/* =========================================================
   帮邻科技 · 帮邻安诺 官网样式
   设计令牌 + 深色科技主题 + 玻璃拟态 + 响应式
   ========================================================= */

:root {
  /* 颜色令牌 */
  --bg: #060912;
  --bg-soft: #0b1020;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-strong: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.10);
  --border-strong: rgba(255, 255, 255, 0.18);

  --text: #eef2ff;
  --text-dim: #9aa6c4;
  --text-mute: #6b7796;

  --cyan: #22d3ee;
  --blue: #3b82f6;
  --purple: #a855f7;
  --green: #34d399;

  --grad: linear-gradient(120deg, #22d3ee 0%, #3b82f6 45%, #a855f7 100%);
  --grad-soft: linear-gradient(120deg, rgba(34,211,238,.18), rgba(168,85,247,.18));

  /* 字体 */
  --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;

  /* 间距（8pt 基准） */
  --s1: 4px; --s2: 8px; --s3: 12px; --s4: 16px;
  --s6: 24px; --s8: 32px; --s10: 40px; --s12: 48px; --s16: 64px; --s24: 96px;

  /* 阴影 / 圆角 */
  --r-sm: 10px; --r-md: 16px; --r-lg: 24px;
  --shadow: 0 20px 50px -20px rgba(0, 0, 0, 0.7);
  --glow: 0 0 0 1px rgba(34,211,238,.25), 0 12px 40px -12px rgba(59,130,246,.45);

  /* 动画 */
  --ease: cubic-bezier(.22,.61,.36,1);
  --t-fast: 160ms var(--ease);
  --t: 320ms var(--ease);
}

/* 基础重置 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; }
::selection { background: rgba(34,211,238,.3); color: #fff; }

.container { width: 100%; max-width: 1180px; margin: 0 auto; padding: 0 var(--s6); }

/* 背景层 */
.bg-layer { position: fixed; inset: 0; z-index: -2; overflow: hidden; pointer-events: none; }
.bg-grid {
  position: absolute; inset: -2px;
  background-image:
    linear-gradient(rgba(120,160,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120,160,255,.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 75%);
}
.bg-glow { position: absolute; border-radius: 50%; filter: blur(90px); opacity: .55; will-change: transform; }
.bg-glow--1 { width: 520px; height: 520px; background: #1e40af; top: -120px; left: -100px; animation: float1 18s var(--ease) infinite; }
.bg-glow--2 { width: 460px; height: 460px; background: #7c3aed; top: 30%; right: -140px; animation: float2 22s var(--ease) infinite; }
.bg-glow--3 { width: 420px; height: 420px; background: #0891b2; bottom: -120px; left: 30%; animation: float1 26s var(--ease) infinite reverse; }
@keyframes float1 { 50% { transform: translate(40px, 50px) scale(1.08); } }
@keyframes float2 { 50% { transform: translate(-50px, -30px) scale(1.1); } }

/* 滚动进度条 */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: var(--grad); z-index: 100; transition: width 80ms linear;
}

/* ===== 导航 ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 90;
  transition: background var(--t), backdrop-filter var(--t), border-color var(--t);
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(6, 9, 18, .72);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.nav__brand { display: flex; align-items: center; gap: var(--s3); }
.nav__logo { display: grid; place-items: center; }
.nav__logo-img { width: 34px; height: 34px; object-fit: contain; filter: drop-shadow(0 0 8px rgba(245,180,60,.35)); }
.nav__brandtext { display: flex; flex-direction: column; line-height: 1.1; }
.nav__brandtext strong { font-size: 16px; letter-spacing: .5px; }
.nav__brandtext em { font-style: normal; font-size: 11px; color: var(--text-mute); letter-spacing: 3px; }

.nav__links { display: flex; align-items: center; gap: var(--s8); }
.nav__links a { font-size: 15px; color: var(--text-dim); transition: color var(--t-fast); position: relative; }
.nav__links a:not(.nav__cta)::after {
  content: ""; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
  background: var(--grad); transition: width var(--t);
}
.nav__links a:not(.nav__cta):hover { color: var(--text); }
.nav__links a:not(.nav__cta):hover::after { width: 100%; }
.nav__cta {
  padding: 9px 18px; border-radius: 999px; color: #fff !important;
  background: var(--grad); box-shadow: var(--glow); font-weight: 600;
  transition: transform var(--t-fast), box-shadow var(--t-fast);
}
.nav__cta:hover { transform: translateY(-2px); box-shadow: 0 0 0 1px rgba(34,211,238,.4), 0 16px 44px -10px rgba(59,130,246,.7); }

.nav__toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); flex-direction: column; gap: 5px; align-items: center; justify-content: center; }
.nav__toggle span { width: 20px; height: 2px; background: var(--text); border-radius: 2px; transition: var(--t-fast); }
.nav__toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle.is-open span:nth-child(2) { opacity: 0; }
.nav__toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; gap: var(--s2);
  padding: 14px 26px; border-radius: 999px; font-size: 15px; font-weight: 600;
  border: 1px solid transparent; transition: transform var(--t-fast), box-shadow var(--t-fast), background var(--t-fast);
  white-space: nowrap;
}
.btn--primary { background: var(--grad); color: #fff; box-shadow: var(--glow); }
.btn--primary:hover { transform: translateY(-3px); box-shadow: 0 0 0 1px rgba(34,211,238,.45), 0 20px 50px -14px rgba(59,130,246,.8); }
.btn--primary .btn__arrow { transition: transform var(--t-fast); }
.btn--primary:hover .btn__arrow { transform: translateX(4px); }
.btn--ghost { background: var(--surface-strong); border-color: var(--border-strong); color: var(--text); }
.btn--ghost:hover { transform: translateY(-3px); background: var(--surface); border-color: var(--cyan); }

/* ===== HERO ===== */
.hero { position: relative; min-height: 100vh; min-height: 100dvh; display: flex; align-items: center; padding: 120px 0 80px; overflow: hidden; }
.hero__canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; }
.hero__inner { max-width: 880px; }
.hero__badge {
  display: inline-flex; align-items: center; gap: var(--s2);
  padding: 8px 16px; border-radius: 999px; font-size: 13px; color: var(--cyan);
  background: var(--grad-soft); border: 1px solid var(--border);
  margin-bottom: var(--s6);
}
.hero__title { font-size: clamp(34px, 7vw, 68px); line-height: 1.08; font-weight: 800; letter-spacing: -1px; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero__sub { margin: var(--s6) 0 var(--s8); font-size: clamp(15px, 2.2vw, 18px); color: var(--text-dim); max-width: 640px; }
.hero__actions { display: flex; flex-wrap: wrap; gap: var(--s4); }
.hero__stats { display: flex; gap: var(--s12); margin-top: var(--s16); flex-wrap: wrap; }
.hero__stat b { display: block; font-size: clamp(30px, 5vw, 46px); font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; font-family: var(--font-mono); }
.hero__stat span { font-size: 13px; color: var(--text-mute); letter-spacing: 1px; }
.hero__scroll { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); font-size: 12px; color: var(--text-mute); display: flex; flex-direction: column; align-items: center; gap: var(--s2); }
.hero__scroll span { width: 22px; height: 36px; border: 1px solid var(--border-strong); border-radius: 12px; position: relative; }
.hero__scroll span::after { content: ""; position: absolute; top: 7px; left: 50%; transform: translateX(-50%); width: 3px; height: 7px; border-radius: 2px; background: var(--cyan); animation: scrollDot 1.8s infinite; }
@keyframes scrollDot { 0% { opacity: 0; top: 7px; } 40% { opacity: 1; } 80% { opacity: 0; top: 18px; } 100% { opacity: 0; } }

/* ===== 通用 section ===== */
.section { padding: var(--s24) 0; position: relative; }
.section--alt { background: linear-gradient(180deg, rgba(11,16,32,.6), rgba(6,9,18,.2)); }
.section__head { max-width: 720px; margin: 0 auto var(--s16); text-align: center; }
.kicker { display: inline-block; font-size: 12px; letter-spacing: 3px; color: var(--cyan); font-weight: 600; margin-bottom: var(--s4); padding: 6px 14px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); }
.section__title { font-size: clamp(26px, 4.4vw, 42px); font-weight: 800; letter-spacing: -.5px; line-height: 1.15; }
.section__lead { margin-top: var(--s6); font-size: clamp(15px, 2vw, 17px); color: var(--text-dim); }

/* ===== 使命卡片 ===== */
.mission-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--s6); }
.mission-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-md);
  padding: var(--s8); transition: transform var(--t), border-color var(--t), box-shadow var(--t);
  backdrop-filter: blur(8px);
}
.mission-card:hover { transform: translateY(-6px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.mission-card__icon { font-size: 30px; margin-bottom: var(--s4); filter: drop-shadow(0 0 12px rgba(34,211,238,.4)); }
.mission-card h3 { font-size: 18px; margin-bottom: var(--s2); }
.mission-card p { font-size: 14px; color: var(--text-dim); }

/* ===== 特性卡片 ===== */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s6); }
.feature-card {
  position: relative; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-md); padding: var(--s8); overflow: hidden;
  transition: transform var(--t), border-color var(--t), box-shadow var(--t);
}
.feature-card::before {
  content: ""; position: absolute; inset: 0; background: var(--grad-soft); opacity: 0; transition: opacity var(--t);
}
.feature-card:hover { transform: translateY(-6px); border-color: var(--cyan); box-shadow: 0 0 0 1px rgba(34,211,238,.3), var(--shadow); }
.feature-card:hover::before { opacity: 1; }
.feature-card__num { font-family: var(--font-mono); font-size: 14px; color: var(--cyan); font-weight: 700; margin-bottom: var(--s4); position: relative; }
.feature-card h3 { font-size: 19px; margin-bottom: var(--s2); position: relative; }
.feature-card p { font-size: 14px; color: var(--text-dim); position: relative; }

/* ===== 连接生态网络 ===== */
.network { display: flex; justify-content: center; }
.network__svg { width: 100%; max-width: 760px; height: auto; }
.network__lines line { stroke-dasharray: 8 8; animation: dash 3s linear infinite; }
@keyframes dash { to { stroke-dashoffset: -32; } }
.network__core circle { filter: drop-shadow(0 0 24px rgba(59,130,246,.7)); }
.network__pulse { animation: pulse 2.6s var(--ease) infinite; transform-origin: 400px 260px; }
@keyframes pulse { 0%,100% { transform: scale(1); opacity: .9; } 50% { transform: scale(1.18); opacity: .35; } }
.network__core-text { fill: #fff; font-size: 17px; font-weight: 700; font-family: var(--font-sans); }
.network__node circle { fill: var(--bg-soft); stroke: url(#lineGrad); stroke-width: 2; transition: r var(--t); }
.network__node text { fill: var(--text); font-size: 14px; text-anchor: middle; font-family: var(--font-sans); }
.network__node:hover circle { r: 34; }

/* ===== 创新模式流程 ===== */
.model-flow { display: flex; align-items: stretch; justify-content: center; gap: var(--s4); flex-wrap: wrap; }
.model-step {
  flex: 1 1 200px; max-width: 250px; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-md); padding: var(--s8) var(--s6); text-align: center;
  transition: transform var(--t), border-color var(--t), box-shadow var(--t);
}
.model-step:hover { transform: translateY(-6px); border-color: var(--purple); box-shadow: 0 0 0 1px rgba(168,85,247,.35), var(--shadow); }
.model-step__dot {
  display: grid; place-items: center; width: 48px; height: 48px; margin: 0 auto var(--s4);
  border-radius: 50%; background: var(--grad); color: #fff; font-weight: 800; font-size: 20px;
  box-shadow: var(--glow);
}
.model-step h3 { font-size: 17px; margin-bottom: var(--s2); }
.model-step p { font-size: 13px; color: var(--text-dim); }
.model-arrow { display: grid; place-items: center; color: var(--cyan); font-size: 26px; opacity: .6; }

/* ===== 数据成绩 ===== */
.metrics-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--s6); }
.metric { text-align: center; padding: var(--s8) var(--s4); background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-md); }
.metric b { display: block; font-size: clamp(30px, 5vw, 48px); font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; font-family: var(--font-mono); line-height: 1.1; }
.metric span { font-size: 14px; color: var(--text-mute); letter-spacing: 1px; }

/* ===== CTA ===== */
.cta { text-align: center; }
.cta__inner {
  background: var(--grad-soft); border: 1px solid var(--border-strong); border-radius: var(--r-lg);
  padding: var(--s16) var(--s8); box-shadow: var(--shadow);
}
.cta__title { font-size: clamp(26px, 4.5vw, 44px); font-weight: 800; }
.cta__lead { margin: var(--s4) auto var(--s10); color: var(--text-dim); max-width: 560px; }
.cta__form { display: flex; flex-wrap: wrap; gap: var(--s4); justify-content: center; max-width: 720px; margin: 0 auto; }
.cta__form input, .cta__form select {
  flex: 1 1 180px; padding: 14px 18px; border-radius: 12px; font-size: 15px; color: var(--text);
  background: rgba(6,9,18,.6); border: 1px solid var(--border-strong); transition: border-color var(--t-fast), box-shadow var(--t-fast);
}
.cta__form input::placeholder { color: var(--text-mute); }
.cta__form input:focus, .cta__form select:focus { outline: none; border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(34,211,238,.15); }
.cta__form .btn { flex: 0 0 auto; }
.cta__hint { margin-top: var(--s4); font-size: 14px; min-height: 20px; color: var(--green); }
.cta__contact { margin-top: var(--s10); display: flex; gap: var(--s8); justify-content: center; flex-wrap: wrap; color: var(--text-dim); font-size: 14px; }

/* ===== 页脚 ===== */
.footer { border-top: 1px solid var(--border); padding: var(--s16) 0 var(--s8); margin-top: var(--s8); }
.footer__inner { display: flex; justify-content: space-between; gap: var(--s12); flex-wrap: wrap; }
.footer__brand-head { display: flex; align-items: center; gap: var(--s3); margin-bottom: var(--s2); }
.footer__logo-img { width: 38px; height: 38px; object-fit: contain; }
.footer__brand strong { font-size: 18px; }
.footer__brand p { color: var(--text-mute); font-size: 14px; max-width: 380px; margin-top: var(--s2); }
.footer__links { display: flex; gap: var(--s8); flex-wrap: wrap; }
.footer__links a { color: var(--text-dim); font-size: 14px; transition: color var(--t-fast); }
.footer__links a:hover { color: var(--cyan); }
.footer__bottom { display: flex; justify-content: space-between; gap: var(--s4); flex-wrap: wrap; margin-top: var(--s12); padding-top: var(--s6); border-top: 1px solid var(--border); color: var(--text-mute); font-size: 13px; }
.footer__bottom a { color: var(--text-mute); transition: color var(--t-fast); }
.footer__bottom a:hover { color: var(--cyan); }

/* ===== 滚动揭示动画 ===== */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }

/* 倾斜卡片（桌面指针设备） */
@media (hover: hover) and (pointer: fine) {
  .tilt { transition: transform .25s var(--ease); }
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .mission-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  .container { padding: 0 var(--s4); }
  .nav__links {
    position: fixed; top: 68px; left: 0; right: 0; flex-direction: column; align-items: flex-start;
    gap: var(--s2); padding: var(--s6) var(--s6) var(--s8); background: rgba(6,9,18,.96);
    backdrop-filter: blur(16px); border-bottom: 1px solid var(--border);
    transform: translateY(-12px); opacity: 0; pointer-events: none; transition: var(--t);
  }
  .nav__links.is-open { transform: none; opacity: 1; pointer-events: auto; }
  .nav__links a { width: 100%; padding: var(--s3) 0; font-size: 17px; }
  .nav__cta { width: 100%; text-align: center; margin-top: var(--s2); }
  .nav__toggle { display: flex; }
  .hero { padding: 110px 0 70px; min-height: auto; }
  /* 移动端关闭 backdrop-filter，降低重采样开销 */
  .nav.is-scrolled { backdrop-filter: none; background: rgba(6, 9, 18, .94); }
  .mission-card { backdrop-filter: none; }
  .hero__stats { gap: var(--s8); margin-top: var(--s12); }
  .mission-grid, .feature-grid, .metrics-grid { grid-template-columns: 1fr; }
  .model-flow { flex-direction: column; align-items: center; }
  .model-arrow { transform: rotate(90deg); }
  .section { padding: var(--s16) 0; }
  .section__head { margin-bottom: var(--s12); }
  .cta__inner { padding: var(--s12) var(--s6); }
  .cta__form input, .cta__form select { flex: 1 1 100%; }
  .footer__inner { flex-direction: column; gap: var(--s8); }
}

/* 尊重减少动态偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}