/* ============================================================
   vr-home.cn — 设计系统
   风格：深空观测站 (Deep Space Observatory)
   暗色为主 + 纸张暖白双主题，spectral 光谱描边作为签名元素
   ============================================================ */

:root {
  /* ---- 排版 ---- */
  --font-display: 'Space Grotesk', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Noto Sans SC', 'Space Grotesk', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Consolas, 'Courier New', monospace;

  --fs-eyebrow: 0.6875rem;
  --fs-micro: 0.75rem;
  --fs-small: 0.8125rem;
  --fs-body: 0.9375rem;
  --fs-lead: 1.0625rem;
  --fs-h4: 1.125rem;
  --fs-h3: clamp(1.25rem, 1.1rem + 0.7vw, 1.6rem);
  --fs-h2: clamp(1.75rem, 1.4rem + 1.6vw, 2.6rem);
  --fs-h1: clamp(2.4rem, 1.7rem + 3.2vw, 4.25rem);
  --fs-display: clamp(3rem, 2rem + 5vw, 6.5rem);

  --lh-tight: 1.12;
  --lh-snug: 1.35;
  --lh-body: 1.78;

  /* ---- 间距 ---- */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
  --sp-9: 96px;
  --sp-10: 128px;

  --radius: 3px;
  --radius-lg: 5px;
  --shell: 1320px;
  --shell-narrow: 940px;

  /* ---- 色彩：暗色主题（默认） ---- */
  --bg: #06080c;
  --bg-deep: #030508;
  --surface: #0b0f16;
  --surface-2: #10151e;
  --surface-3: #161d28;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.17);
  --text: #e9edf4;
  --text-dim: #98a3b4;
  --text-faint: #5f6a7a;

  --accent: #2ad9e6;
  --accent-deep: #0e7c8a;
  --warm: #ff6b4a;
  --violet: #7d6cf7;

  --accent-soft: rgba(42, 217, 230, 0.12);
  --warm-soft: rgba(255, 107, 74, 0.12);
  --violet-soft: rgba(125, 108, 247, 0.12);

  --shadow-card: 0 1px 0 rgba(255, 255, 255, 0.04) inset, 0 18px 40px -24px rgba(0, 0, 0, 0.9);
  --grid-line: rgba(255, 255, 255, 0.038);

  --header-h: 66px;
  --ease: cubic-bezier(0.22, 0.68, 0.34, 1);
}

[data-theme='light'] {
  --bg: #f5f4f0;
  --bg-deep: #eceae4;
  --surface: #fbfaf7;
  --surface-2: #ffffff;
  --surface-3: #f0eee8;
  --line: rgba(18, 22, 28, 0.11);
  --line-strong: rgba(18, 22, 28, 0.22);
  --text: #14181f;
  --text-dim: #4d5663;
  --text-faint: #7b8492;

  --accent: #0b7f8c;
  --accent-deep: #07545e;
  --warm: #d94a28;
  --violet: #4f3fd6;

  --accent-soft: rgba(11, 127, 140, 0.1);
  --warm-soft: rgba(217, 74, 40, 0.1);
  --violet-soft: rgba(79, 63, 214, 0.1);

  --shadow-card: 0 1px 0 rgba(255, 255, 255, 0.7) inset, 0 14px 34px -22px rgba(20, 24, 31, 0.35);
  --grid-line: rgba(18, 22, 28, 0.045);
}

/* ============================================================
   基础
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 20%, transparent 78%);
}

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

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: var(--lh-tight);
  letter-spacing: -0.018em;
  margin: 0;
  text-wrap: balance;
}

p { margin: 0; text-wrap: pretty; }

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

button, input, select, textarea { font: inherit; color: inherit; }

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ============================================================
   布局工具
   ============================================================ */

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 48px);
}

.shell--narrow { max-width: var(--shell-narrow); }

.section { padding-block: clamp(64px, 9vw, 128px); position: relative; z-index: 1; }
.section--tight { padding-block: clamp(48px, 6vw, 84px); }

.rule {
  height: 1px;
  background: var(--line);
  border: 0;
  margin: 0;
}

.grid { display: grid; gap: var(--sp-5); }
.stack { display: flex; flex-direction: column; }

/* 两栏图文区，移动端收成单列 */
@media (max-width: 900px) {
  .split-grid { grid-template-columns: 1fr !important; }
}

/* ============================================================
   排版原子
   ============================================================ */

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-4);
}

.eyebrow::before {
  content: '';
  width: 26px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.eyebrow--warm { color: var(--warm); }
.eyebrow--violet { color: var(--violet); }

.lead {
  font-size: var(--fs-lead);
  color: var(--text-dim);
  line-height: 1.72;
  max-width: 62ch;
}

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.04em;
}

.dim { color: var(--text-dim); }
.faint { color: var(--text-faint); }

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
  gap: clamp(24px, 4vw, 64px);
  align-items: end;
  margin-bottom: clamp(36px, 5vw, 60px);
}

.section-head__aside { justify-self: end; text-align: right; }

@media (max-width: 880px) {
  .section-head { grid-template-columns: 1fr; }
  .section-head__aside { justify-self: start; text-align: left; }
}

/* 签名元素：光谱描边 */
.spectral {
  background: linear-gradient(94deg, var(--accent) 0%, var(--violet) 46%, var(--warm) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.spectral-rule {
  height: 2px;
  width: 100%;
  background: linear-gradient(90deg, var(--accent), var(--violet) 50%, var(--warm));
  border-radius: 2px;
}

/* ============================================================
   按钮
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 13px 22px;
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.02em;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease),
    color 0.22s var(--ease), transform 0.22s var(--ease);
  white-space: nowrap;
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  background: var(--accent);
  color: #04161a;
  border-color: var(--accent);
}

[data-theme='light'] .btn--primary { color: #fff; }

.btn--primary:hover { background: var(--text); border-color: var(--text); }

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

.btn--ghost:hover { border-color: var(--accent); color: var(--accent); }

.btn--quiet {
  background: transparent;
  color: var(--text-dim);
  padding-inline: 0;
  border: 0;
}

.btn--quiet:hover { color: var(--accent); }
.btn--quiet .arrow { transition: transform 0.22s var(--ease); }
.btn--quiet:hover .arrow { transform: translateX(4px); }

.arrow { font-family: var(--font-mono); }

/* ============================================================
   顶栏
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  height: var(--header-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background-color 0.3s var(--ease), border-color 0.3s var(--ease),
    backdrop-filter 0.3s var(--ease);
}

.site-header.is-stuck {
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom-color: var(--line);
}

.site-header__inner {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 48px);
  display: flex;
  align-items: center;
  gap: var(--sp-6);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.brand__mark {
  width: 30px;
  height: 30px;
  flex: none;
}

.brand__text { display: flex; flex-direction: column; line-height: 1.05; }

.brand__name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 28px);
  margin-left: auto;
}

.site-nav a {
  font-size: var(--fs-small);
  color: var(--text-dim);
  position: relative;
  padding-block: 6px;
  transition: color 0.2s var(--ease);
}

.site-nav a::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.site-nav a:hover,
.site-nav a[aria-current='page'] { color: var(--text); }
.site-nav a:hover::after,
.site-nav a[aria-current='page']::after { transform: scaleX(1); }

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  flex: none;
}

.icon-btn {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text-dim);
  cursor: pointer;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.icon-btn:hover { border-color: var(--accent); color: var(--accent); }
.icon-btn svg { width: 16px; height: 16px; }

.nav-toggle { display: none; }

@media (max-width: 1000px) {
  .site-nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: var(--sp-4) clamp(20px, 4vw, 48px) var(--sp-6);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s;
  }
  .site-nav.is-open { opacity: 1; visibility: visible; transform: translateY(0); }
  .site-nav a { padding-block: 13px; border-bottom: 1px solid var(--line); font-size: var(--fs-body); }
  .nav-toggle { display: grid; }
  .header-actions .btn { display: none; }
}

/* ============================================================
   Hero
   ============================================================ */

.hero {
  position: relative;
  min-height: min(88vh, 860px);
  display: flex;
  align-items: center;
  padding-block: clamp(56px, 8vw, 110px);
  overflow: hidden;
  isolation: isolate;
}

.hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  opacity: 0.85;
}

.hero__glow {
  position: absolute;
  z-index: -1;
  width: min(900px, 110vw);
  aspect-ratio: 1;
  right: -12%;
  top: 50%;
  translate: 0 -50%;
  background: radial-gradient(
    circle,
    color-mix(in srgb, var(--accent) 22%, transparent) 0%,
    color-mix(in srgb, var(--violet) 12%, transparent) 34%,
    transparent 66%
  );
  filter: blur(14px);
  pointer-events: none;
}

.hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: center;
  width: 100%;
}

@media (max-width: 980px) {
  .hero__inner { grid-template-columns: 1fr; }
  .hero__glow { right: -30%; top: 30%; }
}

.hero__title {
  font-size: var(--fs-h1);
  font-weight: 600;
  margin-bottom: var(--sp-5);
}

.hero__title span { display: block; }

.hero__desc {
  font-size: var(--fs-lead);
  color: var(--text-dim);
  max-width: 52ch;
  margin-bottom: var(--sp-6);
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  margin-bottom: var(--sp-7);
}

.hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-5);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--line);
}

@media (max-width: 560px) {
  .hero__stats { grid-template-columns: 1fr; gap: var(--sp-4); }
}

.stat__num {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 1.1rem + 1.4vw, 2.1rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  display: block;
}

.stat__unit {
  font-size: 0.62em;
  color: var(--accent);
  margin-left: 2px;
  font-weight: 500;
}

.stat__label {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.1em;
  color: var(--text-faint);
  display: block;
  margin-top: 6px;
}

/* Hero 侧栏：实时索引卡 */
.index-card {
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 72%, transparent);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.index-card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  background: var(--surface-2);
}

.index-card__head h3 {
  font-size: var(--fs-small);
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  font-weight: 400;
}

.pulse {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.14em;
  color: var(--accent);
  text-transform: uppercase;
}

.pulse::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2.2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent) 60%, transparent); }
  50% { opacity: 0.5; box-shadow: 0 0 0 6px transparent; }
}

.index-list { list-style: none; margin: 0; padding: 0; }

.index-list li {
  display: flex;
  align-items: baseline;
  gap: var(--sp-4);
  padding: 15px 18px;
  border-bottom: 1px solid var(--line);
  transition: background-color 0.2s var(--ease);
}

.index-list li:last-child { border-bottom: 0; }
.index-list li:hover { background: var(--surface-2); }

.index-list__no {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  color: var(--accent);
  flex: none;
  width: 2ch;
}

.index-list__body { flex: 1; min-width: 0; }

.index-list__title {
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.01em;
  display: block;
}

.index-list__meta {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  color: var(--text-faint);
  letter-spacing: 0.05em;
}

.index-card__foot {
  padding: 14px 18px;
  background: var(--surface-2);
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ============================================================
   卡片 / 面板
   ============================================================ */

.card {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 2.4vw, 30px);
  position: relative;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease),
    background-color 0.25s var(--ease);
}

.card--link:hover {
  border-color: color-mix(in srgb, var(--accent) 55%, var(--line));
  transform: translateY(-3px);
  background: var(--surface-2);
}

.card__no {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  color: var(--text-faint);
  letter-spacing: 0.1em;
}

.card__title {
  font-size: var(--fs-h4);
  font-weight: 600;
  margin-bottom: 10px;
}

.card__text {
  color: var(--text-dim);
  font-size: var(--fs-small);
  line-height: 1.72;
}

/* 角标装饰（替代左侧色条） */
.card--ticked::before,
.card--ticked::after {
  content: '';
  position: absolute;
  width: 9px;
  height: 9px;
  border-color: var(--accent);
  opacity: 0;
  transition: opacity 0.25s var(--ease);
}

.card--ticked::before {
  top: -1px; left: -1px;
  border-top: 1px solid;
  border-left: 1px solid;
}

.card--ticked::after {
  bottom: -1px; right: -1px;
  border-bottom: 1px solid;
  border-right: 1px solid;
}

.card--ticked:hover::before,
.card--ticked:hover::after { opacity: 1; }

/* ============================================================
   板块导航
   ============================================================ */

.pillar-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.pillar {
  background: var(--bg);
  padding: clamp(24px, 3vw, 36px);
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  min-height: 260px;
  transition: background-color 0.25s var(--ease);
}

.pillar:hover { background: var(--surface); }

.pillar__icon {
  width: 38px;
  height: 38px;
  color: var(--accent);
}

.pillar__kicker {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.pillar__title {
  font-family: var(--font-display);
  font-size: 1.1875rem;
  font-weight: 600;
}

.pillar__desc {
  color: var(--text-dim);
  font-size: var(--fs-small);
  line-height: 1.75;
  flex: 1;
}

.pillar__foot {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.12em;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ============================================================
   数据条
   ============================================================ */

.metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1px;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.metric {
  background: var(--bg);
  padding: clamp(24px, 3vw, 38px) clamp(18px, 2.4vw, 30px);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.metric__value {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 1.3rem + 1.6vw, 2.6rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1;
}

.metric__value small {
  font-size: 0.5em;
  color: var(--text-dim);
  margin-left: 3px;
  font-weight: 500;
}

.metric__label {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.6;
}

.metric__src {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  margin-top: auto;
  padding-top: 6px;
}

/* ============================================================
   路线对比（技术路线）
   ============================================================ */

.route-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.route-tab {
  flex: 1 1 auto;
  min-width: 140px;
  padding: 15px 18px;
  background: var(--bg);
  border: 0;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--text-dim);
  transition: background-color 0.22s var(--ease), color 0.22s var(--ease);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.route-tab:hover { background: var(--surface); color: var(--text); }

.route-tab[aria-selected='true'] {
  background: var(--surface-3);
  color: var(--text);
  box-shadow: inset 0 -2px 0 var(--accent);
}

.route-tab__idx {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.14em;
  color: var(--text-faint);
}

.route-tab[aria-selected='true'] .route-tab__idx { color: var(--accent); }

.route-panel { display: none; }
.route-panel.is-active { display: block; animation: fadeUp 0.4s var(--ease); }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.route-panel__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: clamp(24px, 3.5vw, 52px);
  align-items: start;
}

@media (max-width: 900px) {
  .route-panel__grid { grid-template-columns: 1fr; }
}

.spec-list { list-style: none; margin: 0; padding: 0; }

.spec-list li {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: var(--sp-4);
  padding-block: 13px;
  border-bottom: 1px solid var(--line);
  font-size: var(--fs-small);
}

.spec-list li:last-child { border-bottom: 0; }

.spec-list__key {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding-top: 2px;
}

.spec-list__val { color: var(--text); line-height: 1.65; }

.pros-cons { display: grid; gap: var(--sp-4); }

.pros-cons__block {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  background: var(--surface);
}

.pros-cons__block h4 {
  font-size: var(--fs-small);
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 400;
  margin-bottom: 12px;
}

.pros-cons__block--pro h4 { color: var(--accent); }
.pros-cons__block--con h4 { color: var(--warm); }

.pros-cons ul { margin: 0; padding-left: 18px; font-size: var(--fs-small); color: var(--text-dim); }
.pros-cons li { margin-bottom: 7px; line-height: 1.65; }
.pros-cons li:last-child { margin-bottom: 0; }

/* ============================================================
   设备选型中心
   ============================================================ */

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-5);
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  margin-bottom: var(--sp-6);
  align-items: flex-start;
}

.filter-group { display: flex; flex-direction: column; gap: 9px; }

.filter-group__label {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.chips { display: flex; flex-wrap: wrap; gap: 7px; }

.chip {
  padding: 7px 14px;
  font-size: var(--fs-small);
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--text-dim);
  border-radius: 100px;
  cursor: pointer;
  transition: all 0.2s var(--ease);
  font-family: var(--font-body);
}

.chip:hover { border-color: var(--accent); color: var(--text); }

.chip[aria-pressed='true'] {
  background: var(--accent);
  border-color: var(--accent);
  color: #04161a;
  font-weight: 500;
}

[data-theme='light'] .chip[aria-pressed='true'] { color: #fff; }

.device-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--sp-5);
}

.device {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
  animation: fadeUp 0.35s var(--ease) both;
}

.device:hover { border-color: var(--line-strong); transform: translateY(-3px); }

.device__fig {
  height: 148px;
  background: var(--bg-deep);
  border-bottom: 1px solid var(--line);
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
}

.device__fig svg { width: 100%; height: 100%; }

.device__tag {
  position: absolute;
  top: 12px;
  left: 12px;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 4px 9px;
  border-radius: 100px;
  background: color-mix(in srgb, var(--bg-deep) 78%, transparent);
  border: 1px solid var(--line-strong);
  color: var(--accent);
}

.device__body { padding: 20px 22px 22px; flex: 1; display: flex; flex-direction: column; gap: 10px; }

.device__title {
  font-size: var(--fs-h4);
  font-weight: 600;
  line-height: 1.4;
}

.device__desc {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.72;
  flex: 1;
}

.device__specs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.device__spec { display: flex; flex-direction: column; gap: 3px; }

.device__spec b {
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.device__spec span {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.device__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  padding-top: 12px;
  border-top: 1px solid var(--line);
  margin-top: 4px;
}

.price {
  font-family: var(--font-display);
  font-size: var(--fs-body);
  font-weight: 600;
}

.price small {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  color: var(--text-faint);
  font-weight: 400;
  letter-spacing: 0.08em;
  display: block;
  margin-top: 2px;
}

.empty-state {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-lg);
  padding: 56px 24px;
  text-align: center;
  color: var(--text-faint);
  font-size: var(--fs-small);
}

/* ============================================================
   表格
   ============================================================ */

.table-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  background: var(--surface);
}

table.spec-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

.spec-table th,
.spec-table td {
  padding: 15px 18px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  font-size: var(--fs-small);
  vertical-align: top;
}

.spec-table thead th {
  background: var(--surface-2);
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--text-faint);
  font-weight: 400;
  position: sticky;
  top: 0;
}

.spec-table tbody tr:last-child td { border-bottom: 0; }
.spec-table tbody tr:hover { background: var(--surface-2); }
.spec-table td:first-child { color: var(--text); font-weight: 500; }
.spec-table td { color: var(--text-dim); line-height: 1.6; }

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 100px;
  border: 1px solid var(--line-strong);
  color: var(--text-dim);
}

.tag--accent { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 45%, transparent); }
.tag--warm { color: var(--warm); border-color: color-mix(in srgb, var(--warm) 45%, transparent); }
.tag--violet { color: var(--violet); border-color: color-mix(in srgb, var(--violet) 45%, transparent); }

/* ============================================================
   案例 / 场景
   ============================================================ */

.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--sp-5);
}

.case {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--surface);
  display: flex;
  flex-direction: column;
  transition: border-color 0.25s var(--ease);
}

.case:hover { border-color: var(--line-strong); }

.case__top {
  padding: 22px 24px 20px;
  border-bottom: 1px solid var(--line);
  position: relative;
}

.case__sector {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.case__title {
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.45;
  margin-bottom: 8px;
}

.case__where {
  font-size: var(--fs-small);
  color: var(--text-faint);
}

.case__body { padding: 18px 24px 22px; flex: 1; }

.case__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 14px;
}

.case__stat b {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  display: block;
  letter-spacing: -0.02em;
}

.case__stat span {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.case__note {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.7;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

/* ============================================================
   决策树
   ============================================================ */

.tree { display: grid; gap: var(--sp-4); }

.tree__step {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  overflow: hidden;
}

.tree__q {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-4);
  padding: 18px 20px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--line);
}

.tree__q b {
  font-family: var(--font-display);
  font-size: var(--fs-body);
  font-weight: 600;
  line-height: 1.5;
}

.tree__q .mono { color: var(--accent); flex: none; padding-top: 3px; }

.tree__opts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1px; background: var(--line); }

.tree__opt {
  background: var(--bg);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.tree__opt-label {
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}

.tree__opt-label::before {
  content: '';
  width: 6px;
  height: 6px;
  border: 1px solid var(--accent);
  flex: none;
  rotate: 45deg;
}

.tree__opt p {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.6;
  padding-left: 14px;
}

/* ============================================================
   引用 / 来源
   ============================================================ */

.pull {
  border-left: 2px solid var(--accent);
  padding: var(--sp-4) 0 var(--sp-4) var(--sp-6);
  font-size: var(--fs-lead);
  line-height: 1.72;
  color: var(--text);
}

.pull cite {
  display: block;
  margin-top: var(--sp-4);
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.1em;
  color: var(--text-faint);
  font-style: normal;
}

.source-note {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.06em;
  color: var(--text-faint);
  line-height: 1.7;
}

/* ============================================================
   表单
   ============================================================ */

.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--sp-4); }
.form-grid > .span-2 { grid-column: 1 / -1; }

@media (max-width: 640px) {
  .form-grid { grid-template-columns: 1fr; }
}

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

.field label {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.field input,
.field select,
.field textarea {
  background: var(--bg);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 12px 14px;
  font-size: var(--fs-small);
  color: var(--text);
  width: 100%;
  transition: border-color 0.2s var(--ease);
  font-family: var(--font-body);
}

.field input:focus,
.field select:focus,
.field textarea:focus { border-color: var(--accent); outline: none; }
.field textarea { resize: vertical; min-height: 110px; }

.form-note {
  font-size: var(--fs-micro);
  color: var(--text-faint);
  margin-top: var(--sp-3);
}

/* ============================================================
   页脚
   ============================================================ */

.site-footer {
  border-top: 1px solid var(--line);
  padding-block: clamp(48px, 6vw, 80px) var(--sp-6);
  background: var(--bg-deep);
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 1fr));
  gap: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(32px, 4vw, 52px);
}

@media (max-width: 860px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 520px) {
  .footer-grid { grid-template-columns: 1fr; }
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-faint);
  font-weight: 400;
  margin-bottom: var(--sp-4);
}

.footer-col ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 11px; }

.footer-col a {
  font-size: var(--fs-small);
  color: var(--text-dim);
  transition: color 0.2s var(--ease);
}

.footer-col a:hover { color: var(--accent); }

.footer-col p { font-size: var(--fs-small); color: var(--text-dim); line-height: 1.8; }

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: var(--sp-5);
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.1em;
  color: var(--text-faint);
}

.footer-bottom a { color: var(--text-dim); }
.footer-bottom a:hover { color: var(--accent); }

/* ============================================================
   产品页组件
   ============================================================ */

/* 产品视频播放器 */
.video-frame {
  position: relative;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-deep);
  box-shadow: var(--shadow-card);
}

.video-frame video {
  width: 100%;
  display: block;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  background: #000;
}

.video-frame__bar {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  background: var(--surface);
  flex-wrap: wrap;
}

.video-frame__label {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  display: flex;
  align-items: center;
  gap: 8px;
}

.video-frame__label::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--warm);
}

.video-frame__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.08em;
  color: var(--text-faint);
}

/* 产品卡片 */
.product {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.product:hover { border-color: var(--line-strong); transform: translateY(-3px); }

.product__media {
  position: relative;
  background: var(--bg-deep);
  border-bottom: 1px solid var(--line);
  aspect-ratio: 16 / 10;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.product__media img,
.product__media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.product__media--contain img,
.product__media--contain video { object-fit: contain; }

.product__badge {
  position: absolute;
  top: 12px;
  left: 12px;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 4px 9px;
  border-radius: 100px;
  background: color-mix(in srgb, var(--bg-deep) 82%, transparent);
  border: 1px solid var(--line-strong);
  color: var(--accent);
  z-index: 2;
}

.product__badge--warm { color: var(--warm); border-color: color-mix(in srgb, var(--warm) 45%, transparent); }
.product__badge--violet { color: var(--violet); border-color: color-mix(in srgb, var(--violet) 45%, transparent); }

.product__body {
  padding: 20px 22px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

.product__title {
  font-size: var(--fs-h4);
  font-weight: 600;
  line-height: 1.4;
}

.product__text {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.72;
  flex: 1;
}

.product__specs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 14px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.product__spec { display: flex; flex-direction: column; gap: 3px; }

.product__spec b {
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.product__spec span {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.product__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  padding-top: 14px;
  margin-top: 4px;
  border-top: 1px solid var(--line);
}

/* 购买 / 询价条 */
.buy-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-4);
  padding: 18px 20px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  background: var(--surface-2);
}

.buy-bar__price {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.buy-bar__price small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  color: var(--text-faint);
  font-weight: 400;
  margin-top: 3px;
}

/* 特性网格 */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.feature {
  background: var(--bg);
  padding: clamp(20px, 2.4vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.feature__icon {
  width: 30px;
  height: 30px;
  color: var(--accent);
  flex: none;
}

.feature__title {
  font-family: var(--font-display);
  font-size: var(--fs-body);
  font-weight: 600;
}

.feature__text {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.72;
}

/* 对比矩阵 */
.matrix td:first-child { white-space: nowrap; font-weight: 500; }
.matrix .win { color: var(--accent); font-weight: 600; }

/* 场景卡 */
.use-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--sp-5);
}

.use-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  padding: 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: border-color 0.25s var(--ease);
}

.use-card:hover { border-color: var(--line-strong); }

.use-card__no {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.14em;
  color: var(--text-faint);
}

.use-card__title {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
}

.use-card__text {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.72;
}

.use-card__meta {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.08em;
  color: var(--accent);
}

/* 步骤条 */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.step {
  background: var(--bg);
  padding: 22px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
}

.step__no {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--accent);
  line-height: 1;
  opacity: 0.55;
}

.step__title {
  font-family: var(--font-display);
  font-size: var(--fs-body);
  font-weight: 600;
}

.step__text {
  font-size: var(--fs-small);
  color: var(--text-dim);
  line-height: 1.7;
}

/* 表单：询价 */
.qty-row {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

.qty-row input {
  width: 96px;
  text-align: center;
}

/* 面包屑 */
.crumbs {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: var(--sp-5);
}

.crumbs a { color: var(--text-faint); transition: color 0.2s var(--ease); }
.crumbs a:hover { color: var(--accent); }
.crumbs__sep { opacity: 0.5; }
.crumbs__current { color: var(--accent); }

/* ============================================================
   工具类
   ============================================================ */

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.reveal.is-in { opacity: 1; transform: translateY(0); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* 打印 */
@media print {
  .site-header, .site-footer, .hero__canvas, .hero__glow, .nav-toggle, .theme-toggle { display: none !important; }
  body { background: #fff; color: #000; }
  .section { padding-block: 24px; }
  body::before { display: none; }
}