/* 设计系统与基础样式 */
:root {
  --bg: #0b1020;
  --bg-alt: #11172a;
  --card: #162039;
  --text: #eaf2ff;
  --muted: #b9c4dd;
  --primary: #5b8cff;
  --primary-2: #7bd1ff;
  --accent: #00d4ff;
  --success: #35c48e;
  --shadow: rgba(0, 0, 0, 0.25);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #0b1020 0%, #0d1326 60%, #0f152b 100%);
  line-height: 1.6;
}

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

/* 头部与导航 */
.header {
  position: sticky;
  top: 0;
  backdrop-filter: saturate(140%) blur(8px);
  background: rgba(13, 19, 38, 0.6);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  z-index: 20;
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand__logo { width: 32px; height: 32px; }
.brand__name { font-weight: 700; color: var(--text); }

.nav__toggle { display: none; background: none; border: 1px solid rgba(255,255,255,0.2); color: var(--text); padding: 6px 10px; border-radius: 8px; }
.nav__list { display: flex; gap: 18px; list-style: none; margin: 0; padding: 0; }
.nav__list a { color: var(--muted); text-decoration: none; padding: 8px 10px; border-radius: 8px; }
.nav__list a:hover { color: var(--text); background: rgba(255,255,255,0.06); }

/* 英雄区 */
.hero {
  padding: 72px 0 28px;
  background:
    radial-gradient(1200px 400px at 10% -20%, rgba(91,140,255,0.25) 0%, rgba(91,140,255,0) 60%),
    radial-gradient(1200px 400px at 90% -20%, rgba(123,209,255,0.18) 0%, rgba(123,209,255,0) 60%);
}
.hero__title { font-size: clamp(26px, 4.5vw, 40px); margin: 0 0 12px; letter-spacing: 0.3px; }
.hero__subtitle { color: var(--muted); max-width: 760px; margin: 0 0 20px; }
.hero__ctas { display: flex; gap: 12px; margin: 24px 0; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 16px; border-radius: 10px; text-decoration: none; font-weight: 600; }
.btn--primary { background: linear-gradient(90deg, var(--primary), var(--primary-2)); color: #051022; box-shadow: 0 6px 16px rgba(91,140,255,0.35); }
.btn--outline { border: 1px solid rgba(255,255,255,0.18); color: var(--text); }
.hero__stats { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 12px; margin-top: 18px; }
.stat { background: rgba(255,255,255,0.04); border: 1px solid rgba(255,255,255,0.06); padding: 12px 14px; border-radius: 12px; }
.stat__num { font-weight: 700; }
.stat__label { color: var(--muted); margin-left: 6px; }

/* 通用版块 */
.section { padding: 42px 0; }
.section--alt { background: var(--bg-alt); }
.section__title { font-size: 22px; margin: 0 0 18px; }

.cards { display: grid; gap: 16px; grid-template-columns: repeat(4, minmax(0,1fr)); }
.card { background: var(--card); border: 1px solid rgba(255,255,255,0.08); border-radius: 14px; padding: 16px; box-shadow: 0 6px 22px var(--shadow); }
.card__icon { font-size: 22px; }
.card__title { margin: 8px 0; font-size: 18px; }
.card__text { color: var(--muted); }

.grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 16px; }
.grid__item { background: var(--card); border: 1px solid rgba(255,255,255,0.08); border-radius: 14px; padding: 16px; }
.grid__title { margin: 6px 0 8px; font-size: 18px; }
.grid__text { color: var(--muted); }

/* 联系方式 */
.contact__grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 14px; }
.contact__item { background: rgba(255,255,255,0.04); border: 1px solid rgba(255,255,255,0.08); border-radius: 12px; padding: 14px; }
.contact__label { color: var(--muted); font-size: 13px; }
.contact__value { color: var(--text); text-decoration: none; display: inline-block; margin: 4px 0 8px; }
.contact__copy { background: none; border: 1px solid rgba(255,255,255,0.2); color: var(--text); border-radius: 8px; padding: 6px 10px; cursor: pointer; }
.contact__copy:hover { background: rgba(255,255,255,0.06); }
.contact__note { color: var(--muted); margin-top: 12px; }

/* 页脚 */
.footer { border-top: 1px solid rgba(255,255,255,0.08); background: rgba(13,19,38,0.7); }
.footer__inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.footer__links { display: flex; gap: 12px; }
.footer__links a { color: var(--muted); text-decoration: none; }
.footer__links a:hover { color: var(--text); }

/* 响应式 */
@media (max-width: 960px) {
  .cards { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .hero__stats { grid-template-columns: repeat(3, minmax(0,1fr)); }
}

@media (max-width: 640px) {
  .nav__toggle { display: inline-block; }
  .nav__list { display: none; position: absolute; right: 4%; top: 54px; flex-direction: column; background: rgba(13,19,38,0.95); border: 1px solid rgba(255,255,255,0.08); border-radius: 12px; padding: 8px; }
  .nav__list.is-open { display: flex; }

  .cards { grid-template-columns: 1fr; }
  .grid { grid-template-columns: 1fr; }
  .contact__grid { grid-template-columns: 1fr; }
  .footer__inner { flex-direction: column; gap: 8px; }
}

/* 细节增强 */
a:focus, button:focus { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn--primary:active { transform: translateY(1px); }
.card, .grid__item { transition: transform .2s ease, box-shadow .2s ease; }
.card:hover, .grid__item:hover { transform: translateY(-2px); box-shadow: 0 10px 26px rgba(0,0,0,0.35); }