/* ==========================================================================
   辽宁透平机密封技术有限公司 - 主样式
   风格：深色金属工业风 / 高端制造业 B2B
   ========================================================================== */

:root {
  /* 配色系统 - 工业深色 + 钢蓝主色 + 琥珀强调 */
  --bg-base: #0a0e14;
  --bg-deep: #060912;
  --bg-card: #11161f;
  --bg-card-hover: #161c27;
  --bg-section: #0d1219;
  --bg-section-alt: #11161f;

  --steel-100: #e6edf5;
  --steel-200: #c4cdd9;
  --steel-300: #8b96a8;
  --steel-400: #5a6577;
  --steel-500: #3a4252;
  --steel-600: #232a37;
  --steel-700: #1a1f2a;

  --brand-primary: #2b7fff;       /* 主蓝（工业钢蓝） */
  --brand-primary-glow: rgba(43, 127, 255, 0.45);
  --brand-accent: #ff8a3d;        /* 琥珀强调色（金属高光） */
  --brand-accent-glow: rgba(255, 138, 61, 0.4);
  --brand-cyan: #4ad8ff;

  --text-primary: #e6edf5;
  --text-secondary: #8b96a8;
  --text-muted: #5a6577;

  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-strong: rgba(255, 255, 255, 0.12);
  --border-brand: rgba(43, 127, 255, 0.35);

  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 12px 48px rgba(43, 127, 255, 0.18);
  --shadow-glow: 0 0 60px rgba(43, 127, 255, 0.15);

  --font-sans: "PingFang SC", "Microsoft YaHei", "HarmonyOS Sans SC", "Helvetica Neue", Arial, sans-serif;
  --font-display: "PingFang SC", "Microsoft YaHei", "HarmonyOS Sans SC", "Helvetica Neue", sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", Consolas, "Roboto Mono", monospace;

  --container-w: 1280px;
  --header-h: 76px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */
* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-base);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; transition: color 0.2s var(--ease-out); }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* 全局背景纹理 - 工业微噪点 + 渐变 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(43, 127, 255, 0.12), transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(255, 138, 61, 0.04), transparent 50%);
  pointer-events: none;
  z-index: 0;
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.015) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse at center, black 0%, transparent 80%);
}

main, header, footer, section { position: relative; z-index: 1; }

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
}
.container--narrow { max-width: 1080px; }

.section {
  padding: 100px 0;
  position: relative;
}
.section--dark { background: var(--bg-base); }
.section--panel { background: var(--bg-section); }
.section--panel-alt { background: var(--bg-section-alt); }

.section-header {
  text-align: center;
  margin-bottom: 64px;
}
.section-header__eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 4px;
  color: var(--brand-primary);
  text-transform: uppercase;
  padding: 6px 16px;
  border: 1px solid var(--border-brand);
  border-radius: 999px;
  background: rgba(43, 127, 255, 0.06);
  margin-bottom: 20px;
}
.section-header__title {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}
.section-header__title::after {
  content: "";
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
  border-radius: 2px;
}
.section-header__subtitle {
  font-size: 14px;
  color: var(--text-muted);
  letter-spacing: 6px;
  text-transform: uppercase;
  margin-top: 24px;
  font-family: var(--font-mono);
}
.section-header--left {
  text-align: left;
}
.section-header--left .section-header__title::after { left: 0; transform: none; }
.section-header--left .section-header__subtitle { margin-top: 24px; }

/* ==========================================================================
   Header / Nav
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(10, 14, 20, 0.7);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s var(--ease-out);
}
.site-header::before {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--brand-primary) 50%, transparent);
  opacity: 0.5;
}

.site-header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.site-logo__mark {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--brand-primary) 0%, #1a5fff 100%);
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  font-size: 20px;
  box-shadow: 0 4px 16px var(--brand-primary-glow);
  position: relative;
  overflow: hidden;
}
.site-logo__mark::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 40%, rgba(255, 255, 255, 0.3) 50%, transparent 60%);
  transform: translateX(-100%);
  animation: shimmer 4s infinite;
}
@keyframes shimmer {
  100% { transform: translateX(100%); }
}
.site-logo__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.site-logo__name {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}
.site-logo__name-en {
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 2px;
  font-family: var(--font-mono);
  margin-top: 2px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
.site-nav__item {
  position: relative;
  list-style: none;
}
.site-nav__link {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 6px;
  transition: all 0.2s var(--ease-out);
  position: relative;
}
.site-nav__link:hover,
.site-nav__link.is-active {
  color: var(--text-primary);
  background: rgba(43, 127, 255, 0.08);
}
.site-nav__link.is-active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background: var(--brand-primary);
  border-radius: 1px;
  box-shadow: 0 0 8px var(--brand-primary-glow);
}
.site-nav__caret {
  font-size: 10px;
  opacity: 0.6;
  transition: transform 0.2s;
}
.site-nav__item--has-dropdown:hover .site-nav__caret { transform: rotate(180deg); }

.site-nav__dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 180px;
  padding: 8px;
  background: rgba(17, 22, 31, 0.95);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all 0.2s var(--ease-out);
  list-style: none;
}
.site-nav__item--has-dropdown:hover .site-nav__dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(4px);
}
.site-nav__dropdown li { list-style: none; }
.site-nav__dropdown a {
  display: block;
  padding: 10px 14px;
  font-size: 13px;
  color: var(--text-secondary);
  border-radius: 4px;
  transition: all 0.2s;
}
.site-nav__dropdown a:hover {
  color: var(--text-primary);
  background: rgba(43, 127, 255, 0.1);
  padding-left: 18px;
}

.site-header__cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(135deg, var(--brand-primary), #1a5fff);
  border-radius: 6px;
  box-shadow: 0 4px 16px var(--brand-primary-glow);
  transition: all 0.2s var(--ease-out);
}
.site-header__cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px var(--brand-primary-glow);
}

.site-header__menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--text-primary);
  border-radius: 6px;
}
.site-header__menu-btn:hover { background: rgba(255, 255, 255, 0.05); }

/* ==========================================================================
   Hero Banner
   ========================================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  padding-top: var(--header-h);
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--bg-deep);
}
.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero__bg img,
.hero__bg .hero__bg-fallback {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.45) contrast(1.1);
}
.hero__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(10, 14, 20, 0.5) 0%, rgba(10, 14, 20, 0.85) 70%, var(--bg-base) 100%),
    linear-gradient(90deg, rgba(10, 14, 20, 0.7) 0%, transparent 60%);
}
.hero__bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(43, 127, 255, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(43, 127, 255, 0.08) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.hero__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  padding: 80px 0;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 4px;
  color: var(--brand-cyan);
  text-transform: uppercase;
  padding: 8px 16px;
  border: 1px solid rgba(74, 216, 255, 0.3);
  border-radius: 999px;
  background: rgba(74, 216, 255, 0.05);
  margin-bottom: 28px;
}
.hero__eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--brand-cyan);
  border-radius: 50%;
  box-shadow: 0 0 12px var(--brand-cyan);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero__title {
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1px;
  color: #fff;
  margin-bottom: 24px;
  max-width: 900px;
}
.hero__title .accent {
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__title .highlight {
  position: relative;
  display: inline-block;
}
.hero__title .highlight::after {
  content: "";
  position: absolute;
  bottom: 4px;
  left: 0;
  right: 0;
  height: 12px;
  background: linear-gradient(90deg, var(--brand-accent), transparent);
  opacity: 0.3;
  z-index: -1;
}

.hero__subtitle {
  font-size: clamp(15px, 1.4vw, 18px);
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 720px;
  margin-bottom: 40px;
}
.hero__subtitle b {
  color: var(--text-primary);
  font-weight: 600;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 64px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 6px;
  transition: all 0.25s var(--ease-out);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.btn--primary {
  background: linear-gradient(135deg, var(--brand-primary), #1a5fff);
  color: #fff;
  box-shadow: 0 8px 24px var(--brand-primary-glow);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px var(--brand-primary-glow);
}
.btn--primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 30%, rgba(255, 255, 255, 0.2) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: transform 0.6s;
}
.btn--primary:hover::after { transform: translateX(100%); }

.btn--ghost {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-primary);
  border: 1px solid var(--border-strong);
}
.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--brand-primary);
}

.hero__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 900px;
  padding-top: 48px;
  border-top: 1px solid var(--border-subtle);
}
.hero__stat {
  position: relative;
}
.hero__stat-value {
  font-size: clamp(28px, 3vw, 42px);
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  font-family: var(--font-display);
  letter-spacing: -1px;
}
.hero__stat-value .unit {
  font-size: 0.5em;
  color: var(--brand-primary);
  margin-left: 4px;
  font-weight: 600;
}
.hero__stat-label {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
  letter-spacing: 1px;
}
.hero__stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 24px;
  height: 2px;
  background: linear-gradient(90deg, var(--brand-primary), transparent);
}

/* ==========================================================================
   Trust Bar (滚动 logo / 行业认证)
   ========================================================================== */
.trust-bar {
  background: var(--bg-section);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  padding: 32px 0;
  overflow: hidden;
}
.trust-bar__inner {
  display: flex;
  align-items: center;
  gap: 64px;
  flex-wrap: wrap;
  justify-content: center;
}
.trust-bar__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--text-muted);
  text-transform: uppercase;
  white-space: nowrap;
}
.trust-bar__items {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
  align-items: center;
}
.trust-bar__item {
  font-size: 15px;
  color: var(--text-secondary);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}
.trust-bar__item::before {
  content: "◆";
  color: var(--brand-primary);
  font-size: 8px;
}

/* ==========================================================================
   Technical Advantages - 6 卡片
   ========================================================================== */
.adv-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.adv-card {
  position: relative;
  padding: 36px 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: all 0.3s var(--ease-out);
  overflow: hidden;
}
.adv-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(43, 127, 255, 0.05), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}
.adv-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-brand);
  box-shadow: var(--shadow-hover);
}
.adv-card:hover::before { opacity: 1; }

.adv-card__num {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--brand-primary);
  margin-bottom: 16px;
  letter-spacing: 2px;
}
.adv-card__title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}
.adv-card__desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
}
.adv-card__icon {
  position: absolute;
  top: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: rgba(43, 127, 255, 0.08);
  color: var(--brand-primary);
  font-size: 22px;
  font-weight: 700;
}

/* ==========================================================================
   Products - 双产品卡片
   ========================================================================== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.product-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.3s var(--ease-out);
  cursor: pointer;
}
.product-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-brand);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.5), var(--shadow-glow);
}

.product-card__image {
  position: relative;
  aspect-ratio: 16/10;
  overflow: hidden;
  background: var(--bg-deep);
}
.product-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease-out);
}
.product-card:hover .product-card__image img { transform: scale(1.05); }
.product-card__image::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(10, 14, 20, 0.6) 100%);
}
.product-card__tag {
  position: absolute;
  top: 16px;
  left: 16px;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--brand-cyan);
  padding: 6px 12px;
  background: rgba(10, 14, 20, 0.6);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(74, 216, 255, 0.3);
  border-radius: 4px;
}

.product-card__body {
  padding: 32px;
}
.product-card__title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.product-card__title::before {
  content: "";
  width: 4px;
  height: 24px;
  background: linear-gradient(180deg, var(--brand-primary), var(--brand-accent));
  border-radius: 2px;
}
.product-card__desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}
.product-card__specs {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 16px;
  padding: 16px 0;
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 20px;
}
.product-card__specs li {
  font-size: 13px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}
.product-card__specs li::before {
  content: "▸";
  color: var(--brand-primary);
  font-size: 10px;
}
.product-card__specs li b {
  color: var(--text-primary);
  font-weight: 600;
}
.product-card__more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--brand-primary);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  transition: all 0.2s;
}
.product-card__more::after {
  content: "→";
  transition: transform 0.2s;
}
.product-card:hover .product-card__more { color: var(--brand-cyan); }
.product-card:hover .product-card__more::after { transform: translateX(4px); }

/* ==========================================================================
   Sealing Effect - 数据展示
   ========================================================================== */
.effect-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.effect-content__eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--brand-cyan);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.effect-content__title {
  font-size: clamp(32px, 4vw, 44px);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  margin-bottom: 16px;
  line-height: 1.2;
}
.effect-content__title .accent {
  color: var(--brand-accent);
}
.effect-content__desc {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 32px;
}

.effect-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}
.effect-metric {
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  text-align: center;
}
.effect-metric__value {
  font-size: 32px;
  font-weight: 800;
  color: var(--brand-primary);
  line-height: 1;
  font-family: var(--font-display);
  letter-spacing: -1px;
}
.effect-metric__value .unit {
  font-size: 14px;
  margin-left: 2px;
  color: var(--brand-cyan);
}
.effect-metric__label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 8px;
  letter-spacing: 1px;
}

.effect-image {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
  border: 1px solid var(--border-subtle);
}
.effect-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 4/3;
}
.effect-image__caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 24px;
  background: linear-gradient(0deg, rgba(10, 14, 20, 0.95) 0%, transparent 100%);
}
.effect-image__caption-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.effect-image__caption-sub {
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 2px;
  text-transform: uppercase;
}

/* ==========================================================================
   About Section
   ========================================================================== */
.about-block {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 80px;
  align-items: center;
}
.about-image {
  position: relative;
  aspect-ratio: 1/1;
  max-width: 360px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  display: grid;
  place-items: center;
  position: relative;
}
.about-image__avatar {
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-section) 100%);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 2px;
}
.about-image__corner {
  position: absolute;
  width: 32px;
  height: 32px;
  border: 2px solid var(--brand-primary);
}
.about-image__corner--tl { top: 12px; left: 12px; border-right: none; border-bottom: none; }
.about-image__corner--tr { top: 12px; right: 12px; border-left: none; border-bottom: none; }
.about-image__corner--bl { bottom: 12px; left: 12px; border-right: none; border-top: none; }
.about-image__corner--br { bottom: 12px; right: 12px; border-left: none; border-top: none; }

.about-content__eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--brand-primary);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.about-content__title {
  font-size: clamp(28px, 3vw, 36px);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
  letter-spacing: -0.5px;
}
.about-content__lead {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 16px;
}
.about-content__lead b {
  color: var(--brand-cyan);
  font-weight: 600;
}

.about-credentials {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 32px;
  padding-top: 32px;
  border-top: 1px solid var(--border-subtle);
}
.about-credential {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}
.about-credential__icon {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  background: rgba(43, 127, 255, 0.1);
  color: var(--brand-primary);
  border-radius: 6px;
  font-size: 16px;
  font-weight: 700;
  flex-shrink: 0;
}
.about-credential__text {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.4;
}
.about-credential__text b {
  display: block;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 2px;
}

/* ==========================================================================
   Contact Section
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 60px;
  align-items: stretch;
}

.contact-card {
  padding: 48px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}
.contact-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
}
.contact-card__title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}
.contact-card__sub {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 32px;
  font-family: var(--font-mono);
  letter-spacing: 2px;
}

.contact-list { list-style: none; display: flex; flex-direction: column; gap: 24px; }
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.contact-item__icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  display: grid;
  place-items: center;
  background: rgba(43, 127, 255, 0.1);
  color: var(--brand-primary);
  border-radius: 8px;
  font-size: 18px;
}
.contact-item__label {
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 2px;
  text-transform: uppercase;
  font-family: var(--font-mono);
  margin-bottom: 4px;
}
.contact-item__value {
  font-size: 15px;
  color: var(--text-primary);
  line-height: 1.5;
  word-break: break-all;
}
.contact-item__value a { color: var(--text-primary); }
.contact-item__value a:hover { color: var(--brand-cyan); }

/* QR codes - 公众号 + 企业微信 */
.qr-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 12px;
}
.qr-item {
  padding: 20px 16px;
  background: var(--bg-section);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  text-align: center;
  transition: all 0.2s;
  position: relative;
}
.qr-item:hover {
  border-color: var(--border-brand);
  transform: translateY(-2px);
}
.qr-item__img {
  width: 100%;
  aspect-ratio: 1/1;
  max-width: 160px;
  margin: 0 auto 12px;
  background: #fff;
  border-radius: 6px;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
  padding: 8px;
}
.qr-item__img img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.qr-item__img--placeholder {
  background:
    repeating-linear-gradient(0deg, #111 0 2px, transparent 2px 4px),
    repeating-linear-gradient(90deg, #111 0 2px, transparent 2px 4px);
  background-size: 12px 12px;
  position: relative;
}
.qr-item__img--placeholder::after {
  content: attr(data-text);
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 12px;
  color: #fff;
  background: rgba(0, 0, 0, 0.7);
  font-family: var(--font-mono);
  letter-spacing: 2px;
}
.qr-item__label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.qr-item__hint {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 1px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  padding: 64px 0 24px;
  background: var(--bg-deep);
  border-top: 1px solid var(--border-subtle);
  position: relative;
  z-index: 1;
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--brand-primary), transparent);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-col h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
  letter-spacing: 1px;
}
.footer-col h4::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 24px;
  height: 2px;
  background: var(--brand-primary);
}
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer-col a {
  font-size: 13px;
  color: var(--text-secondary);
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--brand-cyan); }

.footer-brand__desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-top: 16px;
  max-width: 320px;
}
.footer-contact {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: var(--text-muted);
}
.footer-bottom__links { display: flex; gap: 16px; flex-wrap: wrap; }
.footer-bottom__links a { color: var(--text-muted); }
.footer-bottom__links a:hover { color: var(--brand-cyan); }
.footer-beian {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.footer-beian img {
  width: 14px;
  height: 14px;
  display: inline-block;
  vertical-align: middle;
}

/* ==========================================================================
   Floating Actions (右侧悬浮)
   ========================================================================== */
.float-actions {
  position: fixed;
  right: 24px;
  bottom: 32px;
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.float-btn {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 50%;
  color: var(--text-primary);
  font-size: 20px;
  transition: all 0.25s var(--ease-out);
  position: relative;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  cursor: pointer;
}
.float-btn:hover {
  background: var(--brand-primary);
  color: #fff;
  border-color: var(--brand-primary);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--brand-primary-glow);
}
.float-btn--accent {
  background: linear-gradient(135deg, var(--brand-accent), #ff6a1a);
  color: #fff;
  border: none;
}
.float-btn--accent:hover {
  background: linear-gradient(135deg, #ff6a1a, var(--brand-accent));
  box-shadow: 0 8px 24px var(--brand-accent-glow);
}
.float-btn__tooltip {
  position: absolute;
  right: calc(100% + 12px);
  top: 50%;
  transform: translateY(-50%);
  white-space: nowrap;
  padding: 6px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  font-size: 12px;
  color: var(--text-primary);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.float-btn:hover .float-btn__tooltip { opacity: 1; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .product-grid { grid-template-columns: 1fr; }
  .effect-grid, .about-block, .contact-grid { grid-template-columns: 1fr; gap: 48px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .hero__stats { grid-template-columns: repeat(2, 1fr); gap: 32px; }
}
@media (max-width: 720px) {
  :root { --header-h: 64px; }
  .section { padding: 64px 0; }
  .site-nav, .site-header__cta { display: none; }
  .site-header__menu-btn { display: grid; }
  .site-nav--open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--bg-deep);
    padding: 24px;
    border-bottom: 1px solid var(--border-subtle);
    align-items: stretch;
    gap: 0;
  }
  .site-nav--open .site-nav__link {
    padding: 14px 16px;
    border-radius: 0;
    border-bottom: 1px solid var(--border-subtle);
  }
  .adv-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero__actions { flex-direction: column; }
  .hero__actions .btn { width: 100%; justify-content: center; }
  .container { padding: 0 16px; }
  .contact-card { padding: 32px 24px; }
  .qr-grid { grid-template-columns: 1fr; }
}