/* ==========================================================
   光予筑全屋智能 · 系统集成工作室
   深色高端风 / 金色点缀 / 响应式
   ========================================================== */
:root {
  --bg: #0a1428;
  --bg-soft: #0e1a33;
  --bg-card: #12203d;
  --line: rgba(255,255,255,.08);
  --text: #e8e6e1;
  --text-dim: #9aa4b5;
  --gold: #c9a15a;
  --gold-soft: #e6c887;
  --radius: 14px;
  --shadow: 0 20px 60px rgba(0,0,0,.45);
}
* { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  font-family: "PingFang SC","Microsoft YaHei","Noto Sans SC",-apple-system,sans-serif;
  background: var(--bg); color: var(--text);
  line-height: 1.7; -webkit-font-smoothing: antialiased;
}
img { max-width:100%; display:block; }
a { color:inherit; text-decoration:none; }
.container { max-width: 1160px; margin: 0 auto; padding: 0 24px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top:0; left:0; right:0; z-index:100;
  background: rgba(10,20,40,.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  transition: background .3s;
}
.nav-inner {
  max-width: 1160px; margin:0 auto; padding: 12px 24px;
  display:flex; align-items:center; justify-content:space-between;
}
.brand { display:flex; align-items:center; gap:12px; }
.brand-logo {
  height:30px; width:auto; object-fit:contain;
}
.brand-text { display:flex; flex-direction:column; line-height:1.25; }
.brand-text strong { font-size:15px; letter-spacing:.5px; white-space:nowrap; }
.nav-links { display:flex; gap:28px; align-items:center; }
.nav-links a { font-size:14px; color:var(--text-dim); transition:color .2s; }
.nav-links a:hover { color:var(--gold-soft); }
.nav-links .nav-cta {
  color:var(--bg); background:var(--gold);
  padding:8px 18px; border-radius:999px; font-weight:600;
}
.nav-links .nav-cta:hover { background:var(--gold-soft); color:var(--bg); }
.nav-toggle { display:none; background:none; border:none; color:var(--text); font-size:24px; cursor:pointer; }

/* ---------- Hero ---------- */
.hero {
  position:relative; min-height:100vh;
  display:flex; align-items:center; justify-content:center; text-align:center;
  padding:120px 24px 80px; overflow:hidden;
}
.hero-slide {
  position:absolute; inset:0; z-index:0;
  background-size:cover; background-position:center;
  opacity:0; animation: heroFade 24s infinite;
}
.hero-slide:nth-child(1) { animation-delay: 0s; }
.hero-slide:nth-child(2) { animation-delay: 6s; }
.hero-slide:nth-child(3) { animation-delay: 12s; }
.hero-slide:nth-child(4) { animation-delay: 18s; }
@keyframes heroFade {
  0% { opacity:0; }
  4% { opacity:1; }
  24% { opacity:1; }
  28% { opacity:0; }
  100% { opacity:0; }
}
.hero-overlay {
  position:absolute; inset:0; z-index:1;
  background:
    radial-gradient(ellipse 70% 55% at 50% 30%, rgba(201,161,90,.12), transparent 60%),
    linear-gradient(180deg, rgba(10,20,40,.62) 0%, rgba(10,20,40,.55) 45%, rgba(8,17,32,.88) 100%);
}
.hero-content { position:relative; z-index:2; max-width:820px; }
.hero h1 {
  font-size: clamp(38px, 6vw, 64px);
  letter-spacing: 6px; font-weight: 700;
  background: linear-gradient(180deg, #fff 30%, #cbb382 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { margin-top:14px; font-size:16px; letter-spacing:5px; color:var(--text-dim); }
.hero-slogan {
  margin-top:22px; font-size: clamp(16px,2.4vw,21px);
  color:var(--gold-soft); letter-spacing:2px;
}
.hero-actions { margin-top:36px; display:flex; gap:16px; justify-content:center; flex-wrap:wrap; }
.btn {
  display:inline-block; padding:13px 34px; border-radius:999px;
  font-size:15px; letter-spacing:1px; transition:all .25s;
}
.btn-primary { background:var(--gold); color:var(--bg); font-weight:600; }
.btn-primary:hover { background:var(--gold-soft); transform:translateY(-2px); box-shadow:0 12px 30px rgba(201,161,90,.3); }
.btn-ghost { border:1px solid rgba(201,161,90,.5); color:var(--gold-soft); }
.btn-ghost:hover { background:rgba(201,161,90,.1); transform:translateY(-2px); }
.hero-stats {
  margin-top:56px; display:flex; justify-content:center; gap:36px; flex-wrap:wrap;
}
.stat { text-align:center; min-width:120px; }
.stat strong {
  display:block; font-size:26px; color:var(--gold-soft);
  letter-spacing:1px; line-height:1.2;
}
.stat strong sup { font-size:14px; }
.stat span { font-size:13px; color:var(--text-dim); letter-spacing:1px; margin-top:4px; display:block; }

/* ---------- 通用区块 ---------- */
.section { padding: 96px 0; }
.section-dark { background: var(--bg-soft); border-top:1px solid var(--line); border-bottom:1px solid var(--line); }
.section-title {
  text-align:center; font-size: clamp(26px,4vw,36px);
  letter-spacing:3px; font-weight:700;
}
.section-title::after {
  content:""; display:block; width:56px; height:3px; margin:16px auto 0;
  background:linear-gradient(90deg, transparent, var(--gold), transparent);
}
.section-sub { text-align:center; color:var(--text-dim); margin-top:14px; font-size:15px; letter-spacing:2px; }
.proj-note {
  text-align:center; margin-top:18px;
  color:var(--gold-soft); font-size:14px; letter-spacing:1px;
}

/* ---------- 服务 ---------- */
.grid { display:grid; grid-template-columns:repeat(4,1fr); gap:20px; margin-top:52px; }
.card {
  background:var(--bg-card); border:1px solid var(--line);
  border-radius:var(--radius); padding:30px 24px;
  transition: transform .3s, border-color .3s;
}
.card:hover { transform:translateY(-6px); border-color:rgba(201,161,90,.45); }
.service-icon {
  width:52px; height:52px; border-radius:14px;
  display:flex; align-items:center; justify-content:center;
  font-size:24px; color:var(--gold);
  background:rgba(201,161,90,.1); border:1px solid rgba(201,161,90,.3);
  margin-bottom:18px;
}
.card h3 { font-size:18px; margin-bottom:12px; letter-spacing:.5px; }
.card p { font-size:14px; color:var(--text-dim); }

/* ---------- 案例 ---------- */
.case-tabs { display:flex; justify-content:center; gap:12px; margin-top:44px; flex-wrap:wrap; }
.case-tab {
  background:transparent; border:1px solid var(--line); color:var(--text-dim);
  padding:10px 26px; border-radius:999px; font-size:14px; cursor:pointer;
  transition:all .25s;
}
.case-tab:hover { border-color:rgba(201,161,90,.5); color:var(--gold-soft); }
.case-tab.active { background:var(--gold); color:var(--bg); border-color:var(--gold); font-weight:600; }
.case-panel { display:none; margin-top:40px; }
.case-panel.active { display:block; animation:fadeIn .5s ease; }
@keyframes fadeIn { from{opacity:0; transform:translateY(14px);} to{opacity:1; transform:none;} }
.case-info { max-width:760px; margin:0 auto 28px; text-align:center; }
.case-info h3 { font-size:22px; letter-spacing:1px; margin-bottom:12px; color:var(--gold-soft); }
.case-info p { color:var(--text-dim); font-size:15px; }
.case-tags { list-style:none; display:flex; gap:10px; justify-content:center; flex-wrap:wrap; margin-top:16px; }
.case-tags li {
  font-size:12px; color:var(--gold-soft);
  border:1px solid rgba(201,161,90,.35); border-radius:999px;
  padding:4px 14px;
}
.case-slider { position:relative; max-width:880px; margin:0 auto; overflow:hidden; border-radius:var(--radius); border:1px solid var(--line); box-shadow:var(--shadow); }
.slide-track { display:flex; transition:transform .45s ease; }
.slide-track figure { flex:0 0 100%; position:relative; }
.slide-track img { width:100%; height:auto; }
.slide-track figcaption {
  position:absolute; left:16px; bottom:14px;
  background:rgba(13,15,18,.7); backdrop-filter:blur(6px);
  padding:5px 14px; border-radius:999px; font-size:13px; color:var(--gold-soft);
  border:1px solid rgba(201,161,90,.3);
}
.slider-btn {
  position:absolute; top:50%; transform:translateY(-50%);
  width:42px; height:42px; border-radius:50%;
  background:rgba(10,20,40,.6); border:1px solid rgba(255,255,255,.15);
  color:#fff; font-size:22px; cursor:pointer; transition:background .2s; z-index:5;
}
.slider-btn:hover { background:var(--gold); color:var(--bg); }
.slider-btn.prev { left:14px; }
.slider-btn.next { right:14px; }

/* ---------- 落地项目 ---------- */
.proj-grid {
  display:grid; grid-template-columns:repeat(4,1fr); gap:16px; margin-top:44px;
}
.proj-card {
  background:var(--bg-card); border:1px solid var(--line);
  border-radius:var(--radius); padding:22px 20px;
  transition:transform .3s, border-color .3s;
  display:flex; flex-direction:column; gap:8px;
}
.proj-card:hover { transform:translateY(-4px); border-color:rgba(201,161,90,.45); }
.proj-card h3 { font-size:17px; letter-spacing:.5px; }
.proj-card p { font-size:13px; color:var(--text-dim); }
.proj-std {
  font-size:11px; line-height:1.6; color:var(--text-dim);
  border-top:1px dashed var(--line); padding-top:8px; margin-top:2px;
}
.proj-tag {
  align-self:flex-start; font-size:11px; letter-spacing:1px;
  border-radius:999px; padding:3px 12px; margin-top:4px;
  border:1px solid;
}
.tag-knx { color:#7fb8e6; border-color:rgba(127,184,230,.4); background:rgba(127,184,230,.08); }
.tag-zigbee { color:#8fd6a2; border-color:rgba(143,214,162,.4); background:rgba(143,214,162,.08); }
.tag-lighting { color:#c9a15a; border-color:rgba(201,161,90,.4); background:rgba(201,161,90,.08); }
.tag-485 { color:#b58ae6; border-color:rgba(181,138,230,.4); background:rgba(181,138,230,.08); }
.proj-more {
  align-items:center; justify-content:center; text-align:center;
  border-style:dashed; min-height:120px;
}
.proj-more .proj-dots {
  font-size:34px; letter-spacing:6px; color:var(--gold-soft); line-height:1;
}
.proj-more p { font-size:12px; color:var(--text-dim); margin-top:6px; }
.proj-expand-wrap { text-align:center; margin-top:28px; }
.expand-btn {
  background:transparent; border:1px solid rgba(201,161,90,.45);
  color:var(--gold-soft); padding:10px 32px; border-radius:999px;
  font-size:14px; letter-spacing:1px; cursor:pointer;
  transition:all .25s;
}
.expand-btn:hover { background:rgba(201,161,90,.12); transform:translateY(-2px); }

/* ---------- 关于 ---------- */
.about-motto {
  text-align:center; margin:56px auto 0; max-width:720px;
  font-size: clamp(20px,3vw,28px); letter-spacing:3px; font-weight:600;
  background: linear-gradient(120deg, #fff 20%, var(--gold-soft) 60%, var(--gold) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.about-stats {
  display:grid; grid-template-columns:repeat(4,1fr); gap:20px;
  margin-top:56px;
}
.about-stat {
  text-align:center; background:var(--bg-card);
  border:1px solid var(--line); border-radius:var(--radius);
  padding:28px 16px; transition:transform .3s, border-color .3s;
}
.about-stat:hover { transform:translateY(-4px); border-color:rgba(201,161,90,.45); }
.about-stat strong {
  display:block; font-size:34px; color:var(--gold-soft); line-height:1.1;
}
.about-stat strong sup { font-size:18px; }
.about-stat span {
  display:block; margin-top:10px; font-size:13px; color:var(--text-dim); letter-spacing:1px; line-height:1.7;
}
.about-text {
  max-width:780px; margin:56px auto 0; text-align:center;
}
.about-text p {
  margin-bottom:18px; color:var(--text-dim); font-size:15.5px; line-height:2;
}
.about-text b { color:var(--gold-soft); font-weight:600; }
.about-flow {
  display:grid; grid-template-columns:repeat(5,1fr); gap:16px;
  margin-top:60px;
}
.flow-step {
  position:relative; text-align:center; background:var(--bg-card);
  border:1px solid var(--line); border-radius:var(--radius);
  padding:34px 16px 26px;
  transition:transform .3s, border-color .3s;
}
.flow-step:hover { transform:translateY(-4px); border-color:rgba(201,161,90,.45); }
.flow-num {
  position:absolute; top:-14px; left:50%; transform:translateX(-50%);
  background:var(--gold); color:var(--bg); font-size:13px; font-weight:700;
  padding:4px 14px; border-radius:999px; letter-spacing:1px;
}
.flow-step h4 { font-size:16px; margin:6px 0 8px; letter-spacing:1px; color:var(--text); }
.flow-step p { font-size:12.5px; color:var(--text-dim); line-height:1.7; }

/* ---------- 联系 ---------- */
.contact-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:20px; margin-top:52px; }
.contact-item {
  text-align:center; background:var(--bg-card);
  border:1px solid var(--line); border-radius:var(--radius); padding:34px 22px;
  transition:transform .3s, border-color .3s;
}
.contact-item:hover { transform:translateY(-4px); border-color:rgba(201,161,90,.45); }
.contact-icon { font-size:26px; color:var(--gold); margin-bottom:12px; }
.contact-item h3 { font-size:16px; margin-bottom:10px; letter-spacing:1px; }
.contact-item p { font-size:14px; color:var(--text-dim); }
.contact-item .contact-value { font-size:20px; color:var(--gold-soft); font-weight:600; letter-spacing:1px; }

/* ---------- 页脚 ---------- */
.footer { border-top:1px solid var(--line); padding:34px 0; text-align:center; }
.footer p { font-size:13px; color:var(--text-dim); letter-spacing:1px; }
.footer-sub { margin-top:6px; font-size:11px; color:#6b7078; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .grid { grid-template-columns:repeat(2,1fr); }
  .proj-grid { grid-template-columns:repeat(2,1fr); }
  .contact-grid { grid-template-columns:1fr; }
  .about-stats { grid-template-columns:repeat(2,1fr); }
  .about-flow { grid-template-columns:repeat(2,1fr); }
}
@media (max-width: 640px) {
  .nav-links {
    display:none; position:absolute; top:100%; left:0; right:0;
    flex-direction:column; background:var(--bg); padding:18px 24px;
    border-bottom:1px solid var(--line); gap:18px; align-items:flex-start;
  }
  .nav-links.open { display:flex; }
  .nav-toggle { display:block; }
  .grid { grid-template-columns:1fr; }
  .proj-grid { grid-template-columns:1fr; }
  .hero-stats { gap:28px; }
  .section { padding:64px 0; }
  .about-stats { grid-template-columns:1fr; }
  .about-flow { grid-template-columns:1fr; }
}