/* ============================================================
   AquaSpring Water Purifier | 净水器源头工厂官网
   全局样式表 | Global Stylesheet
   设计语言：工业制造 · 简洁专业 · 双语
   ============================================================ */

:root {
  /* 主品牌色 —— 工业蓝，传递专业与信赖 */
  --brand: #0b5ed7;
  --brand-dark: #084aab;
  --brand-light: #e8f0fd;
  --accent: #12a5c9;      /* 水之青，点缀 */
  --accent-light: #e6f7fb;

  /* 中性色 */
  --ink: #16233a;
  --ink-soft: #46536b;
  --line: #e4e9f1;
  --bg: #f6f8fb;
  --bg-white: #ffffff;

  /* 功能色 */
  --ok: #16a34a;
  --warn: #d97706;

  /* 圆角与阴影 */
  --radius: 14px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 3px rgba(22, 35, 58, .06);
  --shadow: 0 6px 24px rgba(22, 35, 58, .08);
  --shadow-lg: 0 16px 48px rgba(22, 35, 58, .12);

  --maxw: 1200px;
  --header-h: 76px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg-white);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--brand); text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand-dark); }
ul, ol { list-style: none; }

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

/* 段落与标题 */
h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; color: var(--ink); }
h2 { font-size: clamp(26px, 3.4vw, 38px); }
h3 { font-size: clamp(18px, 2vw, 22px); }

.section { padding: 72px 0; }
.section--alt { background: var(--bg); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-head .kicker {
  display: inline-block; font-size: 13px; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--brand); margin-bottom: 12px;
}
.section-head h2 { margin-bottom: 14px; }
.section-head p { color: var(--ink-soft); font-size: 16px; }

/* 语言切换：中英双语展示，.en 默认隐藏，body.lang-en 时隐藏中文显示英文 */
body:not(.lang-en) .zh { display: inline; }
body:not(.lang-en) .en { display: none; }
body.lang-en .zh { display: none; }
body.lang-en .en { display: inline; }

/* ============ 顶部导航 ============ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
  height: var(--header-h);
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.brand { display: flex; align-items: center; gap: 14px; min-width: 0; flex: none; }
.brand-logo {
  width: 52px; height: 52px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  flex: none; overflow: hidden; line-height: 0;
}
.brand-logo img { width: 100%; height: 100%; object-fit: contain; }
.brand-name { line-height: 1.25; white-space: nowrap; }
.brand-name .brand-zh { display: block; font-size: 17px; font-weight: 800; color: var(--ink); letter-spacing: .03em; }
.brand-name .brand-en { display: block; font-size: 11px; font-weight: 600; color: var(--ink); letter-spacing: .01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 300px; }

.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  padding: 8px 14px; font-size: 15px; font-weight: 600; color: var(--ink);
  border-radius: var(--radius-sm); white-space: nowrap;
}
.main-nav a:hover { background: var(--brand-light); color: var(--brand); }
.main-nav a.active { color: var(--brand); background: var(--brand-light); }

.header-actions { display: flex; align-items: center; gap: 10px; }
.lang-toggle {
  border: 1px solid var(--line); background: #fff; color: var(--ink-soft);
  padding: 8px 12px; border-radius: var(--radius-sm); font-size: 13px;
  font-weight: 600; cursor: pointer; transition: all .2s;
}
.lang-toggle:hover { border-color: var(--brand); color: var(--brand); }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: var(--radius-sm);
  font-size: 15px; font-weight: 700; cursor: pointer; border: none;
  transition: all .2s; line-height: 1;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); color: #fff; }
.btn-outline { background: #fff; color: var(--brand); border: 1.5px solid var(--brand); }
.btn-outline:hover { background: var(--brand-light); }
.btn-lg { padding: 14px 28px; font-size: 16px; }
.btn-ghost { background: transparent; color: var(--brand); border: none; padding: 8px 12px; }
.btn-ghost:hover { background: var(--brand-light); }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span {
  display: block; width: 22px; height: 2px; background: var(--ink);
  margin: 5px 0; transition: .25s;
}

/* ============ Hero ============ */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(150deg, #0a3f8f 0%, #0b5ed7 55%, #12a5c9 100%);
  color: #fff; padding: 96px 0 84px;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(900px 400px at 85% 20%, rgba(255,255,255,.12), transparent 60%);
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(255,255,255,.14); border: 1px solid rgba(255,255,255,.25);
  padding: 7px 14px; border-radius: 30px; font-size: 13px; font-weight: 600;
  margin-bottom: 20px;
}
.hero h1 { color: #fff; font-size: clamp(30px, 4.6vw, 52px); line-height: 1.15; margin-bottom: 20px; }
.hero h1 .accent-word { color: #7fd4ff; }
.hero p { font-size: 18px; color: rgba(255,255,255,.86); max-width: 560px; margin-bottom: 32px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-cta .btn-primary { background: #fff; color: var(--brand); }
.hero-cta .btn-primary:hover { background: #eaf2ff; }
.hero-cta .btn-outline { border-color: rgba(255,255,255,.6); color: #fff; background: transparent; }
.hero-cta .btn-outline:hover { background: rgba(255,255,255,.12); }

.hero-stats {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px;
  background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.16);
  border-radius: var(--radius); padding: 24px; backdrop-filter: blur(4px);
}
.hero-stats .stat { padding: 6px 4px; }
.hero-stats .stat b {
  display: block; font-size: 48px; font-weight: 900; color: #fff; line-height: 1.1;
  letter-spacing: .01em;
  text-shadow: 0 2px 4px rgba(6, 40, 90, .35), 0 6px 18px rgba(6, 40, 90, .28);
}
.hero-stats .stat span { font-size: 14px; font-weight: 600; color: rgba(255,255,255,.92); }

/* ============ 通用卡片与网格 ============ */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 28px;
  box-shadow: var(--shadow-sm); transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }

.icon-badge {
  width: 56px; height: 56px; border-radius: 14px;
  background: var(--brand-light); color: var(--brand);
  display: flex; align-items: center; justify-content: center; margin-bottom: 18px;
}
.icon-badge svg { width: 28px; height: 28px; }
.icon-badge--cyan { background: var(--accent-light); color: var(--accent); }

.card h3 { margin-bottom: 10px; }
.card p { color: var(--ink-soft); font-size: 15px; }

/* ============ 特性/优势 ============ */
.advantage-item { display: flex; gap: 18px; align-items: flex-start; }
.advantage-item .icon-badge { margin-bottom: 0; flex: none; }

/* 数字统计条 */
.stats-band { background: var(--brand); color: #fff; }
.stats-band .container { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; padding-top: 48px; padding-bottom: 48px; }
.stats-band .stat { text-align: center; }
.stats-band .stat b {
  font-size: 56px; font-weight: 900; display: block; line-height: 1.1;
  letter-spacing: .01em;
  text-shadow: 0 2px 4px rgba(6, 40, 90, .35), 0 6px 18px rgba(6, 40, 90, .28);
}
.stats-band .stat span { font-size: 15px; font-weight: 600; color: rgba(255,255,255,.92); }

/* ============ 页头横幅（内页） ============ */
.page-hero {
  background: linear-gradient(150deg, #0a3f8f 0%, #0b5ed7 70%, #12a5c9 100%);
  color: #fff; padding: 72px 0 60px; position: relative; overflow: hidden;
}
.page-hero::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(700px 300px at 80% 10%, rgba(255,255,255,.12), transparent 60%);
}
.page-hero .container { position: relative; z-index: 1; }
.page-hero h1 { color: #fff; font-size: clamp(28px, 4vw, 44px); margin-bottom: 12px; }
.page-hero p { color: rgba(255,255,255,.85); font-size: 17px; max-width: 640px; }

/* 面包屑 */
.breadcrumb { font-size: 13px; color: rgba(255,255,255,.7); margin-bottom: 18px; }
.breadcrumb a { color: rgba(255,255,255,.9); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { margin: 0 6px; opacity: .5; }

/* ============ 图片占位（SVG 风格） ============ */
.img-ph {
  background: linear-gradient(135deg, #e6eefb, #d3e4fb);
  border-radius: var(--radius); overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  min-height: 220px; color: var(--brand);
}
.img-ph--hero { min-height: 380px; }
.img-ph--product {
  background: #fff !important; border: none; padding: 0;
  min-height: 220px;
}
.img-ph--product img {
  width: 100%; height: 220px; object-fit: contain; display: block;
  border-radius: 0; background: #fff;
  transform: scale(1.15);
}
.img-ph svg { width: 72px; height: 72px; opacity: .55; }

/* ============ 页脚 ============ */
.site-footer { background: #0e1c33; color: rgba(255,255,255,.72); padding: 64px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 44px; }
.site-footer h4 { color: #fff; font-size: 16px; margin-bottom: 18px; }
.site-footer a { color: rgba(255,255,255,.72); font-size: 14px; display: block; padding: 5px 0; }
.site-footer a:hover { color: #fff; }
.footer-brand { color: rgba(255,255,255,.66); font-size: 14px; }
.footer-brand .brand-name { color: #fff; }
.footer-brand p { margin-top: 14px; max-width: 300px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.12);
  padding: 20px 0; text-align: center; font-size: 13px;
  color: rgba(255,255,255,.5);
}

/* ============ 联系方式列表 ============ */
.contact-list li { display: flex; gap: 12px; padding: 10px 0; font-size: 15px; }
.contact-list .c-ico { color: var(--brand); flex: none; margin-top: 2px; }
.contact-list .c-ico svg { width: 20px; height: 20px; }

/* ============ 表单 ============ */
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.form-group input, .form-group select, .form-group textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line);
  border-radius: var(--radius-sm); font-size: 15px; font-family: inherit;
  color: var(--ink); background: #fff; transition: border .2s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-light);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ============ 标签/徽章 ============ */
.tag {
  display: inline-block; padding: 4px 12px; border-radius: 20px;
  font-size: 12px; font-weight: 700; background: var(--brand-light); color: var(--brand);
}
.tag--cyan { background: var(--accent-light); color: var(--accent); }
.tag--green { background: #e7f6ec; color: var(--ok); }

/* ============ 返回顶部 ============ */
.to-top {
  position: fixed; right: 24px; bottom: 24px; z-index: 90;
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--brand); color: #fff; border: none; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow); opacity: 0; visibility: hidden; transition: all .3s;
}
.to-top.show { opacity: 1; visibility: visible; }
.to-top svg { width: 20px; height: 20px; }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-stats { max-width: 480px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 52px 0; }
  .container { padding: 0 18px; }
  .brand-name { font-size: 18px; }
  .brand-logo { width: 42px; height: 42px; }
  .brand-name .brand-zh { font-size: 15px; }
  .brand-name .brand-en { max-width: 180px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .stats-band .container { grid-template-columns: repeat(2, 1fr); gap: 28px; }
  .form-row { grid-template-columns: 1fr; }

  /* 移动端导航 */
  .nav-toggle { display: block; }
  .main-nav {
    position: absolute; top: var(--header-h); left: 0; right: 0;
    background: #fff; flex-direction: column; align-items: stretch;
    padding: 12px 18px 20px; gap: 2px;
    border-bottom: 1px solid var(--line); box-shadow: var(--shadow);
    display: none;
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 13px 14px; font-size: 16px; }
  .header-actions .btn { display: none; }
  .hero { padding: 64px 0 60px; }
  .hero p { font-size: 16px; }
  .page-hero { padding: 52px 0 44px; }
}

@media (max-width: 480px) {
  .hero-stats { grid-template-columns: 1fr 1fr; }
  .hero-stats .stat b { font-size: 36px; }
  .stats-band .stat b { font-size: 44px; }
  .footer-grid { grid-template-columns: 1fr; }
}