/* =========================================================
   长樱牧业 企业官网 — 设计系统与全局样式
   调性：深墨绿 × 香槟金 · 高端农牧品牌
   ========================================================= */

/* ---------- 设计变量 ---------- */
:root {
  /* 主色：深墨绿系 */
  --green-950: #0B1F14;      /* 最深背景 */
  --green-900: #10291B;      /* 页面主背景 */
  --green-850: #143324;      /* 面板背景 */
  --green-800: #1A3F2C;      /* 卡片背景 */
  --green-700: #245239;      /* 描边/分隔 */
  --green-600: #2C7B2E;      /* 品牌绿（与小程序主色呼应） */
  --green-500: #3E9450;      /* 亮绿点缀 */

  /* 香槟金系 */
  --gold-300: #E7CD9C;       /* 亮金（高光文字） */
  --gold-400: #D4B276;       /* 主金 */
  --gold-500: #C9A96A;       /* 标准金 */
  --gold-600: #A8894E;       /* 深金（描边） */

  /* 文字 */
  --ink-hi: #F5F1E8;         /* 主文字（米白） */
  --ink-mid: #C4CFC4;        /* 次级文字 */
  --ink-low: #8FA394;        /* 弱化文字 */

  /* 其他 */
  --line: rgba(201, 169, 106, 0.22);      /* 金色细线 */
  --line-soft: rgba(245, 241, 232, 0.08);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.45);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.35);

  /* 字体栈：标题衬线，正文无衬线；外链字体加载失败自动退化 */
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STZhongsong", "SimSun", serif;
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;

  --container: 1180px;
  --radius: 14px;
}

/* ---------- 基础重置 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--green-900);
  color: var(--ink-hi);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

::selection { background: var(--gold-500); color: var(--green-950); }

/* ---------- 排版 ---------- */
h1, h2, h3, .serif { font-family: var(--font-serif); font-weight: 600; letter-spacing: 0.04em; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 28px; }

/* 区块头：英文 kicker + 中文标题 */
.sec-head { margin-bottom: 52px; }
.kicker {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 12px; letter-spacing: 0.42em; text-transform: uppercase;
  color: var(--gold-500); margin-bottom: 14px;
}
.kicker::before { content: ""; width: 34px; height: 1px; background: var(--gold-600); }
.sec-title { font-size: clamp(28px, 4vw, 40px); line-height: 1.3; }
.sec-sub { color: var(--ink-mid); margin-top: 14px; max-width: 640px; font-size: 15.5px; }

.sec-head--center { text-align: center; }
.sec-head--center .kicker::before { display: none; }
.sec-head--center .sec-sub { margin-left: auto; margin-right: auto; }

/* 金色渐变文字 */
.gold-text {
  background: linear-gradient(105deg, var(--gold-300) 10%, var(--gold-500) 55%, var(--gold-300) 90%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 15px 34px; font-size: 15px; letter-spacing: 0.14em;
  border-radius: 2px; cursor: pointer; transition: all 0.35s ease;
  border: 1px solid transparent; font-family: var(--font-sans);
}
.btn--gold {
  border: 1px solid var(--gold-500);
  color: var(--gold-300);
  background: linear-gradient(120deg, rgba(201, 169, 106, 0.16), rgba(201, 169, 106, 0.05));
  font-weight: 500;
}
.btn--gold:hover {
  background: linear-gradient(120deg, var(--gold-400), var(--gold-500));
  color: var(--green-950); font-weight: 600;
  box-shadow: 0 10px 30px rgba(201, 169, 106, 0.3);
  transform: translateY(-2px);
}
.btn--ghost { border-color: var(--line); color: var(--ink-hi); background: rgba(255, 255, 255, 0.02); }
.btn--ghost:hover { border-color: var(--gold-500); color: var(--gold-300); transform: translateY(-2px); }
.btn--sm { padding: 10px 22px; font-size: 13.5px; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  transition: background 0.4s ease, box-shadow 0.4s ease, border-color 0.4s;
  border-bottom: 1px solid transparent;
}
.nav--scrolled {
  background: rgba(11, 31, 20, 0.92); backdrop-filter: blur(14px);
  border-bottom-color: var(--line-soft); box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}
.nav__inner {
  max-width: var(--container); margin: 0 auto; padding: 0 28px;
  height: 76px; display: flex; align-items: center; justify-content: space-between;
}
.nav__brand { display: flex; align-items: center; gap: 14px; }
.nav__logo {
  width: 42px; height: 42px; border: 1px solid var(--gold-600);
  display: grid; place-items: center; font-family: var(--font-serif);
  color: var(--gold-400); font-size: 20px; border-radius: 2px;
  background: linear-gradient(160deg, rgba(201,169,106,0.12), transparent);
}
.nav__name { font-family: var(--font-serif); font-size: 19px; letter-spacing: 0.18em; }
.nav__name small { display: block; font-family: var(--font-sans); font-size: 9.5px; letter-spacing: 0.34em; color: var(--gold-500); margin-top: 1px; }
.nav__links { display: flex; gap: 38px; align-items: center; }
.nav__links a {
  font-size: 14.5px; letter-spacing: 0.12em; color: var(--ink-mid);
  position: relative; padding: 6px 0; transition: color 0.3s;
}
.nav__links a::after {
  content: ""; position: absolute; left: 50%; bottom: -2px;
  width: 0; height: 1px; background: var(--gold-400); transition: all 0.35s;
  transform: translateX(-50%);
}
.nav__links a:hover, .nav__links a.is-active { color: var(--ink-hi); }
.nav__links a:hover::after, .nav__links a.is-active::after { width: 100%; }
.nav__cta { margin-left: 10px; }
.nav__burger {
  display: none; width: 40px; height: 40px; border: 1px solid var(--line);
  background: none; cursor: pointer; position: relative; border-radius: 2px;
}
.nav__burger span, .nav__burger span::before, .nav__burger span::after {
  content: ""; position: absolute; left: 10px; width: 18px; height: 1.5px;
  background: var(--gold-400); transition: all 0.3s;
}
.nav__burger span { top: 19px; }
.nav__burger span::before { top: -6px; left: 0; }
.nav__burger span::after { top: 6px; left: 0; }

/* 移动端抽屉菜单 */
.nav__drawer {
  display: none; position: fixed; inset: 76px 0 0 0; z-index: 999;
  background: rgba(11, 31, 20, 0.98); backdrop-filter: blur(16px);
  padding: 40px 32px; flex-direction: column; gap: 6px;
}
.nav__drawer a {
  font-family: var(--font-serif); font-size: 21px; letter-spacing: 0.14em;
  padding: 15px 6px; border-bottom: 1px solid var(--line-soft); color: var(--ink-mid);
}
.nav__drawer a.is-active { color: var(--gold-300); }
body.menu-open .nav__drawer { display: flex; }

/* ---------- Hero（首页全屏） ---------- */
.hero {
  min-height: 100vh; position: relative; display: flex; align-items: center;
  background: url("../images/hero-grassland.jpg") center 35% / cover no-repeat;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(11,31,20,0.88) 0%, rgba(11,31,20,0.55) 45%, rgba(11,31,20,0.25) 100%),
              linear-gradient(to top, var(--green-900) 0%, transparent 26%);
}
.hero__inner { position: relative; z-index: 2; width: 100%; padding-top: 76px; }
.hero__tag {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 12.5px; letter-spacing: 0.4em; color: var(--gold-300);
  border: 1px solid var(--line); padding: 9px 20px; margin-bottom: 34px;
  background: rgba(11, 31, 20, 0.35); backdrop-filter: blur(4px);
}
.hero__title { font-size: clamp(38px, 6.4vw, 68px); line-height: 1.28; max-width: 15em; }
.hero__sub { margin-top: 26px; color: var(--ink-mid); max-width: 560px; font-size: 16.5px; }
.hero__actions { display: flex; gap: 18px; margin-top: 46px; flex-wrap: wrap; }

/* Hero 底部数据条 */
.hero__stats {
  margin-top: 84px; border-top: 1px solid var(--line);
  display: grid; grid-template-columns: repeat(4, 1fr);
  background: linear-gradient(to bottom, rgba(11,31,20,0.25), rgba(11,31,20,0.6));
  backdrop-filter: blur(6px);
}
.hero__stat { padding: 26px 10px 34px; text-align: center; border-right: 1px solid var(--line-soft); }
.hero__stat:last-child { border-right: none; }
.hero__stat b { font-family: var(--font-serif); font-size: clamp(26px, 3vw, 38px); color: var(--gold-300); display: block; white-space: nowrap; }
.hero__stat > span { font-size: 13px; color: var(--ink-mid); letter-spacing: 0.2em; margin-top: 6px; display: block; }

/* ---------- 通用 section ---------- */
.section { padding: 110px 0; position: relative; }
.section--tint { background: var(--green-850); }
.section--deep { background: var(--green-950); }

/* 滚动显现动画 */
.reveal { opacity: 0; transform: translateY(36px); transition: opacity 0.9s ease, transform 0.9s ease; }
.reveal.is-in { opacity: 1; transform: none; }
.reveal-d1 { transition-delay: 0.12s; } .reveal-d2 { transition-delay: 0.24s; }
.reveal-d3 { transition-delay: 0.36s; } .reveal-d4 { transition-delay: 0.48s; }

/* ---------- 卡片 ---------- */
.card-grid { display: grid; gap: 26px; }
.card-grid--4 { grid-template-columns: repeat(4, 1fr); }
.card-grid--3 { grid-template-columns: repeat(3, 1fr); }
.card-grid--2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: linear-gradient(165deg, var(--green-800), var(--green-850));
  border: 1px solid var(--line-soft); border-radius: var(--radius);
  padding: 38px 32px; position: relative; overflow: hidden;
  transition: transform 0.4s ease, border-color 0.4s, box-shadow 0.4s;
}
.card:hover { transform: translateY(-8px); border-color: var(--line); box-shadow: var(--shadow-md); }
.card__num {
  font-family: var(--font-serif); font-size: 13px; color: var(--gold-600);
  letter-spacing: 0.3em; margin-bottom: 20px; display: block;
}
.card__icon { font-size: 30px; margin-bottom: 18px; }
.card h3 { font-size: 20px; margin-bottom: 14px; }
.card p { color: var(--ink-mid); font-size: 14.5px; }
.card__more {
  display: inline-block; margin-top: 24px; font-size: 13px; letter-spacing: 0.2em;
  color: var(--gold-400); border-bottom: 1px solid transparent; transition: all 0.3s;
}
.card__more:hover { border-bottom-color: var(--gold-400); }

/* 金色顶线卡片变体 */
.card--topline::before {
  content: ""; position: absolute; top: 0; left: 32px; right: 32px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold-500), transparent);
}

/* 上图下文卡片（意境图变体）：无内边距，图片通栏出血到圆角 */
.card--photo { padding: 0 0 34px; }
.card__img {
  width: 100%; height: 216px; object-fit: cover; display: block;
  filter: saturate(0.88) contrast(1.02);
  transition: transform 0.7s ease, filter 0.7s ease;
}
.card--photo:hover .card__img { transform: scale(1.05); filter: saturate(1) contrast(1.05); }
/* 四列窄卡片用更矮的图，避免头重脚轻 */
.card-grid--4 .card__img { height: 172px; }
.card--photo .card__num { margin: 26px 32px 0; }
.card--photo h3 { margin: 12px 32px 0; }
.card--photo p { margin: 12px 32px 0; }

/* ---------- 图文对排 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: center; }
.split--rev .split__media { order: 2; }
.split__media { position: relative; }
.split__media img { border-radius: var(--radius); box-shadow: var(--shadow-lg); width: 100%; }
.split__media::after {
  content: ""; position: absolute; inset: 18px -18px -18px 18px;
  border: 1px solid var(--line); border-radius: var(--radius); z-index: -1;
}
.split__body h2 { font-size: clamp(26px, 3.2vw, 36px); margin-bottom: 22px; }
.split__body .lead { color: var(--ink-mid); font-size: 15.5px; margin-bottom: 30px; }

/* 特性列表（金色圆点） */
.feat-list li {
  display: flex; gap: 16px; padding: 15px 0; border-bottom: 1px solid var(--line-soft);
  font-size: 15px; color: var(--ink-mid);
}
.feat-list li:last-child { border-bottom: none; }
.feat-list li::before {
  content: ""; flex: none; width: 7px; height: 7px; margin-top: 10px;
  background: var(--gold-400); transform: rotate(45deg);
}
.feat-list b { color: var(--ink-hi); font-weight: 600; }

/* ---------- 步骤时间线 ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; counter-reset: step; }
.step { padding: 0 30px; position: relative; }
.step + .step::before {
  content: ""; position: absolute; left: 0; top: 14px; bottom: 14px; width: 1px;
  background: linear-gradient(to bottom, transparent, var(--line), transparent);
}
.step__no {
  font-family: var(--font-serif); font-size: 42px; color: transparent;
  -webkit-text-stroke: 1px var(--gold-500); line-height: 1; margin-bottom: 18px;
}
.step h3 { font-size: 18px; margin-bottom: 10px; }
.step p { color: var(--ink-mid); font-size: 14px; }

/* ---------- 大图 CTA 带状区 ---------- */
.cta-band {
  position: relative; padding: 130px 0; text-align: center;
  background: url("../images/courtyard.jpg") center 40% / cover no-repeat fixed;
}
.cta-band::before { content: ""; position: absolute; inset: 0; background: rgba(11, 31, 20, 0.78); }
.cta-band .container { position: relative; z-index: 2; }
.cta-band h2 { font-size: clamp(28px, 4vw, 44px); margin-bottom: 18px; }
.cta-band p { color: var(--ink-mid); max-width: 620px; margin: 0 auto 40px; }

/* ---------- 页脚 ---------- */
.footer { background: var(--green-950); border-top: 1px solid var(--line-soft); padding: 80px 0 0; }
.footer__grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.4fr; gap: 48px; padding-bottom: 60px; }
.footer__brand .nav__name { font-size: 21px; }
.footer__brand p { color: var(--ink-low); font-size: 13.5px; margin-top: 20px; max-width: 300px; }
.footer h4 { font-size: 14px; letter-spacing: 0.26em; color: var(--gold-400); margin-bottom: 24px; font-weight: 600; }
.footer__col a, .footer__col li { display: block; color: var(--ink-low); font-size: 14px; padding: 7px 0; transition: color 0.3s; }
.footer__col a:hover { color: var(--gold-300); }
.footer__qr {
  display: flex; gap: 18px; align-items: center; margin-top: 20px;
  border: 1px dashed var(--line); padding: 16px; border-radius: 8px; width: fit-content;
}
.footer__qr-box {
  width: 92px; height: 92px; flex: none; border-radius: 6px;
  background:
    repeating-linear-gradient(0deg, var(--green-700) 0 6px, transparent 6px 12px),
    repeating-linear-gradient(90deg, var(--green-700) 0 6px, var(--green-850) 6px 12px);
  display: grid; place-items: center; color: var(--gold-300); font-size: 11px;
  letter-spacing: 0.1em; text-align: center;
}
.footer__qr p { font-size: 12.5px; color: var(--ink-mid); line-height: 1.8; }
.footer__bottom {
  border-top: 1px solid var(--line-soft); padding: 24px 0;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  color: var(--ink-low); font-size: 12.5px; letter-spacing: 0.06em;
}

/* ---------- 页内 Hero（子页面） ---------- */
.page-hero {
  padding: 210px 0 110px; position: relative; overflow: hidden;
  background: linear-gradient(160deg, var(--green-950) 30%, var(--green-850));
}
.page-hero::after {
  content: ""; position: absolute; right: -140px; top: -140px; width: 460px; height: 460px;
  border: 1px solid var(--line); border-radius: 50%; opacity: 0.5;
}
.page-hero::before {
  content: ""; position: absolute; right: -60px; top: -60px; width: 300px; height: 300px;
  border: 1px solid var(--line-soft); border-radius: 50%;
}
.page-hero .kicker { margin-bottom: 18px; }
.page-hero h1 { font-size: clamp(32px, 5vw, 52px); line-height: 1.3; }
.page-hero p { color: var(--ink-mid); margin-top: 22px; max-width: 640px; font-size: 16px; }

/* 面包屑 */
.crumb { font-size: 13px; color: var(--ink-low); letter-spacing: 0.15em; margin-bottom: 26px; }
.crumb a:hover { color: var(--gold-300); }
.crumb i { font-style: normal; margin: 0 10px; color: var(--gold-600); }

/* ---------- 新闻卡片 ---------- */
.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.news-card {
  background: var(--green-850); border: 1px solid var(--line-soft);
  border-radius: var(--radius); overflow: hidden; transition: all 0.4s;
}
.news-card:hover { transform: translateY(-6px); border-color: var(--line); box-shadow: var(--shadow-md); }
.news-card__body { padding: 30px 28px 34px; }
.news-card__meta { font-size: 12px; color: var(--gold-500); letter-spacing: 0.2em; display: flex; gap: 14px; margin-bottom: 16px; }
.news-card h3 { font-size: 17.5px; line-height: 1.55; margin-bottom: 12px; font-family: var(--font-sans); font-weight: 600; }
.news-card p { color: var(--ink-mid); font-size: 14px; }

/* ---------- 表单 ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.form-item { display: flex; flex-direction: column; gap: 9px; }
.form-item--full { grid-column: 1 / -1; }
.form-item label { font-size: 13px; letter-spacing: 0.18em; color: var(--gold-400); }
.form-item input, .form-item textarea, .form-item select {
  background: var(--green-850); border: 1px solid var(--line-soft); border-radius: 4px;
  padding: 14px 16px; color: var(--ink-hi); font-size: 14.5px; font-family: var(--font-sans);
  transition: border-color 0.3s; outline: none; width: 100%;
}
.form-item input:focus, .form-item textarea:focus, .form-item select:focus { border-color: var(--gold-500); }
.form-item textarea { min-height: 130px; resize: vertical; }

/* ---------- 溯源时间线（自动轮播） ---------- */
.tl__media {
  position: relative; height: clamp(300px, 42vw, 500px);
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-lg); background: var(--green-950);
}
.tl__media img {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: cover; opacity: 0; transform: scale(1.1);
  transition: opacity 1.1s ease; will-change: transform, opacity;
}
.tl__media img.is-on { opacity: 1; animation: tlKen 5s ease-out forwards; }
@keyframes tlKen { from { transform: scale(1.1); } to { transform: scale(1.02); } }
.tl__shade {
  position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(11, 31, 20, 0.9) 0%, rgba(11, 31, 20, 0.2) 45%, transparent 72%);
}
.tl__caption {
  position: absolute; left: clamp(22px, 4vw, 48px); right: clamp(22px, 4vw, 48px);
  bottom: clamp(20px, 4vw, 42px); display: flex; gap: 26px; align-items: flex-end;
}
.tl__cap-roman {
  font-family: var(--font-serif); font-size: clamp(44px, 6vw, 68px); line-height: 0.9;
  color: transparent; -webkit-text-stroke: 1px var(--gold-400); flex: none;
}
.tl__cap-body h3 { font-size: clamp(22px, 2.6vw, 30px); }
.tl__cap-body p { color: var(--ink-mid); max-width: 580px; margin-top: 8px; font-size: 15px; }
.tl__caption.is-in { animation: capIn 0.7s ease both; }
@keyframes capIn { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

.tl__track { position: relative; margin-top: 58px; }
.tl__rail {
  position: absolute; top: 21px; left: 10%; right: 10%; height: 1px;
  background: var(--line-soft);
}
.tl__rail i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--gold-600), var(--gold-300));
  box-shadow: 0 0 14px rgba(201, 169, 106, 0.55);
  transition: width 0.8s ease;
}
.tl__dots { position: relative; display: grid; grid-template-columns: repeat(5, 1fr); }
.tl__dot {
  background: none; border: none; cursor: pointer; padding: 0 6px;
  display: flex; flex-direction: column; align-items: center; gap: 14px;
  font-family: var(--font-sans); color: var(--ink-low);
}
.tl__dot i {
  width: 42px; height: 42px; border-radius: 50%; position: relative; z-index: 2;
  border: 1px solid var(--line); background: var(--green-900);
  display: grid; place-items: center; font-style: normal;
  font-family: var(--font-serif); font-size: 17px; color: var(--ink-low);
  transition: all 0.5s ease;
}
.tl__dot span { font-size: 13.5px; letter-spacing: 0.12em; transition: color 0.4s; }
.tl__dot:hover i { border-color: var(--gold-500); color: var(--gold-300); }
.tl__dot.is-on i {
  border-color: var(--gold-400); color: var(--gold-300);
  background: radial-gradient(circle at 50% 38%, rgba(201, 169, 106, 0.28), var(--green-900) 72%);
  box-shadow: 0 0 0 5px rgba(201, 169, 106, 0.12), 0 0 26px rgba(201, 169, 106, 0.35);
  transform: scale(1.12);
}
.tl__dot.is-on span { color: var(--gold-300); }

@media (max-width: 720px) {
  .tl__media { height: 320px; }
  .tl__track { margin-top: 40px; }
  .tl__rail { top: 16px; }
  .tl__dot i { width: 32px; height: 32px; font-size: 13px; }
  .tl__dot span { font-size: 10px; letter-spacing: 0; white-space: nowrap; }
  .tl__cap-body p { font-size: 13.5px; }
}
@media (prefers-reduced-motion: reduce) {
  .tl__media img.is-on { animation: none; }
}

/* ---------- 数字墙 ---------- */
.stats-wall { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.stats-wall__cell { padding: 44px 24px; text-align: center; border-right: 1px solid var(--line-soft); background: var(--green-850); }
.stats-wall__cell:last-child { border-right: none; }
.stats-wall__cell b { font-family: var(--font-serif); font-size: clamp(30px, 3.6vw, 46px); color: var(--gold-300); display: block; white-space: nowrap; }
.stats-wall__cell > span { color: var(--ink-mid); font-size: 13.5px; letter-spacing: 0.18em; margin-top: 10px; display: block; }

/* ---------- 返回顶部 ---------- */
.backtop {
  position: fixed; right: 30px; bottom: 30px; z-index: 900;
  width: 46px; height: 46px; border: 1px solid var(--line); border-radius: 2px;
  background: rgba(11, 31, 20, 0.85); color: var(--gold-400); font-size: 18px;
  cursor: pointer; opacity: 0; pointer-events: none; transition: all 0.4s;
  backdrop-filter: blur(8px);
}
.backtop.is-show { opacity: 1; pointer-events: auto; }
.backtop:hover { background: var(--gold-500); color: var(--green-950); }

/* ---------- 页面入场 ---------- */
@keyframes fadeUp { from { opacity: 0; transform: translateY(30px); } to { opacity: 1; transform: none; } }
.anim-up { animation: fadeUp 1s ease both; }
.anim-up-1 { animation-delay: 0.1s; } .anim-up-2 { animation-delay: 0.25s; }
.anim-up-3 { animation-delay: 0.4s; } .anim-up-4 { animation-delay: 0.55s; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .card-grid--4 { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; gap: 48px; }
  .split--rev .split__media { order: 0; }
  .steps { grid-template-columns: repeat(2, 1fr); gap: 36px 0; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 720px) {
  .section { padding: 76px 0; }
  .nav__links { display: none; }
  .nav__burger { display: block; }
  .hero__stats { grid-template-columns: repeat(2, 1fr); }
  .hero__stat:nth-child(2) { border-right: none; }
  .hero__stat:nth-child(1), .hero__stat:nth-child(2) { border-bottom: 1px solid var(--line-soft); }
  .card-grid--4, .card-grid--3, .news-grid, .steps, .form-grid, .stats-wall { grid-template-columns: 1fr; }
  .stats-wall__cell { border-right: none; border-bottom: 1px solid var(--line-soft); }
  .stats-wall__cell:last-child { border-bottom: none; }
  .footer__grid { grid-template-columns: 1fr; gap: 36px; }
  .cta-band { background-attachment: scroll; }
  .split__media::after { display: none; }
}