/* ============================================
   QuickQ 必应SEO官网 - 主样式系统
   设计风格：深空科技 + 量子青辉光 + 衬线权威
   ============================================ */

/* CSS 变量定义 - 设计系统 */
:root {
  /* 主色调 */
  --color-bg-primary: #0B1220;
  --color-bg-secondary: #0F172A;
  --color-bg-card: #111827;
  --color-bg-elevated: #1E293B;
  --color-bg-surface: #F8FAFC;
  --color-bg-paper: #FFFFFF;

  /* 强调色 */
  --color-quantum: #22D3EE;
  --color-quantum-dark: #06B6D4;
  --color-quantum-glow: rgba(34, 211, 238, 0.35);
  --color-warning: #F97316;
  --color-success: #10B981;
  --color-danger: #EF4444;

  /* 文字色 */
  --color-text-primary: #0B1220;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-text-inverse: #F8FAFC;
  --color-text-accent: #22D3EE;

  /* 边框 */
  --color-border: #1E293B;
  --color-border-light: #E2E8F0;

  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-body: "Inter", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;

  /* 字号 */
  --fs-h1: clamp(36px, 4.5vw, 56px);
  --fs-h2: clamp(26px, 3vw, 36px);
  --fs-h3: clamp(20px, 2.2vw, 24px);
  --fs-h4: 18px;
  --fs-body: 16px;
  --fs-small: 14px;
  --fs-caption: 12px;

  /* 间距 */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 12px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.12);
  --shadow-glow: 0 0 32px rgba(34, 211, 238, 0.25);
  --shadow-card: 0 2px 16px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);

  /* 容器 */
  --container-max: 1240px;
  --container-padding: clamp(16px, 4vw, 40px);

  /* 动效 */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --duration-fast: 180ms;
  --duration-base: 320ms;
  --duration-slow: 560ms;
}

/* 重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.7;
  color: var(--color-text-primary);
  background: var(--color-bg-paper);
  min-height: 100vh;
  overflow-x: hidden;
}

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

a {
  color: var(--color-quantum-dark);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out);
  position: relative;
}

a:hover {
  color: var(--color-quantum);
}

ul, ol {
  list-style: none;
}

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

/* ============================================
   排版
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.25;
  color: var(--color-text-primary);
  letter-spacing: -0.01em;
}

h1 {
  font-size: var(--fs-h1);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--fs-h2);
  margin-bottom: var(--space-6);
}

h3 {
  font-size: var(--fs-h3);
  margin-bottom: var(--space-4);
}

h4 {
  font-size: var(--fs-h4);
  font-weight: 600;
  margin-bottom: var(--space-3);
}

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

strong {
  color: var(--color-text-primary);
  font-weight: 600;
}

.text-accent {
  color: var(--color-quantum-dark);
}

.text-warning {
  color: var(--color-warning);
}

/* ============================================
   容器与栅格
   ============================================ */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section {
  padding: var(--space-20) 0;
}

.section-tight {
  padding: var(--space-12) 0;
}

.section-dark {
  background: var(--color-bg-primary);
  color: var(--color-text-inverse);
}

.section-dark h1,
.section-dark h2,
.section-dark h3,
.section-dark h4 {
  color: var(--color-text-inverse);
}

.section-dark p {
  color: var(--color-text-muted);
}

.section-surface {
  background: var(--color-bg-surface);
}

.grid {
  display: grid;
  gap: var(--space-6);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ============================================
   顶部导航
   ============================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 18, 32, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(34, 211, 238, 0.12);
}

.site-header.scrolled {
  background: rgba(11, 18, 32, 0.98);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  padding: 0 var(--container-padding);
  max-width: var(--container-max);
  margin: 0 auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text-inverse);
  letter-spacing: 0.02em;
}

.brand:hover {
  color: var(--color-quantum);
}

.brand-mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--color-quantum), var(--color-quantum-dark));
  border-radius: var(--radius-md);
  color: var(--color-bg-primary);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  box-shadow: 0 0 16px var(--color-quantum-glow);
}

.brand-mark::after {
  content: "Q";
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-text small {
  font-size: 10px;
  font-weight: 400;
  font-family: var(--font-body);
  color: var(--color-text-muted);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.nav-main {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-link {
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 var(--space-4);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-out);
}

.nav-link:hover {
  color: var(--color-text-inverse);
  background: rgba(34, 211, 238, 0.08);
}

.nav-link.is-active {
  color: var(--color-quantum);
  background: rgba(34, 211, 238, 0.12);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 var(--space-5);
  margin-left: var(--space-3);
  background: var(--color-quantum);
  color: var(--color-bg-primary);
  font-weight: 600;
  font-size: 14px;
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-out);
}

.nav-cta:hover {
  background: var(--color-quantum-dark);
  color: var(--color-bg-primary);
  transform: translateY(-1px);
  box-shadow: 0 8px 16px var(--color-quantum-glow);
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--color-text-inverse);
}

.nav-toggle svg {
  width: 24px;
  height: 24px;
}

/* ============================================
   按钮
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 48px;
  padding: 0 var(--space-6);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-out);
  white-space: nowrap;
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--color-quantum);
  color: var(--color-bg-primary);
}

.btn-primary:hover {
  background: var(--color-quantum-dark);
  color: var(--color-bg-primary);
  transform: translateY(-2px);
  box-shadow: 0 12px 24px var(--color-quantum-glow);
}

.btn-warning {
  background: var(--color-warning);
  color: #fff;
}

.btn-warning:hover {
  background: #EA580C;
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(249, 115, 22, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--color-quantum);
  border-color: var(--color-quantum);
}

.btn-outline:hover {
  background: var(--color-quantum);
  color: var(--color-bg-primary);
}

.btn-ghost {
  background: rgba(34, 211, 238, 0.08);
  color: var(--color-text-inverse);
}

.btn-ghost:hover {
  background: rgba(34, 211, 238, 0.18);
  color: var(--color-text-inverse);
}

.btn-lg {
  height: 56px;
  padding: 0 var(--space-8);
  font-size: 16px;
}

.btn-sm {
  height: 36px;
  padding: 0 var(--space-4);
  font-size: 13px;
}

/* ============================================
   Hero 区
   ============================================ */
.hero {
  position: relative;
  padding: var(--space-24) 0 var(--space-20);
  background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
  color: var(--color-text-inverse);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 60%;
  height: 80%;
  background: radial-gradient(circle, var(--color-quantum-glow) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-quantum), transparent);
  opacity: 0.4;
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: var(--space-16);
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 14px;
  margin-bottom: var(--space-6);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-quantum);
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.25);
  border-radius: var(--radius-full);
  letter-spacing: 0.04em;
}

.hero-eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--color-quantum);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--color-quantum);
  animation: pulse 2s var(--ease-in-out) infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero h1 {
  color: var(--color-text-inverse);
  font-size: var(--fs-h1);
  margin-bottom: var(--space-6);
}

.hero h1 .highlight {
  color: var(--color-quantum);
  position: relative;
  display: inline-block;
}

.hero h1 .highlight::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 4px;
  height: 8px;
  background: var(--color-quantum-glow);
  z-index: -1;
}

.hero-lede {
  font-size: 18px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-8);
  max-width: 540px;
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-10);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-stat .num {
  display: block;
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 700;
  color: var(--color-quantum);
  line-height: 1.1;
  margin-bottom: 4px;
}

.hero-stat .label {
  font-size: 13px;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

.hero-visual {
  position: relative;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-bg-elevated), var(--color-bg-secondary));
  border: 1px solid rgba(34, 211, 238, 0.2);
  box-shadow: 0 32px 80px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(34, 211, 238, 0.1);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-visual-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0%, rgba(11, 18, 32, 0.6) 100%);
  display: flex;
  align-items: flex-end;
  padding: var(--space-6);
}

.hero-visual-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 12px;
  background: rgba(11, 18, 32, 0.7);
  border: 1px solid rgba(34, 211, 238, 0.3);
  border-radius: var(--radius-full);
  font-size: 12px;
  color: var(--color-quantum);
  backdrop-filter: blur(8px);
}

/* ============================================
   卡片
   ============================================ */
.card {
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: all var(--duration-base) var(--ease-out);
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-quantum);
}

.card-icon {
  display: inline-grid;
  place-items: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.1), rgba(34, 211, 238, 0.02));
  color: var(--color-quantum-dark);
  margin-bottom: var(--space-5);
}

.card-icon svg {
  width: 28px;
  height: 28px;
}

.card h3 {
  margin-bottom: var(--space-3);
  font-size: 20px;
}

.card p {
  font-size: 15px;
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.card-arrow {
  position: absolute;
  top: var(--space-6);
  right: var(--space-6);
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  background: var(--color-bg-surface);
  color: var(--color-text-muted);
  border-radius: 50%;
  transition: all var(--duration-fast) var(--ease-out);
}

.card:hover .card-arrow {
  background: var(--color-quantum);
  color: var(--color-bg-primary);
  transform: translate(2px, -2px);
}

/* ============================================
   步骤时间轴
   ============================================ */
.steps {
  display: grid;
  gap: var(--space-6);
  margin: var(--space-8) 0;
}

.step {
  position: relative;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: var(--space-5);
  padding: var(--space-6);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  transition: all var(--duration-base) var(--ease-out);
}

.step:hover {
  border-color: var(--color-quantum);
  box-shadow: var(--shadow-md);
}

.step-num {
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--color-quantum), var(--color-quantum-dark));
  color: var(--color-bg-primary);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 12px var(--color-quantum-glow);
}

.step-num-zh {
  display: block;
  font-size: 18px;
  line-height: 1.1;
  font-weight: 700;
}

.step-num-en {
  display: block;
  font-size: 10px;
  letter-spacing: 0.1em;
  opacity: 0.7;
  margin-top: 2px;
  text-transform: uppercase;
}

.step-body h3 {
  margin-bottom: var(--space-3);
  font-size: 18px;
}

.step-body p {
  margin-bottom: var(--space-2);
  font-size: 15px;
}

.step-body .step-tip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding: 6px 12px;
  background: rgba(249, 115, 22, 0.08);
  color: var(--color-warning);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
}

.step-body .step-tip::before {
  content: "!";
  display: grid;
  place-items: center;
  width: 16px;
  height: 16px;
  background: var(--color-warning);
  color: #fff;
  border-radius: 50%;
  font-size: 11px;
  font-weight: 700;
}

.step-body .step-result {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding: 6px 12px;
  background: rgba(16, 185, 129, 0.08);
  color: var(--color-success);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
}

.step-body .step-result::before {
  content: "✓";
  display: grid;
  place-items: center;
  width: 16px;
  height: 16px;
  background: var(--color-success);
  color: #fff;
  border-radius: 50%;
  font-size: 11px;
  font-weight: 700;
}

/* ============================================
   FAQ 折叠卡
   ============================================ */
.faq-list {
  display: grid;
  gap: var(--space-3);
}

.faq-item {
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--duration-fast) var(--ease-out);
}

.faq-item.is-open {
  border-color: var(--color-quantum);
  box-shadow: var(--shadow-sm);
}

.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-6);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text-primary);
  text-align: left;
  background: transparent;
  transition: color var(--duration-fast) var(--ease-out);
}

.faq-q:hover {
  color: var(--color-quantum-dark);
}

.faq-q::after {
  content: "";
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--color-quantum);
  border-bottom: 2px solid var(--color-quantum);
  transform: rotate(45deg);
  margin-top: -4px;
  margin-right: 4px;
  transition: transform var(--duration-base) var(--ease-out);
  flex-shrink: 0;
}

.faq-item.is-open .faq-q::after {
  transform: rotate(-135deg);
  margin-top: 4px;
}

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--duration-base) var(--ease-out);
}

.faq-item.is-open .faq-a {
  max-height: 1200px;
}

.faq-a-inner {
  padding: 0 var(--space-6) var(--space-6);
  color: var(--color-text-secondary);
  font-size: 15px;
  line-height: 1.75;
}

.faq-a-inner p {
  margin-bottom: var(--space-3);
}

/* ============================================
   板块标题
   ============================================ */
.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto var(--space-12);
}

.section-head .eyebrow {
  display: inline-block;
  margin-bottom: var(--space-3);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-quantum-dark);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.section-head h2 {
  margin-bottom: var(--space-4);
}

.section-head p {
  font-size: 17px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.section-head.left {
  text-align: left;
  margin-left: 0;
}

/* ============================================
   节点加速 - 拓扑
   ============================================ */
.node-wrap {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.node-list {
  display: grid;
  gap: var(--space-3);
}

.node-item {
  display: grid;
  grid-template-columns: 40px 1fr auto;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: var(--color-bg-elevated);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-out);
}

.node-item:hover {
  border-color: var(--color-quantum);
  transform: translateX(4px);
}

.node-flag {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: var(--color-bg-secondary);
  border-radius: var(--radius-sm);
  font-size: 20px;
}

.node-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text-inverse);
}

.node-region {
  font-size: 12px;
  color: var(--color-text-muted);
}

.node-ping {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
}

.node-ping-val {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-quantum);
}

.node-ping-bar {
  display: flex;
  gap: 2px;
}

.node-ping-bar span {
  width: 4px;
  height: 12px;
  background: var(--color-quantum);
  border-radius: 1px;
  opacity: 0.3;
}

.node-ping-bar span.on {
  opacity: 1;
}

/* 拓扑图 */
.node-topology {
  position: relative;
  aspect-ratio: 1;
  background: radial-gradient(circle at center, rgba(34, 211, 238, 0.05), transparent 70%);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(34, 211, 238, 0.1);
  display: grid;
  place-items: center;
  padding: var(--space-8);
}

.node-topology svg {
  width: 100%;
  height: 100%;
}

/* ============================================
   下载端卡片
   ============================================ */
.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.download-card {
  display: grid;
  grid-template-columns: 80px 1fr auto;
  align-items: center;
  gap: var(--space-5);
  padding: var(--space-6) var(--space-8);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  transition: all var(--duration-base) var(--ease-out);
}

.download-card:hover {
  border-color: var(--color-quantum);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.download-icon {
  display: grid;
  place-items: center;
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--color-quantum), var(--color-quantum-dark));
  border-radius: var(--radius-lg);
  color: var(--color-bg-primary);
  box-shadow: 0 8px 20px var(--color-quantum-glow);
}

.download-icon svg {
  width: 40px;
  height: 40px;
}

.download-info h3 {
  margin-bottom: 4px;
  font-size: 18px;
}

.download-meta {
  display: flex;
  gap: var(--space-3);
  font-size: 13px;
  color: var(--color-text-muted);
}

.download-meta span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ============================================
   环境要求表
   ============================================ */
.req-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-bg-paper);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-card);
}

.req-table thead {
  background: var(--color-bg-elevated);
  color: var(--color-text-inverse);
}

.req-table th {
  padding: var(--space-4) var(--space-5);
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.req-table td {
  padding: var(--space-4) var(--space-5);
  border-top: 1px solid var(--color-border-light);
  font-size: 14px;
  color: var(--color-text-secondary);
}

.req-table tr:hover td {
  background: var(--color-bg-surface);
}

.req-table .tag {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 600;
  border-radius: var(--radius-sm);
}

.req-table .tag-warn {
  background: rgba(249, 115, 22, 0.1);
  color: var(--color-warning);
}

.req-table .tag-ok {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
}

/* ============================================
   场景卡
   ============================================ */
.scenario-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-8);
}

.scenario-card {
  display: grid;
  grid-template-rows: 200px auto;
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--duration-base) var(--ease-out);
}

.scenario-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-quantum);
}

.scenario-img {
  position: relative;
  background-size: cover;
  background-position: center;
  background-color: var(--color-bg-elevated);
}

.scenario-img::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 50%, rgba(11, 18, 32, 0.4) 100%);
}

.scenario-tag {
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  z-index: 1;
  padding: 4px 10px;
  background: rgba(11, 18, 32, 0.7);
  color: var(--color-quantum);
  font-size: 12px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  backdrop-filter: blur(8px);
}

.scenario-body {
  padding: var(--space-6);
}

.scenario-body h3 {
  font-size: 20px;
  margin-bottom: var(--space-3);
}

.scenario-body p {
  font-size: 14px;
  margin-bottom: var(--space-4);
}

.scenario-steps {
  display: grid;
  gap: var(--space-2);
}

.scenario-step {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: var(--space-3);
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.scenario-step::before {
  content: attr(data-num);
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  background: var(--color-bg-surface);
  color: var(--color-quantum-dark);
  border-radius: 50%;
  font-size: 11px;
  font-weight: 600;
  flex-shrink: 0;
}

/* ============================================
   面包屑
   ============================================ */
.breadcrumb {
  padding: var(--space-4) 0;
  font-size: 13px;
  color: var(--color-text-muted);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.breadcrumb li:not(:last-child)::after {
  content: "/";
  color: var(--color-text-muted);
  opacity: 0.5;
}

.breadcrumb a {
  color: var(--color-text-muted);
}

.breadcrumb a:hover {
  color: var(--color-quantum-dark);
}

.breadcrumb li:last-child {
  color: var(--color-text-primary);
  font-weight: 500;
}

/* ============================================
   页面头部
   ============================================ */
.page-head {
  background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
  color: var(--color-text-inverse);
  padding: var(--space-16) 0 var(--space-12);
  position: relative;
  overflow: hidden;
}

.page-head::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -10%;
  width: 50%;
  height: 100%;
  background: radial-gradient(circle, var(--color-quantum-glow) 0%, transparent 60%);
  pointer-events: none;
}

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

.page-head .breadcrumb {
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.page-head .breadcrumb a {
  color: var(--color-text-muted);
}

.page-head .breadcrumb a:hover {
  color: var(--color-quantum);
}

.page-head h1 {
  color: var(--color-text-inverse);
  margin-bottom: var(--space-4);
  max-width: 800px;
}

.page-head .lede {
  font-size: 17px;
  color: var(--color-text-muted);
  max-width: 720px;
  line-height: 1.7;
  margin-bottom: 0;
}

/* ============================================
   底部
   ============================================ */
.site-footer {
  background: var(--color-bg-primary);
  color: var(--color-text-muted);
  padding: var(--space-16) 0 var(--space-8);
  border-top: 1px solid rgba(34, 211, 238, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-brand .brand {
  margin-bottom: var(--space-4);
}

.footer-brand p {
  font-size: 14px;
  color: var(--color-text-muted);
  max-width: 320px;
  line-height: 1.7;
}

.footer-col h4 {
  color: var(--color-text-inverse);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: var(--space-4);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.footer-col ul {
  display: grid;
  gap: var(--space-3);
}

.footer-col a {
  font-size: 14px;
  color: var(--color-text-muted);
  transition: color var(--duration-fast) var(--ease-out);
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 13px;
}

.footer-bottom-meta {
  display: flex;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.footer-bottom-meta [data-last-modified] {
  color: var(--color-quantum);
  font-weight: 500;
}

.footer-tip {
  font-size: 12px;
  color: var(--color-text-muted);
  opacity: 0.8;
}

/* ============================================
   装饰元素
   ============================================ */
.deco-line {
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-quantum);
  border-radius: 2px;
  margin-bottom: var(--space-5);
}

.section-dark .deco-line {
  background: var(--color-quantum);
}

.kbd {
  display: inline-block;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--color-bg-elevated);
  color: var(--color-quantum);
  border: 1px solid rgba(34, 211, 238, 0.2);
  border-radius: var(--radius-sm);
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.3);
}

.code-inline {
  display: inline-block;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--color-bg-elevated);
  color: var(--color-quantum);
  border-radius: var(--radius-sm);
}

.section-dark .kbd,
.section-dark .code-inline {
  background: rgba(34, 211, 238, 0.1);
  color: var(--color-quantum);
}

.alert {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  border-left: 3px solid;
  margin: var(--space-5) 0;
  font-size: 14px;
  line-height: 1.7;
}

.alert-info {
  background: rgba(34, 211, 238, 0.05);
  border-color: var(--color-quantum);
  color: var(--color-text-secondary);
}

.alert-warning {
  background: rgba(249, 115, 22, 0.05);
  border-color: var(--color-warning);
  color: var(--color-text-secondary);
}

.alert-success {
  background: rgba(16, 185, 129, 0.05);
  border-color: var(--color-success);
  color: var(--color-text-secondary);
}

.alert-title {
  display: block;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 4px;
}

.alert svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.alert-info svg { color: var(--color-quantum-dark); }
.alert-warning svg { color: var(--color-warning); }
.alert-success svg { color: var(--color-success); }

/* ============================================
   数据指标块
   ============================================ */
.metric-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  margin: var(--space-10) 0;
}

.metric {
  padding: var(--space-6);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  text-align: left;
  transition: all var(--duration-base) var(--ease-out);
}

.metric:hover {
  border-color: var(--color-quantum);
  transform: translateY(-2px);
}

.metric-val {
  display: block;
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 700;
  color: var(--color-quantum-dark);
  line-height: 1.1;
  margin-bottom: var(--space-2);
}

.metric-label {
  font-size: 13px;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

/* ============================================
   关于页品牌信息
   ============================================ */
.brand-hero {
  text-align: center;
  padding: var(--space-16) 0;
}

.brand-mark-lg {
  display: inline-grid;
  place-items: center;
  width: 96px;
  height: 96px;
  background: linear-gradient(135deg, var(--color-quantum), var(--color-quantum-dark));
  color: var(--color-bg-primary);
  font-family: var(--font-display);
  font-size: 48px;
  font-weight: 800;
  border-radius: var(--radius-lg);
  box-shadow: 0 0 48px var(--color-quantum-glow);
  margin-bottom: var(--space-6);
}

.brand-title {
  font-family: var(--font-display);
  font-size: 64px;
  font-weight: 700;
  color: var(--color-text-inverse);
  margin-bottom: var(--space-3);
  letter-spacing: 0.04em;
}

.brand-tagline {
  font-size: 18px;
  color: var(--color-quantum);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: var(--space-6);
}

.brand-desc {
  max-width: 640px;
  margin: 0 auto;
  font-size: 17px;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.contact-list {
  display: grid;
  gap: var(--space-3);
}

.contact-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: var(--space-4);
  padding: var(--space-5);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-out);
}

.contact-item:hover {
  border-color: var(--color-quantum);
  transform: translateX(4px);
}

.contact-icon {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.1), rgba(34, 211, 238, 0.02));
  color: var(--color-quantum-dark);
  border-radius: var(--radius-md);
}

.contact-icon svg {
  width: 24px;
  height: 24px;
}

.contact-body .contact-label {
  font-size: 12px;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}

.contact-body .contact-value {
  font-size: 16px;
  color: var(--color-text-primary);
  font-weight: 500;
}

/* ============================================
   错位网格（场景页用）
   ============================================ */
.feature-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.feature-split.reverse {
  direction: rtl;
}

.feature-split.reverse > * {
  direction: ltr;
}

.feature-visual {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-bg-elevated);
}

.feature-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.feature-text h2 {
  margin-bottom: var(--space-4);
}

.feature-text p {
  font-size: 16px;
  line-height: 1.8;
}

.feature-text ul {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-5);
}

.feature-text li {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: var(--space-3);
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.feature-text li::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--color-quantum);
  border-radius: 50%;
  margin-top: 9px;
  box-shadow: 0 0 8px var(--color-quantum);
}

/* ============================================
   文章正文
   ============================================ */
.prose {
  max-width: 760px;
  margin: 0 auto;
}

.prose h2 {
  margin-top: var(--space-12);
  margin-bottom: var(--space-5);
  padding-top: var(--space-4);
  font-size: 28px;
}

.prose h3 {
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
  font-size: 22px;
}

.prose p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

.prose ul, .prose ol {
  margin: var(--space-4) 0;
  padding-left: var(--space-6);
}

.prose ul {
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  font-size: 16px;
  line-height: 1.85;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2);
}

.prose a {
  color: var(--color-quantum-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--color-quantum);
}

.prose blockquote {
  border-left: 3px solid var(--color-quantum);
  padding-left: var(--space-5);
  margin: var(--space-6) 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

/* 文章中的步骤列表 */
.prose .article-steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: var(--space-6) 0;
  display: grid;
  gap: var(--space-4);
}

.prose .article-steps li {
  counter-increment: step;
  position: relative;
  padding: var(--space-5) var(--space-5) var(--space-5) 72px;
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.prose .article-steps li::before {
  content: "第" counter(step, cjk-ideographic) "步";
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  display: grid;
  place-items: center;
  min-width: 48px;
  height: 28px;
  padding: 0 10px;
  background: linear-gradient(135deg, var(--color-quantum), var(--color-quantum-dark));
  color: var(--color-bg-primary);
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  letter-spacing: 0.04em;
}

.prose .article-steps li strong {
  display: block;
  margin-bottom: 4px;
  color: var(--color-text-primary);
  font-size: 16px;
}

/* ============================================
   动画
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.reveal {
  opacity: 0;
  animation: fadeInUp 0.8s var(--ease-out) forwards;
}

.reveal-d1 { animation-delay: 0.1s; }
.reveal-d2 { animation-delay: 0.2s; }
.reveal-d3 { animation-delay: 0.3s; }
.reveal-d4 { animation-delay: 0.4s; }
.reveal-d5 { animation-delay: 0.5s; }
.reveal-d6 { animation-delay: 0.6s; }

/* ============================================
   响应式
   ============================================ */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: var(--space-10);
  }
  .hero-visual {
    max-width: 480px;
    margin: 0 auto;
  }
  .node-wrap {
    grid-template-columns: 1fr;
  }
  .feature-split,
  .feature-split.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
    gap: var(--space-8);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .metric-row {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --space-20: 56px;
    --space-16: 48px;
    --space-12: 36px;
  }

  .nav-main,
  .nav-cta {
    display: none;
  }
  .nav-toggle {
    display: flex;
  }
  .nav-main.is-open {
    display: flex;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-4) var(--container-padding);
    background: var(--color-bg-primary);
    border-bottom: 1px solid rgba(34, 211, 238, 0.12);
  }
  .nav-main.is-open .nav-link {
    height: 48px;
    border-radius: var(--radius-sm);
  }
  .nav-main.is-open .nav-cta {
    display: inline-flex;
    margin: var(--space-2) 0 0;
  }

  .grid-2,
  .grid-3,
  .grid-4,
  .download-grid,
  .scenario-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: var(--space-16) 0;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-actions .btn {
    width: 100%;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .step {
    grid-template-columns: 48px 1fr;
    gap: var(--space-4);
    padding: var(--space-4);
  }
  .step-num {
    width: 48px;
    height: 48px;
    font-size: 14px;
  }

  .download-card {
    grid-template-columns: 64px 1fr;
    grid-template-rows: auto auto;
    gap: var(--space-4);
    padding: var(--space-5);
  }
  .download-card .btn {
    grid-column: 1 / -1;
  }
  .download-icon {
    width: 64px;
    height: 64px;
  }
  .download-icon svg {
    width: 32px;
    height: 32px;
  }

  .brand-title {
    font-size: 40px;
  }

  .req-table {
    font-size: 13px;
  }
  .req-table th,
  .req-table td {
    padding: var(--space-3);
  }

  .page-head {
    padding: var(--space-12) 0 var(--space-8);
  }
}

@media (max-width: 480px) {
  .nav-wrap {
    height: 64px;
  }
  .nav-main.is-open {
    top: 64px;
  }
  .container {
    padding: 0 var(--space-4);
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
  .metric-row {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   无障碍 - 减少动效
   ============================================ */
@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;
  }
}

/* 焦点环 */
:focus-visible {
  outline: 2px solid var(--color-quantum);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* 选区 */
::selection {
  background: var(--color-quantum);
  color: var(--color-bg-primary);
}