/* =====================================================
   诗健明家居馆 SJM HOME — 国际高端家居艺术馆
   Design: editorial / gallery / warm neutral
   ===================================================== */
:root {
  --bg: #FAF8F4;
  --bg-alt: #F2EEE6;
  --ink: #1C1A17;
  --ink-soft: #5C574E;
  --ink-faint: #8B857A;
  --line: #E2DCD0;
  --accent: #A98B5F;
  --accent-deep: #8A6E44;
  --dark: #16130F;
  --dark-soft: #211D18;
  --dark-line: #363026;
  --gold-light: #D8B77E;
  --font-display: "Cormorant Garamond", "Playfair Display", Georgia, "Songti SC", "STSong", "SimSun", serif;
  --font-body: "Jost", "Inter", -apple-system, BlinkMacSystemFont, "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --vh: 1vh;
  --nav-h: 76px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 300;
  letter-spacing: .01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font-family: inherit; border: 0; background: none; cursor: pointer; }

::selection { background: var(--accent); color: #fff; }

/* ---------- 通用 ---------- */
.wrap { width: min(1240px, calc(100% - 48px)); margin: 0 auto; }
.section { padding: 120px 0; position: relative; }
.section-alt { background: var(--bg-alt); }
.section-dark { background: var(--dark); color: #EFE9DE; }
.m-only { display: inline; }

h1, h2, h3 { font-weight: 400; }
h2 {
  font-family: var(--font-display);
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1.18;
  letter-spacing: .01em;
}
h3 { font-size: 20px; letter-spacing: .02em; }

.eyebrow {
  font-size: 12px;
  letter-spacing: .32em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
  font-weight: 400;
}
.sec-head { max-width: 640px; margin-bottom: 64px; }
.sec-head h2 { margin-bottom: 18px; }
.sec-desc { color: var(--ink-soft); font-size: 15.5px; }

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(40px, 6vw, 96px);
  align-items: center;
}

/* 图片框：模糊占位 + 懒加载淡入 */
.img-frame {
  position: relative;
  overflow: hidden;
  background: #E9E3D8 center / cover no-repeat;
}
.img-frame img { width: 100%; height: 100%; object-fit: cover; opacity: 0; transition: opacity .9s var(--ease), transform 1.2s var(--ease); }
.img-frame img.lz-on { opacity: 1; }
.ratio-43 { aspect-ratio: 4 / 3; }
.ratio-32 { aspect-ratio: 3 / 2; }
.ratio-34 { aspect-ratio: 3 / 4; }
.ratio-11 { aspect-ratio: 1 / 1; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 38px;
  font-size: 13px;
  letter-spacing: .22em;
  text-transform: uppercase;
  border: 1px solid transparent;
  transition: all .45s var(--ease);
  white-space: nowrap;
}
.btn-light { background: var(--ink); color: #F6F2EA; border-color: var(--ink); }
.btn-light:hover { background: var(--accent-deep); border-color: var(--accent-deep); color: #fff; }
.btn-ghost { border-color: rgba(255,255,255,.55); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,.12); border-color: #fff; }
.btn-dark { background: var(--ink); color: #F6F2EA; }
.btn-dark:hover { background: var(--accent-deep); }
.btn-full { width: 100%; }

/* =====================================================
   加载动效
   ===================================================== */
.loader {
  position: fixed; inset: 0; z-index: 200;
  background: var(--dark);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 26px;
  transition: opacity .7s var(--ease), visibility .7s;
}
.loader-mark {
  font-family: var(--font-display);
  font-size: 44px; color: var(--gold-light);
  letter-spacing: .5em; margin-left: .5em;
  animation: breathe 2s var(--ease) infinite;
}
.loader-bar { width: 150px; height: 1px; background: rgba(255,255,255,.14); overflow: hidden; }
.loader-bar span { display: block; height: 100%; width: 40%; background: var(--gold-light); animation: sweep 1.4s var(--ease) infinite; }
@keyframes sweep { 0% { transform: translateX(-110%);} 100% { transform: translateX(400%);} }
@keyframes breathe { 0%,100% { opacity: .55;} 50% { opacity: 1;} }
body.ready .loader { opacity: 0; visibility: hidden; }

/* 滚动进度 */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 2px; width: 0;
  background: linear-gradient(90deg, var(--accent), var(--gold-light));
  z-index: 130;
}

/* =====================================================
   导航
   ===================================================== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 120;
  transition: background .5s var(--ease), box-shadow .5s var(--ease), transform .5s var(--ease);
}
.nav-inner {
  width: min(1360px, calc(100% - 48px));
  margin: 0 auto;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px;
}
.nav.solid { background: rgba(250,248,244,.92); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); box-shadow: 0 1px 0 var(--line); }
.nav.hide { transform: translateY(-100%); }

.brand { display: flex; align-items: center; gap: 14px; }
.brand-mark {
  width: 44px; height: 44px; flex: none;
  display: grid; place-items: center;
  border: 1px solid currentColor; border-radius: 50%;
  font-family: var(--font-display); font-size: 22px;
  color: var(--gold-light);
  transition: all .4s var(--ease);
}
.brand-text { line-height: 1.2; }
.brand-text strong { display: block; font-size: 17px; font-weight: 500; letter-spacing: .14em; }
.brand-text em { display: block; font-style: normal; font-size: 9.5px; letter-spacing: .34em; color: var(--accent); margin-top: 3px; }

.nav-links { display: flex; align-items: center; gap: 34px; }
.nav-links > a {
  font-size: 13.5px; letter-spacing: .12em; position: relative;
  padding: 6px 0; transition: color .35s var(--ease);
}
.nav-links > a:not(.nav-cta)::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 100%; height: 1px; background: var(--accent);
  transform: scaleX(0); transform-origin: right;
  transition: transform .45s var(--ease);
}
.nav-links > a:not(.nav-cta):hover::after { transform: scaleX(1); transform-origin: left; }
.nav-cta {
  border: 1px solid currentColor; padding: 10px 24px;
  font-size: 12px; letter-spacing: .2em; text-transform: uppercase;
  transition: all .4s var(--ease);
}
.nav-cta:hover { background: var(--ink); color: var(--gold-light); border-color: var(--ink); }

/* 顶部透明态（叠在 hero 上） */
.nav:not(.solid) { color: #fff; }
.nav:not(.solid) .brand-mark { color: var(--gold-light); border-color: rgba(255,255,255,.4); }
.nav:not(.solid) .brand-text em { color: var(--gold-light); }
.nav:not(.solid) .nav-cta:hover { background: #fff; color: var(--ink); }

.nav-burger { display: none; width: 44px; height: 44px; position: relative; z-index: 140; }
.nav-burger span {
  position: absolute; left: 10px; right: 10px; height: 1.5px;
  background: currentColor; transition: all .4s var(--ease);
}
.nav-burger span:nth-child(1) { top: 18px; }
.nav-burger span:nth-child(2) { top: 26px; }
.nav-burger.open span:nth-child(1) { top: 22px; transform: rotate(45deg); }
.nav-burger.open span:nth-child(2) { top: 22px; transform: rotate(-45deg); }
.nav:not(.solid) .nav-burger { color: #fff; }
.nav.solid .nav-burger { color: var(--ink); }

/* 移动端全屏菜单 */
.mobile-menu {
  position: fixed; inset: 0; z-index: 135;
  background: var(--dark);
  display: flex; flex-direction: column; justify-content: center;
  padding: 0 10vw;
  opacity: 0; visibility: hidden;
  transition: opacity .5s var(--ease), visibility .5s;
}
.mobile-menu.open { opacity: 1; visibility: visible; }
.mobile-menu nav { display: flex; flex-direction: column; gap: 6px; }
.mobile-menu a {
  color: #EFE9DE; font-family: var(--font-display);
  font-size: clamp(30px, 7vw, 42px); padding: 10px 0;
  border-bottom: 1px solid var(--dark-line);
  display: flex; align-items: baseline; gap: 18px;
  transform: translateY(24px); opacity: 0;
  transition: all .5s var(--ease);
}
.mobile-menu.open a { transform: none; opacity: 1; }
.mobile-menu a:nth-child(1) { transition-delay: .08s; }
.mobile-menu a:nth-child(2) { transition-delay: .14s; }
.mobile-menu a:nth-child(3) { transition-delay: .2s; }
.mobile-menu a:nth-child(4) { transition-delay: .26s; }
.mobile-menu a:nth-child(5) { transition-delay: .32s; }
.mobile-menu a:nth-child(6) { transition-delay: .38s; }
.mobile-menu a i { font-style: normal; font-family: var(--font-body); font-size: 12px; color: var(--accent); letter-spacing: .2em; }
.mobile-menu-foot { margin-top: 40px; font-size: 11px; letter-spacing: .3em; color: var(--ink-faint); }

/* =====================================================
   HERO
   ===================================================== */
.hero {
  position: relative;
  min-height: calc(var(--vh, 1vh) * 100);
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
}
.hero-media, .hero-media img {
  position: absolute; inset: 0; width: 100%; height: 100%;
}
.hero-media img { object-fit: cover; opacity: 0; transition: opacity 1.2s var(--ease), transform 8s linear; }
.hero-media img.lz-on { opacity: 1; animation: heroZoom 14s var(--ease) forwards; }
@keyframes heroZoom { from { transform: scale(1.12);} to { transform: scale(1);} }
.hero-veil {
  position: absolute; inset: 0;
  background:
    linear-gradient(180deg, rgba(18,15,11,.52) 0%, rgba(18,15,11,.18) 34%, rgba(18,15,11,.24) 66%, rgba(18,15,11,.62) 100%);
}
.hero-content { position: relative; z-index: 2; padding: 140px 24px 120px; max-width: 880px; }
.hero-eyebrow { font-size: 12px; letter-spacing: .42em; color: var(--gold-light); margin-bottom: 26px; text-transform: uppercase; }
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(40px, 7.2vw, 86px);
  line-height: 1.12; font-weight: 500;
  letter-spacing: .02em;
  margin-bottom: 26px;
}
.hero h1 span { font-style: italic; color: var(--gold-light); }
.hero-sub { font-size: clamp(15px, 1.6vw, 17px); color: rgba(255,255,255,.86); letter-spacing: .06em; margin-bottom: 44px; }
.hero-actions { display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; }

.hero-foot {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 2;
  display: flex; justify-content: space-between; align-items: flex-end;
  padding: 0 clamp(20px, 4vw, 56px) 30px;
  font-size: 10.5px; letter-spacing: .3em; color: rgba(255,255,255,.72);
}
.hero-scroll { display: inline-flex; align-items: center; gap: 12px; }
.hero-scroll i { display: block; width: 1px; height: 44px; background: rgba(255,255,255,.4); position: relative; overflow: hidden; }
.hero-scroll i::after { content: ""; position: absolute; left: 0; top: -100%; width: 100%; height: 100%; background: var(--gold-light); animation: scrollHint 2.2s var(--ease) infinite; }
@keyframes scrollHint { 0% { top: -100%;} 60%,100% { top: 100%;} }

/* =====================================================
   跑马灯
   ===================================================== */
.marquee { background: var(--dark); color: #CFC7B8; overflow: hidden; padding: 18px 0; border-block: 1px solid var(--dark-line); }
.marquee-track { display: flex; align-items: center; gap: 34px; width: max-content; animation: marquee 26s linear infinite; }
.marquee-track span { font-size: 12.5px; letter-spacing: .34em; text-transform: uppercase; white-space: nowrap; }
.marquee-track i { color: var(--accent); font-style: normal; font-size: 8px; }
@keyframes marquee { from { transform: translateX(0);} to { transform: translateX(-50%);} }

/* =====================================================
   品牌理念
   ===================================================== */
.ph-media { position: relative; }
.ph-badge {
  position: absolute; right: -14px; top: 34px;
  writing-mode: vertical-rl;
  background: var(--ink); color: var(--gold-light);
  font-size: 10.5px; letter-spacing: .4em;
  padding: 22px 10px;
}
.ph-copy h2 { margin-bottom: 24px; }
.ph-copy p { color: var(--ink-soft); margin-bottom: 16px; max-width: 56ch; }

.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 44px; }
.stat { border-top: 1px solid var(--line); padding-top: 18px; }
.stat strong { display: flex; align-items: baseline; font-family: var(--font-display); font-size: clamp(26px, 2.6vw, 38px); color: var(--ink); line-height: 1; }
.stat strong i { font-style: normal; }
.stat strong em { font-style: normal; font-size: 13px; color: var(--accent); margin-left: 3px; }
.stat span { display: block; font-size: 12px; letter-spacing: .14em; color: var(--ink-faint); margin-top: 8px; }

/* =====================================================
   空间系列
   ===================================================== */
.col-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 22px;
}
.col-card {
  position: relative;
  grid-column: span 2;
  overflow: hidden;
  background: var(--dark);
}
.col-card.tall { grid-column: span 2; grid-row: span 2; }
.col-card.wide { grid-column: span 2; }
.col-card .img-frame { aspect-ratio: 3 / 4; height: 100%; }
.col-card.tall .img-frame { aspect-ratio: auto; }
.col-card img { transition: transform 1.1s var(--ease), opacity .9s var(--ease); }
.col-card:hover img { transform: scale(1.07); }
.col-meta {
  position: absolute; inset: auto 0 0 0;
  padding: 60px 26px 24px;
  background: linear-gradient(180deg, transparent, rgba(16,13,9,.82));
  color: #fff;
  display: grid; grid-template-columns: auto 1fr auto; align-items: end; gap: 4px 14px;
}
.col-no { grid-row: 1; font-size: 11px; letter-spacing: .3em; color: var(--gold-light); }
.col-meta h3 { grid-row: 2; grid-column: 1; font-family: var(--font-display); font-size: 27px; letter-spacing: .08em; }
.col-meta p { grid-row: 2; grid-column: 2; font-size: 12.5px; color: rgba(255,255,255,.78); letter-spacing: .1em; align-self: end; }
.col-arrow {
  grid-row: 1 / span 2; grid-column: 3; align-self: center;
  width: 40px; height: 40px; border: 1px solid rgba(255,255,255,.5); border-radius: 50%;
  display: grid; place-items: center; font-size: 16px;
  transition: all .4s var(--ease);
}
.col-card:hover .col-arrow { background: var(--gold-light); border-color: var(--gold-light); color: var(--ink); }

/* =====================================================
   明星单品
   ===================================================== */
.prod-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px 28px; }
.prod-card .img-frame { background: #E7E1D6; }
.prod-card img { transition: transform .9s var(--ease), opacity .9s var(--ease); }
.prod-card:hover img { transform: scale(1.05); }
.prod-info {
  display: flex; justify-content: space-between; align-items: flex-start; gap: 14px;
  padding-top: 20px;
}
.prod-info h3 { font-size: 17.5px; letter-spacing: .06em; }
.prod-mat { font-size: 12.5px; color: var(--ink-faint); letter-spacing: .08em; margin-top: 6px; }
.prod-price { font-family: var(--font-display); font-size: 20px; color: var(--accent-deep); white-space: nowrap; padding-top: 2px; }

/* =====================================================
   匠心工艺（深色）
   ===================================================== */
.section-dark .eyebrow { color: var(--gold-light); }
.section-dark .ph-copy p { color: rgba(239,233,222,.66); }
.grid-2-dark .img-frame { background: var(--dark-soft); }
.steps { margin-top: 36px; display: grid; gap: 0; }
.steps li {
  display: flex; gap: 22px; padding: 22px 0;
  border-top: 1px solid var(--dark-line);
}
.steps li span {
  font-family: var(--font-display); font-size: 15px; color: var(--gold-light);
  letter-spacing: .12em; padding-top: 4px; flex: none;
}
.steps h3 { font-size: 16.5px; letter-spacing: .12em; margin-bottom: 6px; }
.steps p { font-size: 13.5px; line-height: 1.7; color: rgba(239,233,222,.6); }

/* =====================================================
   空间灵感
   ===================================================== */
.ins-grid { display: grid; grid-template-columns: 1.55fr 1fr; gap: 26px; align-items: end; }
.ins-item { position: relative; }
.ins-item .img-frame { background: #E7E1D6; }
.ins-item img { transition: transform 1s var(--ease); }
.ins-item:hover img { transform: scale(1.05); }
.ins-item figcaption { padding: 18px 4px 0; }
.ins-item figcaption span { font-size: 11px; letter-spacing: .3em; color: var(--accent); text-transform: uppercase; }
.ins-item figcaption h3 { font-family: var(--font-display); font-size: 24px; margin-top: 8px; letter-spacing: .04em; }

.quote { text-align: center; padding: 90px 20px 10px; }
.quote p {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 34px);
  line-height: 1.5; letter-spacing: .04em; max-width: 720px; margin: 0 auto;
}
.quote cite { display: block; margin-top: 22px; font-style: normal; font-size: 12px; letter-spacing: .3em; color: var(--ink-faint); }

/* =====================================================
   专属服务
   ===================================================== */
.svc-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.svc { border-top: 1px solid var(--ink); padding-top: 26px; }
.svc span { font-family: var(--font-display); font-size: 14px; color: var(--accent); letter-spacing: .16em; }
.svc h3 { margin: 14px 0 10px; font-size: 18px; letter-spacing: .1em; }
.svc p { font-size: 13.5px; color: var(--ink-soft); }

/* =====================================================
   联系我们
   ===================================================== */
.contact-list { margin-top: 36px; }
.contact-list li {
  display: grid; grid-template-columns: 72px 1fr; gap: 18px;
  padding: 16px 0; border-bottom: 1px solid var(--line);
  font-size: 14.5px;
}
.contact-list em { font-style: normal; color: var(--accent); font-size: 12px; letter-spacing: .3em; padding-top: 3px; }
.contact-list a:hover { color: var(--accent-deep); }

.contact-form-wrap { position: relative; }

/* 前台提示条 */
.flash { padding: 13px 18px; border-left: 3px solid var(--accent); background: #FBF3E6; color: #7D5213; font-size: 13.5px; }
.flash-err { border-left-color: #B03A2E; background: #FBECEA; color: #8C2A20; }

/* 画廊式卡框：外层细线 + 内嵌青铜装饰框 + 柔和漫射投影 */
.contact-form, .form-done {
  position: relative;
  background: linear-gradient(180deg, #FFFEFB 0%, #FAF6EF 100%);
  border: 1px solid var(--line);
  padding: clamp(36px, 4vw, 58px);
  box-shadow:
    0 46px 90px -58px rgba(28, 26, 23, .42),
    0 1px 0 rgba(255, 255, 255, .9) inset;
}
/* 内嵌青铜细框 */
.contact-form::before, .form-done::before {
  content: "";
  position: absolute;
  inset: 10px;
  border: 1px solid rgba(169, 139, 95, .26);
  pointer-events: none;
  transition: border-color .5s var(--ease);
}
.contact-form:hover::before, .form-done:hover::before { border-color: rgba(169, 139, 95, .45); }
.contact-form-wrap::after {
  content: "";
  position: absolute; right: -18px; bottom: -18px;
  width: 128px; height: 128px; z-index: -1;
  background: repeating-linear-gradient(135deg, rgba(169,139,95,.22) 0 1px, transparent 1px 9px);
}

.form-head { padding-bottom: 24px; margin-bottom: 30px; border-bottom: 1px solid var(--line); }
.contact-form h3 { position: relative; padding-left: 18px; }
.contact-form h3::before {
  content: "";
  position: absolute; left: 0; top: 7px; bottom: 7px; width: 2px;
  background: linear-gradient(180deg, var(--accent), var(--gold-light));
}
.form-sub { font-size: 12.5px; color: var(--ink-faint); letter-spacing: .08em; margin: 8px 0 0 18px; }
.contact-form h3 { font-family: var(--font-display); font-size: 28px; }
.contact-form label { display: block; margin-bottom: 20px; }
.contact-form label span { display: block; font-size: 12px; letter-spacing: .2em; color: var(--ink-soft); margin-bottom: 8px; }
.contact-form input, .contact-form select {
  width: 100%; padding: 13px 14px;
  border: 1px solid var(--line); background: #fff;
  font-family: inherit; font-size: 15px; color: var(--ink);
  border-radius: 0; outline: none;
  transition: border-color .3s var(--ease), box-shadow .3s var(--ease), background .3s var(--ease);
  -webkit-appearance: none; appearance: none;
}
.contact-form select { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%235C574E' fill='none'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 14px center; }
.contact-form input:focus, .contact-form select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(169, 139, 95, .13);
  background: #FFFEFB;
}
.contact-form .btn { margin-top: 6px; }
.form-tip { font-size: 11.5px; color: var(--ink-faint); text-align: center; margin-top: 16px; letter-spacing: .05em; }
.form-done { text-align: center; display: flex; flex-direction: column; justify-content: center; min-height: 480px; }
.form-done[hidden] { display: none; }
.form-done > * { position: relative; z-index: 1; }
.done-mark {
  display: grid; place-items: center; width: 64px; height: 64px; margin: 0 auto 22px;
  border-radius: 50%; background: var(--ink); color: var(--gold-light); font-size: 26px;
}
.form-done h3 { font-family: var(--font-display); font-size: 26px; margin-bottom: 8px; }
.form-done p { color: var(--ink-soft); font-size: 14px; }

/* =====================================================
   页脚
   ===================================================== */
.footer { background: var(--dark); color: #CFC7B8; padding: 80px 0 40px; position: relative; }
.foot-brand { display: flex; flex-direction: column; align-items: center; gap: 12px; text-align: center; }
.foot-brand .brand-mark { width: 52px; height: 52px; font-size: 26px; color: var(--gold-light); }
.foot-brand strong { font-size: 20px; letter-spacing: .3em; color: #EFE9DE; font-weight: 400; }
.foot-brand em { font-style: normal; font-size: 10px; letter-spacing: .4em; color: var(--ink-faint); }
.foot-links { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px 34px; margin: 40px 0 30px; }
.foot-links a { font-size: 13px; letter-spacing: .16em; color: #CFC7B8; transition: color .3s; }
.foot-links a:hover { color: var(--gold-light); }
.foot-line, .foot-copy { text-align: center; font-size: 12px; color: var(--ink-faint); letter-spacing: .08em; }
.foot-copy { margin-top: 10px; }

.back-top {
  position: fixed; right: 22px; bottom: 26px; z-index: 110;
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--ink); color: var(--gold-light); font-size: 18px;
  opacity: 0; visibility: hidden; transform: translateY(14px);
  transition: all .45s var(--ease);
  box-shadow: 0 14px 30px -12px rgba(0,0,0,.4);
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top:hover { background: var(--accent-deep); color: #fff; }

/* =====================================================
   进场动效
   ===================================================== */
.reveal { opacity: 0; transform: translateY(34px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.d1 { transition-delay: .1s; }
.reveal.d2 { transition-delay: .2s; }
.reveal.d3 { transition-delay: .3s; }
.reveal.d4 { transition-delay: .4s; }
.reveal.on { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .marquee-track, .hero-media img.lz-on { animation: none; }
}

/* =====================================================
   响应式
   ===================================================== */
@media (max-width: 1024px) {
  .section { padding: 88px 0; }
  .nav-links { display: none; }
  .nav-burger { display: block; }
  .col-grid { grid-template-columns: repeat(2, 1fr); }
  .col-card, .col-card.tall, .col-card.wide { grid-column: span 1; grid-row: auto; }
  .col-card .img-frame { aspect-ratio: 4 / 5; }
  .prod-grid { grid-template-columns: repeat(2, 1fr); gap: 32px 20px; }
  .svc-grid { grid-template-columns: repeat(2, 1fr); gap: 34px 26px; }
  .ins-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  :root { --nav-h: 64px; }
  body { font-size: 15px; }
  .section { padding: 68px 0; }
  .wrap { width: calc(100% - 40px); }
  .grid-2 { grid-template-columns: 1fr; gap: 44px; }
  .ph-media { order: -1; }
  .ph-badge { right: 8px; top: 16px; }
  .grid-2-dark .ph-media { order: 0; }
  .stats { grid-template-columns: repeat(2, 1fr); gap: 22px 14px; }
  .hero-content { padding: 120px 20px 110px; }
  .hero-foot { display: none; }
  .m-only { display: inline; }
  .col-grid { grid-template-columns: 1fr; gap: 16px; }
  .col-card .img-frame { aspect-ratio: 4 / 3; }
  .prod-grid { grid-template-columns: 1fr 1fr; gap: 26px 14px; }
  .prod-info { flex-direction: column; gap: 6px; padding-top: 14px; }
  .prod-price { padding-top: 0; }
  .svc-grid { grid-template-columns: 1fr; }
  .contact-list li { grid-template-columns: 58px 1fr; }
  .contact-form, .form-done { padding: 34px 26px; }
  .contact-form::before, .form-done::before { inset: 7px; }
  .contact-form-wrap::after { display: none; }
  .form-done { min-height: 360px; }
  .back-top { right: 14px; bottom: 18px; width: 42px; height: 42px; }
}

@media (max-width: 420px) {
  .hero-actions .btn { width: 100%; }
  .prod-grid { grid-template-columns: 1fr; }
  .brand-text strong { font-size: 15px; letter-spacing: .1em; }
  .brand-text em { letter-spacing: .24em; }
}

/* iOS 安全区 */
@supports (padding: max(0px)) {
  .nav-inner { padding-left: env(safe-area-inset-left); padding-right: env(safe-area-inset-right); }
  .back-top { bottom: max(18px, env(safe-area-inset-bottom)); }
}