/* ===== 钠银科技官网样式 ===== */
:root {
  --bg: #0a0e1a;
  --bg2: #0d1326;
  --card: #111830;
  --border: rgba(90, 130, 255, .14);
  --text: #e8edf7;
  --muted: #8b96b5;
  --cyan: #22d3ee;
  --blue: #4f7cff;
  --purple: #a06bff;
  --grad: linear-gradient(120deg, var(--cyan), var(--blue) 55%, var(--purple));
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}
.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
a { color: inherit; text-decoration: none; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* ===== 头部导航 ===== */
#header {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  background: rgba(10, 14, 26, .72);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: .3s;
}
#header.scrolled { border-bottom-color: var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-mark {
  width: 38px; height: 38px; border-radius: 10px;
  background: var(--grad); color: #fff;
  display: grid; place-items: center;
  font-weight: 800; font-size: 20px;
  box-shadow: 0 4px 18px rgba(79, 124, 255, .45);
}
.logo-text { font-weight: 700; font-size: 18px; letter-spacing: 1px; display: flex; flex-direction: column; line-height: 1.15; }
.logo-text small { font-size: 10px; color: var(--muted); letter-spacing: 3px; font-weight: 400; }
#nav { display: flex; gap: 30px; }
#nav a { color: var(--muted); font-size: 15px; position: relative; padding: 4px 0; transition: .25s; }
#nav a:hover, #nav a.active { color: var(--text); }
#nav a.active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px;
  height: 2px; border-radius: 2px; background: var(--grad);
}
#menu-btn { display: none; background: none; border: 0; cursor: pointer; }
#menu-btn span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; border-radius: 2px; }

/* ===== 首屏 ===== */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center;
  padding: 120px 0 60px;
  overflow: hidden;
}
#particles { position: absolute; inset: 0; }
.hero-glow {
  position: absolute; width: 900px; height: 900px; border-radius: 50%;
  background: radial-gradient(circle, rgba(79,124,255,.16), transparent 60%);
  top: -300px; right: -200px; pointer-events: none;
}
.hero-content { position: relative; z-index: 2; text-align: center; }
.hero-tag {
  display: inline-block; padding: 6px 18px; border-radius: 100px;
  border: 1px solid var(--border); color: var(--cyan);
  font-size: 13px; letter-spacing: 2px; margin-bottom: 26px;
  background: rgba(34, 211, 238, .06);
}
.hero h1 { font-size: clamp(34px, 6vw, 60px); line-height: 1.25; font-weight: 800; }
.hero-sub { color: var(--muted); font-size: 17px; margin: 24px 0 36px; }
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  padding: 13px 34px; border-radius: 12px; font-size: 15px;
  cursor: pointer; border: 0; transition: .25s; display: inline-block;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 8px 26px rgba(79,124,255,.4); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(79,124,255,.55); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); }
.hero-stats { display: flex; gap: 14px; justify-content: center; margin-top: 64px; flex-wrap: wrap; }
.stat {
  min-width: 150px; padding: 18px 22px; border-radius: 14px;
  background: rgba(17, 24, 48, .6); border: 1px solid var(--border);
  backdrop-filter: blur(8px);
}
.stat strong { font-size: 26px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { display: block; color: var(--muted); font-size: 13px; margin-top: 4px; }
.scroll-hint {
  position: absolute; bottom: 26px; left: 50%; width: 24px; height: 38px;
  border: 2px solid var(--muted); border-radius: 14px; transform: translateX(-50%);
}
.scroll-hint::after {
  content: ""; position: absolute; top: 7px; left: 50%; width: 4px; height: 8px;
  border-radius: 2px; background: var(--cyan); transform: translateX(-50%);
  animation: drop 1.6s infinite;
}
@keyframes drop { 0%{opacity:1;transform:translate(-50%,0)} 70%{opacity:0;transform:translate(-50%,14px)} 100%{opacity:0} }

/* ===== 通用区块 ===== */
.section { padding: 96px 0; }
.section-alt { background: var(--bg2); }
.sec-head { text-align: center; margin-bottom: 56px; }
.sec-tag { color: var(--cyan); letter-spacing: 4px; font-size: 13px; margin-bottom: 10px; }
.sec-head h2 { font-size: clamp(26px, 4vw, 38px); font-weight: 800; }
.sec-sub { color: var(--muted); margin-top: 12px; }
.grid { display: grid; gap: 22px; }
.cards { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 30px 26px; transition: .3s; position: relative; overflow: hidden;
}
.card::before {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 3px;
  background: var(--grad); opacity: 0; transition: .3s;
}
.card:hover { transform: translateY(-6px); border-color: rgba(79,124,255,.4); box-shadow: 0 16px 40px rgba(0,0,0,.35); }
.card:hover::before { opacity: 1; }
.card .icon {
  width: 52px; height: 52px; border-radius: 13px; font-size: 24px;
  display: grid; place-items: center; margin-bottom: 18px;
  background: rgba(79,124,255,.12); color: var(--cyan);
}
.card h3 { font-size: 18px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 14px; }

/* 优势 */
.advantages { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.adv {
  text-align: center; padding: 34px 20px;
  border: 1px solid var(--border); border-radius: 16px;
  background: rgba(17,24,48,.5); transition: .3s;
}
.adv:hover { border-color: rgba(34,211,238,.4); transform: translateY(-4px); }
.adv .num { font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.adv h4 { margin: 8px 0 8px; font-size: 16px; }
.adv p { color: var(--muted); font-size: 13px; }

/* 关于 */
.about-wrap { display: grid; grid-template-columns: 1.1fr .9fr; gap: 50px; align-items: center; }
.about-text p { color: var(--muted); margin-bottom: 14px; font-size: 15px; }
.about-text h2 { margin-bottom: 18px; }
.about-list { list-style: none; margin-top: 8px; }
.about-list li { padding: 6px 0 6px 26px; position: relative; color: var(--text); font-size: 14px; }
.about-list li::before {
  content: "◆"; position: absolute; left: 0; color: var(--cyan); font-size: 11px; top: 10px;
}
.code-window {
  background: #0b1120; border: 1px solid var(--border); border-radius: 14px; overflow: hidden;
  box-shadow: 0 20px 60px rgba(0,0,0,.45);
}
.code-bar { display: flex; align-items: center; gap: 7px; padding: 12px 16px; background: rgba(255,255,255,.04); border-bottom: 1px solid var(--border); }
.code-bar i { width: 11px; height: 11px; border-radius: 50%; background: #ff5f57; }
.code-bar i:nth-child(2) { background: #febc2e; }
.code-bar i:nth-child(3) { background: #28c840; }
.code-bar span { margin-left: 8px; color: var(--muted); font-size: 12px; }
.code-window pre { padding: 20px; overflow-x: auto; }
.code-window code { color: #9fb4e8; font-family: "JetBrains Mono", Consolas, monospace; font-size: 13px; line-height: 1.9; }

/* 新闻 */
.news { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.news-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 26px; transition: .3s;
}
.news-card:hover { transform: translateY(-5px); border-color: rgba(79,124,255,.4); }
.news-card time { color: var(--cyan); font-size: 12px; letter-spacing: 1px; }
.news-card h4 { margin: 10px 0; font-size: 16px; line-height: 1.5; }
.news-card p { color: var(--muted); font-size: 13px; }
.news-card .more { display: inline-block; margin-top: 14px; color: var(--cyan); font-size: 13px; }

/* 联系 */
.contact-wrap { display: grid; grid-template-columns: .9fr 1.1fr; gap: 40px; align-items: start; }
.contact-cards { display: grid; gap: 16px; }
.contact-card {
  display: flex; gap: 16px; align-items: center;
  background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 20px 22px;
}
.cc-icon {
  width: 46px; height: 46px; border-radius: 12px; flex-shrink: 0;
  background: rgba(34,211,238,.1); color: var(--cyan);
  display: grid; place-items: center; font-size: 19px;
}
.contact-card h4 { font-size: 15px; }
.contact-card p { color: var(--muted); font-size: 13px; }
.contact-form {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 30px;
  display: grid; gap: 14px;
}
.contact-form input, .contact-form textarea {
  width: 100%; background: rgba(255,255,255,.04); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px; color: var(--text);
  font-size: 14px; outline: none; transition: .25s; font-family: inherit; resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--cyan); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form-tip { color: var(--cyan); font-size: 13px; min-height: 18px; }

/* ===== 页脚 ===== */
#footer { background: #070a14; border-top: 1px solid var(--border); padding: 56px 0 28px; }
.footer-top { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; padding-bottom: 34px; border-bottom: 1px solid var(--border); }
.footer-brand p { color: var(--muted); font-size: 13px; margin-top: 12px; }
.footer-links { display: flex; gap: 70px; }
.footer-links h5 { font-size: 14px; margin-bottom: 14px; }
.footer-links a { display: block; color: var(--muted); font-size: 13px; padding: 4px 0; transition: .2s; }
.footer-links a:hover { color: var(--cyan); }
.footer-beian {
  display: flex; gap: 26px; justify-content: center; flex-wrap: wrap;
  padding: 22px 0 8px;
}
.footer-beian a {
  color: var(--muted); font-size: 12px; display: inline-flex; align-items: center; gap: 5px; transition: .2s;
}
.footer-beian a:hover { color: var(--text); }
.footer-copy { text-align: center; color: #5a6584; font-size: 12px; padding-top: 8px; }

/* 入场动画 */
.reveal { opacity: 0; transform: translateY(30px); transition: .8s cubic-bezier(.2,.7,.3,1); }
.reveal.show { opacity: 1; transform: none; }

/* 响应式 */
@media (max-width: 860px) {
  #nav {
    position: fixed; top: 68px; right: 0; left: 0;
    flex-direction: column; gap: 0; background: rgba(10,14,26,.97);
    border-bottom: 1px solid var(--border);
    max-height: 0; overflow: hidden; transition: .35s;
  }
  #nav.open { max-height: 400px; }
  #nav a { padding: 14px 28px; border-bottom: 1px solid rgba(90,130,255,.06); }
  #menu-btn { display: block; }
  .about-wrap, .contact-wrap { grid-template-columns: 1fr; }
  .footer-links { gap: 40px; }
}