/* =========================================================
   提电科技 Tidian Tech — 官方站点样式
   主视觉：深蓝 / 背景白 / 阳光暖色点缀
   ========================================================= */
:root{
  /* 深蓝主色阶 */
  --blue-900:#07203f;
  --blue-800:#0b2e66;
  --blue-700:#103a8c;
  --blue-600:#1650b8;
  --blue-500:#1e6fe0;
  --blue-400:#3b8ef0;
  --blue-200:#bcd7ff;
  --blue-100:#e8f1ff;
  --blue-50:#f3f8ff;

  /* 阳光暖色点缀 */
  --gold-500:#ffb020;
  --gold-400:#ffc24d;
  --cyan-500:#19c3ff;
  --cyan-400:#5fd6ff;
  --green-500:#22c55e;
  --green-400:#4ade80;

  /* 中性 */
  --ink:#0f1b2d;
  --muted:#56657d;
  --line:#e4ecf6;
  --bg:#ffffff;
  --bg-soft:#f4f8ff;
  --surface:#ffffff;

  --shadow-sm:0 2px 10px rgba(16,58,140,.06);
  --shadow-md:0 12px 32px rgba(16,58,140,.10);
  --shadow-lg:0 24px 60px rgba(11,46,102,.16);
  --radius:18px;
  --radius-lg:28px;
  --maxw:1200px;
  --nav-h:72px;
  --font:"Segoe UI",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Noto Sans CJK TC",sans-serif;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:var(--nav-h)}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img,svg{display:block;max-width:100%}
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px}
section{position:relative}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  font-weight:600;font-size:15px;
  padding:13px 26px;border-radius:999px;
  border:1.5px solid transparent;cursor:pointer;
  transition:transform .2s ease,box-shadow .2s ease,background .2s ease;
  white-space:nowrap;
}
.btn-primary{background:linear-gradient(135deg,var(--blue-700),var(--blue-500));color:#fff;box-shadow:0 10px 24px rgba(22,80,184,.32)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 34px rgba(22,80,184,.42)}
.btn-ghost{background:#fff;color:var(--blue-700);border-color:var(--blue-200);box-shadow:var(--shadow-sm)}
.btn-ghost:hover{transform:translateY(-2px);border-color:var(--blue-400);color:var(--blue-600)}
.btn-gold{background:linear-gradient(135deg,var(--gold-500),var(--gold-400));color:#5a3a00;box-shadow:0 10px 24px rgba(255,176,32,.35)}
.btn-gold:hover{transform:translateY(-2px);box-shadow:0 16px 34px rgba(255,176,32,.45)}

/* ---------- 顶部导航 ---------- */
header.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  height:var(--nav-h);
  display:flex;align-items:center;
  background:rgba(255,255,255,.82);
  backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--line);
  transition:box-shadow .25s ease,background .25s ease;
}
header.nav.scrolled{box-shadow:var(--shadow-sm)}
.nav .container{display:flex;align-items:center;justify-content:space-between;gap:18px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;font-size:19px;letter-spacing:.3px;color:var(--blue-800)}
.brand .logo{width:38px;height:38px;flex:0 0 auto}
.brand small{display:block;font-size:11px;font-weight:600;color:var(--muted);letter-spacing:1.5px}
.nav-links{display:flex;align-items:center;gap:6px}
.nav-links a{
  padding:9px 15px;border-radius:10px;font-weight:600;font-size:15px;color:var(--ink);
  transition:background .2s,color .2s;
}
.nav-links a:hover{background:var(--blue-50);color:var(--blue-700)}
.nav-right{display:flex;align-items:center;gap:14px}
/* 语言切换 */
.lang{position:relative}
.lang-btn{
  display:flex;align-items:center;gap:7px;cursor:pointer;
  background:#fff;border:1.5px solid var(--blue-200);color:var(--blue-700);
  font-weight:600;font-size:14px;padding:8px 13px;border-radius:999px;
}
.lang-btn:hover{border-color:var(--blue-400)}
.lang-btn .caret{transition:transform .2s}
.lang.open .lang-btn .caret{transform:rotate(180deg)}
.lang-menu{
  position:absolute;top:calc(100% + 10px);right:0;min-width:188px;
  background:#fff;border:1px solid var(--line);border-radius:14px;
  box-shadow:var(--shadow-lg);padding:8px;opacity:0;visibility:hidden;transform:translateY(-6px);
  transition:opacity .18s,transform .18s,visibility .18s;z-index:120;
}
.lang.open .lang-menu{opacity:1;visibility:visible;transform:translateY(0)}
.lang-menu button{
  display:flex;align-items:center;justify-content:space-between;width:100%;
  background:none;border:none;cursor:pointer;text-align:left;
  padding:10px 12px;border-radius:10px;font-size:14px;color:var(--ink);font-weight:500;
}
.lang-menu button:hover{background:var(--blue-50)}
.lang-menu button.active{color:var(--blue-700);font-weight:700;background:var(--blue-50)}
.lang-menu button .tick{color:var(--blue-500);opacity:0}
.lang-menu button.active .tick{opacity:1}
.lang-menu .flag{margin-right:10px}
.hamburger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:8px}
.hamburger span{width:24px;height:2.5px;background:var(--blue-800);border-radius:2px;transition:.25s}

/* ---------- Hero ---------- */
.hero{
  padding:calc(var(--nav-h) + 78px) 0 90px;
  background:
    radial-gradient(1100px 520px at 82% -8%,rgba(25,195,255,.16),transparent 60%),
    radial-gradient(900px 520px at 10% 8%,rgba(255,176,32,.14),transparent 55%),
    linear-gradient(180deg,var(--blue-50),#ffffff 60%);
  overflow:hidden;
}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:48px;align-items:center}
.hero-badge{
  display:inline-flex;align-items:center;gap:8px;
  background:#fff;border:1px solid var(--blue-200);color:var(--blue-700);
  font-weight:600;font-size:13px;padding:7px 15px;border-radius:999px;box-shadow:var(--shadow-sm);
}
.hero-badge .dot{width:8px;height:8px;border-radius:50%;background:var(--green-500);box-shadow:0 0 0 4px rgba(34,197,94,.18)}
.hero h1{
  font-size:clamp(34px,4.4vw,56px);line-height:1.12;margin:22px 0 18px;
  color:var(--blue-900);font-weight:800;letter-spacing:-.5px;
}
.hero h1 .hl{
  background:linear-gradient(120deg,var(--blue-600),var(--cyan-500));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero h1 .hl-gold{
  background:linear-gradient(120deg,var(--gold-500),#ff8a3d);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero p.lead{font-size:18px;color:var(--muted);max-width:540px;margin-bottom:30px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:38px}
.hero-stats{display:flex;gap:34px;flex-wrap:wrap}
.hero-stats .stat .num{font-size:30px;font-weight:800;color:var(--blue-700)}
.hero-stats .stat .lbl{font-size:13.5px;color:var(--muted);font-weight:600}
.hero-visual{position:relative;min-height:420px}
.hero-card{
  position:absolute;background:#fff;border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);
  padding:18px;border:1px solid var(--line);
}
.hero-card.c1{top:6%;left:2%;width:240px;animation:floaty 6s ease-in-out infinite}
.hero-card.c2{top:38%;right:0;width:228px;animation:floaty 7s ease-in-out infinite .6s}
.hero-card.c3{bottom:2%;left:14%;width:210px;animation:floaty 6.5s ease-in-out infinite .3s}
.hero-card .ic{width:46px;height:46px;border-radius:13px;display:flex;align-items:center;justify-content:center;margin-bottom:10px}
.hero-card h4{font-size:15px;color:var(--blue-800);margin-bottom:3px}
.hero-card p{font-size:12.5px;color:var(--muted);line-height:1.5}
.glow-orb{position:absolute;border-radius:50%;filter:blur(8px);opacity:.5;z-index:-1}
.glow-orb.o1{width:160px;height:160px;background:radial-gradient(circle,var(--cyan-400),transparent 70%);top:-20px;right:40px}
.glow-orb.o2{width:130px;height:130px;background:radial-gradient(circle,var(--gold-400),transparent 70%);bottom:30px;left:-10px}
@keyframes floaty{0%,100%{transform:translateY(0)}50%{transform:translateY(-14px)}}

/* ---------- 通用区块 ---------- */
.section{padding:84px 0}
.section.alt{background:var(--bg-soft)}
.section-head{text-align:center;max-width:720px;margin:0 auto 52px}
.eyebrow{
  display:inline-block;font-size:13px;font-weight:700;letter-spacing:1.5px;text-transform:uppercase;
  color:var(--blue-500);background:var(--blue-100);padding:6px 14px;border-radius:999px;margin-bottom:16px;
}
.section-head h2{font-size:clamp(26px,3vw,38px);color:var(--blue-900);font-weight:800;letter-spacing:-.4px}
.section-head p{margin-top:14px;color:var(--muted);font-size:17px}

/* ---------- 业务板块 ---------- */
.biz{display:grid;gap:30px}
.biz-row{
  display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius-lg);
  padding:38px;box-shadow:var(--shadow-sm);transition:transform .25s,box-shadow .25s;
}
.biz-row:hover{transform:translateY(-4px);box-shadow:var(--shadow-md)}
.biz-row.reverse .biz-media{order:2}
.biz-media{
  position:relative;border-radius:var(--radius);overflow:hidden;min-height:300px;
  background:linear-gradient(135deg,var(--blue-700),var(--blue-500));
  display:flex;align-items:center;justify-content:center;
}
.biz-media .art{width:100%;height:100%}
.biz-info .tag{
  display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;color:#fff;
  background:linear-gradient(135deg,var(--blue-600),var(--cyan-500));padding:6px 14px;border-radius:999px;margin-bottom:16px;
}
.biz-info h3{font-size:25px;color:var(--blue-900);font-weight:800;margin-bottom:12px}
.biz-info p{color:var(--muted);font-size:15.5px;margin-bottom:20px}
.biz-feats{list-style:none;display:grid;gap:12px}
.biz-feats li{display:flex;gap:12px;align-items:flex-start;font-size:15px;color:var(--ink)}
.biz-feats .chk{
  flex:0 0 auto;width:24px;height:24px;border-radius:50%;background:var(--blue-100);
  display:flex;align-items:center;justify-content:center;margin-top:2px;
}
.biz-feats .chk svg{width:14px;height:14px}
.biz-cta{margin-top:22px;display:flex;gap:12px;flex-wrap:wrap}

/* ---------- 关于我们 ---------- */
.about-grid{display:grid;grid-template-columns:1fr 1fr;gap:54px;align-items:center}
.about-copy h2{font-size:clamp(26px,3vw,36px);color:var(--blue-900);font-weight:800;margin-bottom:18px}
.about-copy p{color:var(--muted);font-size:16px;margin-bottom:16px}
.about-stats{display:grid;grid-template-columns:repeat(2,1fr);gap:18px;margin-top:26px}
.about-stats .box{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow-sm)}
.about-stats .box .num{font-size:32px;font-weight:800;color:var(--blue-700)}
.about-stats .box .lbl{font-size:13.5px;color:var(--muted);font-weight:600}
.about-visual{position:relative;background:linear-gradient(135deg,var(--blue-800),var(--blue-500));border-radius:var(--radius-lg);padding:34px;color:#fff;box-shadow:var(--shadow-md);overflow:hidden}
.about-visual .ring{position:absolute;width:280px;height:280px;border:2px dashed rgba(255,255,255,.22);border-radius:50%;top:-90px;right:-90px}
.about-visual h3{font-size:22px;margin-bottom:18px;position:relative}
.value-list{display:grid;gap:16px;position:relative}
.value-list .v{display:flex;gap:14px;align-items:flex-start}
.value-list .v .vic{width:40px;height:40px;border-radius:12px;background:rgba(255,255,255,.14);display:flex;align-items:center;justify-content:center;flex:0 0 auto}
.value-list .v h4{font-size:16px;margin-bottom:2px}
.value-list .v p{font-size:13.5px;color:rgba(255,255,255,.82)}

/* ---------- 核心优势 ---------- */
.adv-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.adv-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px;
  box-shadow:var(--shadow-sm);transition:transform .25s,box-shadow .25s,border-color .25s;
}
.adv-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-md);border-color:var(--blue-200)}
.adv-card .aic{width:56px;height:56px;border-radius:16px;display:flex;align-items:center;justify-content:center;margin-bottom:18px}
.adv-card h4{font-size:18px;color:var(--blue-900);font-weight:800;margin-bottom:10px}
.adv-card p{color:var(--muted);font-size:14.5px}

/* ---------- 联系我们 ---------- */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:46px;align-items:start}
.contact-info h2{font-size:clamp(26px,3vw,36px);color:var(--blue-900);font-weight:800;margin-bottom:14px}
.contact-info p{color:var(--muted);font-size:16px;margin-bottom:24px}
.info-list{display:grid;gap:18px}
.info-item{display:flex;gap:16px;align:flex-start}
.info-item .iic{width:46px;height:46px;border-radius:13px;background:var(--blue-100);display:flex;align-items:center;justify-content:center;flex:0 0 auto}
.info-item h5{font-size:15px;color:var(--blue-900);margin-bottom:2px}
.info-item p{font-size:14.5px;color:var(--muted)}
.form-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius-lg);padding:32px;box-shadow:var(--shadow-md)}
.form-card .field{margin-bottom:18px}
.form-card label{display:block;font-size:14px;font-weight:600;color:var(--blue-900);margin-bottom:7px}
.form-card input,.form-card textarea{
  width:100%;padding:13px 15px;border:1.5px solid var(--line);border-radius:12px;
  font-family:inherit;font-size:15px;color:var(--ink);background:var(--blue-50);transition:border .2s,background .2s;
}
.form-card input:focus,.form-card textarea:focus{outline:none;border-color:var(--blue-400);background:#fff}
.form-card textarea{resize:vertical;min-height:120px}
.form-card .row2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.form-note{font-size:13px;color:var(--muted);margin-top:8px}
.form-ok{display:none;margin-top:14px;padding:12px 16px;border-radius:12px;background:#eafaf0;color:#14803a;font-size:14px;font-weight:600}
.form-ok.show{display:block}

/* ---------- 页脚 ---------- */
footer.site{
  background:linear-gradient(180deg,var(--blue-800),var(--blue-900));color:#dce8ff;padding:64px 0 28px;
}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:40px;margin-bottom:42px}
.foot-brand .brand{color:#fff;margin-bottom:14px}
.foot-brand p{font-size:14px;color:#a9c0e8;max-width:320px}
.foot-col h5{font-size:15px;color:#fff;margin-bottom:16px;font-weight:700}
.foot-col a{display:block;font-size:14px;color:#a9c0e8;padding:6px 0;transition:color .2s}
.foot-col a:hover{color:#fff}
.foot-bottom{border-top:1px solid rgba(255,255,255,.12);padding-top:22px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:13px;color:#8fabdc}
.foot-bottom .langs{display:flex;gap:14px;flex-wrap:wrap}
.foot-bottom .langs button{background:none;border:none;color:#8fabdc;cursor:pointer;font-size:13px;font-family:inherit}
.foot-bottom .langs button:hover{color:#fff}
.foot-bottom .langs button.active{color:#fff;font-weight:700}

/* ---------- 滚动动画 ---------- */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.08s}.reveal.d2{transition-delay:.16s}.reveal.d3{transition-delay:.24s}
.reveal.d4{transition-delay:.32s}.reveal.d5{transition-delay:.40s}.reveal.d6{transition-delay:.48s}

/* ---------- 响应式 ---------- */
@media (max-width:980px){
  .hero-grid{grid-template-columns:1fr;gap:30px}
  .hero-visual{min-height:340px;margin-top:10px}
  .biz-row,.biz-row.reverse{grid-template-columns:1fr}
  .biz-row.reverse .biz-media{order:0}
  .about-grid{grid-template-columns:1fr;gap:36px}
  .adv-grid{grid-template-columns:1fr 1fr}
  .contact-grid{grid-template-columns:1fr;gap:34px}
  .foot-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:680px){
  .nav-links,.nav-right .btn{display:none}
  .hamburger{display:flex}
  .nav.mobile-open .nav-links{
    display:flex;flex-direction:column;position:absolute;top:var(--nav-h);left:0;right:0;
    background:#fff;border-bottom:1px solid var(--line);padding:14px 24px;gap:4px;box-shadow:var(--shadow-md);
  }
  .nav.mobile-open .nav-links a{padding:12px 10px}
  .adv-grid,.about-stats{grid-template-columns:1fr}
  .form-card .row2{grid-template-columns:1fr}
  .hero-stats{gap:22px}
  .section{padding:64px 0}
  .foot-grid{grid-template-columns:1fr}
  .biz-row{padding:26px}
}