/* ============================================================
   数智核星官网 · 蓝白色系 · 纯 CSS 动效，零依赖
   ============================================================ */
:root {
  --blue-900: #071c4d;
  --blue-700: #0a3aa8;
  --blue-600: #0a4fd5;
  --blue-500: #1668ff;
  --blue-400: #4d8dff;
  --blue-100: #d9e8ff;
  --blue-50: #eef4ff;
  --ink: #10224e;
  --ink-soft: #5a6b94;
  --white: #ffffff;
  --radius: 16px;
  --shadow: 0 12px 40px rgba(10, 79, 213, 0.12);
  --shadow-lg: 0 24px 64px rgba(10, 79, 213, 0.22);
  --grad: linear-gradient(120deg, #1668ff 0%, #4d8dff 50%, #7fb0ff 100%);
  --font: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.pc-only { display: inline; }
@media (max-width: 768px) { .pc-only { display: none; } }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-block; padding: 12px 28px; border-radius: 999px;
  font-size: 15px; font-weight: 600; border: none; cursor: pointer;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
}
.btn-primary {
  background: var(--grad); color: #fff;
  box-shadow: 0 8px 24px rgba(22, 104, 255, 0.35);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 14px 32px rgba(22, 104, 255, 0.5); }
.btn-ghost { color: #cfe0ff; border: 1.5px solid rgba(255,255,255,.4); background: rgba(255,255,255,.06); backdrop-filter: blur(4px); }
.btn-ghost:hover { background: rgba(255,255,255,.16); transform: translateY(-3px); }
.btn-lg { padding: 15px 36px; font-size: 16px; }
.btn-block { width: 100%; }

/* ---------- 滚动进度条 ---------- */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0; z-index: 200;
  background: var(--grad); box-shadow: 0 0 12px rgba(22, 104, 255, 0.8);
  border-radius: 0 3px 3px 0;
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  padding: 18px 0; transition: all .35s ease;
  /* logo 渐变：深色首屏用亮蓝，滚动到白底后切深蓝保证对比度 */
  --logo-c1: #9ecbff; --logo-c2: #4d8dff; --logo-c3: #cfe4ff;
}
.navbar.scrolled { --logo-c1: #7fb4ff; --logo-c2: #1668ff; --logo-c3: #0a4fd5;
  padding: 10px 0; background: rgba(255,255,255,.86);
  backdrop-filter: blur(14px); box-shadow: 0 4px 24px rgba(10,79,213,.1);
}
.nav-inner { display: flex; align-items: center; gap: 28px; }
.logo { display: flex; align-items: center; gap: 11px; margin-right: auto; }
.logo-mark { width: 40px; height: 40px; display: grid; place-items: center; }
.logo-mark svg { width: 100%; height: 100%; display: block; overflow: visible; transition: transform .55s ease; }
.logo:hover .logo-mark svg { transform: rotate(20deg); }
.logo-text { font-size: 19px; font-weight: 800; color: #fff; display: flex; flex-direction: column; line-height: 1.15; }
.logo-text small { font-size: 10px; font-weight: 500; letter-spacing: 2px; opacity: .75; }
.navbar.scrolled .logo-text { color: var(--ink); }
.nav-links { display: flex; gap: 26px; }
.nav-links a {
  font-size: 15px; font-weight: 500; color: rgba(255,255,255,.85);
  position: relative; padding: 4px 0; transition: color .25s;
}
.navbar.scrolled .nav-links a { color: var(--ink-soft); }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: -2px; height: 2px; width: 0;
  background: var(--grad); border-radius: 2px; transition: width .3s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--blue-500); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; }
.nav-toggle span { display: block; width: 24px; height: 2.5px; background: #fff; margin: 5px 0; border-radius: 2px; transition: .3s; }
.navbar.scrolled .nav-toggle span { background: var(--ink); }

/* ---------- Hero ---------- */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: radial-gradient(ellipse at 50% 40%, #060b18 0%, #04070f 60%, #010204 100%);
  overflow: hidden; text-align: center;
}
#particles { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-bg-grid {
  position: absolute; inset: 0; opacity: .04;
  transform: translate(calc(var(--px, 0) * 16px), calc(var(--py, 0) * 12px));
  background-image:
    linear-gradient(rgba(120,170,255,.5) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120,170,255,.5) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
}
.hero-glow { position: absolute; border-radius: 50%; filter: blur(90px); opacity: .18; pointer-events: none; }
.hero-glow-1 { width: 480px; height: 480px; background: #1668ff; top: -120px; right: -100px; animation: float1 9s ease-in-out infinite; }
.hero-glow-2 { width: 380px; height: 380px; background: #4d8dff; bottom: -80px; left: -80px; animation: float2 11s ease-in-out infinite; }
@keyframes float1 { 50% { transform: translate(-50px, 40px) scale(1.1); } }
@keyframes float2 { 50% { transform: translate(50px, -30px) scale(1.12); } }

.hero-content {
  position: relative; z-index: 2;
  max-width: 980px; padding: 0 24px;
  transform: translate(calc(var(--px, 0) * -10px), calc(var(--py, 0) * -8px));
  transition: transform .25s ease-out;
  will-change: transform;
}
/* 底部渐隐，让流光自然没入下一屏 */
.hero::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 180px;
  background: linear-gradient(to bottom, transparent, rgba(1, 2, 5, .9));
  pointer-events: none; z-index: 1;
}
.hero-hint {
  color: #7d97c9; font-size: 13px; letter-spacing: 1px;
  margin-top: 26px; margin-bottom: 0;
  animation: hintPulse 3s ease-in-out infinite;
}
@keyframes hintPulse { 50% { opacity: .45; } }
.hero-badge {
  display: inline-block; padding: 7px 18px; border-radius: 999px;
  border: 1px solid rgba(127,176,255,.45); color: #9ec3ff;
  font-size: 13px; letter-spacing: 1px; margin-bottom: 26px;
  background: rgba(22,104,255,.12); backdrop-filter: blur(4px);
}
.hero h1 {
  font-size: clamp(38px, 6.4vw, 74px); font-weight: 800; color: #fff;
  line-height: 1.22; letter-spacing: 1px; margin-bottom: 26px;
  text-shadow: 0 0 60px rgba(60, 130, 255, .25);
}
.grad-text {
  background: linear-gradient(120deg, #6ea8ff, #b9d4ff, #6ea8ff);
  background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
  animation: gradFlow 4s linear infinite;
}
@keyframes gradFlow { to { background-position: 200% center; } }
.hero-sub { color: #b8c9ec; font-size: 17px; line-height: 1.9; max-width: 720px; margin: 0 auto 42px; }
.hero-actions { display: flex; gap: 18px; justify-content: center; margin-bottom: 0; flex-wrap: wrap; }
.scroll-hint {
  position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%);
  width: 26px; height: 44px; border: 2px solid rgba(158,195,255,.6);
  border-radius: 14px; z-index: 2;
}
.scroll-hint span {
  position: absolute; top: 8px; left: 50%; width: 4px; height: 9px;
  margin-left: -2px; border-radius: 3px; background: #9ec3ff;
  animation: scrollDot 1.6s ease-in-out infinite;
}
@keyframes scrollDot { 70% { top: 22px; opacity: .3; } 100% { top: 8px; opacity: 0; } }

/* ---------- 通用 Section ---------- */
.section { padding: 100px 0; position: relative; }
.section-alt { background: linear-gradient(180deg, var(--blue-50) 0%, #f7faff 100%); }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 60px; }
.section-tag {
  color: var(--blue-500); font-weight: 700; letter-spacing: 4px; font-size: 13px;
  margin-bottom: 10px;
}
.section-head h2 { font-size: clamp(30px, 4vw, 42px); font-weight: 800; }
.section-desc { color: var(--ink-soft); margin-top: 16px; font-size: 16px; }

/* ---------- 关于我们 ---------- */
.about-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.about-card {
  background: #fff; border-radius: var(--radius); padding: 38px 30px;
  box-shadow: var(--shadow); border: 1px solid var(--blue-100);
  transition: transform .35s ease, box-shadow .35s ease;
}
.about-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.about-icon {
  width: 58px; height: 58px; border-radius: 14px; font-size: 28px;
  display: grid; place-items: center; margin-bottom: 18px;
  background: var(--blue-50); border: 1px solid var(--blue-100);
}
.about-card h3 { font-size: 20px; margin-bottom: 10px; }
.about-card p { color: var(--ink-soft); font-size: 15px; }
.about-band {
  margin-top: 46px; display: grid; grid-template-columns: repeat(3, 1fr);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
}
.band-item {
  background: var(--grad); color: #fff; padding: 26px 30px; position: relative;
}
.band-item:nth-child(2) { background: linear-gradient(120deg, #0a4fd5, #1668ff); }
.band-item:nth-child(3) { background: linear-gradient(120deg, #0a3aa8, #0a4fd5); }
.band-item strong { display: block; font-size: 19px; margin-bottom: 4px; }
.band-item span { font-size: 13.5px; opacity: .92; }

/* ---------- 核心能力卡片 ---------- */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; perspective: 1000px; }
.ai-card {
  position: relative; background: #fff; border-radius: var(--radius);
  padding: 36px 30px; border: 1px solid var(--blue-100); overflow: hidden;
  transition: box-shadow .35s ease; transform-style: preserve-3d; will-change: transform;
}
.ai-card::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(400px circle at var(--mx, 50%) var(--my, 0%), rgba(22,104,255,.09), transparent 45%);
  opacity: 0; transition: opacity .35s;
}
.ai-card:hover::before { opacity: 1; }
.ai-card:hover { box-shadow: var(--shadow-lg); }
.ai-card-icon {
  width: 62px; height: 62px; border-radius: 16px; font-size: 30px;
  display: grid; place-items: center; margin-bottom: 20px;
  background: linear-gradient(135deg, var(--blue-50), var(--blue-100));
  transition: transform .35s ease;
}
.ai-card:hover .ai-card-icon { transform: scale(1.12) rotate(-6deg); }
.ai-card h3 { font-size: 20px; margin-bottom: 10px; }
.ai-card p { color: var(--ink-soft); font-size: 14.5px; min-height: 66px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.tag-row li {
  font-size: 12px; color: var(--blue-600); background: var(--blue-50);
  border: 1px solid var(--blue-100); padding: 3px 12px; border-radius: 999px;
}

/* ---------- 解决方案 Tabs ---------- */
.tabs { max-width: 960px; margin: 0 auto; }
.tab-bar { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; margin-bottom: 34px; }
.tab-btn {
  padding: 11px 26px; border-radius: 999px; border: 1.5px solid var(--blue-100);
  background: #fff; color: var(--ink-soft); font-size: 15px; font-weight: 600;
  cursor: pointer; transition: all .3s ease; font-family: var(--font);
}
.tab-btn:hover { border-color: var(--blue-400); color: var(--blue-600); }
.tab-btn.active { background: var(--grad); color: #fff; border-color: transparent; box-shadow: 0 8px 20px rgba(22,104,255,.35); }
.tab-panel {
  display: none; background: #fff; border-radius: var(--radius);
  box-shadow: var(--shadow); border: 1px solid var(--blue-100);
  grid-template-columns: 1fr 220px; gap: 30px; padding: 44px 46px; align-items: center;
}
.tab-panel.active { display: grid; animation: fadeUp .5s ease; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }
.tab-body h3 { font-size: 21px; margin-bottom: 12px; }
.tab-body p { color: var(--ink-soft); margin-bottom: 18px; font-size: 15px; }
.tab-body ul li {
  position: relative; padding-left: 24px; margin: 7px 0; color: var(--ink); font-size: 14.5px;
}
.tab-body ul li::before {
  content: "✓"; position: absolute; left: 0; color: var(--blue-500); font-weight: 700;
}
.tab-visual {
  font-size: 84px; text-align: center; line-height: 1;
  filter: drop-shadow(0 14px 22px rgba(22,104,255,.28));
  animation: bob 3.4s ease-in-out infinite;
}
@keyframes bob { 50% { transform: translateY(-12px); } }

/* ---------- 技术优势 ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.adv-item { text-align: center; padding: 20px 12px; }
.adv-num {
  font-size: 44px; font-weight: 800; margin-bottom: 10px;
  background: var(--grad); -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent; opacity: .9;
}
.adv-item h3 { font-size: 18px; margin-bottom: 8px; }
.adv-item p { color: var(--ink-soft); font-size: 14px; }

/* ---------- 联系我们 ---------- */
.contact-wrap { max-width: 680px; margin: 0 auto; text-align: center; }
.wx-card {
  display: inline-flex; align-items: center; gap: 24px; text-align: left;
  margin-top: 34px; padding: 22px 28px;
  background: #fff; border: 1px solid var(--blue-100); border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.wx-qr { width: 160px; height: 160px; display: block; border-radius: 12px; }
.wx-text { display: grid; gap: 8px; font-size: 14px; color: var(--ink-soft); }
.wx-text strong { font-size: 17px; color: var(--ink); font-weight: 700; }

/* ---------- 页脚 ---------- */
.footer { background: var(--blue-900); color: #9db4e4; padding: 70px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 50px; }
.footer-brand p { font-size: 14px; margin-top: 14px; line-height: 1.9; }
.footer .logo-text { color: #fff; }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; padding: 4px 0; transition: color .25s, transform .25s; }
.footer-col a:hover { color: #fff; transform: translateX(4px); }
.footer-bottom {
  border-top: 1px solid rgba(157,180,228,.18); text-align: center;
  padding: 22px 0; font-size: 13px;
}
.footer-bottom a { color: inherit; }
.footer-bottom a:hover { color: #fff; text-decoration: underline; }

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed; right: 28px; bottom: 28px; z-index: 90;
  width: 48px; height: 48px; border-radius: 50%; border: none; cursor: pointer;
  background: var(--grad); color: #fff; font-size: 20px;
  box-shadow: 0 10px 26px rgba(22,104,255,.45);
  opacity: 0; transform: translateY(16px); pointer-events: none;
  transition: all .35s ease;
}
.back-top.show { opacity: 1; transform: none; pointer-events: auto; }
.back-top:hover { transform: translateY(-4px); }

/* ---------- 滚动浮现动画 ---------- */
.reveal { opacity: 0; transform: translateY(34px); transition: opacity .8s ease, transform .8s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .about-grid, .card-grid { grid-template-columns: repeat(2, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .about-band { grid-template-columns: 1fr; }
  .contact-wrap { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .tab-panel { grid-template-columns: 1fr; }
  .tab-visual { display: none; }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-links.open {
    display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0;
    background: rgba(255,255,255,.97); backdrop-filter: blur(14px);
    padding: 20px 24px; gap: 16px; box-shadow: 0 16px 32px rgba(10,79,213,.15);
  }
  .nav-links.open a { color: var(--ink); }
  .about-grid, .card-grid, .adv-grid { grid-template-columns: 1fr; }
  .section { padding: 70px 0; }
  .tab-panel { padding: 30px 24px; }
  .wx-card { flex-direction: column; text-align: center; padding: 22px; }
}