/*
 * 龙树 AI 硬件 — 暗调蓝紫底 #16213E + 深海面板 #0F3460 + 亮蓝 #3B82F6
 * 气质参考：红点奖级 AI 大模型 / AIGC 官网（与历史截图一致）
 */
:root {
  --bg-canvas: #16213e;
  --bg-surface: #0f3460;
  --bg-elevated: #134872;
  --bg-inset: #0a2848;
  --bg-muted-band: rgba(15, 52, 96, 0.14);
  --brand: #3b82f6;
  --brand-bright: #60a5fa;
  --brand-deep: #1e40af;
  --brand-hover: #2563eb;
  --brand-soft: rgba(59, 130, 246, 0.22);
  --brand-border: rgba(59, 130, 246, 0.45);
  --brand-glow: rgba(59, 130, 246, 0.35);
  --text: #f8fafc;
  --text-secondary: #e2e8f0;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --border: rgba(148, 163, 184, 0.11);
  --border-strong: rgba(148, 163, 184, 0.2);
  --accent-green: #34d399;
  --accent-amber: #fbbf24;
  --contact-label: #7dd3fc;
  --contact-value: #f1f5f9;
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-3xl: 1.5rem;
  --radius-full: 9999px;
  --font-sans: "Inter", ui-sans-serif, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.22);
  --shadow-md: 0 12px 36px rgba(0, 0, 0, 0.32);
  --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.36);
  --shadow-brand: 0 0 44px var(--brand-glow);
  --shadow-window: 0 22px 48px rgba(0, 0, 0, 0.42),
    0 0 0 1px rgba(59, 130, 246, 0.18);
  --max: 72rem;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  background-image: radial-gradient(
      ellipse 120% 80% at 50% -32%,
      rgba(15, 52, 96, 0.22) 0%,
      transparent 58%
    ),
    radial-gradient(
      ellipse 52% 40% at 92% 18%,
      rgba(99, 102, 241, 0.06) 0%,
      transparent 52%
    ),
    radial-gradient(
      ellipse 58% 44% at 8% 22%,
      rgba(15, 52, 96, 0.08) 0%,
      transparent 50%
    ),
    linear-gradient(180deg, #16213e 0%, #121a36 50%, #16213e 100%);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: linear-gradient(
      rgba(148, 163, 184, 0.04) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      rgba(148, 163, 184, 0.04) 1px,
      transparent 1px
    ),
    linear-gradient(
      rgba(59, 130, 246, 0.035) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      rgba(59, 130, 246, 0.035) 1px,
      transparent 1px
    ),
    linear-gradient(
      rgba(99, 102, 241, 0.018) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      rgba(99, 102, 241, 0.018) 1px,
      transparent 1px
    );
  background-size: 56px 56px, 56px 56px, 14px 14px, 14px 14px, 28px 28px, 28px 28px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% -3%, black 18%, transparent 76%);
}

body::after {
  content: "";
  position: fixed;
  inset: -25% 0 auto;
  height: 72vh;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(
      ellipse 48% 34% at 50% -6%,
      rgba(15, 52, 96, 0.14),
      transparent 68%
    ),
    radial-gradient(
      ellipse 40% 28% at 62% 0%,
      rgba(99, 102, 241, 0.05),
      transparent 65%
    );
}

.page-shell {
  position: relative;
  z-index: 1;
}

a {
  color: var(--brand-bright);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
  background: rgba(22, 33, 62, 0.78);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

/* 锚点跳转时避免标题被吸顶栏遮挡 */
main > section[id] {
  scroll-margin-top: 5rem;
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 600;
  font-size: 1rem;
  color: var(--text);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
  opacity: 0.92;
}

.brand-mark {
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #5eb0e4 0%, var(--brand) 45%, var(--brand-deep) 100%);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 0.875rem;
  font-weight: 700;
  box-shadow: var(--shadow-brand);
}

.nav-links {
  display: flex;
  gap: 0.125rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-muted);
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}

.nav-links a:hover {
  color: var(--text);
  background: var(--brand-soft);
  text-decoration: none;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-full);
  border: none;
  font-weight: 600;
  font-size: 0.875rem;
  font-family: inherit;
  cursor: pointer;
  color: #fff;
  background: linear-gradient(135deg, var(--brand-hover) 0%, var(--brand) 100%);
  box-shadow: 0 4px 22px rgba(59, 130, 246, 0.42);
  transition: transform 0.15s var(--ease), filter 0.2s var(--ease),
    box-shadow 0.2s var(--ease);
}

.btn-primary:hover {
  filter: brightness(1.05);
  transform: translateY(-1px);
  box-shadow: 0 6px 30px rgba(59, 130, 246, 0.52);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary--block {
  width: 100%;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--border-strong);
  text-decoration: none;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease),
    color 0.2s var(--ease);
}

.btn-secondary:hover {
  border-color: var(--brand-border);
  background: var(--brand-soft);
  color: var(--text);
  text-decoration: none;
}

.header-cta {
  flex-shrink: 0;
}

@media (max-width: 520px) {
  .header-cta {
    padding: 0.5rem 0.9rem;
    font-size: 0.8125rem;
  }
}

.hero {
  position: relative;
  padding: 2.75rem 1.5rem 3.25rem;
  overflow: hidden;
}

.hero-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 2rem;
  align-items: start;
}

@media (min-width: 900px) {
  .hero-inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 2.5rem;
    align-items: center;
  }
}

.hero-copy {
  min-width: 0;
}

.hero-aside {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-width: 0;
}

.hero-figure-wrap {
  margin: 0;
  border-radius: var(--radius-3xl);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-window);
  background: var(--bg-surface);
}

.hero-figure {
  display: block;
  width: 100%;
  height: auto;
  vertical-align: middle;
}

.hero-live-card {
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  background: rgba(15, 52, 96, 0.55);
  overflow: hidden;
}

.hero-live-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(22, 33, 62, 0.55);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.hero-live-dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 8px rgba(52, 211, 153, 0.55);
  flex-shrink: 0;
}

.hero-live-title {
  letter-spacing: 0.08em;
}

.hero-live-text {
  margin: 0;
  padding: 0.875rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.55;
  color: var(--text-secondary);
}

.hero-live-tag {
  display: inline-flex;
  align-items: center;
  margin-right: 0.35rem;
  padding: 0.12rem 0.4rem;
  border-radius: var(--radius-sm);
  font-size: 0.625rem;
  font-weight: 700;
  font-family: var(--font-mono);
  vertical-align: 0.08em;
  background: linear-gradient(135deg, var(--brand-bright), var(--brand-deep));
  color: #fff;
}

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand-bright);
  margin-bottom: 0.875rem;
}

.hero-title {
  font-size: clamp(2.125rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.07;
  letter-spacing: -0.035em;
  margin: 0 0 1.125rem;
}

.hero-title-line {
  display: block;
  color: var(--text);
}

.hero-title-gradient {
  display: block;
  background: linear-gradient(
    105deg,
    #ffffff 0%,
    #e2e8f0 22%,
    #93c5fc 55%,
    var(--brand) 100%
  );
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero .lead {
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-secondary);
  max-width: 28rem;
  margin: 0 0 1.25rem;
  line-height: 1.6;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.25rem;
}

.pill {
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  border: 1px solid rgba(148, 163, 184, 0.18);
  background: rgba(15, 52, 96, 0.45);
  color: var(--text-muted);
  box-shadow: var(--shadow-sm);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem;
  align-items: center;
}

.browser-frame {
  border-radius: var(--radius-3xl);
  overflow: hidden;
  box-shadow: var(--shadow-window);
  background: var(--bg-surface);
  border: 1px solid var(--border);
}

.browser-chrome {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  background: linear-gradient(180deg, var(--bg-elevated) 0%, var(--bg-surface) 100%);
  border-bottom: 1px solid var(--border);
}

.browser-dots span:nth-child(1) {
  background: #f87171;
  border-color: #ef4444;
}
.browser-dots span:nth-child(2) {
  background: #fbbf24;
  border-color: #f59e0b;
}
.browser-dots span:nth-child(3) {
  background: #34d399;
  border-color: #10b981;
}

.browser-dots {
  display: flex;
  gap: 0.375rem;
}

.browser-dots span {
  width: 0.625rem;
  height: 0.625rem;
  border-radius: 50%;
  border: 1px solid transparent;
}

.browser-url {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  text-align: center;
  padding: 0.4rem 0.75rem;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.preview-card {
  padding: 1.25rem 1.35rem 1.5rem;
  background: var(--bg-canvas);
}

.preview-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.875rem;
  border-bottom: 1px solid var(--border);
}

.preview-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.preview-dots span {
  width: 0.375rem;
  height: 0.375rem;
  border-radius: 50%;
  background: var(--brand);
  opacity: 0.85;
}

.preview-dots {
  display: flex;
  gap: 0.375rem;
}

.preview-body {
  display: grid;
  gap: 0.875rem;
}

.call-row {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.875rem 1rem;
  border-radius: var(--radius-xl);
  background: rgba(30, 41, 59, 0.55);
  border: 1px solid var(--border);
}

.call-row.ai {
  border-color: var(--brand-border);
  background: var(--brand-soft);
  box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.12);
}

.avatar {
  width: 2.125rem;
  height: 2.125rem;
  border-radius: var(--radius-md);
  flex-shrink: 0;
  display: grid;
  place-items: center;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.call-row.ai .avatar {
  background: linear-gradient(135deg, var(--brand-bright), var(--brand-deep));
  border-color: transparent;
  color: #fff;
}

.call-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 0.25rem;
}

.call-text {
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.55;
  color: var(--text-secondary);
}

.trust-strip {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem 2.5rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  border-bottom: 1px solid var(--border);
}

@media (max-width: 640px) {
  .trust-strip {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

.trust-item {
  padding: 1rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
}

.trust-item strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--brand-bright);
  letter-spacing: -0.02em;
}

.trust-item span {
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.5;
  color: var(--text-muted);
}

.section {
  padding: 3.25rem 1.5rem;
  border-top: 1px solid var(--border);
}

.section--muted {
  background: var(--bg-muted-band);
}

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
}

.section-inner--narrow {
  max-width: 56rem;
}

.section-head {
  text-align: center;
  max-width: 38rem;
  margin: 0 auto 2rem;
}

.section-head.left {
  text-align: left;
  margin-left: 0;
  margin-right: auto;
  max-width: 40rem;
}

.section-kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand-bright);
  margin-bottom: 0.5rem;
}

.section h2 {
  font-size: clamp(1.625rem, 2.8vw, 2.125rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  margin: 0 0 0.625rem;
  line-height: 1.2;
  color: var(--text);
}

.section .sub {
  color: var(--text-muted);
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.6;
}

.section-head:not(.left) .sub {
  max-width: 32rem;
  margin-left: auto;
  margin-right: auto;
}

.scenario-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .scenario-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .scenario-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.scenario-grid.scenario-grid--2 {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .scenario-grid.scenario-grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .scenario-grid.scenario-grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.scenario-card {
  padding: 1.35rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  transition: border-color 0.2s var(--ease), box-shadow 0.25s var(--ease),
    transform 0.25s var(--ease);
  box-shadow: var(--shadow-sm);
}

.section--muted .scenario-card {
  background: #0d2d54;
}

.scenario-card:hover {
  border-color: var(--brand-border);
  box-shadow: var(--shadow-md), 0 0 28px rgba(59, 130, 246, 0.14);
  transform: translateY(-2px);
}

.scenario-quote {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--brand-bright);
  margin: 0 0 0.625rem;
  line-height: 1.55;
}

.scenario-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
  color: var(--text);
}

.scenario-card p {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  line-height: 1.6;
}

.cap-strip {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}

@media (min-width: 768px) {
  .cap-strip {
    grid-template-columns: repeat(4, 1fr);
  }
}

.cap-item {
  padding: 1.125rem 1rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s var(--ease), border-color 0.2s var(--ease);
}

.cap-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--brand-border);
}

.cap-item strong {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--brand-bright);
}

.cap-item span {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-dim);
}

.feature-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-grid.feature-grid--2 {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .feature-grid.feature-grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .feature-grid.feature-grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.section-visual {
  margin: 0 0 1.75rem;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  border: 1px solid var(--border);
  background: rgba(15, 52, 96, 0.35);
}

.section-visual img {
  display: block;
  width: 100%;
  max-height: min(420px, 55vh);
  height: auto;
  object-fit: contain;
  object-position: center;
  padding: 0.75rem 1rem;
}

/* 核心能力配图：按栏宽等比铺满，避免 max-height 造成左右留白 */
.section-visual--feature img {
  max-height: none;
  padding: 0;
  width: 100%;
  height: auto;
}

.feature-card {
  padding: 1.5rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
  box-shadow: var(--shadow-sm);
}

.section--muted .feature-card {
  background: #0d2d54;
}

.feature-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-lg);
  display: grid;
  place-items: center;
  margin-bottom: 1rem;
  font-size: 1.125rem;
  border: 1px solid var(--border);
}

.feature-card:nth-child(3n + 1) .feature-icon {
  background: var(--brand-soft);
  border-color: var(--brand-border);
}
.feature-card:nth-child(3n + 2) .feature-icon {
  background: rgba(56, 189, 248, 0.12);
  border-color: rgba(56, 189, 248, 0.3);
}
.feature-card:nth-child(3n) .feature-icon {
  background: rgba(167, 139, 250, 0.12);
  border-color: rgba(167, 139, 250, 0.28);
}

.feature-card h3 {
  font-size: 1rem;
  margin: 0 0 0.5rem;
  font-weight: 600;
  color: var(--text);
}

.feature-card p {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  line-height: 1.6;
}

.specs-split {
  display: grid;
  gap: 1.5rem;
  align-items: start;
}

@media (min-width: 960px) {
  .specs-split {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 380px);
    gap: 2rem;
  }
}

.spec-list {
  display: grid;
  gap: 0.5rem;
  margin: 0;
}

.spec-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-sm);
}

.spec-item dt {
  color: var(--brand-bright);
  font-weight: 700;
  font-size: 0.8125rem;
  font-family: var(--font-mono);
}

.spec-item dd {
  margin: 0;
  color: var(--text-secondary);
  font-weight: 500;
  text-align: right;
}

.dna-block {
  margin: 0;
  padding: 1.25rem 1.35rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--brand-border);
  background: linear-gradient(165deg, #111a32 0%, #16213e 40%, #1a3058 100%);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1.7;
  color: var(--text-secondary);
  overflow-x: auto;
  box-shadow: var(--shadow-md), inset 0 1px 0 rgba(59, 130, 246, 0.12);
}

@media (min-width: 960px) {
  .dna-block {
    position: sticky;
    top: 5.25rem;
  }
}

.dna-block .k {
  color: #93c5fc;
}
.dna-block .s {
  color: #34d399;
}
.dna-block .n {
  color: #c4b5fd;
}

.steps-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 768px) {
  .steps-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.step-card {
  padding: 1.5rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  box-shadow: var(--shadow-sm);
}

.section--muted .step-card {
  background: #0d2d54;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--brand-bright);
  margin-bottom: 0.5rem;
}

.step-card h3 {
  font-size: 1rem;
  margin: 0 0 0.5rem;
  color: var(--text);
  font-weight: 600;
}

.step-card p {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.6;
  color: var(--text-muted);
}

.contact-grid {
  display: grid;
  gap: 1.75rem;
}

@media (min-width: 800px) {
  .contact-grid {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }
}

.contact-info {
  display: grid;
  gap: 0.625rem;
  padding: 1rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: linear-gradient(
    145deg,
    rgba(15, 52, 96, 0.55) 0%,
    rgba(22, 33, 62, 0.94) 100%
  );
  box-shadow: var(--shadow-sm);
}

.contact-line {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: rgba(17, 26, 48, 0.78);
}

.contact-field-label,
.contact-field-value {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  line-height: 1.55;
}

.contact-field-label {
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--contact-label);
}

.contact-field-value {
  font-weight: 500;
  color: var(--contact-value);
}

.contact-field-value a {
  color: var(--brand-bright);
  font-weight: 600;
  font-size: inherit;
  font-family: inherit;
  line-height: inherit;
  text-decoration: none;
  border-bottom: 1px solid rgba(96, 165, 250, 0.45);
}

.contact-field-value a:hover {
  color: #bfdbfe;
  border-bottom-color: var(--brand);
}

.form-panel {
  padding: 1.5rem;
  border-radius: var(--radius-2xl);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 0.875rem;
}

.form-group label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  background: var(--bg-inset);
  color: var(--text);
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-dim);
  font-weight: 500;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px var(--brand-soft);
}

.form-group textarea {
  min-height: 6.5rem;
  resize: vertical;
}

.form-status {
  margin-top: 0.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  min-height: 1.25em;
}

.form-status.ok {
  color: var(--accent-green);
}

.form-status.err {
  color: #fb923c;
}

.site-footer {
  padding: 2.75rem 1.5rem 2.25rem;
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, #16213e 0%, #121a32 50%, #0e1528 100%);
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
}

.footer-company {
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--text);
  font-size: 0.9375rem;
}

.footer-meta {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  line-height: 1.75;
}

.footer-meta a {
  color: var(--text-secondary);
  font-weight: 600;
}

.beian-link:hover {
  color: var(--brand-bright);
}

.section-cta {
  text-align: center;
  padding: 3.5rem 1.5rem;
  border-top: 1px solid var(--border);
  background: radial-gradient(
      ellipse 86% 62% at 50% 0%,
      rgba(59, 130, 246, 0.1) 0%,
      transparent 54%
    ),
    radial-gradient(
      ellipse 50% 40% at 78% 0%,
      rgba(196, 181, 253, 0.05) 0%,
      transparent 48%
    ),
    rgba(22, 33, 62, 0.55);
}

.section-cta-inner {
  max-width: 36rem;
  margin: 0 auto;
}

.section-cta h2 {
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
  color: var(--text);
}

.section-cta p {
  color: var(--text-muted);
  margin: 0 0 1.25rem;
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.6;
}