/* ==========================================================================
   茸海 RONGHAI · Apple-style 企业官网 v2
   主题:光的海(浅色默认,深色跟随系统/手动切换,由 .dark 驱动 CSS 变量)
   accent:苹果蓝 #0071e3(全站唯一;深色下高亮使用亮蓝 #2997ff)
   圆角规则:卡片/图片 20px,按钮 pill,输入框 12px
   动效:仅 transform/opacity,丝滑低速率,cubic-bezier(0.16,1,0.3,1)
   ========================================================================== */

:root {
  color-scheme: light;
  --bg: #f5f5f7;
  --elev: #ffffff;
  --glass: rgba(251, 251, 253, 0.78);
  --ink: #1d1d1f;
  --ink-2: #6e6e73;
  --ink-3: #86868b;
  --line: rgba(0, 0, 0, 0.09);
  --line-strong: rgba(0, 0, 0, 0.17);
  --accent: #0071e3;
  --accent-bright: #0071e3;
  --accent-ink: #ffffff;
  --accent-soft: rgba(0, 113, 227, 0.09);
  --field: rgba(0, 0, 0, 0.028);
  --edge: rgba(255, 255, 255, 0.65);
  --pattern: rgba(0, 0, 0, 0.035);
  --glow-1: rgba(10, 132, 255, 0.14);
  --glow-2: rgba(94, 92, 230, 0.1);
  --glow-3: rgba(69, 214, 195, 0.12);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.03), 0 28px 72px rgba(0, 0, 0, 0.07);
  --shadow-pop: 0 4px 12px rgba(0, 0, 0, 0.04), 0 36px 96px rgba(0, 0, 0, 0.13);
  --grain-opacity: 0.035;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --radius-card: 20px;
  --radius-pill: 999px;
  --z-nav: 50;
  --z-menu: 60;
  --z-grain: 80;
}

html.dark {
  color-scheme: dark;
  --bg: #0b0b0e;
  --elev: #16161a;
  --glass: rgba(19, 19, 23, 0.72);
  --ink: #f5f5f7;
  --ink-2: #a1a1a6;
  --ink-3: #74747a;
  --line: rgba(255, 255, 255, 0.1);
  --line-strong: rgba(255, 255, 255, 0.22);
  --accent: #0071e3;
  --accent-bright: #2997ff;
  --accent-ink: #ffffff;
  --accent-soft: rgba(41, 151, 255, 0.13);
  --field: rgba(255, 255, 255, 0.05);
  --edge: rgba(255, 255, 255, 0.08);
  --pattern: rgba(255, 255, 255, 0.045);
  --glow-1: rgba(10, 132, 255, 0.2);
  --glow-2: rgba(94, 92, 230, 0.14);
  --glow-3: rgba(69, 214, 195, 0.09);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.3), 0 28px 72px rgba(0, 0, 0, 0.45);
  --shadow-pop: 0 4px 12px rgba(0, 0, 0, 0.35), 0 36px 96px rgba(0, 0, 0, 0.6);
  --grain-opacity: 0.05;
}

/* ---------- 语义色工具类(跟随 .dark 变量,免写 dark: 变体) ---------- */

.bg-bg { background-color: var(--bg); }
.bg-elev { background-color: var(--elev); }
.bg-accent { background-color: var(--accent); }
.bg-accentsoft { background-color: var(--accent-soft); }
.text-ink { color: var(--ink); }
.text-ink2 { color: var(--ink-2); }
.text-ink3 { color: var(--ink-3); }
.text-accent { color: var(--accent); }
.border-line { border-color: var(--line); }
.border-linestrong { border-color: var(--line-strong); }
.shadow-card { box-shadow: var(--shadow-card); }

/* reset 交给 Tailwind v4 preflight(分层管理);
   此处不再写未分层的 * { margin/padding: 0 },否则会压过 @layer utilities 里的
   mx-auto / px-* 等工具类,导致整站容器无法居中 */
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

button { cursor: pointer; font: inherit; }

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

a { color: inherit; text-decoration: none; }

img { display: block; max-width: 100%; }

[id] { scroll-margin-top: 76px; }

.icon { width: 1.1em; height: 1.1em; fill: currentColor; flex: none; }

:is(a, button):focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ---------- 颗粒 ---------- */

.grain {
  position: fixed;
  inset: -50%;
  z-index: var(--z-grain);
  pointer-events: none;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='0.6'/%3E%3C/svg%3E");
}

/* ---------- 顶部磨砂导航 ---------- */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  border-bottom: 1px solid transparent;
  transition: background 0.5s var(--ease), border-color 0.5s ease, backdrop-filter 0.5s ease, -webkit-backdrop-filter 0.5s ease;
}
.nav.scrolled {
  background: var(--glass);
  -webkit-backdrop-filter: blur(20px) saturate(1.8);
  backdrop-filter: blur(20px) saturate(1.8);
  border-bottom-color: var(--line);
}

.icon-moon { display: block; }
.icon-sun { display: none; }
html.dark .icon-sun { display: block; }
html.dark .icon-moon { display: none; }
.icon-sun, .icon-moon { width: 1.15rem; height: 1.15rem; }

/* ---------- 移动端菜单 ---------- */

.burger {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  width: 40px;
  height: 40px;
  color: var(--ink);
  align-items: center;
  justify-content: center;
}
.burger .icon { width: 1.25rem; height: 1.25rem; }
.burger .icon-close { display: none; }

.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: var(--z-menu);
  background: var(--glass);
  -webkit-backdrop-filter: blur(28px) saturate(1.8);
  backdrop-filter: blur(28px) saturate(1.8);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0 clamp(24px, 8vw, 48px);
  gap: 6px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s var(--ease), visibility 0.4s;
}
.mobile-menu a {
  font-size: clamp(2rem, 9vw, 2.8rem);
  font-weight: 650;
  padding: 10px 0;
  color: var(--ink);
  letter-spacing: 0.02em;
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease), color 0.25s;
}
.mobile-menu a:hover { color: var(--accent); }
.menu-foot {
  margin-top: 40px;
  font-size: 0.82rem;
  color: var(--ink-3);
  letter-spacing: 0.08em;
  line-height: 2;
  opacity: 0;
  transition: opacity 0.55s var(--ease) 0.3s;
}
.menu-foot a {
  font-size: 0.9rem;
  color: var(--ink-2);
  letter-spacing: 0.02em;
  transition: color 0.25s;
}
.menu-foot a:hover { color: var(--accent); }
body.menu-open .mobile-menu { opacity: 1; visibility: visible; }
body.menu-open .mobile-menu a,
body.menu-open .menu-foot { opacity: 1; transform: none; }
body.menu-open .mobile-menu a:nth-child(1) { transition-delay: 0.06s; }
body.menu-open .mobile-menu a:nth-child(2) { transition-delay: 0.12s; }
body.menu-open .mobile-menu a:nth-child(3) { transition-delay: 0.18s; }
body.menu-open .mobile-menu a:nth-child(4) { transition-delay: 0.24s; }
body.menu-open .burger .icon-menu { display: none; }
body.menu-open .burger .icon-close { display: block; }
body.menu-open { overflow: hidden; }
body.menu-open .nav { z-index: calc(var(--z-menu) + 1); background: transparent; border-bottom-color: transparent; -webkit-backdrop-filter: none; backdrop-filter: none; }

@media (max-width: 767px) {
  .burger { display: inline-flex; }
}

/* ---------- 按钮(pill) ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  line-height: 1;
  white-space: nowrap;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.45s var(--ease), background 0.3s, border-color 0.3s, color 0.3s, box-shadow 0.45s var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(0.97); transition-duration: 0.15s; }

.btn-primary {
  background: var(--accent);
  color: var(--accent-ink);
}
.btn-primary:hover {
  background: #1481ea;
  box-shadow: 0 12px 32px rgba(0, 113, 227, 0.28);
}

.btn-ghost {
  border-color: var(--line-strong);
  color: var(--ink);
  background: transparent;
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-block { width: 100%; justify-content: center; }

/* ---------- HERO:光的海 ---------- */

.hero {
  position: relative;
  min-height: 100dvh;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.hero-bg { position: absolute; inset: 0; pointer-events: none; will-change: transform; }

.aurora, .horizon-glow { position: absolute; border-radius: 50%; will-change: transform; }

.aurora-1 {
  width: 76vmax;
  height: 76vmax;
  left: 50%;
  top: -42vmax;
  background: radial-gradient(circle at 50% 50%, var(--glow-1), transparent 62%);
  animation: drift-1 26s var(--ease) infinite alternate;
}
.aurora-2 {
  width: 54vmax;
  height: 54vmax;
  right: -22vmax;
  top: 16vmax;
  background: radial-gradient(circle, var(--glow-2), transparent 60%);
  animation: drift-2 32s var(--ease) infinite alternate;
}
.aurora-3 {
  width: 46vmax;
  height: 46vmax;
  left: -18vmax;
  bottom: -10vmax;
  background: radial-gradient(circle, var(--glow-3), transparent 60%);
  animation: drift-3 29s var(--ease) infinite alternate;
}

.horizon-glow {
  left: 50%;
  bottom: -18vmax;
  width: 130vmax;
  height: 44vmax;
  border-radius: 50%;
  background: radial-gradient(48% 62% at 50% 100%, var(--glow-1), transparent 72%);
}

@keyframes drift-1 {
  to { transform: translateX(-6%) translateY(5vmax) scale(1.06); }
}
@keyframes drift-2 {
  to { transform: translate(-7%, 6%) scale(0.94); }
}
@keyframes drift-3 {
  to { transform: translate(8%, -6%) scale(1.08); }
}

.hero-inner { will-change: transform, opacity; }

/* ---------- 分段叙事(一屏一主题) ---------- */

.nar-wrap { position: relative; height: 520vh; }

.nar-sticky {
  position: sticky;
  top: 0;
  height: 100dvh;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.nar-panel {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 96px clamp(20px, 4vw, 40px) 64px;
  opacity: 0;
  will-change: transform, opacity;
}

.nar-ghost {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: clamp(11rem, 30vw, 26rem);
  font-weight: 800;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--line-strong);
  opacity: 0.3;
  user-select: none;
  pointer-events: none;
}

/* ---------- 业务 Bento ---------- */

.services::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(52% 42% at 86% 0%, var(--glow-1), transparent 70%),
    radial-gradient(42% 36% at 4% 92%, var(--glow-3), transparent 70%);
}

.bento {
  position: relative;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(14px, 1.6vw, 20px);
}

.cell {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--glass);
  -webkit-backdrop-filter: blur(24px) saturate(1.6);
  backdrop-filter: blur(24px) saturate(1.6);
  box-shadow: var(--shadow-card);
  padding: clamp(24px, 3vw, 40px);
  overflow: hidden;
  transition: transform 0.6s var(--ease), border-color 0.4s ease, box-shadow 0.6s var(--ease);
}
.cell::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  box-shadow: inset 0 1px 0 var(--edge);
}
.cell:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-pop);
}

.spotlight::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transition: opacity 0.5s ease;
  pointer-events: none;
  background: radial-gradient(460px circle at var(--mx, 50%) var(--my, 50%), var(--accent-soft), transparent 62%);
  z-index: 0;
}
.spotlight:hover::before { opacity: 1; }

.cell-head {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 14px;
}
.cell-head h3 {
  font-size: 1.15rem;
  font-weight: 650;
  letter-spacing: 0.03em;
}

.cell-icon {
  width: 42px;
  height: 42px;
  flex: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent-bright);
}
.cell-icon .icon { width: 1.3rem; height: 1.3rem; }

.cell p {
  position: relative;
  z-index: 1;
  color: var(--ink-2);
  font-size: 0.96rem;
  margin-top: 14px;
  max-width: 30em;
}

.cell-list {
  position: relative;
  z-index: 1;
  list-style: none;
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.cell-list li {
  font-size: 0.82rem;
  color: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  padding: 5px 14px;
  letter-spacing: 0.04em;
}

/* Bento 背景多样性(同一冷色家族内的微差) */
.cell-a { background: linear-gradient(135deg, var(--accent-soft), transparent 56%), var(--glass); }
.cell-b::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(90deg, var(--pattern) 0 1px, transparent 1px 26px);
  mask-image: radial-gradient(120% 100% at 100% 0%, #000, transparent 62%);
  -webkit-mask-image: radial-gradient(120% 100% at 100% 0%, #000, transparent 62%);
}
.cell-c { background: radial-gradient(120% 130% at 0% 100%, var(--glow-3), transparent 58%), var(--glass); }
.cell-d::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(var(--pattern) 1px, transparent 1.6px);
  background-size: 22px 22px;
  mask-image: radial-gradient(110% 100% at 100% 100%, #000, transparent 60%);
  -webkit-mask-image: radial-gradient(110% 100% at 100% 100%, #000, transparent 60%);
}

/* ---------- 案例横向画廊 ---------- */

.cases::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(46% 38% at 100% 22%, var(--glow-2), transparent 70%);
}

.gal-wrap { position: relative; }

.gal-sticky {
  position: sticky;
  top: 0;
  height: 100dvh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.gal-track {
  display: flex;
  align-items: stretch;
  gap: clamp(18px, 2vw, 28px);
  padding: 0 clamp(20px, 6vw, 96px);
  width: max-content;
  will-change: transform;
}

.gal-card {
  width: min(78vw, 460px);
  flex: none;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--glass);
  -webkit-backdrop-filter: blur(20px) saturate(1.5);
  backdrop-filter: blur(20px) saturate(1.5);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform 0.6s var(--ease), border-color 0.4s ease, box-shadow 0.6s var(--ease);
}
.gal-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-pop);
}
.gal-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  transition: transform 1.2s var(--ease);
}
.gal-card:hover img { transform: scale(1.04); }

@media (min-width: 1024px) {
  .gal-card { width: min(44vw, 560px); }
}

/* ---------- 关于 ---------- */

.about-facts { display: grid; grid-template-columns: 1fr; }
.fact {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 13px 2px;
  border-bottom: 1px solid var(--line);
}
.fact:first-child { border-top: 1px solid var(--line); }
.fact dt {
  font-size: 0.85rem;
  color: var(--ink-3);
  letter-spacing: 0.08em;
  flex: none;
}
.fact dd {
  font-size: 0.95rem;
  color: var(--ink);
  text-align: right;
}

.about-media { position: relative; }

.tilt {
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--line);
  transform-style: preserve-3d;
  will-change: transform;
  box-shadow: var(--shadow-pop);
}
.tilt img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transform: scale(1.02);
}

/* ---------- 联系 ---------- */

.contact::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(44% 40% at 0% 8%, var(--glow-1), transparent 70%),
    radial-gradient(40% 36% at 100% 96%, var(--glow-3), transparent 70%);
}

.addr-card {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--glass);
  -webkit-backdrop-filter: blur(20px) saturate(1.5);
  backdrop-filter: blur(20px) saturate(1.5);
  box-shadow: var(--shadow-card);
  padding: 24px 26px;
  transition: border-color 0.4s ease, transform 0.6s var(--ease), box-shadow 0.6s var(--ease);
}
.addr-card:hover {
  border-color: var(--line-strong);
  transform: translateY(-3px);
  box-shadow: var(--shadow-pop);
}
.addr-card p { font-size: 0.98rem; line-height: 1.8; }

.contact-form {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--elev);
  box-shadow: var(--shadow-card);
  padding: clamp(26px, 3.5vw, 40px);
}

.field { display: flex; flex-direction: column; gap: 8px; }

.field label {
  font-size: 0.88rem;
  letter-spacing: 0.05em;
  color: var(--ink-2);
  font-weight: 500;
}

.field input,
.field textarea {
  width: 100%;
  background: var(--field);
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  color: var(--ink);
  font: inherit;
  font-size: 0.96rem;
  padding: 13px 16px;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.field textarea { resize: vertical; min-height: 110px; }

.field input::placeholder,
.field textarea::placeholder { color: var(--ink-3); }

.field input:focus-visible,
.field textarea:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.field.invalid input,
.field.invalid textarea { border-color: #e5484d; }

.field-error {
  font-size: 0.8rem;
  color: #e5484d;
  display: none;
}
.field-error.show { display: block; }

.btn-loading {
  display: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.35);
  border-top-color: var(--accent-ink);
  animation: spin 0.7s linear infinite;
}
.contact-form.sending .btn-loading { display: inline-block; }
.contact-form.sending .btn-label { display: none; }
.contact-form.sending #submit-btn { pointer-events: none; opacity: 0.85; }
@keyframes spin { to { transform: rotate(360deg); } }

.form-success {
  display: none;
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: var(--elev);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 8px;
  padding: 24px;
}
.contact-form.done .form-success { display: flex; }
.success-icon {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-bright);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 8px;
}
.success-icon .icon { width: 1.5rem; height: 1.5rem; }
.form-success strong { font-size: 1.05rem; }
.form-success p { color: var(--ink-2); font-size: 0.92rem; }

/* ---------- 页脚 ---------- */

.footer { border-top: 1px solid var(--line); }
.footer-base { border-top: 1px solid var(--line); }

/* ---------- 滚动显现 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 1s var(--ease), transform 1s var(--ease);
  transition-delay: var(--d, 0s);
}
.reveal.in { opacity: 1; transform: none; }

/* ---------- 画廊:窄屏与降级 → 原生横向滑动 ---------- */

@media (max-width: 1023px), (prefers-reduced-motion: reduce) {
  .gal-wrap { height: auto !important; }
  .gal-sticky {
    position: static;
    height: auto;
    padding: 2.5rem 0 3rem;
  }
  .gal-track {
    width: auto;
    overflow-x: auto;
    transform: none !important;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 6px;
  }
  .gal-track::-webkit-scrollbar { display: none; }
  .gal-card { scroll-snap-align: center; }
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .aurora, .horizon-glow { animation: none; }
  .nar-wrap { height: auto; }
  .nar-sticky { position: static; height: auto; padding: 6rem 0 3rem; }
  .nar-panel {
    position: static;
    opacity: 1;
    padding: 0 clamp(20px, 4vw, 40px);
    margin-bottom: 6rem;
  }
  .nar-panel:last-child { margin-bottom: 0; }
  .nar-ghost { display: none; }
  .cell, .gal-card, .tilt, .btn, .addr-card { transition: none; }
  .cell:hover, .gal-card:hover, .addr-card:hover { transform: none; }
  .gal-card:hover img { transform: none; }
}

@media (prefers-reduced-transparency: reduce) {
  .nav.scrolled, .mobile-menu { -webkit-backdrop-filter: none; backdrop-filter: none; }
  .nav.scrolled, .mobile-menu { background: var(--elev); }
  .cell, .gal-card, .addr-card {
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    background: var(--elev);
  }
  .cell-a, .cell-c { background: var(--elev); }
}