/* 易贝妍官网 — 对齐首页 sy.png 的冷灰蓝，按比例适配 PC / 移动端 */

/* 设计基准：PC 1920 / 移动 375，根字号随视口线性缩放 */
:root {
  --bg: #eef2f6;
  --bg-soft: #e4ebf2;
  --surface: #ffffff;
  --ink: #1a2430;
  --muted: #3e4c5e;
  --line: #d5dee8;
  --accent: #8c9fc0;
  --accent-deep: #6e82a4;
  --accent-soft: #c3cedd;
  --dark: #1c2633;
  --header: #1c2633;

  /* 比例变量：宽度百分比 + 相对间距 */
  --page-w: 92%;
  --page-max: 61.458%; /* ≈1180/1920 */
  --narrow-max: 47.917%; /* ≈920/1920 */
  --header-h: 5.5%;
  --header-h-min: 3.75rem;
  --gutter: 2.5%;
  --section-y: 6%;
  --gap: 1.8%;
  --radius: 0.125rem;
  --font-cn: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-display: "Cormorant Garamond", "Noto Sans SC", serif;
  --shadow: 0 1rem 2.25rem rgba(110, 130, 164, 0.12);
  --fs-xs: 0.75rem;
  --fs-sm: 0.8125rem;
  --fs-base: 0.9375rem;
  --fs-md: 1rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-hero: clamp(1.75rem, 2.5vw + 0.8rem, 3rem);
  --fs-banner: clamp(2rem, 3vw + 0.6rem, 3.5rem);
}

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

html {
  scroll-behavior: smooth;
  /* 375→14px，1920→16px，中间按比例 */
  font-size: clamp(14px, 0.129vw + 13.516px, 16px);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-cn);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  font-weight: 400;
  font-size: var(--fs-base);
  overflow-x: hidden;
  width: 100%;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
ul { list-style: none; }

.container {
  width: var(--page-w);
  max-width: 73.75rem; /* 1180px @16 */
  margin-left: auto;
  margin-right: auto;
}
.container.narrow {
  width: var(--page-w);
  max-width: 57.5rem; /* 920px @16 */
}

/* ========== Header ========== */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: max(var(--header-h-min), 7.5vh);
  z-index: 1000;
  width: 100%;
  background: rgba(28, 38, 51, 0.96);
  backdrop-filter: blur(0.75rem);
  border-bottom: 1px solid rgba(140, 159, 192, 0.35);
  transition: background .3s, box-shadow .3s;
}
.site-header.is-scrolled {
  background: rgba(28, 38, 51, 0.98);
  box-shadow: 0 0.5rem 1.875rem rgba(28, 38, 51, 0.18);
}
.nav-inner {
  width: var(--page-w);
  max-width: 73.75rem;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2%;
}
.brand-logo {
  flex: 0 0 auto;
  max-width: 42%;
}
.brand-logo img {
  display: block;
  height: auto;
  width: auto;
  max-height: 2.75rem;
  max-width: min(220px, 100%);
  object-fit: contain;
}
.main-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex: 1 1 auto;
  gap: clamp(0.25rem, 0.6vw, 0.75rem);
}
.nav-link {
  position: relative;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(0.75rem, 0.7vw + 0.55rem, 0.875rem);
  letter-spacing: 0.12em;
  padding: 0.625em 1em;
  white-space: nowrap;
  transition: color .25s;
}
.nav-link:hover,
.nav-link.is-active { color: var(--accent-soft); }
.nav-link::after {
  content: "";
  position: absolute;
  left: 1em; right: 1em; bottom: 0.25em;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s ease;
}
.nav-link:hover::after,
.nav-link.is-active::after { transform: scaleX(1); }

.nav-toggle {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  flex: 0 0 auto;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 0.375rem;
}
.nav-toggle span {
  display: block;
  width: 55%;
  height: 1.5px;
  background: #fff;
  transition: .25s;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(0.46875rem) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-0.46875rem) rotate(-45deg); }

/* ========== Pages ========== */
.page {
  display: none;
  width: 100%;
  min-height: calc(100vh - max(var(--header-h-min), 7.5vh));
  min-height: calc(100dvh - max(var(--header-h-min), 7.5vh));
}
.page.is-active { display: block; animation: pageIn .45s ease; }
@keyframes pageIn {
  from { opacity: 0; transform: translateY(2%); }
  to { opacity: 1; transform: none; }
}

/* ========== Hero ========== */
.hero {
  width: 100%;
  height: calc(100vh - max(var(--header-h-min), 7.5vh));
  height: calc(100dvh - max(var(--header-h-min), 7.5vh));
  margin-top: max(var(--header-h-min), 7.5vh);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #e7eef4;
}
.hero-visual {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: min(40%, 9rem);
  width: auto;
  height: 2.875rem;
  padding: 0 6%;
  font-size: clamp(0.75rem, 0.6vw + 0.55rem, 0.875rem);
  letter-spacing: 0.14em;
  transition: .25s;
}
.btn-primary {
  background: var(--accent-deep);
  color: #fff;
}
.btn-primary:hover { background: #5c7094; }
.btn-ghost {
  border: 1px solid rgba(255, 255, 255, 0.65);
  color: #fff;
}
.btn-ghost:hover {
  border-color: var(--accent-soft);
  background: rgba(126, 179, 209, 0.18);
  color: #fff;
}
.btn-outline {
  border: 1px solid var(--dark);
  color: var(--dark);
  background: transparent;
}
.btn-outline:hover {
  background: var(--dark);
  color: #fff;
}

/* ========== Page banner ========== */
.page-banner {
  margin-top: max(var(--header-h-min), 7.5vh);
  width: 100%;
  text-align: center;
  background: linear-gradient(180deg, #93a6bf 0%, #c5d0e0 58%, var(--bg) 100%);
  color: var(--ink);
  padding: 9vh 4% 7vh;
}
.page-banner-inner {
  width: 100%;
  max-width: 73.75rem;
  margin: 0 auto;
}
.eyebrow {
  font-size: var(--fs-xs);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: #243044;
  margin-bottom: 0.6em;
}
.page-banner h1 {
  font-family: var(--font-display);
  font-size: var(--fs-banner);
  font-weight: 500;
  letter-spacing: 0.1em;
  margin-bottom: 0.4em;
}
.page-banner p {
  color: #1a2430;
  font-weight: 400;
  font-size: clamp(0.875rem, 0.8vw + 0.6rem, 1rem);
}

.section {
  width: 100%;
  padding: clamp(2.5rem, 6vh, 5.5rem) 0 clamp(3rem, 8vh, 6rem);
}

/* ========== Brand ========== */
.brand-block { margin-bottom: 6%; }
.brand-block h2 {
  display: flex;
  align-items: baseline;
  gap: 0.75em;
  font-size: clamp(1.125rem, 1.2vw + 0.7rem, 1.5rem);
  font-weight: 500;
  margin-bottom: 3%;
  letter-spacing: 0.08em;
}
.brand-block h2 span {
  font-family: var(--font-display);
  color: var(--accent-deep);
  font-size: 0.75em;
  letter-spacing: 0.2em;
}
.brand-block p,
.brand-block .lead {
  color: var(--ink);
  font-size: clamp(0.875rem, 0.5vw + 0.75rem, 0.9375rem);
  font-weight: 400;
}
.brand-block .lead { margin-bottom: 4%; color: var(--ink); }

.principle-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(0.75rem, 1.5vw, 1.25rem);
  width: 100%;
}
.principle-grid article {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 3px solid var(--accent);
  padding: 8% 7%;
  box-shadow: var(--shadow);
  transition: transform .35s, box-shadow .35s, border-color .35s;
}
.principle-grid article:hover {
  transform: translateY(-3%);
  box-shadow: var(--shadow);
  border-color: var(--accent);
}
.principle-grid h3 {
  font-size: clamp(0.9375rem, 0.6vw + 0.7rem, 1rem);
  margin-bottom: 0.75em;
  letter-spacing: 0.08em;
  color: var(--dark);
}
.principle-grid p {
  font-size: clamp(0.8125rem, 0.4vw + 0.7rem, 0.875rem);
  color: var(--ink);
  font-weight: 400;
}
.brand-motto {
  text-align: center;
  padding: 8% 4%;
  background: linear-gradient(180deg, #d7e0ec, var(--bg));
  border-top: none;
}
.motto-label {
  font-size: var(--fs-xs);
  letter-spacing: 0.3em;
  color: var(--accent-deep);
  margin-bottom: 0.75em;
}
.motto-text {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.5vw + 0.6rem, 2.625rem);
  letter-spacing: 0.2em;
  color: var(--dark);
}

/* ========== Products ========== */
.series-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 3%;
  width: 100%;
  margin-bottom: 3%;
  padding-bottom: 2%;
  border-bottom: 1px solid var(--line);
}
.series-head h2 {
  font-size: clamp(1.125rem, 1vw + 0.75rem, 1.375rem);
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--dark);
}
.series-head p {
  color: var(--muted);
  font-size: clamp(0.8125rem, 0.4vw + 0.7rem, 0.875rem);
  font-weight: 300;
}
.series-empty { margin-top: 8%; }

.product-grid,
.empty-series {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(0.75rem, 1.6vw, 1.375rem);
  width: 100%;
}
.product-card {
  width: 100%;
  background: var(--surface);
  overflow: hidden;
  cursor: pointer;
  position: relative;
  transition: transform .35s ease, box-shadow .35s, border-color .35s;
  border: 1px solid var(--line);
}
.product-link {
  display: block;
  color: inherit;
  height: 100%;
}
.product-card:hover {
  transform: translateY(-2%);
  box-shadow: var(--shadow);
  border-color: var(--accent);
}
.product-card .thumb {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: linear-gradient(180deg, #f7f9fb 0%, #e3eef3 100%);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2%;
}
.product-card .thumb img {
  width: 96%;
  height: 96%;
  max-width: 96%;
  max-height: 96%;
  object-fit: contain;
  object-position: center center;
  transition: transform .6s ease;
}
.product-card:hover .thumb img { transform: scale(1.03); }
.product-card .info {
  width: 100%;
  padding: 5.5% 6% 6.5%;
  background: #fff;
  color: var(--ink);
  border-top: 1px solid var(--line);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
}
.product-card .tag {
  display: inline-block;
  font-size: clamp(0.625rem, 0.4vw + 0.5rem, 0.6875rem);
  letter-spacing: 0.14em;
  color: var(--accent-deep);
  margin-bottom: 0.55em;
}
.product-card h3 {
  font-size: clamp(0.8125rem, 0.5vw + 0.65rem, 0.9375rem);
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-bottom: 0.4em;
  line-height: 1.45;
  padding-right: 18%;
  color: #1a2430;
}
.product-card .spec {
  font-size: clamp(0.6875rem, 0.3vw + 0.55rem, 0.75rem);
  color: var(--muted);
  font-weight: 300;
  word-break: break-all;
}
.product-card .more {
  position: absolute;
  right: 5%;
  bottom: 5%;
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--accent-deep);
  opacity: 0;
  transform: translateY(20%);
  transition: .3s;
}
.product-card:hover .more,
.product-card.is-touch .more {
  opacity: 1;
  transform: none;
}

.empty-card {
  width: 100%;
  aspect-ratio: 3 / 4;
  border: 1px dashed var(--accent-soft);
  background: linear-gradient(180deg, #f7f9fb, #e7eef4);
  display: grid;
  place-items: center;
  color: var(--muted);
  letter-spacing: 0.2em;
  font-size: clamp(0.75rem, 0.5vw + 0.55rem, 0.8125rem);
  font-weight: 300;
}

/* ========== Detail ========== */
.detail-section {
  margin-top: max(var(--header-h-min), 7.5vh);
  padding-top: 4%;
}
.detail-layout {
  display: grid;
  grid-template-columns: 48% 48%;
  justify-content: space-between;
  gap: 4%;
  align-items: center;
  width: 100%;
}
.detail-visual {
  width: 100%;
  background: linear-gradient(180deg, #f7f9fb 0%, #e3eef3 100%);
  border: 1px solid var(--line);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4%;
  aspect-ratio: 1 / 1;
}
.detail-visual img {
  width: 94%;
  height: 94%;
  max-width: 94%;
  max-height: 94%;
  object-fit: contain;
  object-position: center center;
  aspect-ratio: auto;
}
.detail-copy { width: 100%; }
.detail-copy .series-tag {
  display: inline-block;
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  color: var(--accent-deep);
  margin-bottom: 3%;
}
.detail-copy h1 {
  font-size: clamp(1.25rem, 1.8vw + 0.6rem, 2.125rem);
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: 0.04em;
  margin-bottom: 2%;
  color: var(--dark);
}
.detail-copy .en-name {
  color: var(--muted);
  font-size: clamp(0.75rem, 0.4vw + 0.6rem, 0.8125rem);
  letter-spacing: 0.06em;
  margin-bottom: 5%;
  font-weight: 300;
  word-break: break-word;
}
.detail-meta {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 4% 0;
  margin-bottom: 5%;
}
.detail-meta dt {
  font-size: var(--fs-xs);
  color: var(--muted);
  letter-spacing: 0.12em;
  margin-bottom: 0.25em;
}
.detail-meta dd {
  font-size: clamp(0.875rem, 0.5vw + 0.7rem, 0.9375rem);
  margin-bottom: 0.85em;
  word-break: break-word;
  color: var(--ink);
}
.detail-meta dd:last-child { margin-bottom: 0; }
.detail-desc {
  color: var(--ink);
  font-size: clamp(0.8125rem, 0.4vw + 0.7rem, 0.875rem);
  font-weight: 400;
  margin-bottom: 6%;
}

/* ========== Knowledge ========== */
.knowledge-layout {
  display: grid;
  grid-template-columns: 22% 74%;
  justify-content: space-between;
  gap: 4%;
  align-items: start;
  width: 100%;
}
.knowledge-nav {
  position: sticky;
  top: calc(max(var(--header-h-min), 7.5vh) + 2vh);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  width: 100%;
}
.kn-tab {
  text-align: left;
  width: 100%;
  padding: 0.875em 1em;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  font-size: clamp(0.8125rem, 0.4vw + 0.65rem, 0.875rem);
  letter-spacing: 0.06em;
  transition: .25s;
}
.kn-tab:hover,
.kn-tab.is-active {
  background: linear-gradient(180deg, #9aadc4, #8c9fc0);
  color: #fff;
  border-color: #8c9fc0;
}
.knowledge-panels { width: 100%; }
.kn-panel {
  display: none;
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 5% 4.5%;
}
.kn-panel.is-active { display: block; animation: pageIn .35s ease; }
.kn-panel h2 {
  font-size: clamp(1.125rem, 1vw + 0.7rem, 1.375rem);
  font-weight: 500;
  margin-bottom: 4%;
  letter-spacing: 0.08em;
  color: var(--dark);
}
.kn-panel h3 {
  font-size: clamp(0.9375rem, 0.5vw + 0.7rem, 1rem);
  margin: 4% 0 2%;
  color: var(--accent-deep);
}
.kn-panel p,
.kn-panel li {
  color: var(--ink);
  font-size: clamp(0.8125rem, 0.4vw + 0.7rem, 0.875rem);
  font-weight: 400;
  margin-bottom: 0.7em;
}
.kn-panel ul { padding-left: 0; }
.kn-panel li {
  padding-left: 1em;
  position: relative;
}
.kn-panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 0.3em;
  height: 0.3em;
  border-radius: 50%;
  background: var(--accent);
}
.kn-panel strong { color: var(--dark); font-weight: 500; }

/* ========== Contact ========== */
.contact-card {
  width: min(100%, 45rem);
  margin: 0 auto;
  background:
    linear-gradient(180deg, #d5deea 0%, #f7f9fb 28%, #fff 28%);
  color: var(--dark);
  text-align: center;
  padding: 8% 6% 7%;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}
.contact-logo {
  display: block;
  height: auto;
  width: min(280px, 70%);
  max-width: 70%;
  margin: 0 auto 4%;
  object-fit: contain;
  background: var(--dark);
  padding: 1rem 1.5rem;
}
.contact-motto {
  font-family: var(--font-display);
  letter-spacing: 0.22em;
  font-size: clamp(1.125rem, 1.5vw + 0.6rem, 1.375rem);
  margin-bottom: 8%;
  color: var(--dark);
  opacity: .95;
}
.qr-row {
  display: flex;
  justify-content: center;
  gap: clamp(1.5rem, 5vw, 3rem);
  flex-wrap: wrap;
  width: 100%;
}
.qr-item {
  width: min(42%, 11rem);
  flex: 1 1 8rem;
  max-width: 11rem;
}
.qr-item img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: #fff;
  padding: 4%;
  margin: 0 auto 4%;
  border: 1px solid var(--line);
}
.qr-item p {
  font-size: clamp(0.875rem, 0.5vw + 0.65rem, 0.9375rem);
  letter-spacing: 0.12em;
  margin-bottom: 0.25em;
  color: var(--dark);
}
.qr-item span {
  font-size: var(--fs-xs);
  color: var(--muted);
  font-weight: 300;
}

/* ========== Float bar ========== */
.float-bar {
  position: fixed;
  right: 1.5%;
  bottom: 4vh;
  z-index: 1100;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.float-item {
  position: relative;
  width: clamp(2.75rem, 4.5vw, 3.5rem);
  min-height: clamp(2.75rem, 4.5vw, 3.5rem);
  background: var(--accent-deep);
  color: #fff;
  border: 1px solid var(--accent-deep);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.125rem;
  transition: background .25s, border-color .25s, color .25s;
}
.float-item:hover,
.float-item.is-open {
  background: #93a6bf;
  border-color: #93a6bf;
  color: #fff;
}
.float-icon { font-size: 0.875rem; font-weight: 500; }
.float-label { font-size: 0.625rem; letter-spacing: 0.08em; opacity: .8; }
.float-pop {
  position: absolute;
  right: calc(100% + 0.75rem);
  top: 50%;
  transform: translateY(-50%) translateX(8%);
  background: var(--surface);
  color: var(--ink);
  padding: 0.75rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: .25s;
  white-space: nowrap;
  text-align: center;
}
.float-pop img {
  width: clamp(6rem, 18vw, 7.5rem);
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  margin-bottom: 0.5em;
  background: #fff;
}
.float-pop p { font-size: var(--fs-xs); color: var(--muted); }
.float-item:hover .float-pop,
.float-item.is-open .float-pop {
  opacity: 1;
  visibility: visible;
  transform: translateY(-50%);
  pointer-events: auto;
}

/* ========== Footer ========== */
.site-footer {
  width: 100%;
  background: var(--header);
  color: rgba(255, 255, 255, 0.75);
  padding: 5% 0 3%;
  border-top: 1px solid rgba(140, 159, 192, 0.28);
}
.footer-inner {
  display: grid;
  gap: 4%;
  row-gap: 1.25rem;
  text-align: center;
  justify-items: center;
  width: 100%;
}
.footer-brand img {
  display: block;
  height: auto;
  width: min(260px, 55%);
  max-width: 55%;
  margin: 0 auto 0.85em;
  object-fit: contain;
}
.footer-brand p {
  font-family: var(--font-display);
  letter-spacing: 0.18em;
  font-size: clamp(0.8125rem, 0.5vw + 0.6rem, 0.875rem);
  color: rgba(255,255,255,.55);
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 4%;
  justify-content: center;
  font-size: clamp(0.75rem, 0.4vw + 0.6rem, 0.8125rem);
  letter-spacing: 0.1em;
  width: 100%;
}
.footer-links a:hover { color: var(--accent); }
.copyright {
  font-size: var(--fs-xs);
  color: rgba(255,255,255,.4);
  font-weight: 300;
}

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(4%);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ========== 平板：≤1024px ≈ 53% 设计宽 ========== */
@media (max-width: 64em) {
  :root {
    --page-w: 92%;
    --header-h-min: 3.5rem;
  }

  .principle-grid,
  .product-grid,
  .empty-series {
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5%;
  }

  .detail-layout {
    grid-template-columns: 100%;
    gap: 6%;
  }
  .detail-visual {
    width: min(72%, 26rem);
    margin: 0 auto;
  }

  .knowledge-layout {
    grid-template-columns: 100%;
    gap: 4%;
  }
  .knowledge-nav {
    position: static;
    flex-direction: row;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: 2%;
    padding-bottom: 0.25rem;
  }
  .kn-tab {
    white-space: nowrap;
    flex: 0 0 auto;
    width: auto;
    min-width: 28%;
  }
  .kn-panel { padding: 6% 5%; }
}

/* ========== 手机：≤720px ========== */
@media (max-width: 45em) {
  :root {
    --page-w: 90%;
    --header-h-min: 3.5rem;
    --fs-hero: clamp(1.5rem, 6vw + 0.4rem, 2rem);
    --fs-banner: clamp(1.75rem, 7vw + 0.4rem, 2.5rem);
  }

  .nav-toggle { display: flex; }

  .brand-logo { max-width: 56%; }
  .brand-logo img {
    max-height: 2.25rem;
    max-width: min(180px, 100%);
  }

  .main-nav {
    position: fixed;
    left: 0;
    right: 0;
    top: max(var(--header-h-min), 7.5vh);
    width: 100%;
    background: rgba(28, 38, 51, 0.98);
    flex-direction: column;
    align-items: stretch;
    padding: 2% 4% 4%;
    gap: 0;
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: .3s;
    max-height: calc(100dvh - max(var(--header-h-min), 7.5vh));
    overflow-y: auto;
  }
  .main-nav.is-open {
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }
  .nav-link {
    width: 100%;
    text-align: center;
    padding: 3.5% 2%;
    font-size: 0.9375rem;
  }
  .nav-link::after { left: 30%; right: 30%; }

  .btn {
    width: 100%;
    min-width: 0;
    height: 3rem;
    padding: 0 4%;
  }

  .page-banner { padding: 7vh 5% 5vh; }

  .principle-grid,
  .product-grid,
  .empty-series {
    grid-template-columns: 100%;
    gap: 4%;
  }

  .series-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .product-card .info { padding: 5% 5% 7%; }
  .product-card h3 { padding-right: 0; }
  .product-card .more {
    position: static;
    display: inline-block;
    margin-top: 0.75em;
    opacity: 1;
    transform: none;
  }

  .detail-visual { width: 100%; }
  .detail-section { padding-top: 6%; }

  .kn-tab { min-width: 42%; padding: 0.75em 0.9em; }
  .kn-panel { padding: 7% 5.5%; }

  .contact-card { padding: 10% 6% 9%; width: 100%; }
  .qr-item {
    width: 44%;
    max-width: none;
    flex: 1 1 40%;
  }

  .float-bar {
    right: 2.5%;
    bottom: 3vh;
  }
  .float-item {
    width: 12vw;
    min-width: 2.75rem;
    max-width: 3.25rem;
    min-height: 12vw;
  }
  .float-pop {
    right: auto;
    left: auto;
    bottom: calc(100% + 0.5rem);
    top: auto;
    transform: translateY(10%);
  }
  .float-item:hover .float-pop,
  .float-item.is-open .float-pop {
    transform: none;
  }
  /* 移动端二维码弹层改为向上展开，避免贴边被裁切 */
  .float-item .float-pop {
    right: 0;
    left: auto;
  }

  .site-footer { padding: 8% 0 6%; }
  .footer-brand img {
    width: min(220px, 70%);
    max-width: 70%;
  }
  .footer-links { gap: 0.75rem 6%; }
}

/* 超小屏 */
@media (max-width: 22.5em) {
  :root { --page-w: 92%; }
  .qr-row { flex-direction: column; align-items: center; }
  .qr-item { width: 58%; max-width: 10rem; }
}

/* 大屏：≥1440 保持最大内容宽，避免过度拉伸 */
@media (min-width: 90em) {
  html { font-size: 16px; }
  .container,
  .nav-inner,
  .page-banner-inner {
    max-width: 73.75rem;
  }
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}