/* ============================================================
   求臻机油 · 官网静态页样式
   主色蓝 #1a56db / 背景 #f5f6fa / 灰 #909399（遵循项目铁律）
   ============================================================ */

:root {
  --brand: #1a56db;
  --brand-dark: #1746b0;
  --brand-deep: #123a8f;
  --brand-soft: #eaf0fd;
  --bg: #f5f6fa;
  --card: #ffffff;
  --text: #1c2740;
  --text-2: #4b5871;
  --muted: #909399;
  --line: #e6e9f2;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(20, 44, 102, 0.08);
  --shadow-lg: 0 18px 44px rgba(20, 44, 102, 0.14);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 86px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.container { max-width: 1120px; margin: 0 auto; padding: 0 22px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .2s ease;
  white-space: nowrap;
}
.btn-sm { padding: 8px 18px; font-size: 14px; }
.btn-lg { padding: 13px 34px; font-size: 16px; }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); transform: translateY(-1px); }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.55); }
.btn-ghost:hover { background: rgba(255,255,255,.14); }
.btn-outline { background: transparent; color: var(--brand); border-color: var(--brand); }
.btn-outline:hover { background: var(--brand-soft); }

/* ---------- 头部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .25s ease;
}
.site-header.scrolled { box-shadow: 0 4px 18px rgba(20,44,102,.07); }

.header-inner { display: flex; align-items: center; gap: 22px; height: 68px; }

.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  display: inline-flex;
  width: 34px; height: 34px;
  align-items: center; justify-content: center;
  background: var(--brand);
  color: #fff;
  border-radius: 10px;
  flex: none;
}
.brand-mark svg { width: 20px; height: 20px; fill: #fff; stroke: none; }
.brand-mark svg path { fill: #fff; stroke: none; }
.brand-text { font-size: 19px; font-weight: 700; letter-spacing: 1px; }
.brand-sub { font-size: 12px; color: var(--muted); margin-left: 2px; border-left: 1px solid var(--line); padding-left: 10px; }

.site-nav { margin-left: auto; display: flex; align-items: center; gap: 26px; }
.site-nav > a:not(.btn) { color: var(--text-2); font-size: 15px; transition: color .2s; }
.site-nav > a:not(.btn):hover { color: var(--brand); }

/* 汉堡菜单 */
.nav-toggle {
  display: none;
  margin-left: auto;
  width: 40px; height: 40px;
  border: none; background: transparent;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.nav-toggle span {
  width: 20px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all .25s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: linear-gradient(140deg, #17398f 0%, #1a56db 55%, #2f6ef0 100%);
  color: #fff;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  width: 560px; height: 560px;
  right: -160px; top: -180px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255,255,255,.16) 0%, rgba(255,255,255,0) 68%);
  pointer-events: none;
}
.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  align-items: center;
  gap: 46px;
  padding-top: 88px;
  padding-bottom: 120px;
}
.eyebrow {
  font-size: 13px;
  letter-spacing: 3px;
  opacity: .85;
  margin-bottom: 18px;
}
.hero h1 {
  font-size: 52px;
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 22px;
}
.hero h1 .accent { position: relative; color: #ffd76a; }
.hero-sub { font-size: 18px; color: rgba(255,255,255,.88); margin-bottom: 34px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

.hero-card {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.24);
  backdrop-filter: blur(6px);
  border-radius: 20px;
  padding: 28px 26px;
}
.hero-card-head { display: flex; align-items: center; gap: 10px; margin-bottom: 20px; }
.hero-card-head b { font-size: 18px; }
.hero-dot {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 0 4px rgba(74,222,128,.25);
}
.hero-tag {
  margin-left: auto;
  font-size: 12px;
  background: rgba(255,255,255,.18);
  padding: 4px 12px;
  border-radius: 999px;
}
.hero-points { display: grid; gap: 13px; }
.hero-points li { display: flex; align-items: center; gap: 9px; font-size: 15px; }
.hero-points svg { width: 17px; height: 17px; color: #4ade80; flex: none; }
.hero-link {
  display: inline-block;
  margin-top: 24px;
  font-size: 15px;
  font-weight: 600;
  border-bottom: 1px solid rgba(255,255,255,.6);
  padding-bottom: 2px;
  transition: opacity .2s;
}
.hero-link:hover { opacity: .8; }
.hero-wave {
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 56px;
  background: var(--bg);
  border-radius: 50% 50% 0 0 / 100% 100% 0 0;
  transform: scaleX(1.6);
  transform-origin: bottom;
}

/* ---------- 通用 section ---------- */
.section { padding: 84px 0; }
.section-alt { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-eyebrow {
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--brand);
  font-weight: 600;
  margin-bottom: 10px;
}
.section-title { font-size: 34px; font-weight: 800; letter-spacing: 1px; margin-bottom: 40px; }

/* ---------- 品牌保障 ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.feature {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 22px;
  transition: all .22s ease;
}
.feature:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: transparent; }
.feature-icon {
  display: inline-flex;
  width: 52px; height: 52px;
  border-radius: 14px;
  background: var(--brand-soft);
  color: var(--brand);
  align-items: center; justify-content: center;
  margin-bottom: 16px;
}
.feature-icon svg { width: 26px; height: 26px; }
.feature h3 { font-size: 18px; margin-bottom: 8px; }
.feature p { font-size: 14px; color: var(--text-2); }

/* ---------- 产品系列 ---------- */
.products {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.product {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  flex-direction: column;
  transition: all .22s ease;
}
.product:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: transparent; }
.product-visual {
  height: 150px;
  border-radius: 12px;
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}
.product-visual svg { width: 64px; height: 64px; fill: currentColor; }
.product-visual.v1 { background: linear-gradient(150deg, #1a56db, #3b82f6); }
.product-visual.v2 { background: linear-gradient(150deg, #2e6ed8, #60a5fa); }
.product-visual.v3 { background: linear-gradient(150deg, #1746b0, #4a8af7); }
.product-visual.v4 { background: linear-gradient(150deg, #3559c9, #7aa5fb); }
.product h3 { font-size: 18px; margin-bottom: 8px; }
.product p { font-size: 14px; color: var(--text-2); flex: 1; }
.product-link {
  display: inline-block;
  margin-top: 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--brand);
}
.product-link:hover { text-decoration: underline; }

/* ---------- 官方渠道 ---------- */
.buy-grid {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 44px;
  align-items: center;
}
.buy-desc { font-size: 16px; color: var(--text-2); margin: -14px 0 28px; }
.buy-note { margin-top: 16px; font-size: 13px; color: var(--muted); }

.qr-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 30px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}
.qr-title { font-size: 18px; font-weight: 700; margin-bottom: 18px; }
.qr-box {
  width: 224px; height: 224px;
  margin: 0 auto;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
}
.qr-fallback {
  flex-direction: column;
  gap: 12px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
  padding: 0 18px;
}
.qr-fallback svg { width: 52px; height: 52px; }
.qr-fallback span { font-size: 12px; }
.qr-tip { margin-top: 14px; font-size: 13px; color: var(--muted); }

/* ---------- 联系 ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; max-width: 900px; }
.contact-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px;
}
.contact-card h3 { font-size: 18px; margin-bottom: 10px; }
.contact-card p { font-size: 14px; color: var(--text-2); margin-bottom: 18px; }
.contact-placeholder {
  display: inline-block;
  font-size: 13px !important;
  color: var(--muted) !important;
  background: var(--bg);
  padding: 8px 16px;
  border-radius: 999px;
  margin-bottom: 0 !important;
}

/* ---------- 页脚 ---------- */
.site-footer { background: #101a30; color: #aab4cc; }
.footer-inner { padding-top: 46px; padding-bottom: 40px; }
.footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 22px; }
.footer-brand .brand-mark { background: var(--brand); }
.footer-brand .brand-text { color: #fff; }
.footer-nav { display: flex; gap: 26px; flex-wrap: wrap; margin-bottom: 26px; }
.footer-nav a { font-size: 14px; transition: color .2s; }
.footer-nav a:hover { color: #fff; }
.footer-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  border-top: 1px solid rgba(255,255,255,.08);
  padding-top: 22px;
  font-size: 13px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .features { grid-template-columns: repeat(2, 1fr); }
  .products { grid-template-columns: repeat(2, 1fr); }
  .buy-grid { grid-template-columns: 1fr; }
  .qr-card { max-width: 420px; margin: 0 auto; }
}

@media (max-width: 768px) {
  html { scroll-padding-top: 74px; }
  .brand-sub { display: none; }
  .header-inner { height: 62px; }

  .nav-toggle { display: flex; }
  .site-nav {
    position: absolute;
    top: 62px;
    left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 22px 22px;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
    display: none;
  }
  .site-nav.open { display: flex; }
  .site-nav > a:not(.btn) { padding: 14px 4px; border-bottom: 1px solid var(--line); }
  .site-nav .btn { margin-top: 16px; justify-content: center; }

  .hero-grid { grid-template-columns: 1fr; padding-top: 52px; padding-bottom: 96px; gap: 34px; }
  .hero h1 { font-size: 36px; }
  .hero-sub { font-size: 16px; }

  .section { padding: 58px 0; }
  .section-title { font-size: 27px; margin-bottom: 30px; }
}

@media (max-width: 520px) {
  .features, .products { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .hero-actions .btn-lg { width: 100%; }
  .footer-meta { flex-direction: column; }
}