13.5px; }
.footer-links a { color: var(--text-2); transition: color .2s; }
.footer-links a:hover { color: var(--brand-lt); }

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 22px;
  padding-bottom: 26px;
  font-size: 12.5px;
  color: var(--text-3);
  text-align: center;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.footer-bottom span::after { content: "·"; margin-left: 10px; opacity: .6; }
.footer-bottom a { transition: color .2s; }
.footer-bottom a:hover { color: var(--text-2); }

/* ---------------- 滚动淡入（渐进增强） ----------------
   默认完全可见；只有 JS 成功执行并给 <html> 加上 .anim 后，
   才进入「待播动画」状态。JS 失败 / 不支持 IO 时内容照常显示。 */

.reveal {
  opacity: 1;
  transform: none;
}

html.anim .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s cubic-bezier(.2,.7,.3,1), transform .6s cubic-bezier(.2,.7,.3,1);
}

html.anim .reveal.in {
  opacity: 1;
  transform: none;
}

/* ---------------- 响应式 ---------------- */

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .about-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
}

@media (max-width: 860px) {
  .nav-toggle { display: flex; }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(10,16,26,.98);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
    padding: 8px 24px 20px;
    display: none;
  }

  .nav-links.open { display: flex; }

  .nav-links a {
    padding: 13px 0;
    border-bottom: 1px solid rgba(255,255,255,.05);
  }

  .nav-links .nav-cta {
    text-align: center;
    margin-top: 14px;
    border-bottom: 0;
  }

  .hero { padding: 130px 0 84px; }
  .lead { font-size: 15.5px; }
  .hero-stats li { padding: 0 26px; }

  .section { padding: 76px 0; }

  .dl-item {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 22px;
  }

  .dl-no { font-size: 17px; }

  .cta-inner { flex-direction: column; align-items: flex-start; }

  .footer-inner { grid-template-columns: 1fr; gap: 32px; }

  .about-grid { grid-template-columns: 1fr; gap: 34px; }
  .about-body { max-width: none; }
  .about-qr { margin-top: 26px; }
}

@media (max-width: 560px) {
  .grid-4, .grid-3 { grid-template-columns: 1fr; }
  .hero-stats li { padding: 0 18px; border-left: 0; }
  .hero-stats { gap: 18px 0; }
  .hero-actions .btn { width: 100%; }
  /* 只改左右内边距：用简写会把 .footer-inner 等元素的上下 padding 一起清零 */
  .wrap { padding-left: 18px; padding-right: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.anim .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}