/* ==========================================================================
   维丁科技 Weiding Tech — 门户网站全局样式
   风格：物联科技 · 深色主题
   ========================================================================== */

:root {
  --bg: #070b16;
  --bg-2: #0b1120;
  --surface: #111a2e;
  --surface-2: #16213a;
  --border: rgba(120, 160, 255, 0.14);
  --border-strong: rgba(120, 160, 255, 0.28);
  --primary: #00d4ff;
  --primary-2: #4d7cff;
  --accent: #34e2b0;
  --text: #e8eefc;
  --text-dim: #9fb0cc;
  --text-mute: #6b7a94;
  --grad: linear-gradient(120deg, #00d4ff 0%, #4d7cff 100%);
  --grad-soft: linear-gradient(120deg, rgba(0, 212, 255, 0.14), rgba(77, 124, 255, 0.14));
  --shadow: 0 18px 50px -20px rgba(0, 0, 0, 0.7);
  --glow: 0 0 30px -6px rgba(0, 212, 255, 0.45);
  --radius: 16px;
  --radius-sm: 10px;
  --maxw: 1200px;
  --nav-h: 68px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  background-image:
    radial-gradient(1200px 600px at 80% -10%, rgba(0, 212, 255, 0.10), transparent 60%),
    radial-gradient(900px 500px at 0% 10%, rgba(77, 124, 255, 0.10), transparent 55%);
  background-attachment: fixed;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ----------------------------- Typography ----------------------------- */
h1, h2, h3, h4 { line-height: 1.25; font-weight: 800; letter-spacing: 0.2px; }
.section-title {
  font-size: clamp(26px, 4vw, 40px);
  margin-bottom: 14px;
}
.section-sub {
  color: var(--text-dim);
  font-size: clamp(15px, 1.6vw, 18px);
  max-width: 720px;
}
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase;
  color: var(--primary);
  padding: 6px 14px; border: 1px solid var(--border-strong); border-radius: 999px;
  background: var(--grad-soft);
  margin-bottom: 18px;
}

/* ------------------------------- Layout ------------------------------- */
.section { padding: 92px 0; position: relative; }
.section-head { margin-bottom: 46px; }
.section-head.center { text-align: center; }
.section-head.center .section-sub { margin: 0 auto; }

.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ----------------------------- Navigation ----------------------------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  display: flex; align-items: center;
  transition: background 0.3s, border-color 0.3s, backdrop-filter 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(9, 14, 26, 0.82);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--border);
}
.nav .container { display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: 20px; }
.brand .logo {
  width: 38px; height: 38px; border-radius: 10px;
  background: var(--grad); display: grid; place-items: center;
  color: #041025; font-weight: 900; font-size: 18px;
  box-shadow: var(--glow);
}
.brand small { display: block; font-size: 11px; font-weight: 600; color: var(--text-mute); letter-spacing: 3px; }
.nav-links { display: flex; align-items: center; gap: 8px; }
.nav-links a {
  padding: 9px 16px; border-radius: 10px; font-size: 15px; font-weight: 600; color: var(--text-dim);
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover { color: var(--text); background: var(--surface); }
.nav-links a.active { color: var(--primary); }
.nav-actions { display: flex; align-items: center; gap: 12px; }

.lang-toggle {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid var(--border-strong); border-radius: 999px; padding: 4px;
  background: var(--surface);
}
.lang-toggle button {
  border: 0; background: transparent; color: var(--text-mute); cursor: pointer;
  font-size: 13px; font-weight: 700; padding: 4px 12px; border-radius: 999px; transition: 0.2s;
  font-family: inherit;
}
.lang-toggle button.active { background: var(--grad); color: #041025; }

.nav-burger {
  display: none; border: 1px solid var(--border-strong); background: var(--surface);
  width: 42px; height: 42px; border-radius: 10px; cursor: pointer; color: var(--text);
}

/* ------------------------------- Buttons ------------------------------ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 13px 26px; border-radius: 12px; font-weight: 700; font-size: 15px;
  cursor: pointer; border: 1px solid transparent; transition: transform 0.15s, box-shadow 0.2s, background 0.2s;
  white-space: nowrap;
}
.btn-primary { background: var(--grad); color: #041025; box-shadow: var(--glow); }
.btn-primary:hover { transform: translateY(-2px); }
.btn-ghost { background: var(--surface); color: var(--text); border-color: var(--border-strong); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn-sm { padding: 9px 18px; font-size: 14px; }

/* -------------------------------- Hero -------------------------------- */
.hero { padding: calc(var(--nav-h) + 80px) 0 80px; position: relative; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
.hero h1 { font-size: clamp(32px, 5.4vw, 60px); line-height: 1.12; margin-bottom: 22px; }
.hero p.lead { font-size: clamp(16px, 1.8vw, 20px); color: var(--text-dim); margin-bottom: 32px; max-width: 560px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 34px; margin-top: 44px; flex-wrap: wrap; }
.hero-stats .stat b { font-size: 30px; display: block; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-stats .stat span { color: var(--text-mute); font-size: 14px; }

/* hero visual: stylized device panel */
.hero-visual { position: relative; }
.device-card {
  background: var(--surface); border: 1px solid var(--border-strong); border-radius: 20px;
  padding: 24px; box-shadow: var(--shadow); position: relative; overflow: hidden;
}
.device-card::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(400px 200px at 90% -20%, rgba(0, 212, 255, 0.18), transparent 60%);
  pointer-events: none;
}
.device-screen {
  aspect-ratio: 4 / 3; border-radius: 12px; background: linear-gradient(160deg, #0a1526, #0d1c33);
  border: 1px solid var(--border); display: grid; place-items: center; margin-bottom: 18px; position: relative; overflow: hidden;
}
.device-screen .grid-lines {
  position: absolute; inset: 0; opacity: 0.5;
  background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 26px 26px;
  mask-image: radial-gradient(circle at 50% 50%, #000 30%, transparent 75%);
}
.device-screen .pulse {
  width: 78px; height: 78px; border-radius: 50%; background: var(--grad); box-shadow: var(--glow);
  display: grid; place-items: center; color: #041025; font-weight: 900; z-index: 1; position: relative;
  animation: floaty 4s ease-in-out infinite;
}
@keyframes floaty { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }
.chip-row { display: flex; gap: 10px; flex-wrap: wrap; }
.chip {
  font-size: 13px; font-weight: 600; color: var(--text-dim);
  border: 1px solid var(--border); border-radius: 999px; padding: 6px 12px; background: var(--bg-2);
}
.chip::before { content: "●"; color: var(--accent); margin-right: 6px; font-size: 10px; }

/* ------------------------------- Cards -------------------------------- */
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s; position: relative; overflow: hidden;
}
.card:hover { transform: translateY(-6px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.card .ico {
  width: 54px; height: 54px; border-radius: 14px; background: var(--grad-soft);
  border: 1px solid var(--border-strong); display: grid; place-items: center; margin-bottom: 18px; color: var(--primary);
}
.card .ico svg { width: 26px; height: 26px; }
.card h3 { font-size: 20px; margin-bottom: 10px; }
.card p { color: var(--text-dim); font-size: 15px; }

.feature-compact { padding: 22px; }
.feature-compact .ico { width: 46px; height: 46px; margin-bottom: 14px; }

/* number badge */
.step { display: flex; gap: 18px; align-items: flex-start; }
.step .num {
  flex: none; width: 44px; height: 44px; border-radius: 12px; background: var(--grad); color: #041025;
  font-weight: 900; display: grid; place-items: center; font-size: 18px;
}

/* ------------------------------- Banner ------------------------------- */
.banner-cta {
  background: linear-gradient(120deg, rgba(0, 212, 255, 0.16), rgba(77, 124, 255, 0.16));
  border: 1px solid var(--border-strong); border-radius: 22px; padding: 48px;
  display: flex; align-items: center; justify-content: space-between; gap: 30px; flex-wrap: wrap;
  position: relative; overflow: hidden;
}
.banner-cta::after {
  content: ""; position: absolute; right: -60px; top: -60px; width: 260px; height: 260px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.25), transparent 70%);
}
.banner-cta h2 { font-size: clamp(22px, 3vw, 32px); margin-bottom: 8px; }
.banner-cta p { color: var(--text-dim); }

/* ---------------------------- Product table --------------------------- */
.price-free { color: var(--accent); font-weight: 800; }

.tag-list { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }
.tag { font-size: 12.5px; color: var(--text-dim); background: var(--bg-2); border: 1px solid var(--border); padding: 5px 11px; border-radius: 8px; }

/* ------------------------------- List ------------------------------- */
.check-list li { display: flex; gap: 12px; align-items: flex-start; padding: 10px 0; color: var(--text-dim); }
.check-list li svg { flex: none; width: 22px; height: 22px; color: var(--accent); margin-top: 2px; }

/* ------------------------------ Timeline ------------------------------ */
.timeline { border-left: 2px solid var(--border-strong); padding-left: 28px; margin-left: 8px; }
.timeline .item { position: relative; padding-bottom: 28px; }
.timeline .item::before {
  content: ""; position: absolute; left: -37px; top: 4px; width: 16px; height: 16px; border-radius: 50%;
  background: var(--grad); box-shadow: var(--glow);
}
.timeline .item h4 { font-size: 18px; margin-bottom: 4px; }
.timeline .item .yr { color: var(--primary); font-weight: 800; letter-spacing: 1px; }
.timeline .item p { color: var(--text-dim); font-size: 15px; }

/* ------------------------------- Forms -------------------------------- */
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 7px; color: var(--text-dim); }
.field input, .field textarea, .field select {
  width: 100%; background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px;
  padding: 13px 14px; color: var(--text); font-size: 15px; font-family: inherit; transition: border-color 0.2s, box-shadow 0.2s;
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.15);
}
.field textarea { resize: vertical; min-height: 130px; }

/* ------------------------------ Contact ------------------------------- */
.contact-info { display: grid; gap: 16px; }
.contact-info .ci {
  display: flex; gap: 16px; align-items: flex-start; background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius); padding: 20px;
}
.contact-info .ci .ico { width: 46px; height: 46px; border-radius: 12px; background: var(--grad-soft); display: grid; place-items: center; color: var(--primary); flex: none; }
.contact-info .ci .ico svg { width: 22px; height: 22px; }
.contact-info .ci b { display: block; margin-bottom: 2px; }
.contact-info .ci span { color: var(--text-dim); font-size: 14px; }

/* ------------------------------- Footer ------------------------------- */
.footer { background: var(--bg-2); border-top: 1px solid var(--border); padding: 64px 0 28px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; }
.footer h5 { font-size: 15px; margin-bottom: 16px; color: var(--text); }
.footer a { color: var(--text-dim); font-size: 14px; display: block; padding: 5px 0; transition: color 0.2s; }
.footer a:hover { color: var(--primary); }
.footer .about-txt { color: var(--text-dim); font-size: 14px; max-width: 320px; margin-top: 14px; }
.footer-bottom { border-top: 1px solid var(--border); margin-top: 40px; padding-top: 24px; display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; color: var(--text-mute); font-size: 13px; }

/* --------------------------- Breadcrumb page head -------------------- */
.page-hero { padding: calc(var(--nav-h) + 60px) 0 40px; }
.page-hero h1 { font-size: clamp(30px, 5vw, 48px); margin-bottom: 12px; }
.page-hero p { color: var(--text-dim); font-size: clamp(16px, 2vw, 19px); max-width: 720px; }

/* ----------------------------- Reveal anim ---------------------------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ------------------------------- Mobile ------------------------------- */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 820px) {
  .nav-links {
    position: fixed; inset: var(--nav-h) 0 auto 0; flex-direction: column; align-items: stretch;
    background: rgba(9, 14, 26, 0.98); backdrop-filter: blur(14px); padding: 18px 24px; gap: 4px;
    border-bottom: 1px solid var(--border); transform: translateY(-140%); transition: transform 0.3s; z-index: 99;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 13px 12px; font-size: 16px; }
  .nav-burger { display: grid; place-items: center; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .banner-cta { padding: 32px; }
}
@media (max-width: 560px) {
  .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .section { padding: 68px 0; }
  .hero-stats { gap: 22px; }
}