/* ==========================================================================
   河南谊善车灯制造有限公司 — 主样式表
   Theme: dark automotive-tech  |  无外部依赖，可离线部署
   ========================================================================== */

/* ---------- 1. 变量与基础 ---------- */
:root {
  --ink:        #070a0f;
  --ink-2:      #0b1119;
  --surface:    #111a26;
  --surface-2:  #16212e;
  --line:       rgba(255, 255, 255, .09);
  --line-strong:rgba(255, 255, 255, .16);

  --text:       #e9eff7;
  --muted:      #96a7bd;
  --dim:        #6b7c92;

  --brand:      #1e88ff;
  --brand-soft: #4fc3ff;
  --amber:      #ffb547;
  --amber-soft: #ffd479;

  --radius:     16px;
  --radius-lg:  22px;
  --shadow:     0 18px 48px rgba(0, 0, 0, .45);
  --shadow-sm:  0 8px 24px rgba(0, 0, 0, .32);

  --maxw:       1200px;
  --header-h:   72px;

  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 12px); }

body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0 0 .6em; line-height: 1.25; font-weight: 700; letter-spacing: -.01em; }
h1 { font-size: clamp(2.1rem, 5.2vw, 3.6rem); }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.4rem); }
h3 { font-size: 1.16rem; }
p  { margin: 0 0 1em; }
ul { margin: 0; padding: 0; list-style: none; }
strong { color: #fff; font-weight: 600; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 2. 通用组件 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  padding: 13px 26px; border: 1px solid transparent; border-radius: 999px;
  font-size: .95rem; font-weight: 600; cursor: pointer;
  transition: transform .22s ease, box-shadow .22s ease, background .22s ease, border-color .22s ease;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--brand), #0d6efd 60%, #0a58ca);
  color: #fff; box-shadow: 0 10px 26px rgba(30, 136, 255, .32);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 34px rgba(30, 136, 255, .45); }
.btn-ghost { border-color: var(--line-strong); color: var(--text); background: rgba(255, 255, 255, .03); }
.btn-ghost:hover { border-color: var(--brand-soft); color: #fff; background: rgba(79, 195, 255, .1); }
.btn-sm { padding: 9px 18px; font-size: .86rem; }
.btn-block { width: 100%; }

.eyebrow {
  display: inline-block; margin-bottom: 14px; padding: 5px 14px;
  border: 1px solid rgba(79, 195, 255, .32); border-radius: 999px;
  background: rgba(79, 195, 255, .1);
  color: var(--brand-soft); font-size: .78rem; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase;
}
.lead { font-size: 1.06rem; color: #c3d0e0; }
.section-desc { max-width: 720px; color: var(--muted); }
.section { padding: clamp(64px, 9vw, 116px) 0; position: relative; }
.section-alt { background: var(--ink-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-dark { background: linear-gradient(180deg, #05080c, #0a1017); }
.section-head { max-width: 820px; margin-bottom: clamp(36px, 5vw, 60px); }

.link-arrow { display: inline-flex; align-items: center; gap: .5em; color: var(--brand-soft); font-weight: 600; }
.link-arrow span { transition: transform .22s ease; }
.link-arrow:hover span { transform: translateX(5px); }

/* 滚动进场动画 */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s cubic-bezier(.22,.61,.36,1), transform .7s cubic-bezier(.22,.61,.36,1); }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 3. 顶部导航 ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 90;
  height: var(--header-h);
  background: rgba(7, 10, 15, .55);
  border-bottom: 1px solid transparent;
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  transition: background .3s ease, border-color .3s ease;
}
.site-header.is-stuck { background: rgba(7, 10, 15, .9); border-bottom-color: var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); gap: 20px; }

.brand { display: inline-flex; align-items: center; gap: 11px; }
.brand-mark { width: 40px; height: 40px; flex: 0 0 40px; border-radius: 12px; box-shadow: 0 6px 18px rgba(13, 110, 253, .35); }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 1.06rem; letter-spacing: .04em; }
.brand-text em { font-style: normal; font-size: .6rem; letter-spacing: .18em; color: var(--dim); }

.nav { display: flex; align-items: center; gap: 4px; }
.nav a {
  position: relative; padding: 9px 13px; border-radius: 9px;
  color: #cbd8e8; font-size: .92rem; font-weight: 500;
  transition: color .2s ease, background .2s ease;
}
.nav a:hover { color: #fff; background: rgba(255, 255, 255, .06); }
.nav a.is-active { color: var(--brand-soft); }
.nav a.is-active::after {
  content: ""; position: absolute; left: 13px; right: 13px; bottom: 2px; height: 2px;
  border-radius: 2px; background: var(--brand-soft);
}
.header-actions { display: flex; align-items: center; gap: 12px; }

.nav-toggle {
  display: none; width: 42px; height: 42px; padding: 0;
  border: 1px solid var(--line-strong); border-radius: 11px;
  background: rgba(255, 255, 255, .04); cursor: pointer;
}
.nav-toggle span { display: block; width: 18px; height: 2px; margin: 3.5px auto; background: #d8e3f0; border-radius: 2px; transition: transform .28s ease, opacity .2s ease; }
.nav-toggle.is-open span:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

/* ---------- 4. 首屏 ---------- */
.hero {
  position: relative; min-height: 100vh; min-height: 100svh;
  display: flex; align-items: center;
  padding: calc(var(--header-h) + 60px) 0 90px;
  overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0;
  background: url("../images/hero-headlight.jpg") center 42% / cover no-repeat;
  transform: scale(1.04);
  animation: heroZoom 22s ease-in-out infinite alternate;
}
@keyframes heroZoom { from { transform: scale(1.04); } to { transform: scale(1.13); } }
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: 1;
  background:
    radial-gradient(1100px 620px at 22% 42%, rgba(30, 136, 255, .26), transparent 62%),
    linear-gradient(94deg, rgba(5, 8, 12, .96) 0%, rgba(5, 8, 12, .88) 42%, rgba(5, 8, 12, .48) 72%, rgba(5, 8, 12, .72) 100%);
}
.hero-beams { position: absolute; inset: 0; z-index: 1; pointer-events: none; overflow: hidden; }
.hero-beams i {
  position: absolute; top: -20%; width: 2px; height: 140%;
  background: linear-gradient(180deg, transparent, rgba(79, 195, 255, .5), transparent);
  filter: blur(1px); opacity: .5;
}
.hero-beams i:nth-child(1) { left: 58%; animation: beam 7s ease-in-out infinite; }
.hero-beams i:nth-child(2) { left: 71%; animation: beam 9s ease-in-out infinite .8s; background: linear-gradient(180deg, transparent, rgba(255, 181, 71, .45), transparent); }
.hero-beams i:nth-child(3) { left: 84%; animation: beam 11s ease-in-out infinite 1.6s; }
@keyframes beam { 0%, 100% { opacity: .15; transform: translateX(0) rotate(6deg); } 50% { opacity: .65; transform: translateX(22px) rotate(6deg); } }

.hero-inner { position: relative; z-index: 2; max-width: 860px; }
.hero h1 { margin-bottom: 22px; text-shadow: 0 6px 30px rgba(0, 0, 0, .6); }
.hero h1 .hl {
  background: linear-gradient(115deg, var(--brand-soft), #7fd8ff 40%, var(--amber-soft));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-sub { max-width: 660px; font-size: 1.08rem; color: #c8d5e4; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 30px 0 0; }

.hero-stats {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px; margin-top: 52px; padding-top: 30px;
  border-top: 1px solid var(--line);
}
.hero-stats li { display: flex; flex-direction: column; gap: 4px; }
.hero-stats b {
  font-size: clamp(1.5rem, 3vw, 2.1rem); font-weight: 700; color: #fff;
  background: linear-gradient(120deg, #fff, var(--brand-soft));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-stats span { font-size: .84rem; color: var(--muted); }

.hero-scroll { position: absolute; left: 50%; bottom: 26px; z-index: 2; transform: translateX(-50%); }
.hero-scroll span {
  display: block; width: 24px; height: 38px; border: 1.5px solid var(--line-strong); border-radius: 14px; position: relative;
}
.hero-scroll span::after {
  content: ""; position: absolute; left: 50%; top: 7px; width: 3px; height: 7px; margin-left: -1.5px;
  border-radius: 2px; background: var(--brand-soft); animation: scrollDot 1.8s ease-in-out infinite;
}
@keyframes scrollDot { 0% { opacity: 0; transform: translateY(0); } 40% { opacity: 1; } 100% { opacity: 0; transform: translateY(13px); } }

/* ---------- 5. 客户条 ---------- */
.partners { padding: 26px 0; background: #05080c; border-bottom: 1px solid var(--line); }
.partners-inner { display: flex; align-items: center; gap: 26px; overflow: hidden; }
.partners-label {
  flex: 0 0 auto; padding-right: 22px; border-right: 1px solid var(--line);
  color: var(--dim); font-size: .8rem; letter-spacing: .1em; white-space: nowrap;
}
.partners-track {
  display: flex; align-items: center; gap: 42px; white-space: nowrap;
  animation: marquee 34s linear infinite;
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}
.partners-track span { color: #8fa1b8; font-size: .95rem; font-weight: 500; letter-spacing: .02em; }
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }
.partners-inner:hover .partners-track { animation-play-state: paused; }

/* ---------- 6. 关于我们 ---------- */
.about-grid { display: grid; grid-template-columns: 1fr 1.08fr; gap: clamp(28px, 5vw, 66px); align-items: center; }
.about-media { position: relative; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); }
.about-media img { width: 100%; aspect-ratio: 4 / 3.1; object-fit: cover; transition: transform .8s cubic-bezier(.22,.61,.36,1); }
.about-media:hover img { transform: scale(1.05); }
.about-media::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 45%, rgba(5, 8, 12, .72));
}
.about-media-tag {
  position: absolute; z-index: 2; left: 20px; bottom: 20px;
  display: flex; flex-direction: column; gap: 2px;
  padding: 12px 20px; border-radius: 14px;
  background: rgba(9, 14, 20, .72); border: 1px solid var(--line-strong);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
}
.about-media-tag b { font-size: 1.32rem; color: var(--amber-soft); }
.about-media-tag span { font-size: .8rem; color: var(--muted); }

.fact-list { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 22px; margin: 26px 0; }
.fact-list > div { padding: 13px 16px; border: 1px solid var(--line); border-radius: 12px; background: rgba(255, 255, 255, .025); }
.fact-list dt { font-size: .76rem; color: var(--dim); letter-spacing: .04em; }
.fact-list dd { margin: 3px 0 0; font-size: .95rem; font-weight: 600; color: #fff; }

/* ---------- 7. 产品卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.card {
  position: relative; overflow: hidden;
  border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, var(--surface), var(--ink-2));
  transition: transform .34s ease, border-color .34s ease, box-shadow .34s ease;
}
.card:hover { transform: translateY(-6px); border-color: rgba(79, 195, 255, .38); box-shadow: var(--shadow); }
.card-media { position: relative; overflow: hidden; }
.card-media::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(7, 10, 15, .1) 30%, rgba(17, 26, 38, .96));
}
.card-media img { width: 100%; aspect-ratio: 16 / 9.4; object-fit: cover; transition: transform .8s cubic-bezier(.22,.61,.36,1); }
.card:hover .card-media img { transform: scale(1.06); }
.card-body { position: relative; padding: 0 26px 28px; margin-top: -54px; z-index: 2; }
.tag {
  display: inline-block; margin-bottom: 12px; padding: 4px 11px;
  border: 1px solid rgba(79, 195, 255, .3); border-radius: 6px;
  background: rgba(30, 136, 255, .16); color: var(--brand-soft);
  font-size: .72rem; font-weight: 600; letter-spacing: .08em;
}
.card h3 { font-size: 1.26rem; }
.card p { color: var(--muted); font-size: .95rem; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips li {
  padding: 5px 12px; border: 1px solid var(--line); border-radius: 999px;
  background: rgba(255, 255, 255, .03); color: #b8c6d8; font-size: .78rem;
}

.capability-strip {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px;
  margin-top: 24px; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  background: var(--line);
}
.capability-item { padding: 24px 26px; background: var(--ink-2); }
.capability-item h4 { margin-bottom: 6px; color: var(--amber-soft); font-size: .92rem; letter-spacing: .05em; }
.capability-item p { margin: 0; color: var(--muted); font-size: .88rem; }

/* ---------- 8. 应用领域 ---------- */
.solutions { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; }
.solution {
  padding: 30px 26px; border: 1px solid var(--line); border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, .035), rgba(255, 255, 255, .012));
  transition: transform .3s ease, border-color .3s ease, background .3s ease;
}
.solution:hover { transform: translateY(-5px); border-color: rgba(255, 181, 71, .38); background: linear-gradient(180deg, rgba(255, 181, 71, .09), rgba(255, 255, 255, .015)); }
.solution svg { width: 34px; height: 34px; margin-bottom: 16px; fill: var(--brand-soft); }
.solution h3 { font-size: 1.05rem; }
.solution p { margin: 0; color: var(--muted); font-size: .9rem; }

/* ---------- 9. 技术研发 ---------- */
.tech-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(28px, 5vw, 60px); align-items: center; }
.tech-media { border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--line); }
.tech-media img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.tech-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; margin: 30px 0 24px; }
.tech-stats > div {
  padding: 18px 16px; border: 1px solid var(--line); border-radius: 14px;
  background: rgba(255, 255, 255, .03); text-align: center;
}
.tech-stats b {
  display: block; font-size: 1.9rem; font-weight: 700; line-height: 1.1;
  background: linear-gradient(120deg, var(--brand-soft), var(--amber-soft));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.tech-stats span { font-size: .8rem; color: var(--muted); }
.platforms { display: flex; flex-wrap: wrap; gap: 9px; }
.platforms li {
  padding: 7px 14px; border-left: 2px solid var(--brand); border-radius: 4px;
  background: rgba(79, 195, 255, .08); color: #c4d3e4; font-size: .85rem;
}

/* ---------- 10. 智能制造 ---------- */
.manu-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.manu-item {
  position: relative; padding: 28px 26px 26px 30px;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, .035), rgba(255, 255, 255, .012));
  transition: border-color .3s ease, transform .3s ease;
}
.manu-item::before {
  content: ""; position: absolute; left: 0; top: 26px; bottom: 26px; width: 3px;
  border-radius: 0 3px 3px 0; background: linear-gradient(180deg, var(--brand), var(--brand-soft));
  opacity: .75; transition: opacity .3s ease;
}
.manu-item:hover { transform: translateY(-4px); border-color: rgba(79, 195, 255, .34); }
.manu-item:hover::before { opacity: 1; }
.manu-item h3 { font-size: 1.06rem; }
.manu-item p { margin: 0; color: var(--muted); font-size: .9rem; }

/* ---------- 11. 资质荣誉 ---------- */
.honors { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
.honors li {
  display: flex; flex-direction: column; gap: 6px;
  padding: 24px 22px; border: 1px solid var(--line); border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 181, 71, .07), rgba(255, 255, 255, .015));
  transition: transform .3s ease, border-color .3s ease;
}
.honors li:hover { transform: translateY(-5px); border-color: rgba(255, 181, 71, .4); }
.honors b { font-size: .99rem; color: #fff; line-height: 1.4; }
.honors span { font-size: .8rem; color: var(--muted); }

/* ---------- 12. 企业动态 ---------- */
.news-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.news {
  padding: 28px 26px; border: 1px solid var(--line); border-radius: var(--radius);
  background: linear-gradient(180deg, var(--surface), var(--ink-2));
  transition: transform .3s ease, border-color .3s ease;
}
.news:hover { transform: translateY(-5px); border-color: rgba(79, 195, 255, .34); }
.news time { display: inline-block; margin-bottom: 12px; color: var(--brand-soft); font-size: .78rem; font-weight: 600; letter-spacing: .1em; }
.news h3 { font-size: 1.06rem; }
.news p { margin: 0; color: var(--muted); font-size: .9rem; }

/* ---------- 13. 联系我们 ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(30px, 5vw, 68px); align-items: start; }
.contact-list { display: flex; flex-direction: column; gap: 18px; margin-top: 30px; }
.contact-list li { display: flex; gap: 16px; align-items: flex-start; }
.ci {
  flex: 0 0 42px; width: 42px; height: 42px; display: grid; place-items: center;
  border: 1px solid var(--line-strong); border-radius: 12px; background: rgba(79, 195, 255, .1);
}
.ci svg { width: 20px; height: 20px; fill: var(--brand-soft); }
.contact-list h4 { margin: 0 0 2px; font-size: .86rem; color: var(--muted); font-weight: 500; letter-spacing: .04em; }
.contact-list p { margin: 0; color: #fff; font-size: 1rem; }
.contact-list a:hover { color: var(--brand-soft); }

.contact-form {
  padding: 32px; border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(255, 255, 255, .05), rgba(255, 255, 255, .015));
  box-shadow: var(--shadow-sm);
}
.contact-form h3 { margin-bottom: 22px; font-size: 1.16rem; }
.field { display: flex; flex-direction: column; gap: 7px; margin-bottom: 15px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.field label { font-size: .82rem; color: var(--muted); }
.req { color: var(--amber); font-weight: 700; }
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line-strong); border-radius: 11px;
  background: rgba(6, 10, 15, .6); color: var(--text);
  font-family: inherit; font-size: .93rem; outline: none;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.field textarea { resize: vertical; min-height: 96px; }
.field input::placeholder, .field textarea::placeholder { color: #5f7188; }
.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--brand); box-shadow: 0 0 0 3px rgba(30, 136, 255, .2);
}
.field select option { background: #111a26; color: var(--text); }
.field.has-error input, .field.has-error textarea { border-color: #ff6b6b; }
.form-note { min-height: 20px; margin: 12px 0 0; font-size: .87rem; color: var(--amber-soft); }
.form-note.is-ok { color: #6ee7a8; }
.form-hint { margin: 14px 0 0; color: var(--dim); font-size: .78rem; line-height: 1.7; }
.form-hint a { color: var(--brand-soft); }

/* ---------- 14. 页脚 ---------- */
.site-footer { background: #05080c; border-top: 1px solid var(--line); padding: 60px 0 26px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.2fr; gap: 36px; }
.footer-brand p { margin: 16px 0 0; color: var(--muted); font-size: .88rem; line-height: 1.9; }
.footer-col { display: flex; flex-direction: column; gap: 9px; }
.footer-col h4 { margin: 0 0 6px; font-size: .86rem; color: var(--amber-soft); letter-spacing: .08em; }
.footer-col a, .footer-col span { color: var(--muted); font-size: .88rem; transition: color .2s ease; }
.footer-col a:hover { color: var(--brand-soft); }
.footer-bottom {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px;
  margin-top: 44px; padding-top: 22px; border-top: 1px solid var(--line);
}
.footer-bottom p { margin: 0; color: var(--dim); font-size: .8rem; }

/* ---------- 15. 返回顶部 ---------- */
.to-top {
  position: fixed; right: 24px; bottom: 26px; z-index: 80;
  width: 46px; height: 46px; border: 1px solid var(--line-strong); border-radius: 50%;
  background: rgba(17, 26, 38, .88); color: #fff; font-size: 1.05rem; cursor: pointer;
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  opacity: 0; visibility: hidden; transform: translateY(12px);
  transition: opacity .28s ease, visibility .28s ease, transform .28s ease, background .28s ease;
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--brand); border-color: var(--brand); }

/* ---------- 16. 打印 ---------- */
@media print {
  .site-header, .to-top, .hero-scroll, .hero-beams, .partners-track { display: none; }
  body { background: #fff; color: #111; }
}