/* QUFEI E-Commerce corporate site */
:root {
  --brand: #1a3d5c;
  --brand-dark: #0f2a40;
  --accent: #c8551e;
  --accent-light: #e88756;
  --bg: #ffffff;
  --bg-alt: #f5f3ee;
  --bg-dark: #1a1a1a;
  --text: #1a1a1a;
  --text-muted: #5a5a5a;
  --text-light: #8a8a8a;
  --border: #e3ddd1;
  --border-strong: #c2bba9;
  --success: #2e7d4a;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.08);
  --radius: 4px;
  --radius-lg: 8px;
  --max: 1200px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand); text-decoration: none; transition: color 0.15s ease; }
a:hover { color: var(--accent); }

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 { color: var(--brand-dark); font-weight: 600; line-height: 1.3; margin: 0 0 0.6em; letter-spacing: -0.01em; }
h1 { font-size: clamp(28px, 4vw, 44px); }
h2 { font-size: clamp(24px, 3vw, 32px); }
h3 { font-size: 20px; }
h4 { font-size: 17px; }

p { margin: 0 0 1em; }
.lead { font-size: 17px; color: var(--text-muted); }

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

/* ===== Header ===== */
.site-header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.92);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 18px 24px; max-width: var(--max); margin: 0 auto; }
.brand { display: flex; align-items: center; gap: 12px; font-weight: 700; font-size: 18px; color: var(--brand-dark); letter-spacing: -0.02em; }
.brand-mark {
  width: 36px; height: 36px;
  background: var(--brand);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.02em;
}
.brand small { display: block; font-size: 11px; color: var(--text-light); font-weight: 400; letter-spacing: 0.08em; text-transform: uppercase; margin-top: 2px; }

.nav { display: flex; align-items: center; gap: 32px; }
.nav a { color: var(--text); font-size: 14px; font-weight: 500; padding: 4px 0; border-bottom: 2px solid transparent; }
.nav a:hover, .nav a.active { color: var(--brand); border-bottom-color: var(--accent); }
.nav .cta { background: var(--accent); color: #fff !important; padding: 8px 18px; border-radius: var(--radius); border: none; }
.nav .cta:hover { background: var(--accent-light); }

.menu-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--brand-dark); }

@media (max-width: 820px) {
  .nav { display: none; position: absolute; top: 100%; left: 0; right: 0; background: #fff; flex-direction: column; gap: 0; padding: 16px 0; border-bottom: 1px solid var(--border); box-shadow: var(--shadow); }
  .nav.open { display: flex; }
  .nav a { width: 100%; padding: 12px 24px; border-bottom: none; }
  .nav a:hover, .nav a.active { background: var(--bg-alt); }
  .menu-toggle { display: block; }
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, #f8f6f1 0%, #efe9dd 100%);
  padding: 80px 0 60px;
  border-bottom: 1px solid var(--border);
}
.hero-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 60px; align-items: center; }
@media (max-width: 900px) { .hero-grid { grid-template-columns: 1fr; gap: 40px; } }

.hero-eyebrow { display: inline-block; background: rgba(200, 85, 30, 0.1); color: var(--accent); padding: 6px 14px; border-radius: 100px; font-size: 12px; font-weight: 600; letter-spacing: 0.05em; text-transform: uppercase; margin-bottom: 20px; }
.hero h1 { margin-bottom: 16px; }
.hero h1 .accent { color: var(--accent); }
.hero .lead { margin-bottom: 28px; max-width: 540px; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
}
.btn-primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-light); border-color: var(--accent-light); color: #fff; }
.btn-outline { background: transparent; color: var(--brand-dark); border-color: var(--brand-dark); }
.btn-outline:hover { background: var(--brand-dark); color: #fff; }

.hero-img { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 16px; box-shadow: var(--shadow-lg); }
.hero-img img { border-radius: var(--radius); }

.hero-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-top: 50px; padding-top: 36px; border-top: 1px solid var(--border); }
.hero-stat { text-align: center; }
.hero-stat .num { display: block; font-size: 30px; font-weight: 700; color: var(--accent); line-height: 1.1; }
.hero-stat .lbl { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.06em; margin-top: 4px; }
@media (max-width: 600px) { .hero-stats { grid-template-columns: repeat(2, 1fr); } }

/* ===== Sections ===== */
section { padding: 80px 0; }
section.alt { background: var(--bg-alt); }
section.dark { background: var(--bg-dark); color: #f0f0f0; }
section.dark h2, section.dark h3 { color: #fff; }

.section-head { text-align: center; max-width: 700px; margin: 0 auto 50px; }
.section-head .eyebrow { color: var(--accent); font-size: 13px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 12px; display: block; }

/* ===== Cards ===== */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
@media (max-width: 900px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

.card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px; transition: all 0.2s ease; }
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--border-strong); }
.card-icon { width: 48px; height: 48px; background: rgba(200, 85, 30, 0.1); color: var(--accent); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; font-size: 22px; margin-bottom: 16px; font-weight: 700; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--text-muted); margin: 0; }

.product-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; transition: all 0.2s ease; }
.product-card:hover { box-shadow: var(--shadow-lg); }
.product-card .img-wrap { aspect-ratio: 4/3; background: #f0eee8; overflow: hidden; }
.product-card img { width: 100%; height: 100%; object-fit: cover; }
.product-card .body { padding: 18px 20px 22px; }
.product-card h3 { font-size: 16px; margin-bottom: 6px; }
.product-card .meta { font-size: 12px; color: var(--text-light); text-transform: uppercase; letter-spacing: 0.06em; }

/* ===== Spec table ===== */
.spec-table { width: 100%; border-collapse: collapse; margin: 24px 0; font-size: 14px; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.spec-table th, .spec-table td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
.spec-table th { background: var(--bg-alt); font-weight: 600; color: var(--brand-dark); font-size: 13px; text-transform: uppercase; letter-spacing: 0.04em; }
.spec-table tr:last-child td { border-bottom: none; }
.spec-table td:first-child { font-weight: 500; color: var(--text); }

/* ===== Forms ===== */
.form { max-width: 600px; margin: 0 auto; background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 36px; box-shadow: var(--shadow); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 16px; }
@media (max-width: 600px) { .form-row { grid-template-columns: 1fr; } }
.form label { display: block; font-size: 13px; font-weight: 600; color: var(--brand-dark); margin-bottom: 6px; }
.form input, .form select, .form textarea { width: 100%; padding: 10px 14px; font-family: inherit; font-size: 14px; border: 1px solid var(--border-strong); border-radius: var(--radius); background: #fff; transition: border-color 0.15s ease; }
.form input:focus, .form select:focus, .form textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(200, 85, 30, 0.12); }
.form textarea { min-height: 120px; resize: vertical; }
.form button { width: 100%; justify-content: center; }
.form-status { padding: 12px; border-radius: var(--radius); margin-top: 12px; font-size: 14px; display: none; }
.form-status.success { display: block; background: rgba(46, 125, 74, 0.1); color: var(--success); border: 1px solid rgba(46, 125, 74, 0.2); }
.form-status.error { display: block; background: rgba(200, 30, 30, 0.1); color: #a01a1a; border: 1px solid rgba(200, 30, 30, 0.2); }

/* ===== Footer ===== */
.site-footer { background: var(--brand-dark); color: #c5cdd6; padding: 56px 0 24px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
@media (max-width: 800px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-grid h4 { color: #fff; font-size: 14px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 16px; }
.footer-grid a { display: block; color: #c5cdd6; padding: 4px 0; font-size: 14px; }
.footer-grid a:hover { color: var(--accent-light); }
.footer-brand p { color: #8a95a3; font-size: 13px; margin-top: 12px; }
.footer-bottom { border-top: 1px solid #2a4055; padding-top: 20px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 12px; color: #8a95a3; }

/* ===== Page header (subpages) ===== */
.page-head {
  background: linear-gradient(135deg, #f8f6f1 0%, #efe9dd 100%);
  padding: 64px 0 48px;
  border-bottom: 1px solid var(--border);
}
.page-head h1 { margin-bottom: 12px; }
.page-head .lead { max-width: 720px; }
.breadcrumb { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; }
.breadcrumb a { color: var(--text-muted); }
.breadcrumb span { color: var(--text-light); margin: 0 6px; }

/* ===== Utility ===== */
.text-center { text-align: center; }
.mb-0 { margin-bottom: 0; }
.mt-4 { margin-top: 32px; }
.badge { display: inline-block; background: rgba(26, 61, 92, 0.08); color: var(--brand-dark); padding: 4px 10px; border-radius: 100px; font-size: 11px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; }
.badge-accent { background: rgba(200, 85, 30, 0.12); color: var(--accent); }