/* ============================================================
   GONGDA — B2B PVC Film / Edge Banding 官网样式
   高端深色质感：近黑底 + 香槟金强调色 + 玻璃拟态卡片
   响应式、移动优先、Core Web Vitals 友好
   上线前将 "GONGDA" / "gongdaa.com" / 占位文案 全局替换
   ============================================================ */

:root {
  --bg:       #0c0f14;   /* 近黑主背景 */
  --bg-2:     #141a23;   /* 卡片/分区表面 */
  --bg-3:     #1b2330;   /* 抬升表面 / 深色分区 */
  --line:     #2a3342;   /* 描边 */
  --text:     #e9eef5;   /* 主文字 */
  --muted:    #97a4b4;   /* 次级文字 */
  --gold:     #d4af37;   /* 香槟金 主强调 */
  --gold-2:   #ecc869;   /* 浅金 hover/渐变 */
  --gold-soft:rgba(212,175,55,.12);
  --radius:   14px;
  --shadow:   0 8px 30px rgba(0,0,0,.45);
  --shadow-lg:0 24px 60px rgba(0,0,0,.55);
  --glow:     0 0 0 1px rgba(212,175,55,.25), 0 12px 40px rgba(212,175,55,.10);
  --maxw:     1200px;
  --font: "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--gold); text-decoration: none; }
a:hover { color: var(--gold-2); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; }
.section.soft { background: var(--bg-2); }
.section.dark { background: linear-gradient(160deg, var(--bg-3), var(--bg)); color: var(--text); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: 999px;
  font-weight: 600; font-size: 16px; cursor: pointer; border: 0;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease, color .15s ease;
}
.btn-primary { background: linear-gradient(135deg, var(--gold-2), var(--gold)); color: #1a1300; box-shadow: var(--glow); }
.btn-primary:hover { background: linear-gradient(135deg, var(--gold), var(--gold-2)); color: #1a1300; transform: translateY(-2px); }
.btn-ghost { background: transparent; color: #fff; border: 1.5px solid rgba(255,255,255,.45); }
.btn-ghost:hover { border-color: var(--gold); color: var(--gold); }
.btn-outline { background: transparent; color: var(--gold); border: 1.5px solid var(--gold); }
.btn-outline:hover { background: var(--gold); color: #1a1300; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(12,15,20,.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; color: var(--text); }
.logo .mark { width: 34px; height: 34px; border-radius: 8px; background: linear-gradient(135deg, var(--gold-2), #8a6a2e); }
.logo-img { height: 42px; width: auto; object-fit: contain; }
.nav-links { display: flex; align-items: center; gap: 26px; list-style: none; margin: 0; padding: 0; }
.nav-links a { font-weight: 500; color: var(--text); }
.nav-links a:hover { color: var(--gold); }
.nav-cta { display: flex; align-items: center; gap: 14px; }
.lang-switch {
  font-size: 13px; font-weight: 600; color: var(--muted);
  border: 1px solid var(--line); border-radius: 999px; padding: 7px 14px;
  transition: all .15s ease;
}
.lang-switch:hover { color: var(--gold); border-color: var(--gold); }
.menu-toggle { display: none; background: none; border: 0; font-size: 26px; cursor: pointer; color: var(--text); }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(1100px 560px at 82% -12%, rgba(212,175,55,.18), transparent 60%),
    radial-gradient(700px 420px at 10% 110%, rgba(212,175,55,.08), transparent 60%),
    linear-gradient(160deg, #0a0d12, #11161f);
  color: #fff;
}
.hero .container { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; padding: 92px 24px; }
.hero h1 { font-size: 46px; line-height: 1.15; margin: 0 0 18px; font-weight: 800; letter-spacing: -.5px; }
.hero p.lead { font-size: 19px; color: #cdd6e2; margin: 0 0 28px; max-width: 560px; }
.hero .badge { display: inline-flex; gap: 8px; align-items: center; background: var(--gold-soft); border: 1px solid rgba(212,175,55,.35); color: var(--gold-2); padding: 6px 14px; border-radius: 999px; font-size: 13px; margin-bottom: 20px; letter-spacing: .3px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-visual { background: rgba(255,255,255,.04); border: 1px solid var(--line); border-radius: 16px; padding: 22px; box-shadow: var(--shadow-lg); }
.hero-visual .roll { height: 150px; border-radius: 10px; margin-bottom: 14px; background: linear-gradient(120deg,#caa46a,#8a6a3a); box-shadow: inset 0 0 40px rgba(0,0,0,.35); }
.hero-visual .roll.b { background: linear-gradient(120deg,#9fb6c4,#5d7689); }
.hero-visual .roll.c { background: linear-gradient(120deg,#d9d9d9,#9a9a9a); margin-bottom: 0; }

/* ---------- Section heads ---------- */
.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-head .eyebrow { color: var(--gold); font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; font-size: 18px; }
.section-head h1, .section-head h2 { font-size: 34px; margin: 10px 0 12px; color: var(--text); font-weight: 800; }
.section-head p { color: var(--muted); font-size: 17px; margin: 0; }
.section.dark .section-head p { color: #aab6c4; }

/* ---------- Cards / Grid ---------- */
.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3,1fr); }
.grid-4 { grid-template-columns: repeat(4,1fr); }
.grid-2 { grid-template-columns: repeat(2,1fr); }

.card {
  background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: rgba(212,175,55,.4); }
.card .thumb { height: 150px; border-radius: 10px; margin-bottom: 18px; background: var(--bg-3); box-shadow: inset 0 0 40px rgba(0,0,0,.35); overflow: hidden; }
.card .thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.card h3 { margin: 0 0 8px; font-size: 19px; color: var(--text); }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.card .more { display: inline-block; margin-top: 14px; font-weight: 600; color: var(--gold); }

/* feature with icon */
.feature { display: flex; gap: 16px; align-items: flex-start; }
.feature .ico { flex: 0 0 46px; width: 46px; height: 46px; border-radius: 12px; background: var(--gold-soft); color: var(--gold-2); display: grid; place-items: center; font-weight: 800; font-size: 20px; }
.feature h3 { margin: 0 0 6px; font-size: 18px; color: var(--text); }
.feature p { margin: 0; color: var(--muted); font-size: 15px; }

/* ---------- Stats ---------- */
.stats { display: grid; grid-template-columns: repeat(4,1fr); gap: 24px; text-align: center; }
.stat .num { font-size: 40px; font-weight: 800; color: var(--gold); }
.stat .lbl { color: #aab6c4; font-size: 15px; }

/* ---------- CTA band ---------- */
.cta-band { text-align: center; }
.cta-band h2 { font-size: 32px; margin: 0 0 12px; color: var(--text); }
.cta-band p { color: #aab6c4; font-size: 18px; margin: 0 0 26px; }

/* ---------- Breadcrumb ---------- */
.breadcrumb { font-size: 14px; color: var(--muted); padding: 18px 0; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--gold); }
.breadcrumb span { margin: 0 8px; }

/* ---------- Footer ---------- */
.site-footer { background: #080b0f; color: #8b97a6; padding: 56px 0 28px; border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.site-footer h4 { color: var(--text); font-size: 16px; margin: 0 0 16px; }
.site-footer ul { list-style: none; margin: 0; padding: 0; }
.site-footer ul li { margin-bottom: 10px; }
.site-footer a { color: #8b97a6; }
.site-footer a:hover { color: var(--gold); }
.footer-bottom { border-top: 1px solid var(--line); margin-top: 36px; padding-top: 20px; font-size: 14px; color: #69757f; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field.full { grid-column: 1 / -1; }
.field label { font-weight: 600; font-size: 14px; color: var(--text); }
.field input, .field textarea, .field select {
  padding: 12px 14px; border: 1px solid var(--line); border-radius: 10px; font-size: 15px; font-family: var(--font); color: var(--text); background: var(--bg-2);
}
.field input:focus, .field textarea:focus, .field select:focus { outline: none; border-color: var(--gold); }
.field select option { background: var(--bg-2); color: var(--text); }

/* ---------- Tables (spec) ---------- */
table { width: 100%; border-collapse: collapse; color: var(--text); }
th, td { text-align: left; padding: 12px 10px; border-bottom: 1px solid var(--line); }
th { color: var(--gold-2); font-weight: 700; }

/* ---------- FAQ ---------- */
.faq-item { border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin-bottom: 14px; background: var(--bg-2); }
.faq-item h3 { margin: 0; font-size: 17px; color: var(--text); }
.faq-item p { margin: 10px 0 0; color: var(--muted); }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero .container { grid-template-columns: 1fr; padding: 64px 24px; }
  .hero h1 { font-size: 36px; }
  .grid-3, .grid-4 { grid-template-columns: repeat(2,1fr); }
  .stats { grid-template-columns: repeat(2,1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
  .menu-toggle { display: block; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .section { padding: 56px 0; }
  .hero h1 { font-size: 30px; }
  .section-head h1, .section-head h2 { font-size: 26px; }
}