/* ============================================================
   鹿安净水 · 官网样式  |  Apple 官网风格
   ============================================================ */

:root {
  --text: #1d1d1f;
  --text-2: #6e6e73;
  --text-3: #86868b;
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --bg-dark: #000000;
  --dark-text: #f5f5f7;
  --dark-text-2: #86868b;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --radius-card: 18px;
  --nav-h: 48px;
  --content-w: 980px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro SC", "SF Pro Display",
    "PingFang SC", "Helvetica Neue", "Microsoft YaHei", "Segoe UI", sans-serif;
}

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

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

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  font-size: 17px;
  line-height: 1.47;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { display: block; max-width: 100%; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection { background: #b3d7ff; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 9999;
  background: rgba(255, 255, 255, 0.72);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  transition: background 0.3s ease;
}
.nav-inner {
  max-width: 1024px;
  height: 100%;
  margin: 0 auto;
  padding: 0 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--text);
  text-decoration: none;
}
.nav-logo:hover { text-decoration: none; opacity: 0.75; }
.nav-logo sup { font-size: 9px; color: var(--text-3); margin-left: 1px; }
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}
.nav-links a {
  font-size: 12px;
  color: rgba(0, 0, 0, 0.8);
  text-decoration: none;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }
.nav-links a.on { color: var(--text); }
.nav-cta {
  font-size: 12px;
  color: #fff !important;
  background: var(--accent);
  padding: 5px 14px;
  border-radius: 980px;
  transition: background 0.2s;
}
.nav-cta:hover { background: var(--accent-hover); text-decoration: none; }
.nav-burger {
  display: none;
  width: 40px; height: 40px;
  border: 0; background: transparent;
  cursor: pointer;
  position: relative;
}
.nav-burger span,
.nav-burger span::before,
.nav-burger span::after {
  content: "";
  position: absolute;
  left: 10px;
  width: 18px; height: 1.5px;
  background: var(--text);
  transition: transform 0.25s, top 0.25s;
}
.nav-burger span { top: 19px; }
.nav-burger span::before { top: -6px; left: 0; }
.nav-burger span::after { top: 6px; left: 0; }
.nav.open .nav-burger span { background: transparent; }
.nav.open .nav-burger span::before { transform: translateY(6px) rotate(45deg); }
.nav.open .nav-burger span::after { transform: translateY(-6px) rotate(-45deg); }

/* ---------- 通用布局 ---------- */
.content { max-width: var(--content-w); margin: 0 auto; padding: 0 22px; }

.section { padding: 110px 0; }
.section-alt { background: var(--bg-alt); }
.section-dark { background: var(--bg-dark); color: var(--dark-text); }
.section-dark .eyebrow, .section-dark .sub { color: var(--dark-text-2); }

.eyebrow {
  font-size: 21px;
  line-height: 1.2;
  font-weight: 600;
  color: var(--text-2);
  margin-bottom: 8px;
}
h1, h2, h3 { letter-spacing: -0.015em; }
.headline-xl {
  font-size: 80px;
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.02em;
}
.headline-lg {
  font-size: 56px;
  font-weight: 700;
  line-height: 1.07;
}
.headline-md {
  font-size: 40px;
  font-weight: 700;
  line-height: 1.1;
}
.headline-sm {
  font-size: 28px;
  font-weight: 700;
  line-height: 1.14;
}
.sub {
  font-size: 21px;
  line-height: 1.38;
  color: var(--text-2);
  margin-top: 14px;
}
.small-note { font-size: 12px; color: var(--text-3); margin-top: 14px; }

.cta-row { margin-top: 26px; display: flex; align-items: center; gap: 28px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  font-size: 17px;
  color: #fff;
  background: var(--accent);
  padding: 12px 26px;
  border-radius: 980px;
  transition: background 0.2s, transform 0.2s;
  text-decoration: none;
}
.btn:hover { background: var(--accent-hover); text-decoration: none; }
.btn:active { transform: scale(0.98); }
.btn-ghost {
  color: var(--accent);
  background: transparent;
  padding: 12px 0;
}
.btn-ghost:hover { text-decoration: underline; background: transparent; }
.section-dark .btn-ghost { color: #2997ff; }
.section-dark .small-note { color: var(--dark-text-2); }

.price { font-size: 21px; font-weight: 600; color: var(--text); }
.price small { font-size: 15px; font-weight: 400; color: var(--text-2); }
.section-dark .price { color: var(--dark-text); }

/* ---------- Hero ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  text-align: center;
  padding: calc(var(--nav-h) + 88px) 22px 0;
  overflow: hidden;
}
.hero .headline-xl { font-size: clamp(48px, 8vw, 88px); }
.hero .sub { font-size: clamp(19px, 2.6vw, 26px); }
.hero-media {
  margin-top: 44px;
  width: min(1100px, calc(100% + 44px));
  border-radius: 24px 24px 0 0;
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.12);
}
.hero-media img { width: 100%; aspect-ratio: 2 / 1; object-fit: cover; object-position: center 62%; }

/* hero 渐显动画 */
.hero .fade-item { opacity: 0; transform: translateY(24px); animation: rise 0.9s cubic-bezier(0.22, 0.61, 0.36, 1) forwards; }
.hero .fade-item:nth-child(2) { animation-delay: 0.12s; }
.hero .fade-item:nth-child(3) { animation-delay: 0.24s; }
.hero .fade-item:nth-child(4) { animation-delay: 0.4s; }
@keyframes rise { to { opacity: 1; transform: none; } }

/* ---------- 滚动渐显 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(34px);
  transition: opacity 0.8s cubic-bezier(0.22, 0.61, 0.36, 1),
    transform 0.8s cubic-bezier(0.22, 0.61, 0.36, 1);
}
.reveal.in { opacity: 1; transform: none; }
.reveal-d1 { transition-delay: 0.1s; }
.reveal-d2 { transition-delay: 0.2s; }
.reveal-d3 { transition-delay: 0.3s; }

/* ---------- 数据带 ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  text-align: center;
}
.stat b { display: block; font-size: 44px; font-weight: 700; letter-spacing: -0.02em; }
.stat span { font-size: 14px; color: var(--text-3); }

/* ---------- 产品卡片 ---------- */
.product-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.product-card {
  background: var(--bg);
  border-radius: var(--radius-card);
  padding: 52px 40px 0;
  text-align: center;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 580px;
}
.product-card .tag { font-size: 13px; font-weight: 600; color: #b64400; margin-bottom: 6px; }
.product-card .headline-md { font-size: 34px; }
.product-card .sub { font-size: 17px; margin-top: 8px; }
.product-card .cta-row { margin-top: 18px; justify-content: center; gap: 20px; }
.product-card .cta-row a { font-size: 15px; }
.product-media { margin-top: auto; padding-top: 28px; }
.product-media img {
  width: 78%;
  margin: 0 auto;
  mix-blend-mode: multiply;   /* 白底图融入卡片背景 */
  transition: transform 0.5s cubic-bezier(0.22, 0.61, 0.36, 1);
}
.product-card:hover .product-media img { transform: scale(1.035) translateY(-4px); }

/* ---------- 三心理念 ---------- */
.values { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; text-align: center; }
.value .glyph {
  width: 72px; height: 72px;
  margin: 0 auto 18px;
  border-radius: 50%;
  background: var(--bg);
  color: var(--text);
  font-size: 30px; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
}
.value h3 { font-size: 22px; margin-bottom: 8px; }
.value p { font-size: 15px; color: var(--dark-text-2); }

/* ---------- 特性大图 ---------- */
.feature-media {
  border-radius: 24px;
  overflow: hidden;
  margin-top: 56px;
}
.feature-media img { width: 100%; object-fit: cover; }
.feature-media.tall img { aspect-ratio: 3 / 4; object-position: top; }

.split {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 60px;
  align-items: center;
}
.split .feature-media { margin-top: 0; }

/* ---------- 图标特性网格 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 56px 40px;
  margin-top: 64px;
}
.feature-item .fi-num,
.feature-item .fi-icon {
  font-size: 34px; font-weight: 700; letter-spacing: -0.02em;
  margin-bottom: 12px;
}
.feature-item h3 { font-size: 19px; margin-bottom: 8px; }
.feature-item p { font-size: 15px; color: var(--text-2); line-height: 1.55; }
.section-dark .feature-item p { color: var(--dark-text-2); }

/* ---------- 对比表 ---------- */
.compare {
  width: 100%;
  border-collapse: collapse;
  margin-top: 48px;
  font-size: 15px;
}
.compare th, .compare td {
  padding: 16px 18px;
  text-align: center;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}
.compare th { font-size: 19px; font-weight: 700; }
.compare td:first-child, .compare th:first-child { text-align: left; color: var(--text-2); font-weight: 400; }
.compare td:first-child { font-size: 14px; }
.compare .row-name { font-weight: 600; font-size: 15px !important; color: var(--text) !important; }
.compare a { font-weight: 600; }

/* ---------- 服务 ---------- */
.service-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-top: 56px; text-align: center; }
.service-item { padding: 34px 18px; background: var(--bg); border-radius: var(--radius-card); transition: transform 0.35s cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 0.35s ease; }
.service-item:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(0, 0, 0, 0.08); }
.service-item .si-icon { display: flex; justify-content: center; margin-bottom: 14px; }
.service-item .si-icon svg { width: 26px; height: 26px; color: var(--text); }
.service-item b { display: block; font-size: 20px; margin-bottom: 6px; }
.service-item span { font-size: 14px; color: var(--text-2); }

/* ---------- FAQ ---------- */
.faq { max-width: 760px; margin: 56px auto 0; }
.faq-item { border-bottom: 1px solid rgba(0, 0, 0, 0.1); }
.faq-q {
  width: 100%;
  background: transparent; border: 0;
  font-family: var(--font);
  font-size: 18px; font-weight: 600; color: var(--text);
  text-align: left;
  padding: 22px 40px 22px 0;
  cursor: pointer;
  position: relative;
}
.faq-q::after {
  content: "";
  position: absolute; right: 8px; top: 50%;
  width: 9px; height: 9px;
  border-right: 1.5px solid var(--text-3);
  border-bottom: 1.5px solid var(--text-3);
  transform: translateY(-70%) rotate(45deg);
  transition: transform 0.25s;
}
.faq-item.open .faq-q::after { transform: translateY(-30%) rotate(225deg); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}
.faq-a p { font-size: 16px; color: var(--text-2); padding: 0 0 24px; line-height: 1.6; }

/* ---------- CTA 大区块 ---------- */
.cta-block { text-align: center; padding: 130px 0; }
.cta-block .headline-lg { font-size: clamp(36px, 6vw, 64px); }

/* ---------- 页脚 ---------- */
.footer {
  background: var(--bg-alt);
  padding: 44px 0 60px;
  font-size: 12px;
  color: var(--text-3);
}
.footer-inner { max-width: 1024px; margin: 0 auto; padding: 0 22px; }
.footer-nav {
  display: flex; flex-wrap: wrap; gap: 10px 28px;
  padding-bottom: 18px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}
.footer-nav a { color: var(--text-2); font-size: 12px; }
.footer-meta { padding-top: 18px; line-height: 2; }
.footer-meta a { color: var(--text-3); }
.footer-brand { font-size: 15px; font-weight: 600; letter-spacing: 2px; color: var(--text-2); margin-bottom: 12px; }

/* ---------- 产品页 ---------- */
.p-hero {
  padding: calc(var(--nav-h) + 84px) 0 0;
  text-align: center;
  background: var(--bg);
}
.p-hero .eyebrow { color: #b64400; }
.p-hero .price { margin-top: 16px; font-size: 24px; }
.p-hero .cta-row { justify-content: center; }
.p-hero-media {
  max-width: 860px;
  margin: 40px auto 0;
  padding: 0 22px;
}
.p-hero-media img {
  width: 100%;
  mix-blend-mode: multiply;
  transition: transform 0.6s cubic-bezier(0.22, 0.61, 0.36, 1);
}
.p-hero-media img:hover { transform: scale(1.02); }

.spec { margin-top: 60px; border-top: 1px solid rgba(0, 0, 0, 0.1); }
.spec-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 20px;
  padding: 16px 4px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  font-size: 15px;
}
.spec-row dt { color: var(--text-3); }
.spec-row dd { color: var(--text); }

.chip-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.chip {
  font-size: 13px;
  padding: 7px 15px;
  border-radius: 980px;
  background: var(--bg);
  color: var(--text-2);
}
.section-dark .chip { background: #1d1d1f; color: var(--dark-text-2); }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .section { padding: 72px 0; }
  .headline-xl { font-size: 52px; }
  .headline-lg { font-size: 40px; }
  .headline-md { font-size: 32px; }
  .split { grid-template-columns: 1fr; gap: 36px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 40px 28px; }
  .product-grid { grid-template-columns: 1fr; }
  .values, .stats, .service-grid { grid-template-columns: repeat(2, 1fr); }
  .stat b { font-size: 32px; }
}

@media (max-width: 640px) {
  .nav-links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: rgba(255, 255, 255, 0.96);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }
  .nav.open .nav-links { max-height: 320px; }
  .nav-links li { width: 100%; }
  .nav-links a {
    display: block;
    width: 100%;
    padding: 15px 28px;
    font-size: 16px;
  }
  .nav-links .nav-cta { margin: 12px 28px 18px; padding: 10px 22px; font-size: 14px; }
  .nav-burger { display: block; }

  .headline-xl { font-size: 42px; }
  .headline-lg { font-size: 34px; }
  .headline-md { font-size: 28px; }
  .sub { font-size: 18px; }
  .feature-grid { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr; }
  .compare th, .compare td { padding: 12px 8px; font-size: 13px; }
  .compare th { font-size: 15px; }
  .spec-row { grid-template-columns: 1fr; gap: 2px; padding: 14px 4px; }
  .product-card { padding: 40px 24px 0; min-height: 500px; }
  .hero { padding-top: calc(var(--nav-h) + 60px); }
}