/* 越屿AI 官网样式 v1 —— 乘帆越屿智能科技中心
   改颜色/字号：只改下面 :root 里的 CSS 变量即可全站生效 */
:root {
  --c-bg: #0b1524;
  --c-bg-alt: #101e33;
  --c-card: #16263f;
  --c-line: #24374f;
  --c-text: #eaf1fa;
  --c-muted: #9fb2c8;
  --c-accent: #38bdf8;
  --c-accent-2: #34d399;
  --max-w: 1080px;
  --radius: 14px;
  font-size: 17px; /* 全文可调大，读屏与低视力友好 */
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  line-height: 1.75;
}

a { color: var(--c-accent); }

/* 键盘可达性：所有可聚焦元素必须有明显焦点框 */
a:focus-visible, button:focus-visible, [tabindex]:focus-visible {
  outline: 3px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 跳转正文链接：Tab 第一下即可跳过导航 */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--c-accent);
  color: #04121f;
  padding: 0.6rem 1.2rem;
  z-index: 99;
  font-weight: 700;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

.wrap { max-width: var(--max-w); margin: 0 auto; padding: 0 1.25rem; }

/* ---------- 顶部导航 ---------- */
header.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 21, 36, 0.94);
  border-bottom: 1px solid var(--c-line);
}
.nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--c-text);
  text-decoration: none;
}
.brand svg { flex: none; }
button.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--c-line);
  color: var(--c-text);
  border-radius: 8px;
  padding: 0.45rem 0.8rem;
  font-size: 0.95rem;
  cursor: pointer;
}
nav.main-nav ul {
  display: flex;
  gap: 1.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
nav.main-nav a {
  color: var(--c-muted);
  text-decoration: none;
  font-weight: 600;
  padding: 0.3rem 0.1rem;
}
nav.main-nav a:hover, nav.main-nav a[aria-current="true"] { color: var(--c-text); }

@media (max-width: 760px) {
  button.nav-toggle { display: inline-block; }
  nav.main-nav { display: none; width: 100%; }
  nav.main-nav.open { display: block; padding-bottom: 0.8rem; }
  nav.main-nav ul { flex-direction: column; gap: 0.2rem; }
  nav.main-nav a { display: block; padding: 0.65rem 0.5rem; font-size: 1.05rem; }
  .nav-row { flex-wrap: wrap; }
}

/* ---------- 首屏 ---------- */
.hero { padding: 4.5rem 0 3.5rem; background:
  radial-gradient(60rem 30rem at 85% -10%, rgba(56,189,248,0.16), transparent 60%),
  radial-gradient(40rem 24rem at 10% 110%, rgba(52,211,153,0.10), transparent 60%);
}
.hero h1 {
  font-size: clamp(1.9rem, 5vw, 3rem);
  line-height: 1.3;
  margin: 0 0 1rem;
}
.hero p.lead { color: var(--c-muted); font-size: 1.15rem; max-width: 44rem; margin: 0 0 1.8rem; }
.hero .tag {
  display: inline-block;
  border: 1px solid var(--c-line);
  background: var(--c-card);
  color: var(--c-accent-2);
  border-radius: 999px;
  padding: 0.25rem 0.9rem;
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
}
.btn {
  display: inline-block;
  background: var(--c-accent);
  color: #04121f;
  font-weight: 800;
  text-decoration: none;
  border-radius: 10px;
  padding: 0.75rem 1.6rem;
  margin-right: 0.8rem;
}
.btn.secondary { background: transparent; color: var(--c-text); border: 1px solid var(--c-line); }
.btn:hover { filter: brightness(1.12); }

/* ---------- 通用区块 ---------- */
section.block { padding: 3.2rem 0; border-top: 1px solid var(--c-line); }
section.block h2 { font-size: 1.7rem; margin: 0 0 0.4rem; }
section.block p.sub { color: var(--c-muted); margin: 0 0 1.8rem; }

.grid { display: grid; gap: 1.2rem; }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 860px) { .grid.cols-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid.cols-2, .grid.cols-3 { grid-template-columns: 1fr; } }

.card {
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
}
.card h3 { margin: 0 0 0.5rem; font-size: 1.15rem; color: var(--c-text); }
.card p { margin: 0; color: var(--c-muted); }
.card .icon { font-size: 1.6rem; margin-bottom: 0.6rem; color: var(--c-accent); }

/* 产品大卡 */
.product-card { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; align-items: start; padding: 2rem; }
.product-card .meta .kind {
  display: inline-block; color: #04121f; background: var(--c-accent-2);
  border-radius: 999px; padding: 0.15rem 0.8rem; font-weight: 800; font-size: 0.85rem;
}
.product-card.alt .meta .kind { background: var(--c-accent); }
.product-card h3 { font-size: 1.5rem; margin: 0.7rem 0 0.4rem; }
.product-card .slogan { color: var(--c-accent); font-weight: 700; margin: 0 0 0.8rem; }
.product-card ul { margin: 0; padding-left: 1.2rem; color: var(--c-muted); }
.product-card ul li { margin-bottom: 0.45rem; }
@media (max-width: 760px) { .product-card { grid-template-columns: 1fr; } }

/* 数字带 */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.stat { text-align: center; }
.stat .num { font-size: 2rem; font-weight: 900; color: var(--c-accent); }
.stat .lbl { color: var(--c-muted); font-size: 0.95rem; }
@media (max-width: 640px) { .stats { grid-template-columns: repeat(2, 1fr); } }

/* 联系方式 */
.contact-line { display: flex; gap: 0.6rem; align-items: baseline; margin-bottom: 0.6rem; }
.contact-line strong { color: var(--c-text); min-width: 7em; }
.contact-line span { color: var(--c-muted); }

/* 页脚 */
footer.site-foot {
  border-top: 1px solid var(--c-line);
  background: var(--c-bg-alt);
  padding: 1.8rem 0 2.4rem;
  color: var(--c-muted);
  font-size: 0.95rem;
}
footer.site-foot .company { color: var(--c-text); font-weight: 700; }
footer.site-foot a { color: var(--c-muted); }

/* 屏幕阅读器专用文本 */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}